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Commit 09e6be12 authored by Marc Zyngier's avatar Marc Zyngier Committed by Catalin Marinas
Browse files

arm/arm64: KVM: Advertise SMCCC v1.1 



The new SMC Calling Convention (v1.1) allows for a reduced overhead
when calling into the firmware, and provides a new feature discovery
mechanism.

Make it visible to KVM guests.

Tested-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 58e0b223

arch/arm/kvm/handle_exit.c

+1 −1
Original line number Diff line number Diff line
@@ -36,7 +36,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) 
		      kvm_vcpu_hvc_get_imm(vcpu));

	vcpu->stat.hvc_exit_stat++;



	ret = kvm_psci_call(vcpu);

	ret = kvm_hvc_call_handler(vcpu);

	if (ret < 0) {

		vcpu_set_reg(vcpu, 0, ~0UL);

		return 1;

arch/arm64/kvm/handle_exit.c

+1 −1
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) 
			    kvm_vcpu_hvc_get_imm(vcpu));

	vcpu->stat.hvc_exit_stat++;



	ret = kvm_psci_call(vcpu);

	ret = kvm_hvc_call_handler(vcpu);

	if (ret < 0) {

		vcpu_set_reg(vcpu, 0, ~0UL);

		return 1;

include/kvm/arm_psci.h

+1 −1
Original line number Diff line number Diff line
@@ -27,6 +27,6 @@ 
#define KVM_ARM_PSCI_LATEST	KVM_ARM_PSCI_1_0



int kvm_psci_version(struct kvm_vcpu *vcpu);

int kvm_psci_call(struct kvm_vcpu *vcpu);

int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);



#endif /* __KVM_ARM_PSCI_H__ */

include/linux/arm-smccc.h

+13 −0
Original line number Diff line number Diff line
@@ -60,6 +60,19 @@ 
#define ARM_SMCCC_QUIRK_NONE		0

#define ARM_SMCCC_QUIRK_QCOM_A6		1 /* Save/restore register a6 */



#define ARM_SMCCC_VERSION_1_0		0x10000

#define ARM_SMCCC_VERSION_1_1		0x10001



#define ARM_SMCCC_VERSION_FUNC_ID					\

	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\

			   ARM_SMCCC_SMC_32,				\

			   0, 0)



#define ARM_SMCCC_ARCH_FEATURES_FUNC_ID					\

	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\

			   ARM_SMCCC_SMC_32,				\

			   0, 1)



#ifndef __ASSEMBLY__



#include <linux/linkage.h>

virt/kvm/arm/psci.c

+23 −1
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#include <linux/arm-smccc.h>

#include <linux/preempt.h>

#include <linux/kvm_host.h>

#include <linux/wait.h>
@@ -339,6 +340,7 @@ static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu) 
		case PSCI_0_2_FN_SYSTEM_OFF:

		case PSCI_0_2_FN_SYSTEM_RESET:

		case PSCI_1_0_FN_PSCI_FEATURES:

		case ARM_SMCCC_VERSION_FUNC_ID:

			val = 0;

			break;

		default:
@@ -393,7 +395,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) 
 * Errors:

 * -EINVAL: Unrecognized PSCI function

 */

int kvm_psci_call(struct kvm_vcpu *vcpu)

static int kvm_psci_call(struct kvm_vcpu *vcpu)

{

	switch (kvm_psci_version(vcpu)) {

	case KVM_ARM_PSCI_1_0:
@@ -406,3 +408,23 @@ int kvm_psci_call(struct kvm_vcpu *vcpu) 
		return -EINVAL;

	};

}



int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)

{

	u32 func_id = smccc_get_function(vcpu);

	u32 val = PSCI_RET_NOT_SUPPORTED;



	switch (func_id) {

	case ARM_SMCCC_VERSION_FUNC_ID:

		val = ARM_SMCCC_VERSION_1_1;

		break;

	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:

		/* Nothing supported yet */

		break;

	default:

		return kvm_psci_call(vcpu);

	}



	smccc_set_retval(vcpu, val, 0, 0, 0);

	return 1;

}