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| author | Joerg Roedel <joerg.roedel@amd.com> | 2009-09-16 15:24:18 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-10-04 13:57:23 +0200 |
| commit | 20824f30bb0b8ae0a4099895fd4509f54cf2e1e2 (patch) | |
| tree | 253c30ec098720c1c2ac69f3bd38967c02d26b7b /arch/x86 | |
| parent | 77b1ab1732feb5e3dcbaf31d2f7547c5229f5f3a (diff) | |
| download | lwn-20824f30bb0b8ae0a4099895fd4509f54cf2e1e2.tar.gz lwn-20824f30bb0b8ae0a4099895fd4509f54cf2e1e2.zip | |
KVM: SVM: Handle tsc in svm_get_msr/svm_set_msr correctly
When running nested we need to touch the l1 guests
tsc_offset. Otherwise changes will be lost or a wrong value
be read.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/svm.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index bf5799dc4f9f..c17404add91f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2059,10 +2059,14 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 *data) switch (ecx) { case MSR_IA32_TSC: { - u64 tsc; + u64 tsc_offset; - rdtscll(tsc); - *data = svm->vmcb->control.tsc_offset + tsc; + if (is_nested(svm)) + tsc_offset = svm->nested.hsave->control.tsc_offset; + else + tsc_offset = svm->vmcb->control.tsc_offset; + + *data = tsc_offset + native_read_tsc(); break; } case MSR_K6_STAR: @@ -2148,10 +2152,17 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data) switch (ecx) { case MSR_IA32_TSC: { - u64 tsc; + u64 tsc_offset = data - native_read_tsc(); + u64 g_tsc_offset = 0; + + if (is_nested(svm)) { + g_tsc_offset = svm->vmcb->control.tsc_offset - + svm->nested.hsave->control.tsc_offset; + svm->nested.hsave->control.tsc_offset = tsc_offset; + } + + svm->vmcb->control.tsc_offset = tsc_offset + g_tsc_offset; - rdtscll(tsc); - svm->vmcb->control.tsc_offset = data - tsc; break; } case MSR_K6_STAR: |