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Diffstat (limited to 'arch/powerpc/kvm/book3s_pr.c')
-rw-r--r--arch/powerpc/kvm/book3s_pr.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index fe14ca3dd171..5b9e9063cfaf 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -66,6 +66,7 @@ static void kvmppc_core_vcpu_load_pr(struct kvm_vcpu *vcpu, int cpu)
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
memcpy(svcpu->slb, to_book3s(vcpu)->slb_shadow, sizeof(svcpu->slb));
svcpu->slb_max = to_book3s(vcpu)->slb_shadow_max;
+ svcpu->in_use = 0;
svcpu_put(svcpu);
#endif
vcpu->cpu = smp_processor_id();
@@ -78,6 +79,9 @@ static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_PPC_BOOK3S_64
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
+ if (svcpu->in_use) {
+ kvmppc_copy_from_svcpu(vcpu, svcpu);
+ }
memcpy(to_book3s(vcpu)->slb_shadow, svcpu->slb, sizeof(svcpu->slb));
to_book3s(vcpu)->slb_shadow_max = svcpu->slb_max;
svcpu_put(svcpu);
@@ -110,12 +114,26 @@ void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu,
svcpu->ctr = vcpu->arch.ctr;
svcpu->lr = vcpu->arch.lr;
svcpu->pc = vcpu->arch.pc;
+ svcpu->in_use = true;
}
/* Copy data touched by real-mode code from shadow vcpu back to vcpu */
void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu,
struct kvmppc_book3s_shadow_vcpu *svcpu)
{
+ /*
+ * vcpu_put would just call us again because in_use hasn't
+ * been updated yet.
+ */
+ preempt_disable();
+
+ /*
+ * Maybe we were already preempted and synced the svcpu from
+ * our preempt notifiers. Don't bother touching this svcpu then.
+ */
+ if (!svcpu->in_use)
+ goto out;
+
vcpu->arch.gpr[0] = svcpu->gpr[0];
vcpu->arch.gpr[1] = svcpu->gpr[1];
vcpu->arch.gpr[2] = svcpu->gpr[2];
@@ -139,6 +157,10 @@ void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu,
vcpu->arch.fault_dar = svcpu->fault_dar;
vcpu->arch.fault_dsisr = svcpu->fault_dsisr;
vcpu->arch.last_inst = svcpu->last_inst;
+ svcpu->in_use = false;
+
+out:
+ preempt_enable();
}
static int kvmppc_core_check_requests_pr(struct kvm_vcpu *vcpu)
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