[PATCH 8/8] KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8

[Paul Mackerras <paulus@samba.org>]

Currently we save the host PMU configuration, counter values, etc.,
when entering a guest, and restore it on return from the guest.
(We have to do this because the guest has control of the PMU while
it is executing.)  However, we missed saving/restoring the SIAR and
SDAR registers, as well as the registers which are new on POWER8,
namely SIER and MMCR2.

This adds code to save the values of these registers when entering
the guest and restore them on exit.  This also works around the bug
in POWER8 where setting PMAE with a counter already negative doesn't
generate an interrupt.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/kvm_book3s_asm.h |  2 +-
 arch/powerpc/kvm/book3s_hv_interrupts.S   | 22 ++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 10 ++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index f3a91dc..821725c 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -94,7 +94,7 @@ struct kvmppc_host_state {
 	unsigned long xics_phys;
 	u32 saved_xirr;
 	u64 dabr;
-	u64 host_mmcr[3];
+	u64 host_mmcr[7];	/* MMCR 0,1,A, SIAR, SDAR, MMCR2, SIER */
 	u32 host_pmc[8];
 	u64 host_purr;
 	u64 host_spurr;
diff --git a/arch/powerpc/kvm/book3s_hv_interrupts.S b/arch/powerpc/kvm/book3s_hv_interrupts.S
index e873796..e18e3cf 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupts.S
+++ b/arch/powerpc/kvm/book3s_hv_interrupts.S
@@ -71,6 +71,14 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	mtmsrd  r10,1
 
 	/* Save host PMU registers */
+BEGIN_FTR_SECTION
+	/* Work around P8 PMAE bug */
+	li	r3, -1
+	clrrdi	r3, r3, 10
+	mfspr	r8, SPRN_MMCR2
+	mtspr	SPRN_MMCR2, r3		/* freeze all counters using MMCR2 */
+	isync
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	li	r3, 1
 	sldi	r3, r3, 31		/* MMCR0_FC (freeze counters) bit */
 	mfspr	r7, SPRN_MMCR0		/* save MMCR0 */
@@ -87,9 +95,18 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
 	cmpwi	r5, 0
 	beq	31f			/* skip if not */
 	mfspr	r5, SPRN_MMCR1
+	mfspr	r9, SPRN_SIAR
+	mfspr	r10, SPRN_SDAR
 	std	r7, HSTATE_MMCR(r13)
 	std	r5, HSTATE_MMCR + 8(r13)
 	std	r6, HSTATE_MMCR + 16(r13)
+	std	r9, HSTATE_MMCR + 24(r13)
+	std	r10, HSTATE_MMCR + 32(r13)
+BEGIN_FTR_SECTION
+	mfspr	r9, SPRN_SIER
+	std	r8, HSTATE_MMCR + 40(r13)
+	std	r9, HSTATE_MMCR + 48(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	mfspr	r3, SPRN_PMC1
 	mfspr	r5, SPRN_PMC2
 	mfspr	r6, SPRN_PMC3
@@ -110,6 +127,11 @@ BEGIN_FTR_SECTION
 	stw	r10, HSTATE_PMC + 24(r13)
 	stw	r11, HSTATE_PMC + 28(r13)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
+BEGIN_FTR_SECTION
+	mfspr	r9, SPRN_SIER
+	std	r8, HSTATE_MMCR + 40(r13)
+	std	r9, HSTATE_MMCR + 48(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 31:
 
 	/*
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 0e6d9e5..9be5b3a 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -109,8 +109,18 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	ld	r3, HSTATE_MMCR(r13)
 	ld	r4, HSTATE_MMCR + 8(r13)
 	ld	r5, HSTATE_MMCR + 16(r13)
+	ld	r6, HSTATE_MMCR + 24(r13)
+	ld	r7, HSTATE_MMCR + 32(r13)
 	mtspr	SPRN_MMCR1, r4
 	mtspr	SPRN_MMCRA, r5
+	mtspr	SPRN_SIAR, r6
+	mtspr	SPRN_SDAR, r7
+BEGIN_FTR_SECTION
+	ld	r8, HSTATE_MMCR + 40(r13)
+	ld	r9, HSTATE_MMCR + 48(r13)
+	mtspr	SPRN_MMCR2, r8
+	mtspr	SPRN_SIER, r9
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	mtspr	SPRN_MMCR0, r3
 	isync
 23:
-- 
1.9.rc1