Allow adjust_tsc_offset to be in host or guest cycles
PATCH 6/9 Allow adjust_tsc_offset to be in host or guest cycles
-------- Original Message --------
Subject: [KVM TSC emulation 6/9] Allow adjust_tsc_offset to be in host or guest cycles
Date: Mon, 20 Jun 2011 16:59:34 -0700
From: Zachary Amsden <[email protected]>
To: Avi Kivity <[email protected]>, Marcelo Tosatti <[email protected]>, Glauber Costa <[email protected]>, Frank Arnold <[email protected]>, Joerg Roedel <[email protected]>, Jan Kiszka <[email protected]>, [email protected], [email protected], Zachary Amsden <[email protected]>, Avi Kivity <[email protected]>, Marcelo Tosatti <[email protected]>, Glauber Costa <[email protected]>, Frank Arnold <[email protected]>, Joerg Roedel <[email protected]>, Jan Kiszka <[email protected]>, [email protected]
CC: Zachary Amsden <[email protected]>, Zachary Amsden <[email protected]>
Redefine the API to take a parameter indicating whether an adjustment is in host or guest cycles.
--- arch/x86/include/asm/kvm_host.h | 13 ++++++++++++- arch/x86/kvm/svm.c | 6 +++++- arch/x86/kvm/vmx.c | 2 +- arch/x86/kvm/x86.c | 2 +- 4 files changed, 19 insertions(+), 4 deletions(-)
arch/x86/include/asm/kvm_host.h +12 -1
@@ -599,7 +599,7 @@ struct kvm_x86_ops {u64 (*get_mt_mask)(struct kvm_vcpu *vcpu,gfn_t gfn,bool is_mmio);int (*get_lpage_level)(void );bool (*rdtscp_supported)(void ); -void (*adjust_tsc_offset)(struct kvm_vcpu *vcpu,s64 adjustment); +void (*adjust_tsc_offset)(struct kvm_vcpu *vcpu,s64 adjustment,bool host);void (*set_tdp_cr3)(struct kvm_vcpu *vcpu,unsigned long cr3);
@@ -630,6 +630,17 @@ struct kvm_arch_async_pf {extern struct kvm_x86_ops *kvm_x86_ops; +static inline void adjust_tsc_offset_guest (struct kvm_vcpu *vcpu, +s64 adjustment) +{ + kvm_x86_ops->adjust_tsc_offset (vcpu, adjustment, false); +} + +static inline void adjust_tsc_offset_host (struct kvm_vcpu *vcpu,s64 adjustment) +{ + kvm_x86_ops->adjust_tsc_offset (vcpu, adjustment, true); +} +int kvm_mmu_module_init (void );void kvm_mmu_module_exit (void );
arch/x86/kvm/svm.c +5 -1
@@ -957,10 +957,14 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)mark_dirty (svm->vmcb,VMCB_INTERCEPTS ); } -static void svm_adjust_tsc_offset (struct kvm_vcpu *vcpu,s64 adjustment) +static void svm_adjust_tsc_offset (struct kvm_vcpu *vcpu,s64 adjustment,bool host) {struct vcpu_svm *svm =to_svm (vcpu); +WARN_ON (adjustment<0 ); +if (host) + adjustment =svm_scale_tsc (vcpu, adjustment); + svm->vmcb->control.tsc_offset += adjustment;if (is_guest_mode (vcpu)) svm->nested.hsave->control.tsc_offset += adjustment;
arch/x86/kvm/vmx.c +1 -1
@@ -1782,7 +1782,7 @@ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)to_vmx (vcpu)->nested.vmcs01_tsc_offset; } -static void vmx_adjust_tsc_offset (struct kvm_vcpu *vcpu,s64 adjustment) +static void vmx_adjust_tsc_offset (struct kvm_vcpu *vcpu,s64 adjustment,bool host) {u64 offset =vmcs_read64 (TSC_OFFSET );vmcs_write64 (TSC_OFFSET , offset + adjustment);
arch/x86/kvm/x86.c +1 -1
@@ -1125,7 +1125,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)if (vcpu->tsc_catchup) {u64 tsc =compute_guest_tsc (v, kernel_ns);if (tsc> tsc_timestamp) { - kvm_x86_ops->adjust_tsc_offset (v, tsc - tsc_timestamp); +adjust_tsc_offset_guest (v, tsc - tsc_timestamp); tsc_timestamp = tsc; } }
Signature · 1 line
1.7.1
arch/x86/kvm/svm.c static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) · line 967
Quoted 9 lines · Zachary Amsden
arch/x86/kvm/svm.c +5
-1-static void svm_adjust_tsc_offset (struct kvm_vcpu *vcpu,s64 adjustment) +static void svm_adjust_tsc_offset (struct kvm_vcpu *vcpu,s64 adjustment,bool host) {struct vcpu_svm *svm =to_svm (vcpu); +WARN_ON (adjustment<0 ); +if (host) + adjustment =svm_scale_tsc (vcpu, adjustment); +
This is not going to work out with tsc-scaling. The tsc-offset is applied _after_ the hardware-tsc. Just scaling the offset with the same factor will not give you the hardware tsc-value you expect.
Joerg