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Commit cad53d5e authored by Jim Mattson's avatar Jim Mattson Committed by Greg Kroah-Hartman
Browse files

kvm: nVMX: VMWRITE checks unsupported field before read-only field 



commit 693e02cc24090c379217138719d9d84e50036b24 upstream.

According to the SDM, VMWRITE checks to see if the secondary source
operand corresponds to an unsupported VMCS field before it checks to
see if the secondary source operand corresponds to a VM-exit
information field and the processor does not support writing to
VM-exit information fields.

Fixes: 49f705c5 ("KVM: nVMX: Implement VMREAD and VMWRITE")
Signed-off-by: default avatarJim Mattson <jmattson@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarPeter Shier <pshier@google.com>
Reviewed-by: default avatarOliver Upton <oupton@google.com>
Reviewed-by: default avatarJon Cargille <jcargill@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 119b1e58

arch/x86/kvm/vmx/nested.c

+6 −5
Original line number Diff line number Diff line
@@ -4741,6 +4741,12 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu) 




	field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));



	offset = vmcs_field_to_offset(field);

	if (offset < 0)

		return nested_vmx_failValid(vcpu,

			VMXERR_UNSUPPORTED_VMCS_COMPONENT);



	/*

	 * If the vCPU supports "VMWRITE to any supported field in the

	 * VMCS," then the "read-only" fields are actually read/write.
@@ -4757,11 +4763,6 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu) 
	if (!is_guest_mode(vcpu) && !is_shadow_field_rw(field))

		copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);



	offset = vmcs_field_to_offset(field);

	if (offset < 0)

		return nested_vmx_failValid(vcpu,

			VMXERR_UNSUPPORTED_VMCS_COMPONENT);



	/*

	 * Some Intel CPUs intentionally drop the reserved bits of the AR byte

	 * fields on VMWRITE.  Emulate this behavior to ensure consistent KVM