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Commit f3e0dfb3 authored by Oliver Upton's avatar Oliver Upton Committed by Greg Kroah-Hartman
Browse files

KVM: nVMX: Check IO instruction VM-exit conditions 



commit 35a571346a94fb93b5b3b6a599675ef3384bc75c upstream.

Consult the 'unconditional IO exiting' and 'use IO bitmaps' VM-execution
controls when checking instruction interception. If the 'use IO bitmaps'
VM-execution control is 1, check the instruction access against the IO
bitmaps to determine if the instruction causes a VM-exit.

Signed-off-by: default avatarOliver Upton <oupton@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 35523a2d

arch/x86/kvm/vmx.c

+52 −7
Original line number Diff line number Diff line
@@ -4647,7 +4647,7 @@ static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu, 
				       struct vmcs12 *vmcs12)

{

	unsigned long exit_qualification;

	unsigned int port;

	unsigned short port;

	int size;



	if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
@@ -11349,6 +11349,39 @@ static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu, 
		to_vmx(vcpu)->nested.sync_shadow_vmcs = true;

}



static int vmx_check_intercept_io(struct kvm_vcpu *vcpu,

				  struct x86_instruction_info *info)

{

	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

	unsigned short port;

	bool intercept;

	int size;



	if (info->intercept == x86_intercept_in ||

	    info->intercept == x86_intercept_ins) {

		port = info->src_val;

		size = info->dst_bytes;

	} else {

		port = info->dst_val;

		size = info->src_bytes;

	}



	/*

	 * If the 'use IO bitmaps' VM-execution control is 0, IO instruction

	 * VM-exits depend on the 'unconditional IO exiting' VM-execution

	 * control.

	 *

	 * Otherwise, IO instruction VM-exits are controlled by the IO bitmaps.

	 */

	if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))

		intercept = nested_cpu_has(vmcs12,

					   CPU_BASED_UNCOND_IO_EXITING);

	else

		intercept = nested_vmx_check_io_bitmaps(vcpu, port, size);



	return intercept ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE;

}



static int vmx_check_intercept(struct kvm_vcpu *vcpu,

			       struct x86_instruction_info *info,

			       enum x86_intercept_stage stage)
@@ -11356,18 +11389,30 @@ static int vmx_check_intercept(struct kvm_vcpu *vcpu, 
	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;



	switch (info->intercept) {

	/*

	 * RDPID causes #UD if disabled through secondary execution controls.

	 * Because it is marked as EmulateOnUD, we need to intercept it here.

	 */

	if (info->intercept == x86_intercept_rdtscp &&

	    !nested_cpu_has2(vmcs12, SECONDARY_EXEC_RDTSCP)) {

	case x86_intercept_rdtscp:

		if (!nested_cpu_has2(vmcs12, SECONDARY_EXEC_RDTSCP)) {

			ctxt->exception.vector = UD_VECTOR;

			ctxt->exception.error_code_valid = false;

			return X86EMUL_PROPAGATE_FAULT;

		}

		break;



	case x86_intercept_in:

	case x86_intercept_ins:

	case x86_intercept_out:

	case x86_intercept_outs:

		return vmx_check_intercept_io(vcpu, info);



	/* TODO: check more intercepts... */

	default:

		break;

	}



	return X86EMUL_UNHANDLEABLE;

}