KVM: arm64: Add support for protected guest memory with pKVM
Subsystems (4)
Will Deacon
maintainerv4 cover KVM: arm64: Add support for protected guest memory with pKVM
Hi again, folks,
Here's v4 of the pKVM protected memory patches previously posted here:
v1: https://lore.kernel.org/kvmarm/[email protected]/
v2: https://lore.kernel.org/kvmarm/[email protected]/
v3: https://lore.kernel.org/r/[email protected]
Changes since v3 include:
* Rebased onto v7.0-rc4
* Remove unused PKVM_ID_FFA
* Make ARM_PKVM_GUEST depend on DMA_RESTRICTED_POOL
* Use FAR_TO_FIPA_OFFSET() instead of open-coding it
* Remove PROTECTED_VM_UAPI config option and update documentation
As before, I've pushed an updated branch with this series:
https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=kvm/protected-memory
and the kvmtool patches are available at:
https://git.kernel.org/pub/scm/linux/kernel/git/will/kvmtool.git/log/?h=pkvm
I fully expect to send a v5, as this is the first time Sashiko has had a chance to chew on this and I'm expecting a roasting.
Cheers,
Will
--->8
Fuad Tabba (1):
KVM: arm64: Expose self-hosted debug regs as RAZ/WI for protected
guests
Quentin Perret (1):
KVM: arm64: Inject SIGSEGV on illegal accesses
Will Deacon (36):
KVM: arm64: Remove unused PKVM_ID_FFA definition
KVM: arm64: Don't leak stage-2 page-table if VM fails to init under
pKVM
KVM: arm64: Move handle check into pkvm_pgtable_stage2_destroy_range()
KVM: arm64: Rename __pkvm_pgtable_stage2_unmap()
KVM: arm64: Don't advertise unsupported features for protected guests
KVM: arm64: Remove is_protected_kvm_enabled() checks from hypercalls
KVM: arm64: Ignore MMU notifier callbacks for protected VMs
KVM: arm64: Prevent unsupported memslot operations on protected VMs
KVM: arm64: Ignore -EAGAIN when mapping in pages for the pKVM host
KVM: arm64: Split teardown hypercall into two phases
KVM: arm64: Introduce __pkvm_host_donate_guest()
KVM: arm64: Hook up donation hypercall to pkvm_pgtable_stage2_map()
KVM: arm64: Handle aborts from protected VMs
KVM: arm64: Introduce __pkvm_reclaim_dying_guest_page()
KVM: arm64: Hook up reclaim hypercall to pkvm_pgtable_stage2_destroy()
KVM: arm64: Factor out pKVM host exception injection logic
KVM: arm64: Support translation faults in inject_host_exception()
KVM: arm64: Avoid pointless annotation when mapping host-owned pages
KVM: arm64: Generalise kvm_pgtable_stage2_set_owner()
KVM: arm64: Introduce host_stage2_set_owner_metadata_locked()
KVM: arm64: Change 'pkvm_handle_t' to u16
KVM: arm64: Annotate guest donations with handle and gfn in host
stage-2
KVM: arm64: Introduce hypercall to force reclaim of a protected page
KVM: arm64: Reclaim faulting page from pKVM in spurious fault handler
KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte
KVM: arm64: Add hvc handler at EL2 for hypercalls from protected VMs
KVM: arm64: Implement the MEM_SHARE hypercall for protected VMs
KVM: arm64: Implement the MEM_UNSHARE hypercall for protected VMs
KVM: arm64: Allow userspace to create protected VMs when pKVM is
enabled
KVM: arm64: Add some initial documentation for pKVM
KVM: arm64: Extend pKVM page ownership selftests to cover guest
donation
KVM: arm64: Register 'selftest_vm' in the VM table
KVM: arm64: Extend pKVM page ownership selftests to cover forced
reclaim
KVM: arm64: Extend pKVM page ownership selftests to cover guest hvcs
KVM: arm64: Rename PKVM_PAGE_STATE_MASK
drivers/virt: pkvm: Add Kconfig dependency on DMA_RESTRICTED_POOL
.../admin-guide/kernel-parameters.txt | 4 +- Documentation/virt/kvm/arm/index.rst | 1 + Documentation/virt/kvm/arm/pkvm.rst | 106 ++++ arch/arm64/include/asm/kvm_asm.h | 31 +- arch/arm64/include/asm/kvm_host.h | 9 +- arch/arm64/include/asm/kvm_pgtable.h | 45 +- arch/arm64/include/asm/kvm_pkvm.h | 4 +- arch/arm64/include/asm/virt.h | 9 + arch/arm64/kvm/arm.c | 12 +- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 10 +- arch/arm64/kvm/hyp/include/nvhe/memory.h | 12 +- arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 7 +- .../arm64/kvm/hyp/include/nvhe/trap_handler.h | 2 + arch/arm64/kvm/hyp/nvhe/hyp-main.c | 184 +++--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 585 ++++++++++++++++-- arch/arm64/kvm/hyp/nvhe/pkvm.c | 224 ++++++- arch/arm64/kvm/hyp/nvhe/switch.c | 1 + arch/arm64/kvm/hyp/nvhe/sys_regs.c | 8 + arch/arm64/kvm/hyp/pgtable.c | 33 +- arch/arm64/kvm/mmu.c | 114 +++- arch/arm64/kvm/pkvm.c | 151 ++++- arch/arm64/mm/fault.c | 33 +- drivers/virt/coco/pkvm-guest/Kconfig | 2 +- include/uapi/linux/kvm.h | 5 + 24 files changed, 1365 insertions(+), 227 deletions(-) create mode 100644 Documentation/virt/kvm/arm/pkvm.rst
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 1/38 KVM: arm64: Remove unused PKVM_ID_FFA definition
Commit 7cbf7c37718e ("KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing") removed the last users of PKVM_ID_FFA, so drop the definition altogether.
--- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 - 1 file changed, 1 deletion(-)
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +0 -1
@@ -27,7 +27,6 @@ extern struct host_mmu host_mmu;enum pkvm_component_id {PKVM_ID_HOST ,PKVM_ID_HYP , -PKVM_ID_FFA , };extern unsigned long hyp_nr_cpus;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 2/38 KVM: arm64: Don't leak stage-2 page-table if VM fails to init under pKVM
In reply to Will DeaconIf pkvm_init_host_vm() fails, we should free the stage-2 page-table previously allocated by kvm_init_stage2_mmu().
--- arch/arm64/kvm/arm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
arch/arm64/kvm/arm.c +3 -1
@@ -236,7 +236,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)*/ ret =pkvm_init_host_vm (kvm);if (ret) - goto err_free_cpumask; + goto err_uninit_mmu; }kvm_vgic_early_init (kvm);
@@ -252,6 +252,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)return 0 ; +err_uninit_mmu: +kvm_uninit_stage2_mmu (kvm); err_free_cpumask:free_cpumask_var (kvm->arch.supported_cpus); err_unshare_kvm:
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 3/38 KVM: arm64: Move handle check into pkvm_pgtable_stage2_destroy_range()
In reply to Will DeaconWhen pKVM is enabled, a VM has a 'handle' allocated by the hypervisor in kvm_arch_init_vm() and released later by kvm_arch_destroy_vm().
Consequently, the only time __pkvm_pgtable_stage2_unmap() can run into an uninitialised 'handle' is on the kvm_arch_init_vm() failure path, where we destroy the empty stage-2 page-table if we fail to allocate a handle.
Move the handle check into pkvm_pgtable_stage2_destroy_range(), which will additionally handle protected VMs in subsequent patches.
--- arch/arm64/kvm/pkvm.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
arch/arm64/kvm/pkvm.c +6 -3
@@ -329,9 +329,6 @@ static int __pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 start, u64 estruct pkvm_mapping *mapping;int ret; -if (!handle) -return 0 ; -for_each_mapping_in_range_safe (pgt, start, end, mapping) { ret =kvm_call_hyp_nvhe (__pkvm_host_unshare_guest, handle, mapping->gfn, mapping->nr_pages);
@@ -347,6 +344,12 @@ static int __pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 start, u64 evoid pkvm_pgtable_stage2_destroy_range (struct kvm_pgtable *pgt,u64 addr,u64 size) { +struct kvm *kvm =kvm_s2_mmu_to_kvm (pgt->mmu); +pkvm_handle_t handle = kvm->arch.pkvm.handle; + +if (!handle) +return ; +__pkvm_pgtable_stage2_unmap (pgt, addr, addr + size); }
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 4/38 KVM: arm64: Rename __pkvm_pgtable_stage2_unmap()
In reply to Will DeaconIn preparation for adding support for protected VMs, where pages are donated rather than shared, rename __pkvm_pgtable_stage2_unmap() to __pkvm_pgtable_stage2_unshare() to make it clearer about what is going on.
--- arch/arm64/kvm/pkvm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
arch/arm64/kvm/pkvm.c +4 -4
@@ -322,7 +322,7 @@ int pkvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,return 0 ; } -static int __pkvm_pgtable_stage2_unmap (struct kvm_pgtable *pgt,u64 start,u64 end) +static int __pkvm_pgtable_stage2_unshare (struct kvm_pgtable *pgt,u64 start,u64 end) {struct kvm *kvm =kvm_s2_mmu_to_kvm (pgt->mmu);pkvm_handle_t handle = kvm->arch.pkvm.handle;
@@ -350,7 +350,7 @@ void pkvm_pgtable_stage2_destroy_range(struct kvm_pgtable *pgt,if (!handle)return ; -__pkvm_pgtable_stage2_unmap (pgt, addr, addr + size); +__pkvm_pgtable_stage2_unshare (pgt, addr, addr + size); }void pkvm_pgtable_stage2_destroy_pgd (struct kvm_pgtable *pgt)
@@ -386,7 +386,7 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,return -EAGAIN ;/* Remove _any_ pkvm_mapping overlapping with the range, bigger or smaller. */ - ret =__pkvm_pgtable_stage2_unmap (pgt, addr, addr + size); + ret =__pkvm_pgtable_stage2_unshare (pgt, addr, addr + size);if (ret)return ret; mapping =NULL ;
@@ -409,7 +409,7 @@ int pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size) {lockdep_assert_held_write (&kvm_s2_mmu_to_kvm (pgt->mmu)->mmu_lock); -return __pkvm_pgtable_stage2_unmap (pgt, addr, addr + size); +return __pkvm_pgtable_stage2_unshare (pgt, addr, addr + size); }int pkvm_pgtable_stage2_wrprotect (struct kvm_pgtable *pgt,u64 addr,u64 size)
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 5/38 KVM: arm64: Don't advertise unsupported features for protected guests
In reply to Will DeaconBoth SVE and PMUv3 are treated as "restricted" features for protected guests and attempts to access their corresponding architectural state from a protected guest result in an undefined exception being injected by the hypervisor.
Since these exceptions are unexpected and typically fatal for the guest, don't advertise these features for protected guests.
--- arch/arm64/include/asm/kvm_pkvm.h | 2 -- 1 file changed, 2 deletions(-)
arch/arm64/include/asm/kvm_pkvm.h +0 -2
@@ -40,8 +40,6 @@ static inline bool kvm_pkvm_ext_allowed(struct kvm *kvm, long ext)case KVM_CAP_MAX_VCPU_ID :case KVM_CAP_MSI_DEVID :case KVM_CAP_ARM_VM_IPA_SIZE : -case KVM_CAP_ARM_PMU_V3 : -case KVM_CAP_ARM_SVE :case KVM_CAP_ARM_PTRAUTH_ADDRESS :case KVM_CAP_ARM_PTRAUTH_GENERIC :return true;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 6/38 KVM: arm64: Expose self-hosted debug regs as RAZ/WI for protected guests
In reply to Will DeaconFrom: Fuad Tabba <[email protected]>
Debug and trace are not currently supported for protected guests, so trap accesses to the related registers and emulate them as RAZ/WI for now. Although this isn't strictly compatible with the architecture, it's sufficient for Linux guests and means that debug support can be added later on.
--- arch/arm64/kvm/hyp/nvhe/sys_regs.c | 8 ++++++++ 1 file changed, 8 insertions(+)
arch/arm64/kvm/hyp/nvhe/sys_regs.c +8 -0
@@ -392,6 +392,14 @@ static const struct sys_reg_desc pvm_sys_reg_descs[] = {/* Cache maintenance by set/way operations are restricted. */ /* Debug and Trace Registers are restricted. */ +RAZ_WI (SYS_DBGBVRn_EL1 (0 )), +RAZ_WI (SYS_DBGBCRn_EL1 (0 )), +RAZ_WI (SYS_DBGWVRn_EL1 (0 )), +RAZ_WI (SYS_DBGWCRn_EL1 (0 )), +RAZ_WI (SYS_MDSCR_EL1 ), +RAZ_WI (SYS_OSLAR_EL1 ), +RAZ_WI (SYS_OSLSR_EL1 ), +RAZ_WI (SYS_OSDLR_EL1 ),/* Group 1 ID registers */ HOST_HANDLED(SYS_REVIDR_EL1),
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 7/38 KVM: arm64: Remove is_protected_kvm_enabled() checks from hypercalls
In reply to Will DeaconWhen pKVM is not enabled, the host shouldn't issue pKVM-specific hypercalls and so there's no point checking for this in the pKVM hypercall handlers.
Remove the redundant is_protected_kvm_enabled() checks from each hypercall and instead rejig the hypercall table so that the pKVM-specific hypercalls are unreachable when pKVM is not being used.
--- arch/arm64/include/asm/kvm_asm.h | 24 +++++++----- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 63 ++++++++++-------------------- 2 files changed, 34 insertions(+), 53 deletions(-)
arch/arm64/include/asm/kvm_asm.h +14 -10
@@ -51,7 +51,7 @@#include <linux/mm.h> enum __kvm_host_smccc_func { -/* Hypercalls available only prior to pKVM finalisation */ +/* Hypercalls that are unavailable once pKVM has finalised. */ /* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */ __KVM_HOST_SMCCC_FUNC___pkvm_init = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init +1 , __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping,
@@ -60,16 +60,9 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs, __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config, __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize, + __KVM_HOST_SMCCC_FUNC_MIN_PKVM = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize, -/* Hypercalls available after pKVM finalisation */ - __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp, - __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp, - __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest, - __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest, - __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest, - __KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest, - __KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest, - __KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest, +/* Hypercalls that are always available and common to [nh]VHE/pKVM. */ __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc, __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run, __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
@@ -81,6 +74,17 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff, __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs, __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs, + __KVM_HOST_SMCCC_FUNC_MAX_NO_PKVM = __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs, + +/* Hypercalls that are available only when pKVM has finalised. */ + __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp, + __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp, + __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest, + __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest, + __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest, + __KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest, + __KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest, + __KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest, __KVM_HOST_SMCCC_FUNC___pkvm_reserve_vm, __KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
arch/arm64/kvm/hyp/nvhe/hyp-main.c +20 -43
148 lines not on this page · raw message
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 8/38 KVM: arm64: Ignore MMU notifier callbacks for protected VMs
In reply to Will DeaconIn preparation for supporting the donation of pinned pages to protected VMs, return early from the MMU notifiers when called for a protected VM, as the necessary hypercalls are exposed only for non-protected guests.
--- arch/arm64/kvm/mmu.c | 9 ++++++--- arch/arm64/kvm/pkvm.c | 19 ++++++++++++++++++- 2 files changed, 24 insertions(+), 4 deletions(-)
arch/arm64/kvm/mmu.c +6 -3
@@ -340,6 +340,9 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64void kvm_stage2_unmap_range (struct kvm_s2_mmu *mmu,phys_addr_t start,u64 size,bool may_block) { +if (kvm_vm_is_protected (kvm_s2_mmu_to_kvm (mmu))) +return ; +__unmap_stage2_range (mmu, start, size, may_block); }
@@ -2223,7 +2226,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)bool kvm_unmap_gfn_range (struct kvm *kvm,struct kvm_gfn_range *range) { -if (!kvm->arch.mmu.pgt) +if (!kvm->arch.mmu.pgt ||kvm_vm_is_protected (kvm))return false; __unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT,
@@ -2238,7 +2241,7 @@ bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) {u64 size = (range->end - range->start) <<PAGE_SHIFT ; -if (!kvm->arch.mmu.pgt) +if (!kvm->arch.mmu.pgt ||kvm_vm_is_protected (kvm))return false; return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
@@ -2254,7 +2257,7 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) {u64 size = (range->end - range->start) <<PAGE_SHIFT ; -if (!kvm->arch.mmu.pgt) +if (!kvm->arch.mmu.pgt ||kvm_vm_is_protected (kvm))return false; return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
arch/arm64/kvm/pkvm.c +18 -1
@@ -407,7 +407,12 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,int pkvm_pgtable_stage2_unmap (struct kvm_pgtable *pgt,u64 addr,u64 size) { -lockdep_assert_held_write (&kvm_s2_mmu_to_kvm (pgt->mmu)->mmu_lock); +struct kvm *kvm =kvm_s2_mmu_to_kvm (pgt->mmu); + +if (WARN_ON (kvm_vm_is_protected (kvm))) +return -EPERM ; + +lockdep_assert_held_write (&kvm->mmu_lock);return __pkvm_pgtable_stage2_unshare (pgt, addr, addr + size); }
@@ -419,6 +424,9 @@ int pkvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size)struct pkvm_mapping *mapping;int ret =0 ; +if (WARN_ON (kvm_vm_is_protected (kvm))) +return -EPERM ; +lockdep_assert_held (&kvm->mmu_lock);for_each_mapping_in_range_safe (pgt, addr, addr + size, mapping) { ret = kvm_call_hyp_nvhe(__pkvm_host_wrprotect_guest, handle, mapping->gfn,
@@ -450,6 +458,9 @@ bool pkvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr, u64struct pkvm_mapping *mapping;bool young = false; +if (WARN_ON (kvm_vm_is_protected (kvm))) +return -EPERM ; +lockdep_assert_held (&kvm->mmu_lock);for_each_mapping_in_range_safe (pgt, addr, addr + size, mapping) young |= kvm_call_hyp_nvhe(__pkvm_host_test_clear_young_guest, handle, mapping->gfn,
@@ -461,12 +472,18 @@ bool pkvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr, u64int pkvm_pgtable_stage2_relax_perms (struct kvm_pgtable *pgt,u64 addr,enum kvm_pgtable_prot prot,enum kvm_pgtable_walk_flags flags) { +if (WARN_ON (kvm_vm_is_protected (kvm_s2_mmu_to_kvm (pgt->mmu)))) +return -EPERM ; +return kvm_call_hyp_nvhe (__pkvm_host_relax_perms_guest, addr >>PAGE_SHIFT , prot); }void pkvm_pgtable_stage2_mkyoung (struct kvm_pgtable *pgt,u64 addr,enum kvm_pgtable_walk_flags flags) { +if (WARN_ON (kvm_vm_is_protected (kvm_s2_mmu_to_kvm (pgt->mmu)))) +return ; +WARN_ON (kvm_call_hyp_nvhe (__pkvm_host_mkyoung_guest, addr >>PAGE_SHIFT )); }
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 9/38 KVM: arm64: Prevent unsupported memslot operations on protected VMs
In reply to Will DeaconProtected VMs do not support deleting or moving memslots after first run nor do they support read-only or dirty logging.
Return -EPERM to userspace if such an operation is attempted.
--- arch/arm64/kvm/mmu.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
arch/arm64/kvm/mmu.c +13 -0
@@ -2414,6 +2414,19 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,hva_t hva, reg_end;int ret =0 ; +if (kvm_vm_is_protected (kvm)) { +/* Cannot modify memslots once a pVM has run. */ +if (pkvm_hyp_vm_is_created (kvm) && + (change ==KVM_MR_DELETE || change ==KVM_MR_MOVE )) { +return -EPERM ; + } + +if (new && + new->flags & (KVM_MEM_LOG_DIRTY_PAGES |KVM_MEM_READONLY )) { +return -EPERM ; + } + } +if (change !=KVM_MR_CREATE && change !=KVM_MR_MOVE && change !=KVM_MR_FLAGS_ONLY )return 0 ;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 10/38 KVM: arm64: Ignore -EAGAIN when mapping in pages for the pKVM host
In reply to Will DeaconIf the host takes a stage-2 translation fault on two CPUs at the same time, one of them will get back -EAGAIN from the page-table mapping code when it runs into the mapping installed by the other.
Rather than handle this explicitly in handle_host_mem_abort(), pass the new KVM_PGTABLE_WALK_IGNORE_EAGAIN flag to kvm_pgtable_stage2_map() from __host_stage2_idmap() and return -EEXIST if host_stage2_adjust_range() finds a valid pte. This will avoid having to test for -EAGAIN on the reclaim path in subsequent patches.
--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)
arch/arm64/kvm/hyp/nvhe/mem_protect.c +16 -5
@@ -461,8 +461,15 @@ static bool range_is_memory(u64 start, u64 end)static inline int __host_stage2_idmap (u64 start,u64 end,enum kvm_pgtable_prot prot) { +/* +* We don't make permission changes to the host idmap after +* initialisation, so we can squash -EAGAIN to save callers +* having to treat it like success in the case that they try to +* map something that is already mapped. +*/ return kvm_pgtable_stage2_map (&host_mmu.pgt, start, end - start, start, - prot, &host_s2_pool,0 ); + prot, &host_s2_pool, +KVM_PGTABLE_WALK_IGNORE_EAGAIN ); }/*
@@ -504,7 +511,7 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range)return ret;if (kvm_pte_valid (pte)) -return -EAGAIN ; +return -EEXIST ;if (pte) { WARN_ON(addr_is_memory(addr) &&
@@ -609,7 +616,6 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt) {struct kvm_vcpu_fault_info fault;u64 esr, addr; -int ret =0 ; esr =read_sysreg_el2 (SYS_ESR );if (!__get_fault_info (esr, &fault)) {
@@ -628,8 +634,13 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)BUG_ON (!(fault.hpfar_el2 &HPFAR_EL2_NS )); addr =FIELD_GET (HPFAR_EL2_FIPA , fault.hpfar_el2) <<12 ; - ret =host_stage2_idmap (addr); -BUG_ON (ret && ret != -EAGAIN ); +switch (host_stage2_idmap (addr)) { +case -EEXIST : +case 0 : +break ; +default : +BUG (); + } }struct check_walk_data {
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 11/38 KVM: arm64: Split teardown hypercall into two phases
In reply to Will DeaconIn preparation for reclaiming protected guest VM pages from the host during teardown, split the current 'pkvm_teardown_vm' hypercall into separate 'start' and 'finalise' calls.
The 'pkvm_start_teardown_vm' hypercall puts the VM into a new 'is_dying' state, which is a point of no return past which no vCPU of the pVM is allowed to run any more. Once in this new state, 'pkvm_finalize_teardown_vm' can be used to reclaim meta-data and page-table pages from the VM. A subsequent patch will add support for reclaiming the individual guest memory pages.
--- arch/arm64/include/asm/kvm_asm.h | 3 ++- arch/arm64/include/asm/kvm_host.h | 7 +++++ arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 4 ++- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 14 +++++++--- arch/arm64/kvm/hyp/nvhe/pkvm.c | 36 ++++++++++++++++++++++---- arch/arm64/kvm/pkvm.c | 7 ++++- 6 files changed, 60 insertions(+), 11 deletions(-)
arch/arm64/include/asm/kvm_asm.h +2 -1
@@ -89,7 +89,8 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu, - __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm, + __KVM_HOST_SMCCC_FUNC___pkvm_start_teardown_vm, + __KVM_HOST_SMCCC_FUNC___pkvm_finalize_teardown_vm, __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load, __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put, __KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid,
arch/arm64/include/asm/kvm_host.h +7 -0
@@ -255,6 +255,13 @@ struct kvm_protected_vm {struct kvm_hyp_memcache stage2_teardown_mc;bool is_protected;bool is_created; + +/* +* True when the guest is being torn down. When in this state, the +* guest's vCPUs can't be loaded anymore, but its pages can be +* reclaimed by the host. +*/ +bool is_dying; };struct kvm_mpidr_data {
arch/arm64/kvm/hyp/include/nvhe/pkvm.h +3 -1
@@ -73,7 +73,9 @@ int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva, unsigned long pgd_hva);int __pkvm_init_vcpu (pkvm_handle_t handle,struct kvm_vcpu *host_vcpu,unsigned long vcpu_hva); -int __pkvm_teardown_vm (pkvm_handle_t handle); + +int __pkvm_start_teardown_vm (pkvm_handle_t handle); +int __pkvm_finalize_teardown_vm (pkvm_handle_t handle);struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu (pkvm_handle_t handle,unsigned int vcpu_idx);
arch/arm64/kvm/hyp/nvhe/hyp-main.c +11 -3
@@ -553,11 +553,18 @@ static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)cpu_reg (host_ctxt,1 ) =__pkvm_init_vcpu (handle, host_vcpu, vcpu_hva); } -static void handle___pkvm_teardown_vm (struct kvm_cpu_context *host_ctxt) +static void handle___pkvm_start_teardown_vm (struct kvm_cpu_context *host_ctxt) {DECLARE_REG (pkvm_handle_t, handle, host_ctxt,1 ); -cpu_reg (host_ctxt,1 ) =__pkvm_teardown_vm (handle); +cpu_reg (host_ctxt,1 ) =__pkvm_start_teardown_vm (handle); +} + +static void handle___pkvm_finalize_teardown_vm (struct kvm_cpu_context *host_ctxt) +{ +DECLARE_REG (pkvm_handle_t, handle, host_ctxt,1 ); + +cpu_reg (host_ctxt,1 ) =__pkvm_finalize_teardown_vm (handle); }typedef void (*hcall_t )(struct kvm_cpu_context *);
@@ -598,7 +605,8 @@ static const hcall_t host_hcall[] = {HANDLE_FUNC (__pkvm_unreserve_vm),HANDLE_FUNC (__pkvm_init_vm),HANDLE_FUNC (__pkvm_init_vcpu), -HANDLE_FUNC (__pkvm_teardown_vm), +HANDLE_FUNC (__pkvm_start_teardown_vm), +HANDLE_FUNC (__pkvm_finalize_teardown_vm),HANDLE_FUNC (__pkvm_vcpu_load),HANDLE_FUNC (__pkvm_vcpu_put), HANDLE_FUNC(__pkvm_tlb_flush_vmid),
arch/arm64/kvm/hyp/nvhe/pkvm.c +31 -5
@@ -255,7 +255,10 @@ struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu(pkvm_handle_t handle,hyp_spin_lock (&vm_table_lock); hyp_vm =get_vm_by_handle (handle); -if (!hyp_vm || hyp_vm->kvm.created_vcpus <= vcpu_idx) +if (!hyp_vm || hyp_vm->kvm.arch.pkvm.is_dying) + goto unlock; + +if (hyp_vm->kvm.created_vcpus <= vcpu_idx) goto unlock; hyp_vcpu = hyp_vm->vcpus[vcpu_idx];
@@ -859,7 +862,32 @@ teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size)unmap_donated_memory_noclear (addr, size); } -int __pkvm_teardown_vm (pkvm_handle_t handle) +int __pkvm_start_teardown_vm (pkvm_handle_t handle) +{ +struct pkvm_hyp_vm *hyp_vm; +int ret =0 ; + +hyp_spin_lock (&vm_table_lock); + hyp_vm =get_vm_by_handle (handle); +if (!hyp_vm) { + ret = -ENOENT ; + goto unlock; + }else if (WARN_ON (hyp_page_count (hyp_vm))) { + ret = -EBUSY ; + goto unlock; + }else if (hyp_vm->kvm.arch.pkvm.is_dying) { + ret = -EINVAL ; + goto unlock; + } + + hyp_vm->kvm.arch.pkvm.is_dying = true; +unlock: +hyp_spin_unlock (&vm_table_lock); + +return ret; +} + +int __pkvm_finalize_teardown_vm (pkvm_handle_t handle) {struct kvm_hyp_memcache *mc, *stage2_mc;struct pkvm_hyp_vm *hyp_vm;
@@ -873,9 +901,7 @@ int __pkvm_teardown_vm(pkvm_handle_t handle)if (!hyp_vm) { err = -ENOENT ; goto err_unlock; - } - -if (WARN_ON (hyp_page_count (hyp_vm))) { + }else if (!hyp_vm->kvm.arch.pkvm.is_dying) { err = -EBUSY ; goto err_unlock; }
arch/arm64/kvm/pkvm.c +6 -1
@@ -88,7 +88,7 @@ void __init kvm_hyp_reserve(void)static void __pkvm_destroy_hyp_vm (struct kvm *kvm) {if (pkvm_hyp_vm_is_created (kvm)) { -WARN_ON (kvm_call_hyp_nvhe (__pkvm_teardown_vm, +WARN_ON (kvm_call_hyp_nvhe (__pkvm_finalize_teardown_vm, kvm->arch.pkvm.handle)); }else if (kvm->arch.pkvm.handle) {/*
@@ -350,6 +350,11 @@ void pkvm_pgtable_stage2_destroy_range(struct kvm_pgtable *pgt,if (!handle)return ; +if (pkvm_hyp_vm_is_created (kvm) && !kvm->arch.pkvm.is_dying) { +WARN_ON (kvm_call_hyp_nvhe (__pkvm_start_teardown_vm, handle)); + kvm->arch.pkvm.is_dying = true; + } +__pkvm_pgtable_stage2_unshare (pgt, addr, addr + size); }
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 12/38 KVM: arm64: Introduce __pkvm_host_donate_guest()
In reply to Will DeaconIn preparation for supporting protected VMs, whose memory pages are isolated from the host, introduce a new pKVM hypercall to allow the donation of pages to a guest.
--- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/include/asm/kvm_pgtable.h | 2 +- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 ++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 21 +++++++++++++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 30 +++++++++++++++++++ 5 files changed, 55 insertions(+), 1 deletion(-)
arch/arm64/include/asm/kvm_asm.h +1 -0
@@ -79,6 +79,7 @@ enum __kvm_host_smccc_func {/* Hypercalls that are available only when pKVM has finalised. */ __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp, __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp, + __KVM_HOST_SMCCC_FUNC___pkvm_host_donate_guest, __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest, __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest, __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
arch/arm64/include/asm/kvm_pgtable.h +1 -1
@@ -100,7 +100,7 @@ typedef u64 kvm_pte_t; KVM_PTE_LEAF_ATTR_HI_S2_XN)#define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) -#define KVM_MAX_OWNER_ID 1 +#define KVM_MAX_OWNER_ID 2/* * Used to indicate a pte for which a 'break-before-make' sequence is in
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +2 -0
@@ -27,6 +27,7 @@ extern struct host_mmu host_mmu;enum pkvm_component_id {PKVM_ID_HOST ,PKVM_ID_HYP , +PKVM_ID_GUEST , };extern unsigned long hyp_nr_cpus;
@@ -38,6 +39,7 @@ int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages);int __pkvm_hyp_donate_host (u64 pfn,u64 nr_pages);int __pkvm_host_share_ffa (u64 pfn,u64 nr_pages);int __pkvm_host_unshare_ffa (u64 pfn,u64 nr_pages); +int __pkvm_host_donate_guest (u64 pfn,u64 gfn,struct pkvm_hyp_vcpu *vcpu);int __pkvm_host_share_guest (u64 pfn,u64 gfn,u64 nr_pages,struct pkvm_hyp_vcpu *vcpu,enum kvm_pgtable_prot prot);int __pkvm_host_unshare_guest (u64 gfn,u64 nr_pages,struct pkvm_hyp_vm *hyp_vm);
arch/arm64/kvm/hyp/nvhe/hyp-main.c +21 -0
@@ -241,6 +241,26 @@ static int pkvm_refill_memcache(struct pkvm_hyp_vcpu *hyp_vcpu) &host_vcpu->arch.pkvm_memcache); } +static void handle___pkvm_host_donate_guest (struct kvm_cpu_context *host_ctxt) +{ +DECLARE_REG (u64, pfn, host_ctxt,1 ); +DECLARE_REG (u64, gfn, host_ctxt,2 ); +struct pkvm_hyp_vcpu *hyp_vcpu; +int ret = -EINVAL ; + + hyp_vcpu =pkvm_get_loaded_hyp_vcpu (); +if (!hyp_vcpu || !pkvm_hyp_vcpu_is_protected (hyp_vcpu)) + goto out; + + ret =pkvm_refill_memcache (hyp_vcpu); +if (ret) + goto out; + + ret =__pkvm_host_donate_guest (pfn, gfn, hyp_vcpu); +out: +cpu_reg (host_ctxt,1 ) = ret; +} +static void handle___pkvm_host_share_guest (struct kvm_cpu_context *host_ctxt) {DECLARE_REG (u64, pfn, host_ctxt,1 );
@@ -595,6 +615,7 @@ static const hcall_t host_hcall[] = {HANDLE_FUNC (__pkvm_host_share_hyp),HANDLE_FUNC (__pkvm_host_unshare_hyp), +HANDLE_FUNC (__pkvm_host_donate_guest),HANDLE_FUNC (__pkvm_host_share_guest),HANDLE_FUNC (__pkvm_host_unshare_guest), HANDLE_FUNC(__pkvm_host_relax_perms_guest),
arch/arm64/kvm/hyp/nvhe/mem_protect.c +30 -0
@@ -971,6 +971,36 @@ static int __guest_check_transition_size(u64 phys, u64 ipa, u64 nr_pages, u64 *sreturn 0 ; } +int __pkvm_host_donate_guest (u64 pfn,u64 gfn,struct pkvm_hyp_vcpu *vcpu) +{ +struct pkvm_hyp_vm *vm =pkvm_hyp_vcpu_to_hyp_vm (vcpu); +u64 phys =hyp_pfn_to_phys (pfn); +u64 ipa =hyp_pfn_to_phys (gfn); +int ret; + +host_lock_component (); +guest_lock_component (vm); + + ret =__host_check_page_state_range (phys,PAGE_SIZE ,PKVM_PAGE_OWNED ); +if (ret) + goto unlock; + + ret =__guest_check_page_state_range (vm, ipa,PAGE_SIZE ,PKVM_NOPAGE ); +if (ret) + goto unlock; + +WARN_ON (host_stage2_set_owner_locked (phys,PAGE_SIZE ,PKVM_ID_GUEST )); +WARN_ON (kvm_pgtable_stage2_map (&vm->pgt, ipa,PAGE_SIZE , phys, +pkvm_mkstate (KVM_PGTABLE_PROT_RWX ,PKVM_PAGE_OWNED ), + &vcpu->vcpu.arch.pkvm_memcache,0 )); + +unlock: +guest_unlock_component (vm); +host_unlock_component (); + +return ret; +} +int __pkvm_host_share_guest (u64 pfn,u64 gfn,u64 nr_pages,struct pkvm_hyp_vcpu *vcpu,enum kvm_pgtable_prot prot) {
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 13/38 KVM: arm64: Hook up donation hypercall to pkvm_pgtable_stage2_map()
In reply to Will DeaconMapping pages into a protected guest requires the donation of memory from the host.
Extend pkvm_pgtable_stage2_map() to issue a donate hypercall when the target VM is protected. Since the hypercall only handles a single page, the splitting logic used for the share path is not required.
--- arch/arm64/kvm/pkvm.c | 58 ++++++++++++++++++++++++++++++------------- 1 file changed, 41 insertions(+), 17 deletions(-)
arch/arm64/kvm/pkvm.c +41 -17
@@ -373,31 +373,55 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,struct kvm_hyp_memcache *cache = mc;u64 gfn = addr >>PAGE_SHIFT ;u64 pfn = phys >>PAGE_SHIFT ; +u64 end = addr + size;int ret; -if (size !=PAGE_SIZE && size !=PMD_SIZE ) -return -EINVAL ; -lockdep_assert_held_write (&kvm->mmu_lock); + mapping =pkvm_mapping_iter_first (&pgt->pkvm_mappings, addr, end -1 ); -/* -* Calling stage2_map() on top of existing mappings is either happening because of a race -* with another vCPU, or because we're changing between page and block mappings. As per -* user_mem_abort(), same-size permission faults are handled in the relax_perms() path. -*/ - mapping =pkvm_mapping_iter_first (&pgt->pkvm_mappings, addr, addr + size -1 ); -if (mapping) { -if (size == (mapping->nr_pages *PAGE_SIZE )) +if (kvm_vm_is_protected (kvm)) { +/* Protected VMs are mapped using RWX page-granular mappings */ +if (WARN_ON_ONCE (size !=PAGE_SIZE )) +return -EINVAL ; + +if (WARN_ON_ONCE (prot !=KVM_PGTABLE_PROT_RWX )) +return -EINVAL ; + +/* +* We raced with another vCPU. +*/ +if (mapping)return -EAGAIN ; -/* Remove _any_ pkvm_mapping overlapping with the range, bigger or smaller. */ - ret =__pkvm_pgtable_stage2_unshare (pgt, addr, addr + size); -if (ret) -return ret; - mapping =NULL ; + ret =kvm_call_hyp_nvhe (__pkvm_host_donate_guest, pfn, gfn); + }else { +if (WARN_ON_ONCE (size !=PAGE_SIZE && size !=PMD_SIZE )) +return -EINVAL ; + +/* +* We either raced with another vCPU or we're changing between +* page and block mappings. As per user_mem_abort(), same-size +* permission faults are handled in the relax_perms() path. +*/ +if (mapping) { +if (size == (mapping->nr_pages *PAGE_SIZE )) +return -EAGAIN ; + +/* +* Remove _any_ pkvm_mapping overlapping with the range, +* bigger or smaller. +*/ + ret =__pkvm_pgtable_stage2_unshare (pgt, addr, end); +if (ret) +return ret; + + mapping =NULL ; + } + + ret =kvm_call_hyp_nvhe (__pkvm_host_share_guest, pfn, gfn, + size /PAGE_SIZE , prot); } - ret =kvm_call_hyp_nvhe (__pkvm_host_share_guest, pfn, gfn, size /PAGE_SIZE , prot);if (WARN_ON (ret))return ret;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 14/38 KVM: arm64: Handle aborts from protected VMs
In reply to Will DeaconIntroduce a new abort handler for resolving stage-2 page faults from protected VMs by pinning and donating anonymous memory. This is considerably simpler than the infamous user_mem_abort() as we only have to deal with translation faults at the pte level.
--- arch/arm64/kvm/mmu.c | 89 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 81 insertions(+), 8 deletions(-)
arch/arm64/kvm/mmu.c +81 -8
@@ -1642,6 +1642,74 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,return ret != -EAGAIN ? ret :0 ; } +static int pkvm_mem_abort (struct kvm_vcpu *vcpu,phys_addr_t fault_ipa, +struct kvm_memory_slot *memslot,unsigned long hva) +{ +unsigned int flags =FOLL_HWPOISON |FOLL_LONGTERM |FOLL_WRITE ; +struct kvm_pgtable *pgt = vcpu->arch.hw_mmu->pgt; +struct mm_struct *mm = current->mm; +struct kvm *kvm = vcpu->kvm; +void *hyp_memcache; +struct page *page; +int ret; + + ret =prepare_mmu_memcache (vcpu, true, &hyp_memcache); +if (ret) +return -ENOMEM ; + + ret =account_locked_vm (mm,1 , true); +if (ret) +return ret; + +mmap_read_lock (mm); + ret =pin_user_pages (hva,1 , flags, &page); +mmap_read_unlock (mm); + +if (ret == -EHWPOISON ) { +kvm_send_hwpoison_signal (hva,PAGE_SHIFT ); + ret =0 ; + goto dec_account; + }else if (ret !=1 ) { + ret = -EFAULT ; + goto dec_account; + }else if (!folio_test_swapbacked (page_folio (page))) { +/* +* We really can't deal with page-cache pages returned by GUP +* because (a) we may trigger writeback of a page for which we +* no longer have access and (b) page_mkclean() won't find the +* stage-2 mapping in the rmap so we can get out-of-whack with +* the filesystem when marking the page dirty during unpinning +* (see cc5095747edf ("ext4: don't BUG if someone dirty pages +* without asking ext4 first")). +* +* Ideally we'd just restrict ourselves to anonymous pages, but +* we also want to allow memfd (i.e. shmem) pages, so check for +* pages backed by swap in the knowledge that the GUP pin will +* prevent try_to_unmap() from succeeding. +*/ + ret = -EIO ; + goto unpin; + } + +write_lock (&kvm->mmu_lock); + ret =pkvm_pgtable_stage2_map (pgt, fault_ipa,PAGE_SIZE , +page_to_phys (page),KVM_PGTABLE_PROT_RWX , + hyp_memcache,0 ); +write_unlock (&kvm->mmu_lock); +if (ret) { +if (ret == -EAGAIN ) + ret =0 ; + goto unpin; + } + +return 0 ; +unpin: +unpin_user_pages (&page,1 ); +dec_account: +account_locked_vm (mm,1 , false); +return ret; +} + static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, struct kvm_s2_trans *nested, struct kvm_memory_slot *memslot, unsigned long hva,
@@ -2205,15 +2273,20 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) goto out_unlock; } -VM_WARN_ON_ONCE (kvm_vcpu_trap_is_permission_fault (vcpu) && - !write_fault && !kvm_vcpu_trap_is_exec_fault (vcpu)); +if (kvm_vm_is_protected (vcpu->kvm)) { + ret =pkvm_mem_abort (vcpu, fault_ipa, memslot, hva); + }else { +VM_WARN_ON_ONCE (kvm_vcpu_trap_is_permission_fault (vcpu) && + !write_fault && + !kvm_vcpu_trap_is_exec_fault (vcpu)); -if (kvm_slot_has_gmem (memslot)) - ret =gmem_abort (vcpu, fault_ipa, nested, memslot, -esr_fsc_is_permission_fault (esr)); -else - ret =user_mem_abort (vcpu, fault_ipa, nested, memslot, hva, -esr_fsc_is_permission_fault (esr)); +if (kvm_slot_has_gmem (memslot)) + ret =gmem_abort (vcpu, fault_ipa, nested, memslot, +esr_fsc_is_permission_fault (esr)); +else + ret =user_mem_abort (vcpu, fault_ipa, nested, memslot, hva, +esr_fsc_is_permission_fault (esr)); + }if (ret ==0 ) ret =1 ; out:
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 15/38 KVM: arm64: Introduce __pkvm_reclaim_dying_guest_page()
In reply to Will DeaconTo enable reclaim of pages from a protected VM during teardown, introduce a new hypercall to reclaim a single page from a protected guest that is in the dying state.
Since the EL2 code is non-preemptible, the new hypercall deliberately acts on a single page at a time so as to allow EL1 to reschedule frequently during the teardown operation.
--- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 1 + arch/arm64/kvm/hyp/nvhe/hyp-main.c | 9 +++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 79 +++++++++++++++++++ arch/arm64/kvm/hyp/nvhe/pkvm.c | 14 ++++ 6 files changed, 105 insertions(+)
arch/arm64/include/asm/kvm_asm.h +1 -0
@@ -90,6 +90,7 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu, + __KVM_HOST_SMCCC_FUNC___pkvm_reclaim_dying_guest_page, __KVM_HOST_SMCCC_FUNC___pkvm_start_teardown_vm, __KVM_HOST_SMCCC_FUNC___pkvm_finalize_teardown_vm, __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load,
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +1 -0
@@ -40,6 +40,7 @@ int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);int __pkvm_host_share_ffa (u64 pfn,u64 nr_pages);int __pkvm_host_unshare_ffa (u64 pfn,u64 nr_pages);int __pkvm_host_donate_guest (u64 pfn,u64 gfn,struct pkvm_hyp_vcpu *vcpu); +int __pkvm_host_reclaim_page_guest (u64 gfn,struct pkvm_hyp_vm *vm);int __pkvm_host_share_guest (u64 pfn,u64 gfn,u64 nr_pages,struct pkvm_hyp_vcpu *vcpu,enum kvm_pgtable_prot prot);int __pkvm_host_unshare_guest (u64 gfn,u64 nr_pages,struct pkvm_hyp_vm *hyp_vm);
arch/arm64/kvm/hyp/include/nvhe/pkvm.h +1 -0
@@ -74,6 +74,7 @@ int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva,int __pkvm_init_vcpu (pkvm_handle_t handle,struct kvm_vcpu *host_vcpu,unsigned long vcpu_hva); +int __pkvm_reclaim_dying_guest_page (pkvm_handle_t handle,u64 gfn);int __pkvm_start_teardown_vm (pkvm_handle_t handle);int __pkvm_finalize_teardown_vm (pkvm_handle_t handle);
arch/arm64/kvm/hyp/nvhe/hyp-main.c +9 -0
@@ -573,6 +573,14 @@ static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)cpu_reg (host_ctxt,1 ) =__pkvm_init_vcpu (handle, host_vcpu, vcpu_hva); } +static void handle___pkvm_reclaim_dying_guest_page (struct kvm_cpu_context *host_ctxt) +{ +DECLARE_REG (pkvm_handle_t, handle, host_ctxt,1 ); +DECLARE_REG (u64, gfn, host_ctxt,2 ); + +cpu_reg (host_ctxt,1 ) =__pkvm_reclaim_dying_guest_page (handle, gfn); +} +static void handle___pkvm_start_teardown_vm (struct kvm_cpu_context *host_ctxt) {DECLARE_REG (pkvm_handle_t, handle, host_ctxt,1 );
@@ -626,6 +634,7 @@ static const hcall_t host_hcall[] = {HANDLE_FUNC (__pkvm_unreserve_vm),HANDLE_FUNC (__pkvm_init_vm),HANDLE_FUNC (__pkvm_init_vcpu), +HANDLE_FUNC (__pkvm_reclaim_dying_guest_page),HANDLE_FUNC (__pkvm_start_teardown_vm),HANDLE_FUNC (__pkvm_finalize_teardown_vm), HANDLE_FUNC(__pkvm_vcpu_load),
arch/arm64/kvm/hyp/nvhe/mem_protect.c +79 -0
91 lines not on this page · raw message
arch/arm64/kvm/hyp/nvhe/pkvm.c +14 -0
@@ -862,6 +862,20 @@ teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size)unmap_donated_memory_noclear (addr, size); } +int __pkvm_reclaim_dying_guest_page (pkvm_handle_t handle,u64 gfn) +{ +struct pkvm_hyp_vm *hyp_vm; +int ret = -EINVAL ; + +hyp_spin_lock (&vm_table_lock); + hyp_vm =get_vm_by_handle (handle); +if (hyp_vm && hyp_vm->kvm.arch.pkvm.is_dying) + ret =__pkvm_host_reclaim_page_guest (gfn, hyp_vm); +hyp_spin_unlock (&vm_table_lock); + +return ret; +} +int __pkvm_start_teardown_vm (pkvm_handle_t handle) {struct pkvm_hyp_vm *hyp_vm;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 16/38 KVM: arm64: Hook up reclaim hypercall to pkvm_pgtable_stage2_destroy()
In reply to Will DeaconDuring teardown of a protected guest, its memory pages must be reclaimed from the hypervisor by issuing the '__pkvm_reclaim_dying_guest_page' hypercall.
Add a new helper, __pkvm_pgtable_stage2_reclaim(), which is called during the VM teardown operation to reclaim pages from the hypervisor and drop the GUP pin on the host.
--- arch/arm64/kvm/pkvm.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-)
arch/arm64/kvm/pkvm.c +30 -1
@@ -322,6 +322,32 @@ int pkvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,return 0 ; } +static int __pkvm_pgtable_stage2_reclaim (struct kvm_pgtable *pgt,u64 start,u64 end) +{ +struct kvm *kvm =kvm_s2_mmu_to_kvm (pgt->mmu); +pkvm_handle_t handle = kvm->arch.pkvm.handle; +struct pkvm_mapping *mapping; +int ret; + +for_each_mapping_in_range_safe (pgt, start, end, mapping) { +struct page *page; + + ret =kvm_call_hyp_nvhe (__pkvm_reclaim_dying_guest_page, + handle, mapping->gfn); +if (WARN_ON (ret)) +return ret; + + page =pfn_to_page (mapping->pfn); +WARN_ON_ONCE (mapping->nr_pages !=1 ); +unpin_user_pages_dirty_lock (&page,1 , true); +account_locked_vm (current->mm,1 , false); +pkvm_mapping_remove (mapping, &pgt->pkvm_mappings); +kfree (mapping); + } + +return 0 ; +} +static int __pkvm_pgtable_stage2_unshare (struct kvm_pgtable *pgt,u64 start,u64 end) {struct kvm *kvm =kvm_s2_mmu_to_kvm (pgt->mmu);
@@ -355,7 +381,10 @@ void pkvm_pgtable_stage2_destroy_range(struct kvm_pgtable *pgt, kvm->arch.pkvm.is_dying = true; } -__pkvm_pgtable_stage2_unshare (pgt, addr, addr + size); +if (kvm_vm_is_protected (kvm)) +__pkvm_pgtable_stage2_reclaim (pgt, addr, addr + size); +else +__pkvm_pgtable_stage2_unshare (pgt, addr, addr + size); }void pkvm_pgtable_stage2_destroy_pgd (struct kvm_pgtable *pgt)
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 17/38 KVM: arm64: Factor out pKVM host exception injection logic
In reply to Will Deaconinject_undef64() open-codes the logic to inject an exception into the pKVM host. In preparation for reusing this logic to inject a data abort on an unhandled stage-2 fault from the host, factor out the meat and potatoes of the function into a new inject_host_exception() function which takes the ESR as a parameter.
--- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 49 ++++++++++++++---------------- 1 file changed, 23 insertions(+), 26 deletions(-)
arch/arm64/kvm/hyp/nvhe/hyp-main.c +23 -26
@@ -705,43 +705,40 @@ static void handle_host_smc(struct kvm_cpu_context *host_ctxt)kvm_skip_host_instr (); } -/* -* Inject an Undefined Instruction exception into the host. -* -* This is open-coded to allow control over PSTATE construction without -* complicating the generic exception entry helpers. -*/ -static void inject_undef64 (void ) +static void inject_host_exception (u64 esr) { -u64 spsr_mask, vbar, sctlr, old_spsr, new_spsr, esr, offset; +u64 sctlr, spsr_el1, spsr_el2, exc_offset = except_type_sync; +const u64 spsr_mask =PSR_N_BIT |PSR_Z_BIT |PSR_C_BIT | +PSR_V_BIT |PSR_DIT_BIT |PSR_PAN_BIT ; - spsr_mask =PSR_N_BIT |PSR_Z_BIT |PSR_C_BIT |PSR_V_BIT |PSR_DIT_BIT |PSR_PAN_BIT ; + exc_offset += CURRENT_EL_SP_ELx_VECTOR; + + spsr_el1 = spsr_el2 =read_sysreg_el2 (SYS_SPSR ); + spsr_el2 &= spsr_mask; + spsr_el2 |=PSR_D_BIT |PSR_A_BIT |PSR_I_BIT |PSR_F_BIT | + PSR_MODE_EL1h; - vbar =read_sysreg_el1 (SYS_VBAR ); sctlr =read_sysreg_el1 (SYS_SCTLR ); - old_spsr =read_sysreg_el2 (SYS_SPSR ); - - new_spsr = old_spsr & spsr_mask; - new_spsr |=PSR_D_BIT |PSR_A_BIT |PSR_I_BIT |PSR_F_BIT ; - new_spsr |= PSR_MODE_EL1h; -if (!(sctlr &SCTLR_EL1_SPAN )) - new_spsr |=PSR_PAN_BIT ; + spsr_el2 |=PSR_PAN_BIT ;if (sctlr & SCTLR_ELx_DSSBS) - new_spsr |=PSR_SSBS_BIT ; + spsr_el2 |=PSR_SSBS_BIT ;if (system_supports_mte ()) - new_spsr |=PSR_TCO_BIT ; - - esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT) | ESR_ELx_IL; - offset = CURRENT_EL_SP_ELx_VECTOR + except_type_sync; + spsr_el2 |=PSR_TCO_BIT ;write_sysreg_el1 (esr,SYS_ESR );write_sysreg_el1 (read_sysreg_el2 (SYS_ELR ),SYS_ELR ); -write_sysreg_el1 (old_spsr,SYS_SPSR ); -write_sysreg_el2 (vbar + offset,SYS_ELR ); -write_sysreg_el2 (new_spsr,SYS_SPSR ); +write_sysreg_el1 (spsr_el1,SYS_SPSR ); +write_sysreg_el2 (read_sysreg_el1 (SYS_VBAR ) + exc_offset,SYS_ELR ); +write_sysreg_el2 (spsr_el2,SYS_SPSR ); +} + +static void inject_host_undef64 (void ) +{ +inject_host_exception ((ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT) | + ESR_ELx_IL); }static bool handle_host_mte (u64 esr)
@@ -764,7 +761,7 @@ static bool handle_host_mte(u64 esr)return false; } -inject_undef64 (); +inject_host_undef64 ();return true; }
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 18/38 KVM: arm64: Support translation faults in inject_host_exception()
In reply to Will DeaconExtend inject_host_exception() to support the injection of translation faults on both the data and instruction side to 32-bit and 64-bit EL0 as well as 64-bit EL1. This will be used in a subsequent patch when resolving an unhandled host stage-2 abort.
--- arch/arm64/kvm/hyp/include/nvhe/trap_handler.h | 2 ++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 18 +++++++++++++++--- 2 files changed, 17 insertions(+), 3 deletions(-)
arch/arm64/kvm/hyp/include/nvhe/trap_handler.h +2 -0
@@ -16,4 +16,6 @@ __always_unused int ___check_reg_ ## reg; \ type name = (type)cpu_reg(ctxt, (reg)) +void inject_host_exception (u64 esr); +#endif /* __ARM64_KVM_NVHE_TRAP_HANDLER_H__ */
arch/arm64/kvm/hyp/nvhe/hyp-main.c +15 -3
@@ -705,15 +705,24 @@ static void handle_host_smc(struct kvm_cpu_context *host_ctxt)kvm_skip_host_instr (); } -static void inject_host_exception (u64 esr) +void inject_host_exception (u64 esr) {u64 sctlr, spsr_el1, spsr_el2, exc_offset = except_type_sync;const u64 spsr_mask =PSR_N_BIT |PSR_Z_BIT |PSR_C_BIT |PSR_V_BIT |PSR_DIT_BIT |PSR_PAN_BIT ; - exc_offset += CURRENT_EL_SP_ELx_VECTOR; - spsr_el1 = spsr_el2 =read_sysreg_el2 (SYS_SPSR ); +switch (spsr_el1 & (PSR_MODE_MASK |PSR_MODE32_BIT )) { +case PSR_MODE_EL0t: + exc_offset += LOWER_EL_AArch64_VECTOR; +break ; +case PSR_MODE_EL0t |PSR_MODE32_BIT : + exc_offset += LOWER_EL_AArch32_VECTOR; +break ; +default : + exc_offset += CURRENT_EL_SP_ELx_VECTOR; + } + spsr_el2 &= spsr_mask; spsr_el2 |=PSR_D_BIT |PSR_A_BIT |PSR_I_BIT |PSR_F_BIT | PSR_MODE_EL1h;
@@ -728,6 +737,9 @@ static void inject_host_exception(u64 esr)if (system_supports_mte ()) spsr_el2 |=PSR_TCO_BIT ; +if (esr_fsc_is_translation_fault (esr)) +write_sysreg_el1 (read_sysreg_el2 (SYS_FAR ),SYS_FAR ); +write_sysreg_el1 (esr,SYS_ESR );write_sysreg_el1 (read_sysreg_el2 (SYS_ELR ),SYS_ELR );write_sysreg_el1 (spsr_el1,SYS_SPSR );
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 19/38 KVM: arm64: Inject SIGSEGV on illegal accesses
In reply to Will DeaconFrom: Quentin Perret <[email protected]>
The pKVM hypervisor will currently panic if the host tries to access memory that it doesn't own (e.g. protected guest memory). Sadly, as guest memory can still be mapped into the VMM's address space, userspace can trivially crash the kernel/hypervisor by poking into guest memory.
To prevent this, inject the abort back in the host with S1PTW set in the ESR, hence allowing the host to differentiate this abort from normal userspace faults and inject a SIGSEGV cleanly.
--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 37 +++++++++++++++++++++++++++ arch/arm64/mm/fault.c | 22 ++++++++++++++++ 2 files changed, 59 insertions(+)
arch/arm64/kvm/hyp/nvhe/mem_protect.c +37 -0
@@ -18,6 +18,7 @@#include <nvhe/memory.h> #include <nvhe/mem_protect.h> #include <nvhe/mm.h> +#include <nvhe/trap_handler.h> #define KVM_HOST_S2_FLAGS (KVM_PGTABLE_S2_AS_S1 | KVM_PGTABLE_S2_IDMAP)
@@ -612,6 +613,39 @@ static int host_stage2_idmap(u64 addr)return ret; } +static void host_inject_mem_abort (struct kvm_cpu_context *host_ctxt) +{ +u64 ec, esr, spsr; + + esr =read_sysreg_el2 (SYS_ESR ); + spsr =read_sysreg_el2 (SYS_SPSR ); + +/* Repaint the ESR to report a same-level fault if taken from EL1 */ +if ((spsr &PSR_MODE_MASK ) != PSR_MODE_EL0t) { + ec =ESR_ELx_EC (esr); +if (ec == ESR_ELx_EC_DABT_LOW) + ec = ESR_ELx_EC_DABT_CUR; +else if (ec == ESR_ELx_EC_IABT_LOW) + ec = ESR_ELx_EC_IABT_CUR; +else +WARN_ON (1 ); + esr &= ~ESR_ELx_EC_MASK; + esr |= ec << ESR_ELx_EC_SHIFT; + } + +/* +* Since S1PTW should only ever be set for stage-2 faults, we're pretty +* much guaranteed that it won't be set in ESR_EL1 by the hardware. So, +* let's use that bit to allow the host abort handler to differentiate +* this abort from normal userspace faults. +* +* Note: although S1PTW is RES0 at EL1, it is guaranteed by the +* architecture to be backed by flops, so it should be safe to use. +*/ + esr |= ESR_ELx_S1PTW; +inject_host_exception (esr); +} +void handle_host_mem_abort (struct kvm_cpu_context *host_ctxt) {struct kvm_vcpu_fault_info fault;
@@ -635,6 +669,9 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt) addr =FIELD_GET (HPFAR_EL2_FIPA , fault.hpfar_el2) <<12 ;switch (host_stage2_idmap (addr)) { +case -EPERM : +host_inject_mem_abort (host_ctxt); + fallthrough;case -EEXIST :case 0 :break ;
arch/arm64/mm/fault.c +22 -0
@@ -43,6 +43,7 @@#include <asm/system_misc.h> #include <asm/tlbflush.h> #include <asm/traps.h> +#include <asm/virt.h> struct fault_info { int (*fn)(unsigned long far, unsigned long esr,
@@ -269,6 +270,15 @@ static inline bool is_el1_permission_fault(unsigned long addr, unsigned long esrreturn false; } +static bool is_pkvm_stage2_abort (unsigned int esr) +{ +/* +* S1PTW should only ever be set in ESR_EL1 if the pkvm hypervisor +* injected a stage-2 abort -- see host_inject_mem_abort(). +*/ +return is_pkvm_initialized () && (esr & ESR_ELx_S1PTW); +} +static bool __kprobes is_spurious_el1_translation_fault (unsigned long addr,unsigned long esr,struct pt_regs *regs)
@@ -279,6 +289,9 @@ static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr,if (!is_el1_data_abort (esr) || !esr_fsc_is_translation_fault (esr))return false; +if (is_pkvm_stage2_abort (esr)) +return false; +local_irq_save (flags); asmvolatile ("at s1e1r, %0" ::"r" (addr));isb ();
@@ -395,6 +408,8 @@ static void __do_kernel_fault(unsigned long addr, unsigned long esr, msg ="read from unreadable memory" ; }else if (addr <PAGE_SIZE ) { msg ="NULL pointer dereference" ; + }else if (is_pkvm_stage2_abort (esr)) { + msg ="access to hypervisor-protected memory" ; }else {if (esr_fsc_is_translation_fault (esr) &&kfence_handle_page_fault (addr, esr & ESR_ELx_WNR, regs))
@@ -621,6 +636,13 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, addr, esr, regs); } +if (is_pkvm_stage2_abort (esr)) { +if (!user_mode (regs)) + goto no_context; +arm64_force_sig_fault (SIGSEGV ,SEGV_ACCERR , far,"stage-2 fault" ); +return 0 ; + } +perf_sw_event (PERF_COUNT_SW_PAGE_FAULTS ,1 , regs, addr);if (!(mm_flags &FAULT_FLAG_USER ))
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 20/38 KVM: arm64: Avoid pointless annotation when mapping host-owned pages
In reply to Will DeaconWhen a page is transitioned to host ownership, we can eagerly map it into the host stage-2 page-table rather than going via the convoluted step of a faulting annotation to trigger the mapping.
Call host_stage2_idmap_locked() directly when transitioning a page to be owned by the host.
--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 28 +++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-)
arch/arm64/kvm/hyp/nvhe/mem_protect.c +16 -12
@@ -551,23 +551,27 @@ static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm_page_int host_stage2_set_owner_locked (phys_addr_t addr,u64 size,u8 owner_id) { -int ret; +int ret = -EINVAL ;if (!range_is_memory (addr, addr + size))return -EPERM ; - ret =host_stage2_try (kvm_pgtable_stage2_set_owner, &host_mmu.pgt, - addr, size, &host_s2_pool, owner_id); -if (ret) -return ret; +switch (owner_id) { +case PKVM_ID_HOST : + ret =host_stage2_idmap_locked (addr, size,PKVM_HOST_MEM_PROT ); +if (!ret) +__host_update_page_state (addr, size,PKVM_PAGE_OWNED ); +break ; +case PKVM_ID_GUEST : +case PKVM_ID_HYP : + ret =host_stage2_try (kvm_pgtable_stage2_set_owner, &host_mmu.pgt, + addr, size, &host_s2_pool, owner_id); +if (!ret) +__host_update_page_state (addr, size,PKVM_NOPAGE ); +break ; + } -/* Don't forget to update the vmemmap tracking for the host */ -if (owner_id ==PKVM_ID_HOST ) -__host_update_page_state (addr, size,PKVM_PAGE_OWNED ); -else -__host_update_page_state (addr, size,PKVM_NOPAGE ); - -return 0 ; +return ret; }static bool host_stage2_force_pte_cb (u64 addr,u64 end,enum kvm_pgtable_prot prot)
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 21/38 KVM: arm64: Generalise kvm_pgtable_stage2_set_owner()
In reply to Will Deaconkvm_pgtable_stage2_set_owner() can be generalised into a way to store up to 59 bits in the page tables alongside a 4-bit 'type' identifier specific to the format of the 59-bit payload.
Introduce kvm_pgtable_stage2_annotate() and move the existing invalid ptes (for locked ptes and donated pages) over to the new scheme.
--- arch/arm64/include/asm/kvm_pgtable.h | 39 +++++++++++++++++++-------- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 16 +++++++++-- arch/arm64/kvm/hyp/pgtable.c | 33 ++++++++++++++--------- 3 files changed, 62 insertions(+), 26 deletions(-)
arch/arm64/include/asm/kvm_pgtable.h +28 -11
@@ -100,13 +100,25 @@ typedef u64 kvm_pte_t; KVM_PTE_LEAF_ATTR_HI_S2_XN)#define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) -#define KVM_MAX_OWNER_ID 2 -/* -* Used to indicate a pte for which a 'break-before-make' sequence is in -* progress. -*/ -#define KVM_INVALID_PTE_LOCKED BIT(10) +/* pKVM invalid pte encodings */ +#define KVM_INVALID_PTE_TYPE_MASK GENMASK(63, 60) +#define KVM_INVALID_PTE_ANNOT_MASK ~(KVM_PTE_VALID | \ + KVM_INVALID_PTE_TYPE_MASK) + +enum kvm_invalid_pte_type { +/* +* Used to indicate a pte for which a 'break-before-make' +* sequence is in progress. +*/ +KVM_INVALID_PTE_TYPE_LOCKED =1 , + +/* +* pKVM has unmapped the page from the host due to a change of +* ownership. +*/ +KVM_HOST_INVALID_PTE_TYPE_DONATION , +};static inline bool kvm_pte_valid (kvm_pte_t pte) {
@@ -658,14 +670,18 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, void *mc, enum kvm_pgtable_walk_flags flags);/** -* kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to -* track ownership. +* kvm_pgtable_stage2_annotate() - Unmap and annotate pages in the IPA space +* to track ownership (and more). * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Base intermediate physical address to annotate. * @size: Size of the annotated range. * @mc: Cache of pre-allocated and zeroed memory from which to allocate * page-table pages. -* @owner_id: Unique identifier for the owner of the page. +* @type: The type of the annotation, determining its meaning and format. +* @annotation: A 59-bit value that will be stored in the page tables. +* @annotation[0] and @annotation[63:60] must be 0. +* @annotation[59:1] is stored in the page tables, along +* with @type. * * By default, all page-tables are owned by identifier 0. This function can be * used to mark portions of the IPA space as owned by other entities. When a
@@ -674,8 +690,9 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,* * Return: 0 on success, negative error code on failure. */ -int kvm_pgtable_stage2_set_owner (struct kvm_pgtable *pgt,u64 addr,u64 size, -void *mc,u8 owner_id); +int kvm_pgtable_stage2_annotate (struct kvm_pgtable *pgt,u64 addr,u64 size, +void *mc,enum kvm_invalid_pte_type type, +kvm_pte_t annotation);/** * kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 page-table.
arch/arm64/kvm/hyp/nvhe/mem_protect.c +14 -2
@@ -549,10 +549,19 @@ static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm_page_set_host_state (page, state); } +static kvm_pte_t kvm_init_invalid_leaf_owner (u8 owner_id) +{ +return FIELD_PREP (KVM_INVALID_PTE_OWNER_MASK , owner_id); +} +int host_stage2_set_owner_locked (phys_addr_t addr,u64 size,u8 owner_id) { +kvm_pte_t annotation;int ret = -EINVAL ; +if (!FIELD_FIT (KVM_INVALID_PTE_OWNER_MASK , owner_id)) +return -EINVAL ; +if (!range_is_memory (addr, addr + size))return -EPERM ;
@@ -564,8 +573,11 @@ int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)break ;case PKVM_ID_GUEST :case PKVM_ID_HYP : - ret =host_stage2_try (kvm_pgtable_stage2_set_owner, &host_mmu.pgt, - addr, size, &host_s2_pool, owner_id); + annotation =kvm_init_invalid_leaf_owner (owner_id); + ret =host_stage2_try (kvm_pgtable_stage2_annotate, &host_mmu.pgt, + addr, size, &host_s2_pool, +KVM_HOST_INVALID_PTE_TYPE_DONATION , + annotation);if (!ret)__host_update_page_state (addr, size,PKVM_NOPAGE );break ;
arch/arm64/kvm/hyp/pgtable.c +20 -13
@@ -114,11 +114,6 @@ static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, s8 level)return pte; } -static kvm_pte_t kvm_init_invalid_leaf_owner (u8 owner_id) -{ -return FIELD_PREP (KVM_INVALID_PTE_OWNER_MASK , owner_id); -} -static int kvm_pgtable_visitor_cb (struct kvm_pgtable_walk_data *data,const struct kvm_pgtable_visit_ctx *ctx,enum kvm_pgtable_walk_flags visit)
@@ -581,7 +576,7 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)struct stage2_map_data {const u64 phys;kvm_pte_t attr; -u8 owner_id; +kvm_pte_t pte_annot;kvm_pte_t *anchor;kvm_pte_t *childp;
@@ -798,7 +793,11 @@ static bool stage2_pte_is_counted(kvm_pte_t pte)static bool stage2_pte_is_locked (kvm_pte_t pte) { -return !kvm_pte_valid (pte) && (pte &KVM_INVALID_PTE_LOCKED ); +if (kvm_pte_valid (pte)) +return false; + +return FIELD_GET (KVM_INVALID_PTE_TYPE_MASK , pte) == +KVM_INVALID_PTE_TYPE_LOCKED ; }static bool stage2_try_set_pte (const struct kvm_pgtable_visit_ctx *ctx,kvm_pte_t new)
@@ -829,6 +828,7 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, struct kvm_s2_mmu *mmu) {struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; +kvm_pte_t locked_pte;if (stage2_pte_is_locked (ctx->old)) {/*
@@ -839,7 +839,9 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx,return false; } -if (!stage2_try_set_pte (ctx,KVM_INVALID_PTE_LOCKED )) + locked_pte =FIELD_PREP (KVM_INVALID_PTE_TYPE_MASK , +KVM_INVALID_PTE_TYPE_LOCKED ); +if (!stage2_try_set_pte (ctx, locked_pte))return false;if (!kvm_pgtable_walk_skip_bbm_tlbi (ctx)) {
@@ -964,7 +966,7 @@ static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx,if (!data->annotation) new =kvm_init_valid_leaf_pte (phys, data->attr, ctx->level);else - new =kvm_init_invalid_leaf_owner (data->owner_id); + new = data->pte_annot;/* * Skip updating the PTE if we are trying to recreate the exact
@@ -1118,16 +1120,18 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,return ret; } -int kvm_pgtable_stage2_set_owner (struct kvm_pgtable *pgt,u64 addr,u64 size, -void *mc,u8 owner_id) +int kvm_pgtable_stage2_annotate (struct kvm_pgtable *pgt,u64 addr,u64 size, +void *mc,enum kvm_invalid_pte_type type, +kvm_pte_t pte_annot) {int ret;struct stage2_map_data map_data = { .mmu = pgt->mmu, .memcache = mc, - .owner_id = owner_id, .force_pte = true, .annotation = true, + .pte_annot = pte_annot | +FIELD_PREP (KVM_INVALID_PTE_TYPE_MASK , type), };struct kvm_pgtable_walker walker = { .cb = stage2_map_walker,
@@ -1136,7 +1140,10 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, .arg = &map_data, }; -if (owner_id >KVM_MAX_OWNER_ID ) +if (pte_annot & ~KVM_INVALID_PTE_ANNOT_MASK ) +return -EINVAL ; + +if (!type || type ==KVM_INVALID_PTE_TYPE_LOCKED )return -EINVAL ; ret =kvm_pgtable_walk (pgt, addr, size, &walker);
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 22/38 KVM: arm64: Introduce host_stage2_set_owner_metadata_locked()
In reply to Will DeaconRework host_stage2_set_owner_locked() to add a new helper function, host_stage2_set_owner_metadata_locked(), which will allow us to store additional metadata alongside a 3-bit owner ID for invalid host stage-2 entries.
--- arch/arm64/include/asm/kvm_pgtable.h | 2 -- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 47 ++++++++++++++++++--------- 2 files changed, 32 insertions(+), 17 deletions(-)
arch/arm64/include/asm/kvm_pgtable.h +0 -2
@@ -99,8 +99,6 @@ typedef u64 kvm_pte_t; KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \ KVM_PTE_LEAF_ATTR_HI_S2_XN) -#define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) -/* pKVM invalid pte encodings */ #define KVM_INVALID_PTE_TYPE_MASK GENMASK(63, 60)#define KVM_INVALID_PTE_ANNOT_MASK ~(KVM_PTE_VALID | \
arch/arm64/kvm/hyp/nvhe/mem_protect.c +32 -15
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Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 23/38 KVM: arm64: Change 'pkvm_handle_t' to u16
In reply to Will Deacon'pkvm_handle_t' doesn't need to be a 32-bit type and subsequent patches will rely on it being no more than 16 bits so that it can be encoded into a pte annotation.
Change 'pkvm_handle_t' to a u16 and add a compile-type check that the maximum handle fits into the reduced type.
--- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kvm/hyp/nvhe/pkvm.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)
arch/arm64/include/asm/kvm_host.h +1 -1
@@ -247,7 +247,7 @@ struct kvm_smccc_features {unsigned long vendor_hyp_bmap_2;/* Function numbers 64-127 */ }; -typedef unsigned int pkvm_handle_t ; +typedef u16 pkvm_handle_t ;struct kvm_protected_vm {pkvm_handle_t handle;
arch/arm64/kvm/hyp/nvhe/pkvm.c +1 -0
@@ -222,6 +222,7 @@ static struct pkvm_hyp_vm **vm_table;void pkvm_hyp_vm_table_init (void *tbl) { +BUILD_BUG_ON ((u64 )HANDLE_OFFSET +KVM_MAX_PVMS > (pkvm_handle_t)-1 );WARN_ON (vm_table); vm_table = tbl; }
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 24/38 KVM: arm64: Annotate guest donations with handle and gfn in host stage-2
In reply to Will DeaconHandling host kernel faults arising from accesses to donated guest memory will require an rmap-like mechanism to identify the guest mapping of the faulting page.
Extend the page donation logic to encode the guest handle and gfn alongside the owner information in the host stage-2 pte.
--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
arch/arm64/kvm/hyp/nvhe/mem_protect.c +18 -2
@@ -593,7 +593,6 @@ int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)if (!ret)__host_update_page_state (addr, size,PKVM_PAGE_OWNED );break ; -case PKVM_ID_GUEST :case PKVM_ID_HYP : ret =host_stage2_set_owner_metadata_locked (addr, size, owner_id,0 );
@@ -603,6 +602,20 @@ int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)return ret; } +#define KVM_HOST_PTE_OWNER_GUEST_HANDLE_MASK GENMASK(15, 0) +/* We need 40 bits for the GFN to cover a 52-bit IPA with 4k pages and LPA2 */ +#define KVM_HOST_PTE_OWNER_GUEST_GFN_MASK GENMASK(55, 16) +static u64 host_stage2_encode_gfn_meta (struct pkvm_hyp_vm *vm,u64 gfn) +{ +pkvm_handle_t handle = vm->kvm.arch.pkvm.handle; + +BUILD_BUG_ON ((pkvm_handle_t)-1 >KVM_HOST_PTE_OWNER_GUEST_HANDLE_MASK ); +WARN_ON (!FIELD_FIT (KVM_HOST_PTE_OWNER_GUEST_GFN_MASK , gfn)); + +return FIELD_PREP (KVM_HOST_PTE_OWNER_GUEST_HANDLE_MASK , handle) | +FIELD_PREP (KVM_HOST_PTE_OWNER_GUEST_GFN_MASK , gfn); +} +static bool host_stage2_force_pte_cb (u64 addr,u64 end,enum kvm_pgtable_prot prot) {/*
@@ -1125,6 +1138,7 @@ int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu)struct pkvm_hyp_vm *vm =pkvm_hyp_vcpu_to_hyp_vm (vcpu);u64 phys =hyp_pfn_to_phys (pfn);u64 ipa =hyp_pfn_to_phys (gfn); +u64 meta;int ret;host_lock_component ();
@@ -1138,7 +1152,9 @@ int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu)if (ret) goto unlock; -WARN_ON (host_stage2_set_owner_locked (phys,PAGE_SIZE ,PKVM_ID_GUEST )); + meta =host_stage2_encode_gfn_meta (vm, gfn); +WARN_ON (host_stage2_set_owner_metadata_locked (phys,PAGE_SIZE , +PKVM_ID_GUEST , meta));WARN_ON (kvm_pgtable_stage2_map (&vm->pgt, ipa,PAGE_SIZE , phys,pkvm_mkstate (KVM_PGTABLE_PROT_RWX ,PKVM_PAGE_OWNED ), &vcpu->vcpu.arch.pkvm_memcache,0 ));
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 25/38 KVM: arm64: Introduce hypercall to force reclaim of a protected page
In reply to Will DeaconIntroduce a new hypercall, __pkvm_force_reclaim_guest_page(), to allow the host to forcefully reclaim a physical page that was previous donated to a protected guest. This results in the page being zeroed and the previous guest mapping being poisoned so that new pages cannot be subsequently donated at the same IPA.
--- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/include/asm/kvm_pgtable.h | 6 + arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + arch/arm64/kvm/hyp/include/nvhe/memory.h | 6 + arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 1 + arch/arm64/kvm/hyp/nvhe/hyp-main.c | 8 ++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 127 +++++++++++++++++- arch/arm64/kvm/hyp/nvhe/pkvm.c | 4 +- 8 files changed, 152 insertions(+), 2 deletions(-)
arch/arm64/include/asm/kvm_asm.h +1 -0
@@ -90,6 +90,7 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu, + __KVM_HOST_SMCCC_FUNC___pkvm_force_reclaim_guest_page, __KVM_HOST_SMCCC_FUNC___pkvm_reclaim_dying_guest_page, __KVM_HOST_SMCCC_FUNC___pkvm_start_teardown_vm, __KVM_HOST_SMCCC_FUNC___pkvm_finalize_teardown_vm,
arch/arm64/include/asm/kvm_pgtable.h +6 -0
@@ -116,6 +116,12 @@ enum kvm_invalid_pte_type {* ownership. */ KVM_HOST_INVALID_PTE_TYPE_DONATION , + +/* +* The page has been forcefully reclaimed from the guest by the +* host. +*/ + KVM_GUEST_INVALID_PTE_TYPE_POISONED, };static inline bool kvm_pte_valid (kvm_pte_t pte)
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +1 -0
@@ -40,6 +40,7 @@ int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);int __pkvm_host_share_ffa (u64 pfn,u64 nr_pages);int __pkvm_host_unshare_ffa (u64 pfn,u64 nr_pages);int __pkvm_host_donate_guest (u64 pfn,u64 gfn,struct pkvm_hyp_vcpu *vcpu); +int __pkvm_host_force_reclaim_page_guest (phys_addr_t phys);int __pkvm_host_reclaim_page_guest (u64 gfn,struct pkvm_hyp_vm *vm);int __pkvm_host_share_guest (u64 pfn,u64 gfn,u64 nr_pages,struct pkvm_hyp_vcpu *vcpu,enum kvm_pgtable_prot prot);
arch/arm64/kvm/hyp/include/nvhe/memory.h +6 -0
@@ -30,6 +30,12 @@ enum pkvm_page_state {* struct hyp_page. */ PKVM_NOPAGE =BIT (0 ) |BIT (1 ), + +/* +* 'Meta-states' which aren't encoded directly in the PTE's SW bits (or +* the hyp_vmemmap entry for the host) +*/ + PKVM_POISON = BIT(2), };#define PKVM_PAGE_STATE_MASK (BIT(0) | BIT(1))
arch/arm64/kvm/hyp/include/nvhe/pkvm.h +1 -0
@@ -78,6 +78,7 @@ int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn);int __pkvm_start_teardown_vm (pkvm_handle_t handle);int __pkvm_finalize_teardown_vm (pkvm_handle_t handle); +struct pkvm_hyp_vm *get_vm_by_handle (pkvm_handle_t handle);struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu (pkvm_handle_t handle,unsigned int vcpu_idx);void pkvm_put_hyp_vcpu (struct pkvm_hyp_vcpu *hyp_vcpu);
arch/arm64/kvm/hyp/nvhe/hyp-main.c +8 -0
@@ -573,6 +573,13 @@ static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)cpu_reg (host_ctxt,1 ) =__pkvm_init_vcpu (handle, host_vcpu, vcpu_hva); } +static void handle___pkvm_force_reclaim_guest_page (struct kvm_cpu_context *host_ctxt) +{ +DECLARE_REG (phys_addr_t, phys, host_ctxt,1 ); + +cpu_reg (host_ctxt,1 ) =__pkvm_host_force_reclaim_page_guest (phys); +} +static void handle___pkvm_reclaim_dying_guest_page (struct kvm_cpu_context *host_ctxt) {DECLARE_REG (pkvm_handle_t, handle, host_ctxt,1 );
@@ -634,6 +641,7 @@ static const hcall_t host_hcall[] = {HANDLE_FUNC (__pkvm_unreserve_vm),HANDLE_FUNC (__pkvm_init_vm),HANDLE_FUNC (__pkvm_init_vcpu), +HANDLE_FUNC (__pkvm_force_reclaim_guest_page),HANDLE_FUNC (__pkvm_reclaim_dying_guest_page),HANDLE_FUNC (__pkvm_start_teardown_vm), HANDLE_FUNC(__pkvm_finalize_teardown_vm),
arch/arm64/kvm/hyp/nvhe/mem_protect.c +126 -1
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arch/arm64/kvm/hyp/nvhe/pkvm.c +3 -1
@@ -230,10 +230,12 @@ void pkvm_hyp_vm_table_init(void *tbl)/* * Return the hyp vm structure corresponding to the handle. */ -static struct pkvm_hyp_vm *get_vm_by_handle (pkvm_handle_t handle) +struct pkvm_hyp_vm *get_vm_by_handle (pkvm_handle_t handle) {unsigned int idx =vm_handle_to_idx (handle); +hyp_assert_lock_held (&vm_table_lock); +if (unlikely (idx >=KVM_MAX_PVMS ))return NULL ;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 26/38 KVM: arm64: Reclaim faulting page from pKVM in spurious fault handler
In reply to Will DeaconHost kernel accesses to pages that are inaccessible at stage-2 result in the injection of a translation fault, which is fatal unless an exception table fixup is registered for the faulting PC (e.g. for user access routines). This is undesirable, since a get_user_pages() call could be used to obtain a reference to a donated page and then a subsequent access via a kernel mapping would lead to a panic().
Rework the spurious fault handler so that stage-2 faults injected back into the host result in the target page being forcefully reclaimed when no exception table fixup handler is registered.
--- arch/arm64/include/asm/virt.h | 9 +++++++++ arch/arm64/kvm/pkvm.c | 12 ++++++++++++ arch/arm64/mm/fault.c | 17 +++++++++++------ 3 files changed, 32 insertions(+), 6 deletions(-)
arch/arm64/include/asm/virt.h +9 -0
@@ -94,6 +94,15 @@ static inline bool is_pkvm_initialized(void)static_branch_likely (&kvm_protected_mode_initialized); } +#ifdef CONFIG_KVM +bool pkvm_force_reclaim_guest_page (phys_addr_t phys); +#else +static inline bool pkvm_force_reclaim_guest_page (phys_addr_t phys) +{ +return false; +} +#endif +/* Reports the availability of HYP mode */ static inline bool is_hyp_mode_available (void ) {
arch/arm64/kvm/pkvm.c +12 -0
@@ -563,3 +563,15 @@ int pkvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size,WARN_ON_ONCE (1 );return -EINVAL ; } + +/* +* Forcefully reclaim a page from the guest, zeroing its contents and +* poisoning the stage-2 pte so that pages can no longer be mapped at +* the same IPA. The page remains pinned until the guest is destroyed. +*/ +bool pkvm_force_reclaim_guest_page (phys_addr_t phys) +{ +int ret =kvm_call_hyp_nvhe (__pkvm_force_reclaim_guest_page, phys); + +return !ret || ret == -EAGAIN ; +}
arch/arm64/mm/fault.c +11 -6
@@ -289,9 +289,6 @@ static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr,if (!is_el1_data_abort (esr) || !esr_fsc_is_translation_fault (esr))return false; -if (is_pkvm_stage2_abort (esr)) -return false; -local_irq_save (flags); asmvolatile ("at s1e1r, %0" ::"r" (addr));isb ();
@@ -302,8 +299,14 @@ static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr,* If we now have a valid translation, treat the translation fault as * spurious. */ -if (!(par &SYS_PAR_EL1_F )) +if (!(par &SYS_PAR_EL1_F )) { +if (is_pkvm_stage2_abort (esr)) { + par &=SYS_PAR_EL1_PA ; +return pkvm_force_reclaim_guest_page (par); + } +return true; + }/* * If we got a different type of fault from the AT instruction,
@@ -389,9 +392,11 @@ static void __do_kernel_fault(unsigned long addr, unsigned long esr,if (!is_el1_instruction_abort (esr) &&fixup_exception (regs, esr))return ; -if (WARN_RATELIMIT (is_spurious_el1_translation_fault (addr, esr, regs), -"Ignoring spurious kernel translation fault at virtual address %016lx\n" , addr)) +if (is_spurious_el1_translation_fault (addr, esr, regs)) { +WARN_RATELIMIT (!is_pkvm_stage2_abort (esr), +"Ignoring spurious kernel translation fault at virtual address %016lx\n" , addr);return ; + }if (is_el1_mte_sync_tag_check_fault (esr)) {do_tag_recovery (addr, esr, regs);
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 27/38 KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte
In reply to Will DeaconIf a protected vCPU faults on an IPA which appears to be mapped, query the hypervisor to determine whether or not the faulting pte has been poisoned by a forceful reclaim. If the pte has been poisoned, return -EFAULT back to userspace rather than retrying the instruction forever.
--- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + arch/arm64/kvm/hyp/nvhe/hyp-main.c | 10 +++++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 43 +++++++++++++++++++ arch/arm64/kvm/pkvm.c | 9 ++-- 5 files changed, 61 insertions(+), 3 deletions(-)
arch/arm64/include/asm/kvm_asm.h +1 -0
@@ -90,6 +90,7 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu, + __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_in_poison_fault, __KVM_HOST_SMCCC_FUNC___pkvm_force_reclaim_guest_page, __KVM_HOST_SMCCC_FUNC___pkvm_reclaim_dying_guest_page, __KVM_HOST_SMCCC_FUNC___pkvm_start_teardown_vm,
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +1 -0
@@ -40,6 +40,7 @@ int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);int __pkvm_host_share_ffa (u64 pfn,u64 nr_pages);int __pkvm_host_unshare_ffa (u64 pfn,u64 nr_pages);int __pkvm_host_donate_guest (u64 pfn,u64 gfn,struct pkvm_hyp_vcpu *vcpu); +int __pkvm_vcpu_in_poison_fault (struct pkvm_hyp_vcpu *hyp_vcpu);int __pkvm_host_force_reclaim_page_guest (phys_addr_t phys);int __pkvm_host_reclaim_page_guest (u64 gfn,struct pkvm_hyp_vm *vm); int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu,
arch/arm64/kvm/hyp/nvhe/hyp-main.c +10 -0
@@ -573,6 +573,15 @@ static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)cpu_reg (host_ctxt,1 ) =__pkvm_init_vcpu (handle, host_vcpu, vcpu_hva); } +static void handle___pkvm_vcpu_in_poison_fault (struct kvm_cpu_context *host_ctxt) +{ +int ret; +struct pkvm_hyp_vcpu *hyp_vcpu =pkvm_get_loaded_hyp_vcpu (); + + ret = hyp_vcpu ?__pkvm_vcpu_in_poison_fault (hyp_vcpu) : -EINVAL ; +cpu_reg (host_ctxt,1 ) = ret; +} +static void handle___pkvm_force_reclaim_guest_page (struct kvm_cpu_context *host_ctxt) {DECLARE_REG (phys_addr_t, phys, host_ctxt,1 );
@@ -641,6 +650,7 @@ static const hcall_t host_hcall[] = {HANDLE_FUNC (__pkvm_unreserve_vm),HANDLE_FUNC (__pkvm_init_vm),HANDLE_FUNC (__pkvm_init_vcpu), +HANDLE_FUNC (__pkvm_vcpu_in_poison_fault),HANDLE_FUNC (__pkvm_force_reclaim_guest_page),HANDLE_FUNC (__pkvm_reclaim_dying_guest_page), HANDLE_FUNC(__pkvm_start_teardown_vm),
arch/arm64/kvm/hyp/nvhe/mem_protect.c +43 -0
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arch/arm64/kvm/pkvm.c +6 -3
@@ -417,10 +417,13 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,return -EINVAL ;/* -* We raced with another vCPU. +* We either raced with another vCPU or the guest PTE +* has been poisoned by an erroneous host access. */ -if (mapping) -return -EAGAIN ; +if (mapping) { + ret =kvm_call_hyp_nvhe (__pkvm_vcpu_in_poison_fault); +return ret ? -EFAULT : -EAGAIN ; + } ret =kvm_call_hyp_nvhe (__pkvm_host_donate_guest, pfn, gfn); }else {
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 28/38 KVM: arm64: Add hvc handler at EL2 for hypercalls from protected VMs
In reply to Will DeaconAdd a hypercall handler at EL2 for hypercalls originating from protected VMs. For now, this implements only the FEATURES and MEMINFO calls, but subsequent patches will implement the SHARE and UNSHARE functions necessary for virtio.
Unhandled hypercalls (including PSCI) are passed back to the host.
--- arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 1 + arch/arm64/kvm/hyp/nvhe/pkvm.c | 37 ++++++++++++++++++++++++++ arch/arm64/kvm/hyp/nvhe/switch.c | 1 + 3 files changed, 39 insertions(+)
arch/arm64/kvm/hyp/include/nvhe/pkvm.h +1 -0
@@ -88,6 +88,7 @@ struct pkvm_hyp_vm *get_pkvm_hyp_vm(pkvm_handle_t handle);struct pkvm_hyp_vm *get_np_pkvm_hyp_vm (pkvm_handle_t handle);void put_pkvm_hyp_vm (struct pkvm_hyp_vm *hyp_vm); +bool kvm_handle_pvm_hvc64 (struct kvm_vcpu *vcpu,u64 *exit_code);bool kvm_handle_pvm_sysreg (struct kvm_vcpu *vcpu,u64 *exit_code);bool kvm_handle_pvm_restricted (struct kvm_vcpu *vcpu,u64 *exit_code);void kvm_init_pvm_id_regs (struct kvm_vcpu *vcpu);
arch/arm64/kvm/hyp/nvhe/pkvm.c +37 -0
@@ -4,6 +4,8 @@* Author: Fuad Tabba <[email protected]> */ +#include <kvm/arm_hypercalls.h> +#include <linux/kvm_host.h> #include <linux/mm.h>
@@ -965,3 +967,38 @@ int __pkvm_finalize_teardown_vm(pkvm_handle_t handle)hyp_spin_unlock (&vm_table_lock);return err; } +/* +* Handler for protected VM HVC calls. +* +* Returns true if the hypervisor has handled the exit (and control +* should return to the guest) or false if it hasn't (and the handling +* should be performed by the host). +*/ +bool kvm_handle_pvm_hvc64 (struct kvm_vcpu *vcpu,u64 *exit_code) +{ +u64 val[4 ] = {SMCCC_RET_INVALID_PARAMETER }; +bool handled = true; + +switch (smccc_get_function (vcpu)) { +case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID : + val[0 ] =BIT (ARM_SMCCC_KVM_FUNC_FEATURES ); + val[0 ] |=BIT (ARM_SMCCC_KVM_FUNC_HYP_MEMINFO ); +break ; +case ARM_SMCCC_VENDOR_HYP_KVM_HYP_MEMINFO_FUNC_ID : +if (smccc_get_arg1 (vcpu) || +smccc_get_arg2 (vcpu) || +smccc_get_arg3 (vcpu)) { +break ; + } + + val[0 ] =PAGE_SIZE ; +break ; +default : +/* Punt everything else back to the host, for now. */ + handled = false; + } + +if (handled) +smccc_set_retval (vcpu, val[0 ], val[1 ], val[2 ], val[3 ]); +return handled; +}
arch/arm64/kvm/hyp/nvhe/switch.c +1 -0
@@ -190,6 +190,7 @@ static const exit_handler_fn hyp_exit_handlers[] = {static const exit_handler_fn pvm_exit_handlers[] = { [0 ... ESR_ELx_EC_MAX] =NULL , + [ESR_ELx_EC_HVC64] = kvm_handle_pvm_hvc64, [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, [ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted, [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd,
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 29/38 KVM: arm64: Implement the MEM_SHARE hypercall for protected VMs
In reply to Will DeaconImplement the ARM_SMCCC_KVM_FUNC_MEM_SHARE hypercall to allow protected VMs to share memory (e.g. the swiotlb bounce buffers) back to the host.
--- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + arch/arm64/kvm/hyp/nvhe/mem_protect.c | 32 ++++++++++ arch/arm64/kvm/hyp/nvhe/pkvm.c | 61 +++++++++++++++++++ 3 files changed, 94 insertions(+)
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +1 -0
@@ -34,6 +34,7 @@ extern unsigned long hyp_nr_cpus;int __pkvm_prot_finalize (void );int __pkvm_host_share_hyp (u64 pfn); +int __pkvm_guest_share_host (struct pkvm_hyp_vcpu *vcpu,u64 gfn);int __pkvm_host_unshare_hyp (u64 pfn);int __pkvm_host_donate_hyp (u64 pfn,u64 nr_pages);int __pkvm_hyp_donate_host (u64 pfn,u64 nr_pages);
arch/arm64/kvm/hyp/nvhe/mem_protect.c +32 -0
@@ -959,6 +959,38 @@ int __pkvm_host_share_hyp(u64 pfn)return ret; } +int __pkvm_guest_share_host (struct pkvm_hyp_vcpu *vcpu,u64 gfn) +{ +struct pkvm_hyp_vm *vm =pkvm_hyp_vcpu_to_hyp_vm (vcpu); +u64 phys, ipa =hyp_pfn_to_phys (gfn); +kvm_pte_t pte; +int ret; + +host_lock_component (); +guest_lock_component (vm); + + ret =get_valid_guest_pte (vm, ipa, &pte, &phys); +if (ret) + goto unlock; + + ret = -EPERM ; +if (pkvm_getstate (kvm_pgtable_stage2_pte_prot (pte)) !=PKVM_PAGE_OWNED ) + goto unlock; +if (__host_check_page_state_range (phys,PAGE_SIZE ,PKVM_NOPAGE )) + goto unlock; + + ret =0 ; +WARN_ON (kvm_pgtable_stage2_map (&vm->pgt, ipa,PAGE_SIZE , phys, +pkvm_mkstate (KVM_PGTABLE_PROT_RWX ,PKVM_PAGE_SHARED_OWNED ), + &vcpu->vcpu.arch.pkvm_memcache,0 )); +WARN_ON (__host_set_page_state_range (phys,PAGE_SIZE ,PKVM_PAGE_SHARED_BORROWED )); +unlock: +guest_unlock_component (vm); +host_unlock_component (); + +return ret; +} +int __pkvm_host_unshare_hyp (u64 pfn) {u64 phys =hyp_pfn_to_phys (pfn);
arch/arm64/kvm/hyp/nvhe/pkvm.c +61 -0
79 lines not on this page · raw message
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 30/38 KVM: arm64: Implement the MEM_UNSHARE hypercall for protected VMs
In reply to Will DeaconImplement the ARM_SMCCC_KVM_FUNC_MEM_UNSHARE hypercall to allow protected VMs to unshare memory that was previously shared with the host using the ARM_SMCCC_KVM_FUNC_MEM_SHARE hypercall.
--- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + arch/arm64/kvm/hyp/nvhe/mem_protect.c | 34 +++++++++++++++++++ arch/arm64/kvm/hyp/nvhe/pkvm.c | 22 ++++++++++++ 3 files changed, 57 insertions(+)
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +1 -0
@@ -35,6 +35,7 @@ extern unsigned long hyp_nr_cpus;int __pkvm_prot_finalize (void );int __pkvm_host_share_hyp (u64 pfn);int __pkvm_guest_share_host (struct pkvm_hyp_vcpu *vcpu,u64 gfn); +int __pkvm_guest_unshare_host (struct pkvm_hyp_vcpu *vcpu,u64 gfn);int __pkvm_host_unshare_hyp (u64 pfn);int __pkvm_host_donate_hyp (u64 pfn,u64 nr_pages);int __pkvm_hyp_donate_host (u64 pfn,u64 nr_pages);
arch/arm64/kvm/hyp/nvhe/mem_protect.c +34 -0
@@ -991,6 +991,40 @@ int __pkvm_guest_share_host(struct pkvm_hyp_vcpu *vcpu, u64 gfn)return ret; } +int __pkvm_guest_unshare_host (struct pkvm_hyp_vcpu *vcpu,u64 gfn) +{ +struct pkvm_hyp_vm *vm =pkvm_hyp_vcpu_to_hyp_vm (vcpu); +u64 meta, phys, ipa =hyp_pfn_to_phys (gfn); +kvm_pte_t pte; +int ret; + +host_lock_component (); +guest_lock_component (vm); + + ret =get_valid_guest_pte (vm, ipa, &pte, &phys); +if (ret) + goto unlock; + + ret = -EPERM ; +if (pkvm_getstate (kvm_pgtable_stage2_pte_prot (pte)) !=PKVM_PAGE_SHARED_OWNED ) + goto unlock; +if (__host_check_page_state_range (phys,PAGE_SIZE ,PKVM_PAGE_SHARED_BORROWED )) + goto unlock; + + ret =0 ; + meta =host_stage2_encode_gfn_meta (vm, gfn); +WARN_ON (host_stage2_set_owner_metadata_locked (phys,PAGE_SIZE , +PKVM_ID_GUEST , meta)); +WARN_ON (kvm_pgtable_stage2_map (&vm->pgt, ipa,PAGE_SIZE , phys, +pkvm_mkstate (KVM_PGTABLE_PROT_RWX ,PKVM_PAGE_OWNED ), + &vcpu->vcpu.arch.pkvm_memcache,0 )); +unlock: +guest_unlock_component (vm); +host_unlock_component (); + +return ret; +} +int __pkvm_host_unshare_hyp (u64 pfn) {u64 phys =hyp_pfn_to_phys (pfn);
arch/arm64/kvm/hyp/nvhe/pkvm.c +22 -0
@@ -1019,6 +1019,19 @@ static bool pkvm_memshare_call(u64 *ret, struct kvm_vcpu *vcpu, u64 *exit_code)return false; } +static void pkvm_memunshare_call (u64 *ret,struct kvm_vcpu *vcpu) +{ +struct pkvm_hyp_vcpu *hyp_vcpu; +u64 ipa =smccc_get_arg1 (vcpu); + +if (!PAGE_ALIGNED (ipa)) +return ; + + hyp_vcpu = container_of(vcpu, struct pkvm_hyp_vcpu, vcpu); +if (!__pkvm_guest_unshare_host (hyp_vcpu,hyp_phys_to_pfn (ipa))) + ret[0 ] =SMCCC_RET_SUCCESS ; +} +/* * Handler for protected VM HVC calls. *
@@ -1036,6 +1049,7 @@ bool kvm_handle_pvm_hvc64(struct kvm_vcpu *vcpu, u64 *exit_code) val[0 ] =BIT (ARM_SMCCC_KVM_FUNC_FEATURES ); val[0 ] |=BIT (ARM_SMCCC_KVM_FUNC_HYP_MEMINFO ); val[0 ] |=BIT (ARM_SMCCC_KVM_FUNC_MEM_SHARE ); + val[0 ] |=BIT (ARM_SMCCC_KVM_FUNC_MEM_UNSHARE );break ;case ARM_SMCCC_VENDOR_HYP_KVM_HYP_MEMINFO_FUNC_ID : if (smccc_get_arg1(vcpu) ||
@@ -1054,6 +1068,14 @@ bool kvm_handle_pvm_hvc64(struct kvm_vcpu *vcpu, u64 *exit_code) handled =pkvm_memshare_call (val, vcpu, exit_code);break ; +case ARM_SMCCC_VENDOR_HYP_KVM_MEM_UNSHARE_FUNC_ID : +if (smccc_get_arg2 (vcpu) || +smccc_get_arg3 (vcpu)) { +break ; + } + +pkvm_memunshare_call (val, vcpu); +break ;default :/* Punt everything else back to the host, for now. */ handled = false;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 31/38 KVM: arm64: Allow userspace to create protected VMs when pKVM is enabled
In reply to Will DeaconIntroduce a new VM type for KVM/arm64 to allow userspace to request the creation of a "protected VM" when the host has booted with pKVM enabled.
For now, this feature results in a taint on first use as many aspects of a protected VM are not yet protected!
--- arch/arm64/include/asm/kvm_pkvm.h | 2 +- arch/arm64/kvm/arm.c | 8 +++++++- arch/arm64/kvm/mmu.c | 3 --- arch/arm64/kvm/pkvm.c | 8 +++++++- include/uapi/linux/kvm.h | 5 +++++ 5 files changed, 20 insertions(+), 6 deletions(-)
arch/arm64/include/asm/kvm_pkvm.h +1 -1
@@ -17,7 +17,7 @@#define HYP_MEMBLOCK_REGIONS 128 -int pkvm_init_host_vm (struct kvm *kvm); +int pkvm_init_host_vm (struct kvm *kvm,unsigned long type);int pkvm_create_hyp_vm (struct kvm *kvm);bool pkvm_hyp_vm_is_created (struct kvm *kvm);void pkvm_destroy_hyp_vm (struct kvm *kvm);
arch/arm64/kvm/arm.c +7 -1
@@ -203,6 +203,9 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) {int ret; +if (type & ~KVM_VM_TYPE_ARM_MASK ) +return -EINVAL ; +mutex_init (&kvm->arch.config_lock);#ifdef CONFIG_LOCKDEP
@@ -234,9 +237,12 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)* If any failures occur after this is successful, make sure to * call __pkvm_unreserve_vm to unreserve the VM in hyp. */ - ret =pkvm_init_host_vm (kvm); + ret =pkvm_init_host_vm (kvm, type);if (ret) goto err_uninit_mmu; + }else if (type &KVM_VM_TYPE_ARM_PROTECTED ) { + ret = -EINVAL ; + goto err_uninit_mmu; }kvm_vgic_early_init (kvm);
arch/arm64/kvm/mmu.c +0 -3
@@ -881,9 +881,6 @@ static int kvm_init_ipa_range(struct kvm_s2_mmu *mmu, unsigned long type)u64 mmfr0, mmfr1;u32 phys_shift; -if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK ) -return -EINVAL ; - phys_shift =KVM_VM_TYPE_ARM_IPA_SIZE (type);if (is_protected_kvm_enabled ()) { phys_shift = kvm_ipa_limit;
arch/arm64/kvm/pkvm.c +7 -1
@@ -219,9 +219,10 @@ void pkvm_destroy_hyp_vm(struct kvm *kvm)mutex_unlock (&kvm->arch.config_lock); } -int pkvm_init_host_vm (struct kvm *kvm) +int pkvm_init_host_vm (struct kvm *kvm,unsigned long type) {int ret; +bool protected = type &KVM_VM_TYPE_ARM_PROTECTED ;if (pkvm_hyp_vm_is_created (kvm))return -EINVAL ;
@@ -236,6 +237,11 @@ int pkvm_init_host_vm(struct kvm *kvm)return ret; kvm->arch.pkvm.handle = ret; + kvm->arch.pkvm.is_protected = protected; +if (protected) { +pr_warn_once ("kvm: protected VMs are experimental and for development only, tainting kernel\n" ); +add_taint (TAINT_USER ,LOCKDEP_STILL_OK ); + }return 0 ; }
include/uapi/linux/kvm.h +5 -0
@@ -703,6 +703,11 @@ struct kvm_enable_cap {#define KVM_VM_TYPE_ARM_IPA_SIZE_MASK 0xffULL#define KVM_VM_TYPE_ARM_IPA_SIZE (x) \ ((x) & KVM_VM_TYPE_ARM_IPA_SIZE_MASK) + +#define KVM_VM_TYPE_ARM_PROTECTED (1UL << 31) +#define KVM_VM_TYPE_ARM_MASK (KVM_VM_TYPE_ARM_IPA_SIZE_MASK | \ + KVM_VM_TYPE_ARM_PROTECTED) +/* * ioctls for /dev/kvm fds: */
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 32/38 KVM: arm64: Add some initial documentation for pKVM
In reply to Will DeaconAdd some initial documentation for pKVM to help people understand what is supported, the limitations of protected VMs when compared to non-protected VMs and also what is left to do.
--- .../admin-guide/kernel-parameters.txt | 4 +- Documentation/virt/kvm/arm/index.rst | 1 + Documentation/virt/kvm/arm/pkvm.rst | 106 ++++++++++++++++++ 3 files changed, 109 insertions(+), 2 deletions(-) create mode 100644 Documentation/virt/kvm/arm/pkvm.rst
Documentation/admin-guide/kernel-parameters.txt +2 -2
@@ -3247,8 +3247,8 @@ Kernel parameters for the host. To force nVHE on VHE hardware, add "arm64_sw.hvhe=0 id_aa64mmfr1.vh=0" to the command-line. - "nested" is experimental and should be used with - extreme caution. + "nested" and "protected" are experimental and should be + used with extreme caution. kvm-arm.vgic_v3_group0_trap= [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
Documentation/virt/kvm/arm/index.rst +1 -0
@@ -10,6 +10,7 @@ ARM fw-pseudo-registers hyp-abi hypercalls + pkvm pvtime ptp_kvm vcpu-features
Documentation/virt/kvm/arm/pkvm.rst new file +106 -0
106 lines not on this page · raw message
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 33/38 KVM: arm64: Extend pKVM page ownership selftests to cover guest donation
In reply to Will DeaconExtend the pKVM page ownership selftests to donate and reclaim a page to/from a guest.
--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
arch/arm64/kvm/hyp/nvhe/mem_protect.c +22 -0
@@ -1749,6 +1749,7 @@ void pkvm_ownership_selftest(void *base)assert_transition_res (-EPERM , hyp_pin_shared_mem, virt, virt + size);assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot);assert_transition_res (-ENOENT , __pkvm_host_unshare_guest, gfn,1 , vm); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu); selftest_state.host =PKVM_PAGE_OWNED ; selftest_state.hyp =PKVM_NOPAGE ;
@@ -1768,6 +1769,7 @@ void pkvm_ownership_selftest(void *base)assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 );assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot);assert_transition_res (-ENOENT , __pkvm_host_unshare_guest, gfn,1 , vm); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu);assert_transition_res (0 , hyp_pin_shared_mem, virt, virt + size);assert_transition_res (0 , hyp_pin_shared_mem, virt, virt + size);
@@ -1780,6 +1782,7 @@ void pkvm_ownership_selftest(void *base)assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 );assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot);assert_transition_res (-ENOENT , __pkvm_host_unshare_guest, gfn,1 , vm); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu);hyp_unpin_shared_mem (virt, virt + size);assert_page_state ();
@@ -1799,6 +1802,7 @@ void pkvm_ownership_selftest(void *base)assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 );assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot);assert_transition_res (-ENOENT , __pkvm_host_unshare_guest, gfn,1 , vm); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu);assert_transition_res (-EPERM , hyp_pin_shared_mem, virt, virt + size); selftest_state.host =PKVM_PAGE_OWNED ;
@@ -1815,6 +1819,7 @@ void pkvm_ownership_selftest(void *base)assert_transition_res (-EPERM , __pkvm_host_share_hyp, pfn);assert_transition_res (-EPERM , __pkvm_host_unshare_hyp, pfn);assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 ); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu);assert_transition_res (-EPERM , hyp_pin_shared_mem, virt, virt + size); selftest_state.guest[1 ] =PKVM_PAGE_SHARED_BORROWED ;
@@ -1828,6 +1833,23 @@ void pkvm_ownership_selftest(void *base) selftest_state.host =PKVM_PAGE_OWNED ;assert_transition_res (0 , __pkvm_host_unshare_guest, gfn +1 ,1 , vm); + selftest_state.host =PKVM_NOPAGE ; + selftest_state.guest[0 ] =PKVM_PAGE_OWNED ; +assert_transition_res (0 , __pkvm_host_donate_guest, pfn, gfn, vcpu); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn +1 , vcpu); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn +1 ,1 , vcpu, prot); +assert_transition_res (-EPERM , __pkvm_host_share_ffa, pfn,1 ); +assert_transition_res (-EPERM , __pkvm_host_donate_hyp, pfn,1 ); +assert_transition_res (-EPERM , __pkvm_host_share_hyp, pfn); +assert_transition_res (-EPERM , __pkvm_host_unshare_hyp, pfn); +assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 ); + + selftest_state.host =PKVM_PAGE_OWNED ; + selftest_state.guest[0 ] =PKVM_NOPAGE ; +assert_transition_res (0 , __pkvm_host_reclaim_page_guest, gfn, vm); + selftest_state.host =PKVM_NOPAGE ; selftest_state.hyp =PKVM_PAGE_OWNED ;assert_transition_res (0 , __pkvm_host_donate_hyp, pfn,1 );
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 34/38 KVM: arm64: Register 'selftest_vm' in the VM table
In reply to Will DeaconIn preparation for extending the pKVM page ownership selftests to cover forceful reclaim of donated pages, rework the creation of the 'selftest_vm' so that it is registered in the VM table while the tests are running.
--- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 + arch/arm64/kvm/hyp/nvhe/mem_protect.c | 53 ++++--------------- arch/arm64/kvm/hyp/nvhe/pkvm.c | 49 +++++++++++++++++ 3 files changed, 61 insertions(+), 43 deletions(-)
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +2 -0
@@ -76,6 +76,8 @@ static __always_inline void __load_host_stage2(void)#ifdef CONFIG_NVHE_EL2_DEBUG void pkvm_ownership_selftest (void *base); +struct pkvm_hyp_vcpu *init_selftest_vm (void *virt); +void teardown_selftest_vm (void );#else static inline void pkvm_ownership_selftest (void *base) { }#endif
arch/arm64/kvm/hyp/nvhe/mem_protect.c +10 -43
93 lines not on this page · raw message
arch/arm64/kvm/hyp/nvhe/pkvm.c +49 -0
55 lines not on this page · raw message
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 35/38 KVM: arm64: Extend pKVM page ownership selftests to cover forced reclaim
In reply to Will DeaconExtend the pKVM page ownership selftests to forcefully reclaim a donated page and check that it cannot be re-donated at the same IPA.
--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
arch/arm64/kvm/hyp/nvhe/mem_protect.c +14 -2
@@ -1813,8 +1813,20 @@ void pkvm_ownership_selftest(void *base)assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 ); selftest_state.host =PKVM_PAGE_OWNED ; - selftest_state.guest[0 ] =PKVM_NOPAGE ; -assert_transition_res (0 , __pkvm_host_reclaim_page_guest, gfn, vm); + selftest_state.guest[0 ] =PKVM_POISON ; +assert_transition_res (0 , __pkvm_host_force_reclaim_page_guest, phys); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot); + + selftest_state.host =PKVM_NOPAGE ; + selftest_state.guest[1 ] =PKVM_PAGE_OWNED ; +assert_transition_res (0 , __pkvm_host_donate_guest, pfn, gfn +1 , vcpu); + + selftest_state.host =PKVM_PAGE_OWNED ; + selftest_state.guest[1 ] =PKVM_NOPAGE ; +assert_transition_res (0 , __pkvm_host_reclaim_page_guest, gfn +1 , vm); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot); selftest_state.host =PKVM_NOPAGE ; selftest_state.hyp =PKVM_PAGE_OWNED ;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 36/38 KVM: arm64: Extend pKVM page ownership selftests to cover guest hvcs
In reply to Will DeaconNow that the guest can share and unshare memory with the host using hypercalls, extend the pKVM page ownership selftest to exercise these new transitions.
--- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 30 +++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
arch/arm64/kvm/hyp/nvhe/mem_protect.c +30 -0
@@ -1812,11 +1812,41 @@ void pkvm_ownership_selftest(void *base)assert_transition_res (-EPERM , __pkvm_host_unshare_hyp, pfn);assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 ); + selftest_state.host =PKVM_PAGE_SHARED_BORROWED ; + selftest_state.guest[0 ] =PKVM_PAGE_SHARED_OWNED ; +assert_transition_res (0 , __pkvm_guest_share_host, vcpu, gfn); +assert_transition_res (-EPERM , __pkvm_guest_share_host, vcpu, gfn); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn +1 , vcpu); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn +1 ,1 , vcpu, prot); +assert_transition_res (-EPERM , __pkvm_host_share_ffa, pfn,1 ); +assert_transition_res (-EPERM , __pkvm_host_donate_hyp, pfn,1 ); +assert_transition_res (-EPERM , __pkvm_host_share_hyp, pfn); +assert_transition_res (-EPERM , __pkvm_host_unshare_hyp, pfn); +assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 ); + + selftest_state.host =PKVM_NOPAGE ; + selftest_state.guest[0 ] =PKVM_PAGE_OWNED ; +assert_transition_res (0 , __pkvm_guest_unshare_host, vcpu, gfn); +assert_transition_res (-EPERM , __pkvm_guest_unshare_host, vcpu, gfn); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu); +assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn +1 , vcpu); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot); +assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn +1 ,1 , vcpu, prot); +assert_transition_res (-EPERM , __pkvm_host_share_ffa, pfn,1 ); +assert_transition_res (-EPERM , __pkvm_host_donate_hyp, pfn,1 ); +assert_transition_res (-EPERM , __pkvm_host_share_hyp, pfn); +assert_transition_res (-EPERM , __pkvm_host_unshare_hyp, pfn); +assert_transition_res (-EPERM , __pkvm_hyp_donate_host, pfn,1 ); + selftest_state.host =PKVM_PAGE_OWNED ; selftest_state.guest[0 ] =PKVM_POISON ;assert_transition_res (0 , __pkvm_host_force_reclaim_page_guest, phys);assert_transition_res (-EPERM , __pkvm_host_donate_guest, pfn, gfn, vcpu);assert_transition_res (-EPERM , __pkvm_host_share_guest, pfn, gfn,1 , vcpu, prot); +assert_transition_res (-EHWPOISON , __pkvm_guest_share_host, vcpu, gfn); +assert_transition_res (-EHWPOISON , __pkvm_guest_unshare_host, vcpu, gfn); selftest_state.host =PKVM_NOPAGE ; selftest_state.guest[1 ] =PKVM_PAGE_OWNED ;
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 37/38 KVM: arm64: Rename PKVM_PAGE_STATE_MASK
In reply to Will DeaconRename PKVM_PAGE_STATE_MASK to PKVM_PAGE_STATE_VMEMMAP_MASK to make it clear that the mask applies to the page state recorded in the entries of the 'hyp_vmemmap', rather than page states stored elsewhere (e.g. in the ptes).
--- arch/arm64/kvm/hyp/include/nvhe/memory.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
arch/arm64/kvm/hyp/include/nvhe/memory.h +3 -3
@@ -37,7 +37,7 @@ enum pkvm_page_state {*/ PKVM_POISON = BIT(2), }; -#define PKVM_PAGE_STATE_MASK (BIT(0) | BIT(1)) +#define PKVM_PAGE_STATE_VMEMMAP_MASK (BIT(0) | BIT(1))#define PKVM_PAGE_STATE_PROT_MASK (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1) static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
@@ -114,12 +114,12 @@ static inline void set_host_state(struct hyp_page *p, enum pkvm_page_state statestatic inline enum pkvm_page_state get_hyp_state (struct hyp_page *p) { -return p->__hyp_state_comp ^PKVM_PAGE_STATE_MASK ; +return p->__hyp_state_comp ^PKVM_PAGE_STATE_VMEMMAP_MASK ; }static inline void set_hyp_state (struct hyp_page *p,enum pkvm_page_state state) { - p->__hyp_state_comp = state ^PKVM_PAGE_STATE_MASK ; + p->__hyp_state_comp = state ^PKVM_PAGE_STATE_VMEMMAP_MASK ; }/*
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerPATCH v4 38/38 drivers/virt: pkvm: Add Kconfig dependency on DMA_RESTRICTED_POOL
In reply to Will DeaconpKVM guests practically rely on CONFIG_DMA_RESTRICTED_POOL=y in order to establish shared memory regions with the host for virtio buffers.
Make CONFIG_ARM_PKVM_GUEST depend on CONFIG_DMA_RESTRICTED_POOL to avoid the inevitable segmentation faults experience if you have the former but not the latter.
--- drivers/virt/coco/pkvm-guest/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/virt/coco/pkvm-guest/Kconfig +1 -1
@@ -1,6 +1,6 @@ config ARM_PKVM_GUEST bool "Arm pKVM protected guest driver" - depends on ARM64 + depends on ARM64 && DMA_RESTRICTED_POOL help Protected guests running under the pKVM hypervisor on arm64 are isolated from the host and must issue hypercalls to enable
Signature · 1 line
2.53.0.1018.g2bb0e51243-goog
Will Deacon
maintainerQuoted 2 lines · Will Deacon
I fully expect to send a v5, as this is the first time Sashiko has had a chance to chew on this and I'm expecting a roasting.
After going through it, the report isn't as bad as it looks and some of the comments are actively wrong, which I suppose is inevitable.
That being said, I've got a handful of fixes to fold in now and it's pointed out some unrelated life-cycle issues that we want want to fix separately.
Will