tree 738874a15a233eed6e2e18d9cfe99f09482e8b17
parent 45133ecaaec7aea447afc98cc2c24aac638bbe5c
author Kevin Tian <kevin.tian@intel.com> 1314701777 +0300
committer Avi Kivity <avi@redhat.com> 1316969537 +0300

KVM: APIC: avoid instruction emulation for EOI writes

Instruction emulation for EOI writes can be skipped, since sane
guest simply uses MOV instead of string operations. This is a nice
improvement when guest doesn't support x2apic or hyper-V EOI
support.

a single VM bandwidth is observed with ~8% bandwidth improvement
(7.4Gbps->8Gbps), by saving ~5% cycles from EOI emulation.

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
<Based on earlier work from>:
Signed-off-by: Eddie Dong <eddie.dong@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>