Re: [PATCH 3/3] KVM: PPC: Book3S: 64-bit CONFIG_RELOCATABLE support for interrupts

Paul Mackerras [off-list ref] writes:

On Thu, Dec 22, 2016 at 04:29:27AM +1000, Nicholas Piggin wrote:

quoted

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 11882aac8216..c18ce740452b 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S

@@ -1151,7 +1152,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 11:	stw	r3,VCPU_HEIR(r9)
 
 	/* these are volatile across C function calls */
+#ifdef CONFIG_RELOCATABLE
+	ld	r3, HSTATE_SCRATCH1(r13)

The problem is here.  Depending on what sort of interrupt it is, we
can end up going back to the guest via fast_guest_return, which
doesn't reload CTR.  Adding

	mtctr	r3

at this point makes things work.

I folded this in.

cheers