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| author | Zachary Amsden <zamsden@redhat.com> | 2010-08-19 22:07:17 -1000 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-10-24 10:51:22 +0200 |
| commit | 99e3e30aee1a326a98bf3a5f47b8622219c685f3 (patch) | |
| tree | 1b67fc70af33988080784d32725f72b5ce7c07d1 /arch/x86/kvm/vmx.c | |
| parent | f4e1b3c8bd2a044cd0ccf80595bfd088a49fe60b (diff) | |
| download | lwn-99e3e30aee1a326a98bf3a5f47b8622219c685f3.tar.gz lwn-99e3e30aee1a326a98bf3a5f47b8622219c685f3.zip | |
KVM: x86: Move TSC offset writes to common code
Also, ensure that the storing of the offset and the reading of the TSC
are never preempted by taking a spinlock. While the lock is overkill
now, it is useful later in this patch series.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d9bec5ee38b8..138746d3afe9 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1146,10 +1146,9 @@ static u64 guest_read_tsc(void) } /* - * writes 'guest_tsc' into guest's timestamp counter "register" - * guest_tsc = host_tsc + tsc_offset ==> tsc_offset = guest_tsc - host_tsc + * writes 'offset' into guest's timestamp counter offset register */ -static void vmx_write_tsc_offset(u64 offset) +static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) { vmcs_write64(TSC_OFFSET, offset); } @@ -1224,7 +1223,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) { struct vcpu_vmx *vmx = to_vmx(vcpu); struct shared_msr_entry *msr; - u64 host_tsc; int ret = 0; switch (msr_index) { @@ -1254,8 +1252,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) vmcs_writel(GUEST_SYSENTER_ESP, data); break; case MSR_IA32_TSC: - rdtscll(host_tsc); - vmx_write_tsc_offset(data - host_tsc); + kvm_write_tsc(vcpu, data); break; case MSR_IA32_CR_PAT: if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) { @@ -2653,7 +2650,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx) vmx->vcpu.arch.cr4_guest_owned_bits |= X86_CR4_PGE; vmcs_writel(CR4_GUEST_HOST_MASK, ~vmx->vcpu.arch.cr4_guest_owned_bits); - vmx_write_tsc_offset(0-native_read_tsc()); + kvm_write_tsc(&vmx->vcpu, 0); return 0; } @@ -4348,6 +4345,8 @@ static struct kvm_x86_ops vmx_x86_ops = { .set_supported_cpuid = vmx_set_supported_cpuid, .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit, + + .write_tsc_offset = vmx_write_tsc_offset, }; static int __init vmx_init(void) |