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authorJoerg Roedel <joerg.roedel@amd.com>2009-09-16 15:24:18 +0200
committerAvi Kivity <avi@redhat.com>2009-10-04 13:57:23 +0200
commit20824f30bb0b8ae0a4099895fd4509f54cf2e1e2 (patch)
tree253c30ec098720c1c2ac69f3bd38967c02d26b7b
parent77b1ab1732feb5e3dcbaf31d2f7547c5229f5f3a (diff)
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>
-rw-r--r--arch/x86/kvm/svm.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index bf5799dc4f9..c17404add91 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: