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

2013-11-15 Thread Liu Ping Fan
In some scene, e.g openstack CI, PR guest can trigger sc 1 frequently, this patch optimizes the path by directly delivering BOOK3S_INTERRUPT_SYSCALL to HV guest, so powernv can return to HV guest without heavy exit, i.e, no need to swap TLB, HTAB,.. etc Signed-off-by: Liu Ping Fan

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

2013-11-15 Thread Paul Mackerras
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