KVM: PPC: Book3S HV: Save/restore XER in checkpointed register state
When switching from/to a guest that has a transaction in progress,
we need to save/restore the checkpointed register state. Although
XER is part of the CPU state that gets checkpointed, the code that
does this saving and restoring doesn't save/restore XER.
This fixes it by saving and restoring the XER. To allow userspace
to read/write the checkpointed XER value, we also add a new ONE_REG
specifier.
The visible effect of this bug is that the guest may see its XER
value being corrupted when it uses transactions.
Fixes: e4e38121507a ("KVM: PPC: Book3S HV: Add transactional memory support")
Fixes: 0a8eccefcb34 ("KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 20ef27d..0e584ee 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -565,6 +565,7 @@ struct kvm_vcpu_arch {
u64 tfiar;
u32 cr_tm;
+ u64 xer_tm;
u64 lr_tm;
u64 ctr_tm;
u64 amr_tm;