Commit d43583b8 authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest 



PSCI v1.1 introduces the optional SYSTEM_RESET2 call, which allows the
caller to provide a vendor-specific "reset type" and "cookie" to request
a particular form of reset or shutdown.

Expose this call to the guest and handle it in the same way as PSCI
SYSTEM_RESET, along with some basic range checking on the type argument.

Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220221153524.15397-3-will@kernel.org
parent 512865d8

arch/arm64/kvm/psci.c

+29 −4
Original line number Diff line number Diff line
@@ -308,7 +308,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) 
static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)

{

	u32 psci_fn = smccc_get_function(vcpu);

	u32 feature;

	u32 arg;

	unsigned long val;

	int ret = 1;
@@ -320,12 +320,12 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) 
		val = minor == 0 ? KVM_ARM_PSCI_1_0 : KVM_ARM_PSCI_1_1;

		break;

	case PSCI_1_0_FN_PSCI_FEATURES:

		feature = smccc_get_arg1(vcpu);

		val = kvm_psci_check_allowed_function(vcpu, feature);

		arg = smccc_get_arg1(vcpu);

		val = kvm_psci_check_allowed_function(vcpu, arg);

		if (val)

			break;



		switch(feature) {

		switch(arg) {

		case PSCI_0_2_FN_PSCI_VERSION:

		case PSCI_0_2_FN_CPU_SUSPEND:

		case PSCI_0_2_FN64_CPU_SUSPEND:
@@ -341,11 +341,36 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) 
		case ARM_SMCCC_VERSION_FUNC_ID:

			val = 0;

			break;

		case PSCI_1_1_FN_SYSTEM_RESET2:

		case PSCI_1_1_FN64_SYSTEM_RESET2:

			if (minor >= 1) {

				val = 0;

				break;

			}

			fallthrough;

		default:

			val = PSCI_RET_NOT_SUPPORTED;

			break;

		}

		break;

	case PSCI_1_1_FN_SYSTEM_RESET2:

		kvm_psci_narrow_to_32bit(vcpu);

		fallthrough;

	case PSCI_1_1_FN64_SYSTEM_RESET2:

		if (minor >= 1) {

			arg = smccc_get_arg1(vcpu);



			if (arg > PSCI_1_1_RESET_TYPE_SYSTEM_WARM_RESET &&

			    arg < PSCI_1_1_RESET_TYPE_VENDOR_START) {

				val = PSCI_RET_INVALID_PARAMS;

			} else {

				kvm_psci_system_reset(vcpu);

				val = PSCI_RET_INTERNAL_FAILURE;

				ret = 0;

			}

			break;

		};

		fallthrough;

	default:

		return kvm_psci_0_2_call(vcpu);

	}

include/uapi/linux/psci.h

+4 −0
Original line number Diff line number Diff line
@@ -82,6 +82,10 @@ 
#define PSCI_0_2_TOS_UP_NO_MIGRATE		1

#define PSCI_0_2_TOS_MP				2



/* PSCI v1.1 reset type encoding for SYSTEM_RESET2 */

#define PSCI_1_1_RESET_TYPE_SYSTEM_WARM_RESET	0

#define PSCI_1_1_RESET_TYPE_VENDOR_START	0x80000000U



/* PSCI version decoding (independent of PSCI version) */

#define PSCI_VERSION_MAJOR_SHIFT		16

#define PSCI_VERSION_MINOR_MASK			\