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Commit aa024c2f authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

KVM: ARM: Power State Coordination Interface implementation 



Implement the PSCI specification (ARM DEN 0022A) to control
virtual CPUs being "powered" on or off.

PSCI/KVM is detected using the KVM_CAP_ARM_PSCI capability.

A virtual CPU can now be initialized in a "powered off" state,
using the KVM_ARM_VCPU_POWER_OFF feature flag.

The guest can use either SMC or HVC to execute a PSCI function.

Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <c.dall@virtualopensystems.com>
parent 45e96ea6

Documentation/virtual/kvm/api.txt

+4 −0
Original line number Diff line number Diff line
@@ -2185,6 +2185,10 @@ return ENOEXEC for that vcpu. 
Note that because some registers reflect machine topology, all vcpus

should be created before this ioctl is invoked.



Possible features:

	- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.

	  Depends on KVM_CAP_ARM_PSCI.





4.78 KVM_GET_REG_LIST

arch/arm/include/asm/kvm_emulate.h

+10 −0
Original line number Diff line number Diff line
@@ -32,6 +32,11 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu); 
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);

void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);



static inline bool vcpu_mode_is_32bit(struct kvm_vcpu *vcpu)

{

	return 1;

}



static inline u32 *vcpu_pc(struct kvm_vcpu *vcpu)

{

	return (u32 *)&vcpu->arch.regs.usr_regs.ARM_pc;
@@ -42,6 +47,11 @@ static inline u32 *vcpu_cpsr(struct kvm_vcpu *vcpu) 
	return (u32 *)&vcpu->arch.regs.usr_regs.ARM_cpsr;

}



static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)

{

	*vcpu_cpsr(vcpu) |= PSR_T_BIT;

}



static inline bool mode_has_spsr(struct kvm_vcpu *vcpu)

{

	unsigned long cpsr_mode = vcpu->arch.regs.usr_regs.ARM_cpsr & MODE_MASK;

arch/arm/include/asm/kvm_host.h

+4 −1
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ 
#define KVM_COALESCED_MMIO_PAGE_OFFSET 1

#define KVM_HAVE_ONE_REG



#define KVM_VCPU_MAX_FEATURES 0

#define KVM_VCPU_MAX_FEATURES 1



/* We don't currently support large pages. */

#define KVM_HPAGE_GFN_SHIFT(x)	0
@@ -100,6 +100,9 @@ struct kvm_vcpu_arch { 
	int last_pcpu;

	cpumask_t require_dcache_flush;



	/* Don't run the guest on this vcpu */

	bool pause;



	/* IO related fields */

	struct kvm_decode mmio_decode;

arch/arm/include/asm/kvm_psci.h

0 → 100644
+23 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012 - ARM Ltd

 * Author: Marc Zyngier <marc.zyngier@arm.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#ifndef __ARM_KVM_PSCI_H__

#define __ARM_KVM_PSCI_H__



bool kvm_psci_call(struct kvm_vcpu *vcpu);



#endif /* __ARM_KVM_PSCI_H__ */

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

+16 −0
Original line number Diff line number Diff line
@@ -65,6 +65,8 @@ struct kvm_regs { 
#define KVM_ARM_TARGET_CORTEX_A15	0

#define KVM_ARM_NUM_TARGETS		1



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



struct kvm_vcpu_init {

	__u32 target;

	__u32 features[7];
@@ -145,4 +147,18 @@ struct kvm_arch_memory_slot { 
/* Highest supported SPI, from VGIC_NR_IRQS */

#define KVM_ARM_IRQ_GIC_MAX		127



/* PSCI interface */

#define KVM_PSCI_FN_BASE		0x95c1ba5e

#define KVM_PSCI_FN(n)			(KVM_PSCI_FN_BASE + (n))



#define KVM_PSCI_FN_CPU_SUSPEND		KVM_PSCI_FN(0)

#define KVM_PSCI_FN_CPU_OFF		KVM_PSCI_FN(1)

#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)



#endif /* __ARM_KVM_H__ */