On Sat, 14 Oct 2017 09:47:59 +1100
Paul Mackerras [off-list ref] wrote:

On Sun, Aug 13, 2017 at 11:33:44AM +1000, Nicholas Piggin wrote:

quoted

The "lppaca" is a structure registered with the hypervisor. This
is unnecessary when running on non-virtualised platforms. One field
from the lppaca (pmcregs_in_use) is also used by the host, so move
the host part out into the paca (lppaca field is still updated in
guest mode).  

There is an error in the patch, see below...

quoted

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index c52184a8efdf..b838348e3a2b 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S

@@ -99,8 +99,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	mtspr	SPRN_SPRG_VDSO_WRITE,r3
 
 	/* Reload the host's PMU registers */
-	ld	r3, PACALPPACAPTR(r13)	/* is the host using the PMU? */
-	lbz	r4, LPPACA_PMCINUSE(r3)
+	lbz	r4, PACA_PMCINUSE(r13) /* is the host using the PMU? */
 	cmpwi	r4, 0
 	beq	23f			/* skip if not */
 BEGIN_FTR_SECTION

@@ -1671,7 +1670,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	mtspr	SPRN_MMCRA, r7
 	isync
 	beq	21f			/* if no VPA, save PMU stuff anyway */
-	lbz	r7, LPPACA_PMCINUSE(r8)
+	lbz	r7, PACA_PMCINUSE(r13)  

We really do need to check the guest's flag not the host's here, since
we're deciding whether to save the PMU state to the vcpu struct.

Okay I'll fix that up.

Thanks,
Nick