KVM: PPC: Use get/set for to_svcpu to help preemption
When running the 64-bit Book3s PR code without CONFIG_PREEMPT_NONE, we were
doing a few things wrong, most notably access to PACA fields without making
sure that the pointers stay stable accross the access (preempt_disable()).
This patch moves to_svcpu towards a get/put model which allows us to disable
preemption while accessing the shadow vcpu fields in the PACA. That way we
can run preemptible and everyone's happy!
Reported-by: Jörg Sommer <joerg@alea.gnuu.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/include/asm/kvm_book3s_32.h b/arch/powerpc/include/asm/kvm_book3s_32.h
index de604db..38040ff 100644
--- a/arch/powerpc/include/asm/kvm_book3s_32.h
+++ b/arch/powerpc/include/asm/kvm_book3s_32.h
@@ -20,11 +20,15 @@
#ifndef __ASM_KVM_BOOK3S_32_H__
#define __ASM_KVM_BOOK3S_32_H__
-static inline struct kvmppc_book3s_shadow_vcpu *to_svcpu(struct kvm_vcpu *vcpu)
+static inline struct kvmppc_book3s_shadow_vcpu *svcpu_get(struct kvm_vcpu *vcpu)
{
return to_book3s(vcpu)->shadow_vcpu;
}
+static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
+{
+}
+
#define PTE_SIZE 12
#define VSID_ALL 0
#define SR_INVALID 0x00000001 /* VSID 1 should always be unused */