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: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index a464e8d7b6c58f77c5f57fdda4202587f2331962..708e4d8a647f226b4dbdf9722527edd33177912b 100644 (file)
--- 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 86a693a02ba3a78e4288b94c63f3b1fba77a6b38..311263124acf303606b3081ae71fc0169e7f1dac 100644 (file)
--- 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 +35,30 @@ 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;

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index eec073875218049371eb7beed7715f10ae3b067a..6df93cdc652bccdf4bd6287f30bc3eb70779ff4d 100644 (file)
--- 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__ */