Commit d1788191 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: SVM: Drop vcpu_svm.vmcb_pa 



Remove vmcb_pa from vcpu_svm and simply read current_vmcb->pa directly in
the one path where it is consumed.  Unlike svm->vmcb, use of the current
vmcb's address is very limited, as evidenced by the fact that its use
can be trimmed to a single dereference.

Opportunistically add a comment about using vmcb01 for VMLOAD/VMSAVE, at
first glance using vmcb01 instead of vmcb_pa looks wrong.

No functional change intended.

Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210406171811.4043363-3-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 17e5e964

arch/x86/kvm/svm/svm.c

+9 −3
Original line number Diff line number Diff line
@@ -1310,7 +1310,6 @@ void svm_switch_vmcb(struct vcpu_svm *svm, struct kvm_vmcb_info *target_vmcb) 
{

	svm->current_vmcb = target_vmcb;

	svm->vmcb = target_vmcb->ptr;

	svm->vmcb_pa = target_vmcb->pa;

}



static int svm_create_vcpu(struct kvm_vcpu *vcpu)
@@ -3704,6 +3703,7 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu) 
static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)

{

	struct vcpu_svm *svm = to_svm(vcpu);

	unsigned long vmcb_pa = svm->current_vmcb->pa;



	/*

	 * VMENTER enables interrupts (host state), but the kernel state is
@@ -3726,12 +3726,18 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) 
	lockdep_hardirqs_on(CALLER_ADDR0);



	if (sev_es_guest(vcpu->kvm)) {

		__svm_sev_es_vcpu_run(svm->vmcb_pa);

		__svm_sev_es_vcpu_run(vmcb_pa);

	} else {

		struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu);



		/*

		 * Use a single vmcb (vmcb01 because it's always valid) for

		 * context switching guest state via VMLOAD/VMSAVE, that way

		 * the state doesn't need to be copied between vmcb01 and

		 * vmcb02 when switching vmcbs for nested virtualization.

		 */

		vmload(svm->vmcb01.pa);

		__svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&vcpu->arch.regs);

		__svm_vcpu_run(vmcb_pa, (unsigned long *)&vcpu->arch.regs);

		vmsave(svm->vmcb01.pa);



		vmload(__sme_page_pa(sd->save_area));

arch/x86/kvm/svm/svm.h

+0 −1
Original line number Diff line number Diff line
@@ -111,7 +111,6 @@ struct svm_nested_state { 
struct vcpu_svm {

	struct kvm_vcpu vcpu;

	struct vmcb *vmcb;

	unsigned long vmcb_pa;

	struct kvm_vmcb_info vmcb01;

	struct kvm_vmcb_info *current_vmcb;

	struct svm_cpu_data *svm_data;