Commit 8b50b92f authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: VMX: Add a helper and macros to reduce boilerplate for sec exec ctls 



Add a helper function and several wrapping macros to consolidate the
copy-paste code in vmx_compute_secondary_exec_control() for adjusting
controls that are dependent on guest CPUID bits.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200925003011.21016-1-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 7f3603b6

arch/x86/kvm/vmx/vmx.c

+64 −87
Original line number Diff line number Diff line
@@ -4081,6 +4081,61 @@ u32 vmx_exec_control(struct vcpu_vmx *vmx) 
	return exec_control;

}



/*

 * Adjust a single secondary execution control bit to intercept/allow an

 * instruction in the guest.  This is usually done based on whether or not a

 * feature has been exposed to the guest in order to correctly emulate faults.

 */

static inline void

vmx_adjust_secondary_exec_control(struct vcpu_vmx *vmx, u32 *exec_control,

				  u32 control, bool enabled, bool exiting)

{

	/*

	 * If the control is for an opt-in feature, clear the control if the

	 * feature is not exposed to the guest, i.e. not enabled.  If the

	 * control is opt-out, i.e. an exiting control, clear the control if

	 * the feature _is_ exposed to the guest, i.e. exiting/interception is

	 * disabled for the associated instruction.  Note, the caller is

	 * responsible presetting exec_control to set all supported bits.

	 */

	if (enabled == exiting)

		*exec_control &= ~control;



	/*

	 * Update the nested MSR settings so that a nested VMM can/can't set

	 * controls for features that are/aren't exposed to the guest.

	 */

	if (nested) {

		if (enabled)

			vmx->nested.msrs.secondary_ctls_high |= control;

		else

			vmx->nested.msrs.secondary_ctls_high &= ~control;

	}

}



/*

 * Wrapper macro for the common case of adjusting a secondary execution control

 * based on a single guest CPUID bit, with a dedicated feature bit.  This also

 * verifies that the control is actually supported by KVM and hardware.

 */

#define vmx_adjust_sec_exec_control(vmx, exec_control, name, feat_name, ctrl_name, exiting) \

({									 \

	bool __enabled;							 \

									 \

	if (cpu_has_vmx_##name()) {					 \

		__enabled = guest_cpuid_has(&(vmx)->vcpu,		 \

					    X86_FEATURE_##feat_name);	 \

		vmx_adjust_secondary_exec_control(vmx, exec_control,	 \

			SECONDARY_EXEC_##ctrl_name, __enabled, exiting); \

	}								 \

})



/* More macro magic for ENABLE_/opt-in versus _EXITING/opt-out controls. */

#define vmx_adjust_sec_exec_feature(vmx, exec_control, lname, uname) \

	vmx_adjust_sec_exec_control(vmx, exec_control, lname, uname, ENABLE_##uname, false)



#define vmx_adjust_sec_exec_exiting(vmx, exec_control, lname, uname) \

	vmx_adjust_sec_exec_control(vmx, exec_control, lname, uname, uname##_EXITING, true)



static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx)

{
@@ -4130,33 +4185,12 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx) 


		vcpu->arch.xsaves_enabled = xsaves_enabled;



		if (!xsaves_enabled)

			exec_control &= ~SECONDARY_EXEC_XSAVES;



		if (nested) {

			if (xsaves_enabled)

				vmx->nested.msrs.secondary_ctls_high |=

					SECONDARY_EXEC_XSAVES;

			else

				vmx->nested.msrs.secondary_ctls_high &=

					~SECONDARY_EXEC_XSAVES;

		}

		vmx_adjust_secondary_exec_control(vmx, &exec_control,

						  SECONDARY_EXEC_XSAVES,

						  xsaves_enabled, false);

	}



	if (cpu_has_vmx_rdtscp()) {

		bool rdtscp_enabled = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP);

		if (!rdtscp_enabled)

			exec_control &= ~SECONDARY_EXEC_ENABLE_RDTSCP;



		if (nested) {

			if (rdtscp_enabled)

				vmx->nested.msrs.secondary_ctls_high |=

					SECONDARY_EXEC_ENABLE_RDTSCP;

			else

				vmx->nested.msrs.secondary_ctls_high &=

					~SECONDARY_EXEC_ENABLE_RDTSCP;

		}

	}

	vmx_adjust_sec_exec_feature(vmx, &exec_control, rdtscp, RDTSCP);



	/*

	 * Expose INVPCID if and only if PCID is also exposed to the guest.
@@ -4166,71 +4200,14 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx) 
	 */

	if (!guest_cpuid_has(vcpu, X86_FEATURE_PCID))

		guest_cpuid_clear(vcpu, X86_FEATURE_INVPCID);

	vmx_adjust_sec_exec_feature(vmx, &exec_control, invpcid, INVPCID);



	if (cpu_has_vmx_invpcid()) {

		/* Exposing INVPCID only when PCID is exposed */

		bool invpcid_enabled =

			guest_cpuid_has(vcpu, X86_FEATURE_INVPCID);



		if (!invpcid_enabled)

			exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;



		if (nested) {

			if (invpcid_enabled)

				vmx->nested.msrs.secondary_ctls_high |=

					SECONDARY_EXEC_ENABLE_INVPCID;

			else

				vmx->nested.msrs.secondary_ctls_high &=

					~SECONDARY_EXEC_ENABLE_INVPCID;

		}

	}



	if (cpu_has_vmx_rdrand()) {

		bool rdrand_enabled = guest_cpuid_has(vcpu, X86_FEATURE_RDRAND);

		if (rdrand_enabled)

			exec_control &= ~SECONDARY_EXEC_RDRAND_EXITING;



		if (nested) {

			if (rdrand_enabled)

				vmx->nested.msrs.secondary_ctls_high |=

					SECONDARY_EXEC_RDRAND_EXITING;

			else

				vmx->nested.msrs.secondary_ctls_high &=

					~SECONDARY_EXEC_RDRAND_EXITING;

		}

	}



	if (cpu_has_vmx_rdseed()) {

		bool rdseed_enabled = guest_cpuid_has(vcpu, X86_FEATURE_RDSEED);

		if (rdseed_enabled)

			exec_control &= ~SECONDARY_EXEC_RDSEED_EXITING;



		if (nested) {

			if (rdseed_enabled)

				vmx->nested.msrs.secondary_ctls_high |=

					SECONDARY_EXEC_RDSEED_EXITING;

			else

				vmx->nested.msrs.secondary_ctls_high &=

					~SECONDARY_EXEC_RDSEED_EXITING;

		}

	}



	if (cpu_has_vmx_waitpkg()) {

		bool waitpkg_enabled =

			guest_cpuid_has(vcpu, X86_FEATURE_WAITPKG);



		if (!waitpkg_enabled)

			exec_control &= ~SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE;

	vmx_adjust_sec_exec_exiting(vmx, &exec_control, rdrand, RDRAND);

	vmx_adjust_sec_exec_exiting(vmx, &exec_control, rdseed, RDSEED);



		if (nested) {

			if (waitpkg_enabled)

				vmx->nested.msrs.secondary_ctls_high |=

					SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE;

			else

				vmx->nested.msrs.secondary_ctls_high &=

					~SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE;

		}

	}

	vmx_adjust_sec_exec_control(vmx, &exec_control, waitpkg, WAITPKG,

				    ENABLE_USR_WAIT_PAUSE, false);



	vmx->secondary_exec_control = exec_control;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE