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Commit 20824f30 authored by Joerg Roedel's avatar Joerg Roedel Committed by Avi Kivity
Browse files

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: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 77b1ab17

arch/x86/kvm/svm.c

+17 −6
Original line number Diff line number Diff line
@@ -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: