KVM: x86: Move TSC reset out of vmcb_init (47008cd8) · Commits · 戴 / test

The VMCB is reset whenever we receive a startup IPI, so Linux is setting TSC back to zero happens very late in the boot process and destabilizing the TSC. Instead, just set TSC to zero once at VCPU creation time. Why the separate patch? So git-bisect is your friend. Signed-off-by:

Zachary Amsden <zamsden@redhat.com> Signed-off-by:

Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/svm.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -766,7 +766,6 @@ static void init_vmcb(struct vcpu_svm *svm)

		control->iopm_base_pa = iopm_base;
		control->msrpm_base_pa = __pa(svm->msrpm);
		control->tsc_offset = 0-native_read_tsc();
		control->int_ctl = V_INTR_MASKING_MASK;

		init_seg(&save->es);
		@@ -902,6 +901,7 @@ static struct kvm_vcpu svm_create_vcpu(struct kvm kvm, unsigned int id)
		svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
		svm->asid_generation = 0;
		init_vmcb(svm);
		svm->vmcb->control.tsc_offset = 0-native_read_tsc();

		err = fx_init(&svm->vcpu);
		if (err)

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