Commit a7cde481 authored by Liran Alon's avatar Liran Alon Committed by Paolo Bonzini
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KVM: nVMX: Do not forward VMREAD/VMWRITE VMExits to L1 if required so by... 


KVM: nVMX: Do not forward VMREAD/VMWRITE VMExits to L1 if required so by vmcs12 vmread/vmwrite bitmaps

This is done as a preparation for VMCS shadowing emulation.

Signed-off-by: default avatarLiran Alon <liran.alon@oracle.com>
Signed-off-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6d894f49

arch/x86/kvm/vmx.c

+31 −2
Original line number Diff line number Diff line
@@ -9107,6 +9107,30 @@ static bool nested_vmx_exit_handled_cr(struct kvm_vcpu *vcpu, 
	return false;

}



static bool nested_vmx_exit_handled_vmcs_access(struct kvm_vcpu *vcpu,

	struct vmcs12 *vmcs12, gpa_t bitmap)

{

	u32 vmx_instruction_info;

	unsigned long field;

	u8 b;



	if (!nested_cpu_has_shadow_vmcs(vmcs12))

		return true;



	/* Decode instruction info and find the field to access */

	vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);

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



	/* Out-of-range fields always cause a VM exit from L2 to L1 */

	if (field >> 15)

		return true;



	if (kvm_vcpu_read_guest(vcpu, bitmap + field/8, &b, 1))

		return true;



	return 1 & (b >> (field & 7));

}



/*

 * Return 1 if we should exit from L2 to L1 to handle an exit, or 0 if we

 * should handle it ourselves in L0 (and then continue L2). Only call this
@@ -9191,10 +9215,15 @@ static bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason) 
		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_RDSEED_EXITING);

	case EXIT_REASON_RDTSC: case EXIT_REASON_RDTSCP:

		return nested_cpu_has(vmcs12, CPU_BASED_RDTSC_EXITING);

	case EXIT_REASON_VMREAD:

		return nested_vmx_exit_handled_vmcs_access(vcpu, vmcs12,

			vmcs12->vmread_bitmap);

	case EXIT_REASON_VMWRITE:

		return nested_vmx_exit_handled_vmcs_access(vcpu, vmcs12,

			vmcs12->vmwrite_bitmap);

	case EXIT_REASON_VMCALL: case EXIT_REASON_VMCLEAR:

	case EXIT_REASON_VMLAUNCH: case EXIT_REASON_VMPTRLD:

	case EXIT_REASON_VMPTRST: case EXIT_REASON_VMREAD:

	case EXIT_REASON_VMRESUME: case EXIT_REASON_VMWRITE:

	case EXIT_REASON_VMPTRST: case EXIT_REASON_VMRESUME:

	case EXIT_REASON_VMOFF: case EXIT_REASON_VMON:

	case EXIT_REASON_INVEPT: case EXIT_REASON_INVVPID:

		/*