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Commit 79c64880 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

arm/arm64: KVM: PSCI: use MPIDR to identify a target CPU 



The KVM PSCI code blindly assumes that vcpu_id and MPIDR are
the same thing. This is true when vcpus are organized as a flat
topology, but is wrong when trying to emulate any other topology
(such as A15 clusters).

Change the KVM PSCI CPU_ON code to look at the MPIDR instead
of the vcpu_id to pick a target CPU.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 7999b4d1

arch/arm/include/asm/kvm_emulate.h

+5 −0
Original line number Diff line number Diff line
@@ -157,4 +157,9 @@ static inline u32 kvm_vcpu_hvc_get_imm(struct kvm_vcpu *vcpu) 
	return kvm_vcpu_get_hsr(vcpu) & HSR_HVC_IMM_MASK;

}



static inline unsigned long kvm_vcpu_get_mpidr(struct kvm_vcpu *vcpu)

{

	return vcpu->arch.cp15[c0_MPIDR];

}



#endif /* __ARM_KVM_EMULATE_H__ */

arch/arm/kvm/psci.c

+13 −4
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/kvm_host.h>

#include <linux/wait.h>



#include <asm/cputype.h>

#include <asm/kvm_emulate.h>

#include <asm/kvm_psci.h>
@@ -34,22 +35,30 @@ static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) 
static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)

{

	struct kvm *kvm = source_vcpu->kvm;

	struct kvm_vcpu *vcpu;

	struct kvm_vcpu *vcpu = NULL, *tmp;

	wait_queue_head_t *wq;

	unsigned long cpu_id;

	unsigned long mpidr;

	phys_addr_t target_pc;

	int i;



	cpu_id = *vcpu_reg(source_vcpu, 1);

	if (vcpu_mode_is_32bit(source_vcpu))

		cpu_id &= ~((u32) 0);



	if (cpu_id >= atomic_read(&kvm->online_vcpus))

	kvm_for_each_vcpu(i, tmp, kvm) {

		mpidr = kvm_vcpu_get_mpidr(tmp);

		if ((mpidr & MPIDR_HWID_BITMASK) == (cpu_id & MPIDR_HWID_BITMASK)) {

			vcpu = tmp;

			break;

		}

	}



	if (!vcpu)

		return KVM_PSCI_RET_INVAL;



	target_pc = *vcpu_reg(source_vcpu, 2);



	vcpu = kvm_get_vcpu(kvm, cpu_id);



	wq = kvm_arch_vcpu_wq(vcpu);

	if (!waitqueue_active(wq))

		return KVM_PSCI_RET_INVAL;

arch/arm64/include/asm/kvm_emulate.h

+5 −0
Original line number Diff line number Diff line
@@ -177,4 +177,9 @@ static inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu) 
	return kvm_vcpu_get_hsr(vcpu) & ESR_EL2_FSC_TYPE;

}



static inline unsigned long kvm_vcpu_get_mpidr(struct kvm_vcpu *vcpu)

{

	return vcpu_sys_reg(vcpu, MPIDR_EL1);

}



#endif /* __ARM64_KVM_EMULATE_H__ */