diff options
author | Alexander Graf <agraf@suse.de> | 2018-01-31 22:24:58 +0100 |
---|---|---|
committer | Paul Mackerras <paulus@ozlabs.org> | 2018-02-01 13:35:33 +1100 |
commit | 07ae5389e98c53bb9e9f308fce9c903bc3ee7720 (patch) | |
tree | 42e29efe5409097e294b425a1e62cadb0b05b19a /arch/powerpc/kvm/book3s_pr.c | |
parent | 36ee41d161c67a6fcf696d4817a0da31f778938c (diff) |
KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
When copying between the vcpu and svcpu, we may get scheduled away onto
a different host CPU which in turn means our svcpu pointer may change.
That means we need to atomically copy to and from the svcpu with preemption
disabled, so that all code around it always sees a coherent state.
Reported-by: Simon Guo <wei.guo.simon@gmail.com>
Fixes: 3d3319b45eea ("KVM: PPC: Book3S: PR: Enable interrupts earlier")
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc/kvm/book3s_pr.c')
-rw-r--r-- | arch/powerpc/kvm/book3s_pr.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index d0dc8624198f..d6df74a2f744 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -120,7 +120,7 @@ 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); + kvmppc_copy_from_svcpu(vcpu); } memcpy(to_book3s(vcpu)->slb_shadow, svcpu->slb, sizeof(svcpu->slb)); to_book3s(vcpu)->slb_shadow_max = svcpu->slb_max; @@ -142,9 +142,10 @@ static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu) } /* Copy data needed by real-mode code from vcpu to shadow vcpu */ -void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu, - struct kvm_vcpu *vcpu) +void kvmppc_copy_to_svcpu(struct kvm_vcpu *vcpu) { + struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu); + svcpu->gpr[0] = vcpu->arch.gpr[0]; svcpu->gpr[1] = vcpu->arch.gpr[1]; svcpu->gpr[2] = vcpu->arch.gpr[2]; @@ -176,17 +177,14 @@ void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu, if (cpu_has_feature(CPU_FTR_ARCH_207S)) vcpu->arch.entry_ic = mfspr(SPRN_IC); svcpu->in_use = true; + + svcpu_put(svcpu); } /* 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) +void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu) { - /* - * vcpu_put would just call us again because in_use hasn't - * been updated yet. - */ - preempt_disable(); + struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu); /* * Maybe we were already preempted and synced the svcpu from @@ -232,7 +230,7 @@ void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu, svcpu->in_use = false; out: - preempt_enable(); + svcpu_put(svcpu); } static int kvmppc_core_check_requests_pr(struct kvm_vcpu *vcpu) |