[PATCH v2] powerpc: kvm: optimize "sc 1" as fast return

liu ping fan qemulist at gmail.com
Mon Nov 18 12:06:54 EST 2013


On Sat, Nov 16, 2013 at 3:00 PM, Paul Mackerras <paulus at samba.org> wrote:
> On Fri, Nov 15, 2013 at 04:35:01PM +0800, Liu Ping Fan wrote:
>>
>> +sc_1_fast_return:
>> +     mtspr   SPRN_SRR0,r10
>> +     mtspr   SPRN_SRR1,r11
>> +     li      r10, BOOK3S_INTERRUPT_SYSCALL
>> +     li      r11, (MSR_ME << 1) | 1  /* synthesize MSR_SF | MSR_ME */
>> +     rotldi  r11, r11, 63
>
> You need a "mr r4, r9" instruction here, because fast_guest_return
> needs the vcpu pointer in r4.  Apart from that this looks fine.
>
Will fix it.

Thanks and regards,
Pingfan
>> +     b       fast_guest_return
>
> Paul.


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