KVM: nSVM: use nested_svm_load_cr3() on guest->host switch (d82aaef9) · Commits · 戴 / test

Make nSVM code resemble nVMX where nested_vmx_load_cr3() is used on both guest->host and host->guest transitions. Also, we can now eliminate unconditional kvm_mmu_reset_context() and speed things up. Note, nVMX has two different paths: load_vmcs12_host_state() and nested_vmx_restore_host_state() and the later is used to restore from 'partial' switch to L2, it always uses kvm_mmu_reset_context(). nSVM doesn't have this yet. Also, nested_svm_vmexit()'s return value is almost always ignored nowadays. Signed-off-by:

Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-9-vkuznets@redhat.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/nested.c

+7 −10

Original line number	Diff line number	Diff line
		@@ -342,8 +342,8 @@ static inline bool nested_npt_enabled(struct vcpu_svm *svm)
		}

		/*
		* Load guest's cr3 at nested entry. @nested_npt is true if we are
		* emulating VM-Entry into a guest with NPT enabled.
		* Load guest's/host's cr3 on nested vmentry or vmexit. @nested_npt is true
		* if we are emulating VM-Entry into a guest with NPT enabled.
		*/
		static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3,
		bool nested_npt)
		@@ -676,15 +676,12 @@ int nested_svm_vmexit(struct vcpu_svm *svm)

		nested_svm_uninit_mmu_context(&svm->vcpu);

		if (npt_enabled) {
		svm->vmcb->save.cr3 = hsave->save.cr3;
		svm->vcpu.arch.cr3 = hsave->save.cr3;
		} else {
		(void)kvm_set_cr3(&svm->vcpu, hsave->save.cr3);
		}
		rc = nested_svm_load_cr3(&svm->vcpu, hsave->save.cr3, false);
		if (rc)
		return 1;

		kvm_mmu_reset_context(&svm->vcpu);
		kvm_mmu_load(&svm->vcpu);
		if (npt_enabled)
		svm->vmcb->save.cr3 = hsave->save.cr3;

		/*
		* Drop what we picked up for L2 via svm_complete_interrupts() so it

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