Commit cee66664 authored by David Woodhouse's avatar David Woodhouse Committed by Paolo Bonzini
Browse files

KVM: nVMX: Use a gfn_to_hva_cache for vmptrld 



And thus another call to kvm_vcpu_map() can die.

Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-7-dwmw2@infradead.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 7d0172b3

arch/x86/kvm/vmx/nested.c

+17 −9
Original line number Diff line number Diff line
@@ -5286,10 +5286,11 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) 
		return 1;



	if (vmx->nested.current_vmptr != vmptr) {

		struct kvm_host_map map;

		struct vmcs12 *new_vmcs12;

		struct gfn_to_hva_cache *ghc = &vmx->nested.vmcs12_cache;

		struct vmcs_hdr hdr;



		if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmptr), &map)) {

		if (ghc->gpa != vmptr &&

		    kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, vmptr, VMCS12_SIZE)) {

			/*

			 * Reads from an unbacked page return all 1s,

			 * which means that the 32 bits located at the
@@ -5300,12 +5301,16 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) 
				VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);

		}



		new_vmcs12 = map.hva;

		if (kvm_read_guest_offset_cached(vcpu->kvm, ghc, &hdr,

						 offsetof(struct vmcs12, hdr),

						 sizeof(hdr))) {

			return nested_vmx_fail(vcpu,

				VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);

		}



		if (new_vmcs12->hdr.revision_id != VMCS12_REVISION ||

		    (new_vmcs12->hdr.shadow_vmcs &&

		if (hdr.revision_id != VMCS12_REVISION ||

		    (hdr.shadow_vmcs &&

		     !nested_cpu_has_vmx_shadow_vmcs(vcpu))) {

			kvm_vcpu_unmap(vcpu, &map, false);

			return nested_vmx_fail(vcpu,

				VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);

		}
@@ -5316,8 +5321,11 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) 
		 * Load VMCS12 from guest memory since it is not already

		 * cached.

		 */

		memcpy(vmx->nested.cached_vmcs12, new_vmcs12, VMCS12_SIZE);

		kvm_vcpu_unmap(vcpu, &map, false);

		if (kvm_read_guest_cached(vcpu->kvm, ghc, vmx->nested.cached_vmcs12,

					  VMCS12_SIZE)) {

			return nested_vmx_fail(vcpu,

				VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);

		}



		set_current_vmptr(vmx, vmptr);

	}

arch/x86/kvm/vmx/vmx.h

+5 −0
Original line number Diff line number Diff line
@@ -146,6 +146,11 @@ struct nested_vmx { 
	 */

	struct gfn_to_hva_cache shadow_vmcs12_cache;



	/*

	 * GPA to HVA cache for VMCS12

	 */

	struct gfn_to_hva_cache vmcs12_cache;



	/*

	 * Indicates if the shadow vmcs or enlightened vmcs must be updated

	 * with the data held by struct vmcs12.