x86/Hyper-V: Add SEV negotiate protocol support in Isolation VM
Subsystems (3)
PATCH v3 1/1 x86/Hyper-V: Add SEV negotiate protocol support in Isolation VM
From: Tianyu Lan <[email protected]>
Hyper-V Isolation VM current code uses sev_es_ghcb_hv_call() to read/write MSR via GHCB page and depends on the sev code. This may cause regression when sev code changes interface design.
The latest SEV-ES code requires to negotiate GHCB version before reading/writing MSR via GHCB page and sev_es_ghcb_hv_call() doesn't work for Hyper-V Isolation VM. Add Hyper-V ghcb related implementation to decouple SEV and Hyper-V code. Negotiate GHCB version in the hyperv_init() and use the version to communicate with Hyper-V in the ghcb hv call function.
---
Change since v1:
- Negotiate ghcb version in Hyper-V init.
- use native_wrmsrl() instead of native_wrmsr() in the wr_ghcb_msr().
--- arch/x86/hyperv/hv_init.c | 6 +++ arch/x86/hyperv/ivm.c | 84 ++++++++++++++++++++++++++++++--- arch/x86/include/asm/mshyperv.h | 4 ++ 3 files changed, 88 insertions(+), 6 deletions(-)
arch/x86/hyperv/hv_init.c +6 -0
@@ -13,6 +13,7 @@#include <linux/io.h> #include <asm/apic.h> #include <asm/desc.h> +#include <asm/sev.h> #include <asm/hypervisor.h> #include <asm/hyperv-tlfs.h> #include <asm/mshyperv.h>
@@ -405,6 +406,11 @@ void __init hyperv_init(void) }if (hv_isolation_type_snp ()) { +/* Negotiate GHCB Version. */ +if (!hv_ghcb_negotiate_protocol ()) +hv_ghcb_terminate (SEV_TERM_SET_GEN , +GHCB_SEV_ES_PROT_UNSUPPORTED ); + hv_ghcb_pg = alloc_percpu(union hv_ghcb *);if (!hv_ghcb_pg) goto free_vp_assist_page;
arch/x86/hyperv/ivm.c +78 -6
119 lines not on this page · raw message
arch/x86/include/asm/mshyperv.h +4 -0
@@ -179,9 +179,13 @@ int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);#ifdef CONFIG_AMD_MEM_ENCRYPT void hv_ghcb_msr_write (u64 msr,u64 value);void hv_ghcb_msr_read (u64 msr,u64 *value); +bool hv_ghcb_negotiate_protocol (void ); +void hv_ghcb_terminate (unsigned int set,unsigned int reason);#else static inline void hv_ghcb_msr_write (u64 msr,u64 value) {}static inline void hv_ghcb_msr_read (u64 msr,u64 *value) {} +static inline bool hv_ghcb_negotiate_protocol (void ) {return false; } +static inline void hv_ghcb_terminate (unsigned int set,unsigned int reason) {}#endif extern bool hv_isolation_type_snp (void );
Signature · 1 line
2.25.1
From: Tianyu Lan <[email protected]> Sent: Monday, June 13, 2022 6:46 PM
Quoted 20 lines
Hyper-V Isolation VM current code uses
sev_es_ghcb_hv_call()to read/write MSR via GHCB page and depends on the sev code. This may cause regression when sev code changes interface design.The latest SEV-ES code requires to negotiate GHCB version before reading/writing MSR via GHCB page and
sev_es_ghcb_hv_call()doesn't work for Hyper-V Isolation VM. Add Hyper-V ghcb related implementation to decouple SEV and Hyper-V code. Negotiate GHCB version in thehyperv_init()and use the version to communicate with Hyper-V in the ghcb hv call function.Fixes 2ea29c5abbc2 ("x86/sev: Save the negotiated GHCB version")Signed-off-by Tianyu Lan <[email protected]>---
Change since v1:
- Negotiate ghcb version in Hyper-V init.
- usenative_wrmsrl()instead ofnative_wrmsr()in thewr_ghcb_msr().
Quoted 6 lines
--- arch/x86/hyperv/hv_init.c | 6 +++ arch/x86/hyperv/ivm.c | 84 ++++++++++++++++++++++++++++++--- arch/x86/include/asm/mshyperv.h | 4 ++ 3 files changed, 88 insertions(+), 6 deletions(-)
Quoted 28 lines · Michael Kelley (LINUX)
From: Tianyu Lan <[email protected]> Sent: Monday, June 13, 2022 6:46 PM
Quoted 20 lines
Hyper-V Isolation VM current code uses
sev_es_ghcb_hv_call()to read/write MSR via GHCB page and depends on the sev code. This may cause regression when sev code changes interface design.The latest SEV-ES code requires to negotiate GHCB version before reading/writing MSR via GHCB page and
sev_es_ghcb_hv_call()doesn't work for Hyper-V Isolation VM. Add Hyper-V ghcb related implementation to decouple SEV and Hyper-V code. Negotiate GHCB version in thehyperv_init()and use the version to communicate with Hyper-V in the ghcb hv call function.Fixes 2ea29c5abbc2 ("x86/sev: Save the negotiated GHCB version")Signed-off-by Tianyu Lan <[email protected]>---
Change since v1:
- Negotiate ghcb version in Hyper-V init.
- usenative_wrmsrl()instead ofnative_wrmsr()in thewr_ghcb_msr().Quoted 6 lines
--- arch/x86/hyperv/hv_init.c | 6 +++ arch/x86/hyperv/ivm.c | 84 ++++++++++++++++++++++++++++++--- arch/x86/include/asm/mshyperv.h | 4 ++ 3 files changed, 88 insertions(+), 6 deletions(-)
Quoted 2 lines
Reviewed-by Michael Kelley <[email protected]>
Applied to hyperv-fixes. Thanks.
[tip: x86/urgent] Revert "x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV"
In reply to Tianyu LanThe following commit has been merged into the x86/urgent branch of tip:
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 5bb6c1d1126ebcbcd6314f80d82f50b021a9e351 Gitweb: https://git.kernel.org/tip/5bb6c1d1126ebcbcd6314f80d82f50b021a9e351 Author: Borislav Petkov <[email protected]> AuthorDate: Wed, 27 Jul 2022 13:24:21 +02:00 Committer: Borislav Petkov <[email protected]> CommitterDate: Wed, 27 Jul 2022 18:09:13 +02:00
Revert "x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV"
This reverts commit 007faec014cb5d26983c1f86fd08c6539b41392e.
Now that hyperv does its own protocol negotiation:
49d6a3c062a1 ("x86/Hyper-V: Add SEV negotiate protocol support in Isolation VM")
revert this exposure of the sev_es_ghcb_hv_call() helper.
Reviewed-by：Tianyu Lan <[email protected]>
--- arch/x86/include/asm/sev.h | 7 +------ arch/x86/kernel/sev-shared.c | 25 +++++++++---------------- arch/x86/kernel/sev.c | 17 ++++++++--------- 3 files changed, 18 insertions(+), 31 deletions(-)
arch/x86/include/asm/sev.h +1 -6
@@ -72,7 +72,6 @@ static inline u64 lower_bits(u64 val, unsigned int bits)struct real_mode_header ;enum stack_type ; -struct ghcb ;/* Early IDT entry points for #VC handler */ extern void vc_no_ghcb (void );
@@ -156,11 +155,7 @@ static __always_inline void sev_es_nmi_complete(void)__sev_es_nmi_complete (); }extern int __init sev_es_efi_map_ghcbs (pgd_t *pgd); -extern enum es_result sev_es_ghcb_hv_call (struct ghcb *ghcb, -bool set_ghcb_msr, -struct es_em_ctxt *ctxt, -u64 exit_code,u64 exit_info_1, -u64 exit_info_2); +static inline int rmpadjust (unsigned long vaddr,bool rmp_psize,unsigned long attrs) {int rc;
arch/x86/kernel/sev-shared.c +9 -16
@@ -219,9 +219,10 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxtreturn ES_VMM_ERROR ; } -enum es_result sev_es_ghcb_hv_call (struct ghcb *ghcb,bool set_ghcb_msr, -struct es_em_ctxt *ctxt,u64 exit_code, -u64 exit_info_1,u64 exit_info_2) +static enum es_result sev_es_ghcb_hv_call (struct ghcb *ghcb, +struct es_em_ctxt *ctxt, +u64 exit_code,u64 exit_info_1, +u64 exit_info_2) {/* Fill in protocol and format specifiers */ ghcb->protocol_version = ghcb_version;
@@ -231,14 +232,7 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,ghcb_set_sw_exit_info_1 (ghcb, exit_info_1);ghcb_set_sw_exit_info_2 (ghcb, exit_info_2); -/* -* Hyper-V unenlightened guests use a paravisor for communicating and -* GHCB pages are being allocated and set up by that paravisor. Linux -* should not change the GHCB page's physical address. -*/ -if (set_ghcb_msr) -sev_es_wr_ghcb_msr (__pa (ghcb)); - +sev_es_wr_ghcb_msr (__pa (ghcb));VMGEXIT ();return verify_exception_info (ghcb, ctxt);
@@ -795,7 +789,7 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)*/ sw_scratch =__pa (ghcb) + offsetof(struct ghcb , shared_buffer);ghcb_set_sw_scratch (ghcb, sw_scratch); - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt,SVM_EXIT_IOIO , + ret =sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_IOIO , exit_info_1, exit_info_2);if (ret !=ES_OK )return ret;
@@ -837,8 +831,7 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)ghcb_set_rax (ghcb, rax); - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt, -SVM_EXIT_IOIO , exit_info_1,0 ); + ret =sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_IOIO , exit_info_1,0 );if (ret !=ES_OK )return ret;
@@ -894,7 +887,7 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,/* xgetbv will cause #GP - use reset value for xcr0 */ ghcb_set_xcr0 (ghcb,1 ); - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt,SVM_EXIT_CPUID ,0 ,0 ); + ret =sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_CPUID ,0 ,0 );if (ret !=ES_OK )return ret;
@@ -919,7 +912,7 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,bool rdtscp = (exit_code ==SVM_EXIT_RDTSCP );enum es_result ret; - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt, exit_code,0 ,0 ); + ret =sev_es_ghcb_hv_call (ghcb, ctxt, exit_code,0 ,0 );if (ret !=ES_OK )return ret;
arch/x86/kernel/sev.c +8 -9
@@ -786,7 +786,7 @@ static int vmgexit_psc(struct snp_psc_desc *desc)ghcb_set_sw_scratch (ghcb, (u64 )__pa (data));/* This will advance the shared buffer data points to. */ - ret =sev_es_ghcb_hv_call (ghcb, true, &ctxt,SVM_VMGEXIT_PSC ,0 ,0 ); + ret =sev_es_ghcb_hv_call (ghcb, &ctxt,SVM_VMGEXIT_PSC ,0 ,0 );/* * Page State Change VMGEXIT can pass error code through
@@ -1212,8 +1212,7 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)ghcb_set_rdx (ghcb, regs->dx); } - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt,SVM_EXIT_MSR , - exit_info_1,0 ); + ret =sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_MSR , exit_info_1,0 );if ((ret ==ES_OK ) && (!exit_info_1)) { regs->ax = ghcb->save.rax;
@@ -1452,7 +1451,7 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,ghcb_set_sw_scratch (ghcb, ghcb_pa + offsetof(struct ghcb , shared_buffer)); -return sev_es_ghcb_hv_call (ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2); +return sev_es_ghcb_hv_call (ghcb, ctxt, exit_code, exit_info_1, exit_info_2); }/*
@@ -1628,7 +1627,7 @@ static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,/* Using a value of 0 for ExitInfo1 means RAX holds the value */ ghcb_set_rax (ghcb, val); - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt,SVM_EXIT_WRITE_DR7 ,0 ,0 ); + ret =sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_WRITE_DR7 ,0 ,0 );if (ret !=ES_OK )return ret;
@@ -1658,7 +1657,7 @@ static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,static enum es_result vc_handle_wbinvd (struct ghcb *ghcb,struct es_em_ctxt *ctxt) { -return sev_es_ghcb_hv_call (ghcb, true, ctxt,SVM_EXIT_WBINVD ,0 ,0 ); +return sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_WBINVD ,0 ,0 ); }static enum es_result vc_handle_rdpmc (struct ghcb *ghcb,struct es_em_ctxt *ctxt)
@@ -1667,7 +1666,7 @@ static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxtghcb_set_rcx (ghcb, ctxt->regs->cx); - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt,SVM_EXIT_RDPMC ,0 ,0 ); + ret =sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_RDPMC ,0 ,0 );if (ret !=ES_OK )return ret;
@@ -1708,7 +1707,7 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,if (x86_platform.hyper.sev_es_hcall_prepare) x86_platform.hyper.sev_es_hcall_prepare (ghcb, ctxt->regs); - ret =sev_es_ghcb_hv_call (ghcb, true, ctxt,SVM_EXIT_VMMCALL ,0 ,0 ); + ret =sev_es_ghcb_hv_call (ghcb, ctxt,SVM_EXIT_VMMCALL ,0 ,0 );if (ret !=ES_OK )return ret;
@@ -2197,7 +2196,7 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsignedghcb_set_rbx (ghcb, input->data_npages); } - ret =sev_es_ghcb_hv_call (ghcb, true, &ctxt, exit_code, input->req_gpa, input->resp_gpa); + ret =sev_es_ghcb_hv_call (ghcb, &ctxt, exit_code, input->req_gpa, input->resp_gpa);if (ret) goto e_put;