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KVM: PPC: Make PV mtmsrd L=1 work with r30 and r31

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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@suse.de>
This commit is contained in:
Alexander Graf 2010-08-05 15:44:41 +02:00 committed by Avi Kivity
parent 9ee18b1e08
commit df08bd1026
2 changed files with 24 additions and 5 deletions
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21
arch/powerpc/kernel/kvm.c
View File

@ -158,6 +158,7 @@ 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[];
@ -186,7 +187,21 @@ 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 */
@ -423,9 +438,7 @@ 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:

8
arch/powerpc/kernel/kvm_emul.S
View File

@ -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