X86/nVMX: handle_vmon: Read 4 bytes from guest memory (2e408936) · Commits · 戴 / test

Read the data directly from guest memory instead of the map->read->unmap sequence. This also avoids using kvm_vcpu_gpa_to_page() and kmap() which assumes that there is a "struct page" for guest memory. Suggested-by:

Jim Mattson <jmattson@google.com> Signed-off-by:

KarimAllah Ahmed <karahmed@amazon.de> Reviewed-by:

Jim Mattson <jmattson@google.com> Reviewed-by:

David Hildenbrand <david@redhat.com> Reviewed-by:

Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/nested.c

+3 −11

Original line number	Diff line number	Diff line
		@@ -4264,7 +4264,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
		{
		int ret;
		gpa_t vmptr;
		struct page *page;
		uint32_t revision;
		struct vcpu_vmx *vmx = to_vmx(vcpu);
		const u64 VMXON_NEEDED_FEATURES = FEATURE_CONTROL_LOCKED
		\| FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
		@@ -4313,17 +4313,9 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
		if (!PAGE_ALIGNED(vmptr) \|\| (vmptr >> cpuid_maxphyaddr(vcpu)))
		return nested_vmx_failInvalid(vcpu);

		page = kvm_vcpu_gpa_to_page(vcpu, vmptr);
		if (is_error_page(page))
		return nested_vmx_failInvalid(vcpu);

		if ((u32 )kmap(page) != VMCS12_REVISION) {
		kunmap(page);
		kvm_release_page_clean(page);
		if (kvm_read_guest(vcpu->kvm, vmptr, &revision, sizeof(revision)) \|\|
		revision != VMCS12_REVISION)
		return nested_vmx_failInvalid(vcpu);
		}
		kunmap(page);
		kvm_release_page_clean(page);

		vmx->nested.vmxon_ptr = vmptr;
		ret = enter_vmx_operation(vcpu);

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