[PATCH 3.12 07/63] arm/arm64: KVM: PSCI: use MPIDR to identify a target CPU

From: Jiri Slaby
Date: Thu Apr 30 2015 - 08:29:11 EST


From: Marc Zyngier <marc.zyngier@xxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 79c648806f9034abf54332b78043bb242189d953 upstream.

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: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
arch/arm/include/asm/kvm_emulate.h | 5 +++++
arch/arm/kvm/psci.c | 18 ++++++++++++++----
arch/arm64/include/asm/kvm_emulate.h | 5 +++++
3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index a464e8d7b6c5..708e4d8a647f 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -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__ */
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 86a693a02ba3..881c9fcae33c 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -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 +35,31 @@ 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;
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index eec073875218..6df93cdc652b 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -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__ */
--
2.3.5

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