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/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index c93cf35..0fb1326 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -596,6 +596,7 @@ struct kvm_get_htab_header {
#define KVM_REG_PPC_TM_VSCR (KVM_REG_PPC_TM | KVM_REG_SIZE_U32 | 0x67)
#define KVM_REG_PPC_TM_DSCR (KVM_REG_PPC_TM | KVM_REG_SIZE_U64 | 0x68)
#define KVM_REG_PPC_TM_TAR (KVM_REG_PPC_TM | KVM_REG_SIZE_U64 | 0x69)
+#define KVM_REG_PPC_TM_XER (KVM_REG_PPC_TM | KVM_REG_SIZE_U64 | 0x6a)
/* PPC64 eXternal Interrupt Controller Specification */
#define KVM_DEV_XICS_GRP_SOURCES 1 /* 64-bit source attributes */