KVM: PPC: Book3S: PR: Optimize entry path

By shuffling a few instructions around we can execute more memory
loads in parallel, giving us a small performance boost.

With this patch and a simple priviledged SPR access loop guest, I get
a speed bump from 2013052 to 2035607 exits per second.

Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Alexander Graf 2012-04-25 14:28:23 +02:00
parent 30124906db
commit 8c2d0be7ef
1 changed files with 7 additions and 6 deletions

View File

@ -128,24 +128,25 @@ no_dcbz32_on:
/* First clear RI in our current MSR value */
li r0, MSR_RI
andc r6, r6, r0
MTMSR_EERI(r6)
mtsrr0 r9
mtsrr1 r4
PPC_LL r0, SVCPU_R0(r3)
PPC_LL r1, SVCPU_R1(r3)
PPC_LL r2, SVCPU_R2(r3)
PPC_LL r4, SVCPU_R4(r3)
PPC_LL r5, SVCPU_R5(r3)
PPC_LL r6, SVCPU_R6(r3)
PPC_LL r7, SVCPU_R7(r3)
PPC_LL r8, SVCPU_R8(r3)
PPC_LL r9, SVCPU_R9(r3)
PPC_LL r10, SVCPU_R10(r3)
PPC_LL r11, SVCPU_R11(r3)
PPC_LL r12, SVCPU_R12(r3)
PPC_LL r13, SVCPU_R13(r3)
MTMSR_EERI(r6)
mtsrr0 r9
mtsrr1 r4
PPC_LL r4, SVCPU_R4(r3)
PPC_LL r6, SVCPU_R6(r3)
PPC_LL r9, SVCPU_R9(r3)
PPC_LL r3, (SVCPU_R3)(r3)
RFI