diff options
| author | Anthony Liguori <aliguori@us.ibm.com> | 2007-04-29 11:56:06 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2007-05-03 10:52:32 +0300 |
| commit | 94dfbdb3894eda2f673b70e20da2743c4a8d3968 (patch) | |
| tree | 74e7a4a31a72ed0e3753e9390189d2e8132ecf0e /drivers/kvm/kvm_svm.h | |
| parent | 2807696c3791d6dd1dcf20f022eaa2dc7615bc5d (diff) | |
KVM: SVM: Only save/restore MSRs when needed
We only have to save/restore MSR_GS_BASE on every VMEXIT. The rest can be
saved/restored when we leave the VCPU. Since we don't emulate the DEBUGCTL
MSRs and the guest cannot write to them, we don't have to worry about
saving/restoring them at all.
This shaves a whopping 40% off raw vmexit costs on AMD.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm/kvm_svm.h')
| -rw-r--r-- | drivers/kvm/kvm_svm.h | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/kvm/kvm_svm.h b/drivers/kvm/kvm_svm.h index a1a9eba50d4..a869983d683 100644 --- a/drivers/kvm/kvm_svm.h +++ b/drivers/kvm/kvm_svm.h @@ -9,17 +9,15 @@ #include "svm.h" #include "kvm.h" -static const u32 host_save_msrs[] = { +static const u32 host_save_user_msrs[] = { #ifdef CONFIG_X86_64 MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE, - MSR_FS_BASE, MSR_GS_BASE, + MSR_FS_BASE, #endif MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, - MSR_IA32_DEBUGCTLMSR, /*MSR_IA32_LASTBRANCHFROMIP, - MSR_IA32_LASTBRANCHTOIP, MSR_IA32_LASTINTFROMIP,MSR_IA32_LASTINTTOIP,*/ }; -#define NR_HOST_SAVE_MSRS ARRAY_SIZE(host_save_msrs) +#define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs) #define NUM_DB_REGS 4 struct vcpu_svm { @@ -32,7 +30,8 @@ struct vcpu_svm { u64 next_rip; - u64 host_msrs[NR_HOST_SAVE_MSRS]; + u64 host_user_msrs[NR_HOST_SAVE_USER_MSRS]; + u64 host_gs_base; unsigned long host_cr2; unsigned long host_db_regs[NUM_DB_REGS]; unsigned long host_dr6; |