Commit 7d0172b3 authored by David Woodhouse's avatar David Woodhouse Committed by Paolo Bonzini
Browse files

KVM: nVMX: Use kvm_read_guest_offset_cached() for nested VMCS check 



Kill another mostly gratuitous kvm_vcpu_map() which could just use the
userspace HVA for it.

Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-6-dwmw2@infradead.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6a834754

arch/x86/kvm/vmx/nested.c

+15 −11
Original line number Diff line number Diff line
@@ -2925,9 +2925,9 @@ static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu, 
static int nested_vmx_check_vmcs_link_ptr(struct kvm_vcpu *vcpu,

					  struct vmcs12 *vmcs12)

{

	int r = 0;

	struct vmcs12 *shadow;

	struct kvm_host_map map;

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	struct gfn_to_hva_cache *ghc = &vmx->nested.shadow_vmcs12_cache;

	struct vmcs_hdr hdr;



	if (vmcs12->vmcs_link_pointer == INVALID_GPA)

		return 0;
@@ -2935,17 +2935,21 @@ static int nested_vmx_check_vmcs_link_ptr(struct kvm_vcpu *vcpu, 
	if (CC(!page_address_valid(vcpu, vmcs12->vmcs_link_pointer)))

		return -EINVAL;



	if (CC(kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->vmcs_link_pointer), &map)))

	if (ghc->gpa != vmcs12->vmcs_link_pointer &&

	    CC(kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc,

					 vmcs12->vmcs_link_pointer, VMCS12_SIZE)))

                return -EINVAL;



	shadow = map.hva;

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

					    offsetof(struct vmcs12, hdr),

					    sizeof(hdr))))

		return -EINVAL;



	if (CC(shadow->hdr.revision_id != VMCS12_REVISION) ||

	    CC(shadow->hdr.shadow_vmcs != nested_cpu_has_shadow_vmcs(vmcs12)))

		r = -EINVAL;

	if (CC(hdr.revision_id != VMCS12_REVISION) ||

	    CC(hdr.shadow_vmcs != nested_cpu_has_shadow_vmcs(vmcs12)))

		return -EINVAL;



	kvm_vcpu_unmap(vcpu, &map, false);

	return r;

	return 0;

}



/*