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Commit e8e7fcc5 authored by Anup Patel's avatar Anup Patel Committed by Christoffer Dall
Browse files

ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexible 



Currently, the kvm_psci_call() returns 'true' or 'false' based on whether
the PSCI function call was handled successfully or not. This does not help
us emulate system-level PSCI functions where the actual emulation work will
be done by user space (QEMU or KVMTOOL). Examples of such system-level PSCI
functions are: PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET.

This patch updates kvm_psci_call() to return three types of values:
1) > 0 (success)
2) = 0 (success but exit to user space)
3) < 0 (errors)

Signed-off-by: default avatarAnup Patel <anup.patel@linaro.org>
Signed-off-by: default avatarPranavkumar Sawargaonkar <pranavkumar@linaro.org>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 50bb0c94

arch/arm/include/asm/kvm_psci.h

+1 −1
Original line number Diff line number Diff line
@@ -22,6 +22,6 @@ 
#define KVM_ARM_PSCI_0_2	2



int kvm_psci_version(struct kvm_vcpu *vcpu);

bool kvm_psci_call(struct kvm_vcpu *vcpu);

int kvm_psci_call(struct kvm_vcpu *vcpu);



#endif /* __ARM_KVM_PSCI_H__ */

arch/arm/kvm/handle_exit.c

+7 −3
Original line number Diff line number Diff line
@@ -38,16 +38,20 @@ static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run) 


static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	int ret;



	trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),

		      kvm_vcpu_hvc_get_imm(vcpu));



	if (kvm_psci_call(vcpu))

		return 1;



	ret = kvm_psci_call(vcpu);

	if (ret < 0) {

		kvm_inject_undefined(vcpu);

		return 1;

	}



	return ret;

}



static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	kvm_inject_undefined(vcpu);

arch/arm/kvm/psci.c

+16 −12
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu) 
	return KVM_ARM_PSCI_0_1;

}



static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu)

static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)

{

	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);

	unsigned long val;
@@ -128,14 +128,14 @@ static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) 
		val = PSCI_RET_NOT_SUPPORTED;

		break;

	default:

		return false;

		return -EINVAL;

	}



	*vcpu_reg(vcpu, 0) = val;

	return true;

	return 1;

}



static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu)

static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)

{

	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);

	unsigned long val;
@@ -153,11 +153,11 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) 
		val = PSCI_RET_NOT_SUPPORTED;

		break;

	default:

		return false;

		return -EINVAL;

	}



	*vcpu_reg(vcpu, 0) = val;

	return true;

	return 1;

}



/**
@@ -165,12 +165,16 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) 
 * @vcpu: Pointer to the VCPU struct

 *

 * Handle PSCI calls from guests through traps from HVC instructions.

 * The calling convention is similar to SMC calls to the secure world where

 * the function number is placed in r0 and this function returns true if the

 * function number specified in r0 is withing the PSCI range, and false

 * otherwise.

 * The calling convention is similar to SMC calls to the secure world

 * where the function number is placed in r0.

 *

 * This function returns: > 0 (success), 0 (success but exit to user

 * space), and < 0 (errors)

 *

 * Errors:

 * -EINVAL: Unrecognized PSCI function

 */

bool kvm_psci_call(struct kvm_vcpu *vcpu)

int kvm_psci_call(struct kvm_vcpu *vcpu)

{

	switch (kvm_psci_version(vcpu)) {

	case KVM_ARM_PSCI_0_2:
@@ -178,6 +182,6 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) 
	case KVM_ARM_PSCI_0_1:

		return kvm_psci_0_1_call(vcpu);

	default:

		return false;

		return -EINVAL;

	};

}

arch/arm64/include/asm/kvm_psci.h

+1 −1
Original line number Diff line number Diff line
@@ -22,6 +22,6 @@ 
#define KVM_ARM_PSCI_0_2	2



int kvm_psci_version(struct kvm_vcpu *vcpu);

bool kvm_psci_call(struct kvm_vcpu *vcpu);

int kvm_psci_call(struct kvm_vcpu *vcpu);



#endif /* __ARM64_KVM_PSCI_H__ */

arch/arm64/kvm/handle_exit.c

+7 −3
Original line number Diff line number Diff line
@@ -30,13 +30,17 @@ typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *); 


static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	if (kvm_psci_call(vcpu))

		return 1;

	int ret;



	ret = kvm_psci_call(vcpu);

	if (ret < 0) {

		kvm_inject_undefined(vcpu);

		return 1;

	}



	return ret;

}



static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	kvm_inject_undefined(vcpu);