Commit defbba56 authored by Joerg Roedel's avatar Joerg Roedel Committed by Avi Kivity
Browse files

KVM: SVM: optimize nested vmrun 



Only copy the necessary parts of the vmcb save area on vmrun and save
precious time.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Acked-by: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 33740e40

arch/x86/kvm/svm.c

+21 −7
Original line number Diff line number Diff line
@@ -1681,6 +1681,7 @@ static int nested_svm_vmrun(struct vcpu_svm *svm, void *arg1, 
{

	struct vmcb *nested_vmcb = (struct vmcb *)arg1;

	struct vmcb *hsave = svm->hsave;

	struct vmcb *vmcb = svm->vmcb;



	/* nested_vmcb is our indicator if nested SVM is activated */

	svm->nested_vmcb = svm->vmcb->save.rax;
@@ -1691,12 +1692,25 @@ static int nested_svm_vmrun(struct vcpu_svm *svm, void *arg1, 


	/* Save the old vmcb, so we don't need to pick what we save, but

	   can restore everything when a VMEXIT occurs */

	memcpy(hsave, svm->vmcb, sizeof(struct vmcb));

	/* We need to remember the original CR3 in the SPT case */

	if (!npt_enabled)

		hsave->save.cr3 = svm->vcpu.arch.cr3;

	hsave->save.es     = vmcb->save.es;

	hsave->save.cs     = vmcb->save.cs;

	hsave->save.ss     = vmcb->save.ss;

	hsave->save.ds     = vmcb->save.ds;

	hsave->save.gdtr   = vmcb->save.gdtr;

	hsave->save.idtr   = vmcb->save.idtr;

	hsave->save.efer   = svm->vcpu.arch.shadow_efer;

	hsave->save.cr0    = svm->vcpu.arch.cr0;

	hsave->save.cr4    = svm->vcpu.arch.cr4;

	hsave->save.rflags = vmcb->save.rflags;

	hsave->save.rip    = svm->next_rip;

	hsave->save.rsp    = vmcb->save.rsp;

	hsave->save.rax    = vmcb->save.rax;

	if (npt_enabled)

		hsave->save.cr3    = vmcb->save.cr3;

	else

		hsave->save.cr3    = svm->vcpu.arch.cr3;



	hsave->control = vmcb->control;



	if (svm->vmcb->save.rflags & X86_EFLAGS_IF)

		svm->vcpu.arch.hflags |= HF_HIF_MASK;
@@ -1721,7 +1735,7 @@ static int nested_svm_vmrun(struct vcpu_svm *svm, void *arg1, 
		kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3);

		kvm_mmu_reset_context(&svm->vcpu);

	}

	svm->vmcb->save.cr2 = nested_vmcb->save.cr2;

	svm->vmcb->save.cr2 = svm->vcpu.arch.cr2 = nested_vmcb->save.cr2;

	kvm_register_write(&svm->vcpu, VCPU_REGS_RAX, nested_vmcb->save.rax);

	kvm_register_write(&svm->vcpu, VCPU_REGS_RSP, nested_vmcb->save.rsp);

	kvm_register_write(&svm->vcpu, VCPU_REGS_RIP, nested_vmcb->save.rip);