Commit 7d0f84aa authored by Anup Patel's avatar Anup Patel Committed by Christoffer Dall
Browse files

ARM/ARM64: KVM: Add base for PSCI v0.2 emulation 



Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to
VCPUs. This patch extends current in-kernel PSCI emulation to provide
PSCI v0.2 interface to VCPUs.

By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for
keeping the ABI backward-compatible.

To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or
KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU
init using KVM_ARM_VCPU_INIT ioctl.

Signed-off-by: default avatarAnup Patel <anup.patel@linaro.org>
Signed-off-by: default avatarPranavkumar Sawargaonkar <pranavkumar@linaro.org>
Acked-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 e546eea7

arch/arm/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -36,7 +36,7 @@ 
#define KVM_COALESCED_MMIO_PAGE_OFFSET 1

#define KVM_HAVE_ONE_REG



#define KVM_VCPU_MAX_FEATURES 1

#define KVM_VCPU_MAX_FEATURES 2



#include <kvm/arm_vgic.h>

arch/arm/include/asm/kvm_psci.h

+4 −0
Original line number Diff line number Diff line
@@ -18,6 +18,10 @@ 
#ifndef __ARM_KVM_PSCI_H__

#define __ARM_KVM_PSCI_H__



#define KVM_ARM_PSCI_0_1	1

#define KVM_ARM_PSCI_0_2	2



int kvm_psci_version(struct kvm_vcpu *vcpu);

bool kvm_psci_call(struct kvm_vcpu *vcpu);



#endif /* __ARM_KVM_PSCI_H__ */

arch/arm/include/uapi/asm/kvm.h

+6 −4
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#define __ARM_KVM_H__



#include <linux/types.h>

#include <linux/psci.h>

#include <asm/ptrace.h>



#define __KVM_HAVE_GUEST_DEBUG
@@ -83,6 +84,7 @@ struct kvm_regs { 
#define KVM_VGIC_V2_CPU_SIZE		0x2000



#define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */

#define KVM_ARM_VCPU_PSCI_0_2		1 /* CPU uses PSCI v0.2 */



struct kvm_vcpu_init {

	__u32 target;
@@ -201,9 +203,9 @@ struct kvm_arch_memory_slot { 
#define KVM_PSCI_FN_CPU_ON		KVM_PSCI_FN(2)

#define KVM_PSCI_FN_MIGRATE		KVM_PSCI_FN(3)



#define KVM_PSCI_RET_SUCCESS		0

#define KVM_PSCI_RET_NI			((unsigned long)-1)

#define KVM_PSCI_RET_INVAL		((unsigned long)-2)

#define KVM_PSCI_RET_DENIED		((unsigned long)-3)

#define KVM_PSCI_RET_SUCCESS		PSCI_RET_SUCCESS

#define KVM_PSCI_RET_NI			PSCI_RET_NOT_SUPPORTED

#define KVM_PSCI_RET_INVAL		PSCI_RET_INVALID_PARAMS

#define KVM_PSCI_RET_DENIED		PSCI_RET_DENIED



#endif /* __ARM_KVM_H__ */

arch/arm/kvm/psci.c

+77 −16
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) 
	 * turned off.

	 */

	if (!vcpu || !vcpu->arch.pause)

		return KVM_PSCI_RET_INVAL;

		return PSCI_RET_INVALID_PARAMS;



	target_pc = *vcpu_reg(source_vcpu, 2);
@@ -82,20 +82,60 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) 
	wq = kvm_arch_vcpu_wq(vcpu);

	wake_up_interruptible(wq);



	return KVM_PSCI_RET_SUCCESS;

	return PSCI_RET_SUCCESS;

}



/**

 * kvm_psci_call - handle PSCI call if r0 value is in range

 * @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.

int kvm_psci_version(struct kvm_vcpu *vcpu)

{

	if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))

		return KVM_ARM_PSCI_0_2;



	return KVM_ARM_PSCI_0_1;

}



static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu)

{

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

	unsigned long val;



	switch (psci_fn) {

	case PSCI_0_2_FN_PSCI_VERSION:

		/*

		 * Bits[31:16] = Major Version = 0

		 * Bits[15:0] = Minor Version = 2

		 */

bool kvm_psci_call(struct kvm_vcpu *vcpu)

		val = 2;

		break;

	case PSCI_0_2_FN_CPU_OFF:

		kvm_psci_vcpu_off(vcpu);

		val = PSCI_RET_SUCCESS;

		break;

	case PSCI_0_2_FN_CPU_ON:

	case PSCI_0_2_FN64_CPU_ON:

		val = kvm_psci_vcpu_on(vcpu);

		break;

	case PSCI_0_2_FN_CPU_SUSPEND:

	case PSCI_0_2_FN_AFFINITY_INFO:

	case PSCI_0_2_FN_MIGRATE:

	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:

	case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:

	case PSCI_0_2_FN_SYSTEM_OFF:

	case PSCI_0_2_FN_SYSTEM_RESET:

	case PSCI_0_2_FN64_CPU_SUSPEND:

	case PSCI_0_2_FN64_AFFINITY_INFO:

	case PSCI_0_2_FN64_MIGRATE:

	case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:

		val = PSCI_RET_NOT_SUPPORTED;

		break;

	default:

		return false;

	}



	*vcpu_reg(vcpu, 0) = val;

	return true;

}



static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu)

{

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

	unsigned long val;
@@ -103,16 +143,15 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) 
	switch (psci_fn) {

	case KVM_PSCI_FN_CPU_OFF:

		kvm_psci_vcpu_off(vcpu);

		val = KVM_PSCI_RET_SUCCESS;

		val = PSCI_RET_SUCCESS;

		break;

	case KVM_PSCI_FN_CPU_ON:

		val = kvm_psci_vcpu_on(vcpu);

		break;

	case KVM_PSCI_FN_CPU_SUSPEND:

	case KVM_PSCI_FN_MIGRATE:

		val = KVM_PSCI_RET_NI;

		val = PSCI_RET_NOT_SUPPORTED;

		break;



	default:

		return false;

	}
@@ -120,3 +159,25 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) 
	*vcpu_reg(vcpu, 0) = val;

	return true;

}



/**

 * kvm_psci_call - handle PSCI call if r0 value is in range

 * @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.

 */

bool kvm_psci_call(struct kvm_vcpu *vcpu)

{

	switch (kvm_psci_version(vcpu)) {

	case KVM_ARM_PSCI_0_2:

		return kvm_psci_0_2_call(vcpu);

	case KVM_ARM_PSCI_0_1:

		return kvm_psci_0_1_call(vcpu);

	default:

		return false;

	};

}

arch/arm64/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ 
#include <kvm/arm_vgic.h>

#include <kvm/arm_arch_timer.h>



#define KVM_VCPU_MAX_FEATURES 2

#define KVM_VCPU_MAX_FEATURES 3



struct kvm_vcpu;

int kvm_target_cpu(void);

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