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

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>
Acked-by: Scott Wood <scottwood@freescale.com>

diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index f3a91dc..821725c 100644 (file)
--- 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 (file)
--- 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 42bd2e6..4963335 100644 (file)
--- 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: