We had an arbitrary limitation in mtmsrd L=1 that kept us from using r30 and
r31 as input registers. Let's get rid of that and get more potential speedups!
Signed-off-by: Alexander Graf <agraf@xxxxxxx>
---
arch/powerpc/kernel/kvm.c | 21 +++++++++++++++++----
arch/powerpc/kernel/kvm_emul.S | 8 +++++++-
2 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 517967d..517da39 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -159,6 +159,7 @@ static u32 *kvm_alloc(int len)
extern u32 kvm_emulate_mtmsrd_branch_offs;
extern u32 kvm_emulate_mtmsrd_reg_offs;
+extern u32 kvm_emulate_mtmsrd_orig_ins_offs;
extern u32 kvm_emulate_mtmsrd_len;
extern u32 kvm_emulate_mtmsrd[];
@@ -187,7 +188,21 @@ static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
/* Modify the chunk to fit the invocation */
memcpy(p, kvm_emulate_mtmsrd, kvm_emulate_mtmsrd_len * 4);
p[kvm_emulate_mtmsrd_branch_offs] |= distance_end & KVM_INST_B_MASK;
- p[kvm_emulate_mtmsrd_reg_offs] |= rt;
+ switch (get_rt(rt)) {
+ case 30:
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
+ magic_var(scratch2), KVM_RT_30);
+ break;
+ case 31:
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
+ magic_var(scratch1), KVM_RT_30);
+ break;
+ default:
+ p[kvm_emulate_mtmsrd_reg_offs] |= rt;
+ break;
+ }
+
+ p[kvm_emulate_mtmsrd_orig_ins_offs] = *inst;
flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsrd_len * 4);
/* Patch the invocation */
@@ -424,9 +439,7 @@ static void kvm_check_ins(u32 *inst, u32 features)
/* Rewrites */
case KVM_INST_MTMSRD_L1:
- /* We use r30 and r31 during the hook */
- if (get_rt(inst_rt) < 30)
- kvm_patch_ins_mtmsrd(inst, inst_rt);
+ kvm_patch_ins_mtmsrd(inst, inst_rt);
break;
case KVM_INST_MTMSR:
case KVM_INST_MTMSRD_L0:
diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S
index 6530532..f2b1b25 100644
--- a/arch/powerpc/kernel/kvm_emul.S
+++ b/arch/powerpc/kernel/kvm_emul.S
@@ -78,7 +78,8 @@ kvm_emulate_mtmsrd:
/* OR the register's (MSR_EE|MSR_RI) on MSR */
kvm_emulate_mtmsrd_reg:
- andi. r30, r0, (MSR_EE|MSR_RI)
+ ori r30, r0, 0
+ andi. r30, r30, (MSR_EE|MSR_RI)
or r31, r31, r30
/* Put MSR back into magic page */
@@ -96,6 +97,7 @@ kvm_emulate_mtmsrd_reg:
SCRATCH_RESTORE
/* Nag hypervisor */
+kvm_emulate_mtmsrd_orig_ins:
tlbsync
b kvm_emulate_mtmsrd_branch
@@ -117,6 +119,10 @@ kvm_emulate_mtmsrd_branch_offs:
kvm_emulate_mtmsrd_reg_offs:
.long (kvm_emulate_mtmsrd_reg - kvm_emulate_mtmsrd) / 4
+.global kvm_emulate_mtmsrd_orig_ins_offs
+kvm_emulate_mtmsrd_orig_ins_offs:
+ .long (kvm_emulate_mtmsrd_orig_ins - kvm_emulate_mtmsrd) / 4
+
.global kvm_emulate_mtmsrd_len
kvm_emulate_mtmsrd_len:
.long (kvm_emulate_mtmsrd_end - kvm_emulate_mtmsrd) / 4
--
1.6.0.2
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