tree 68daabdafa535043ab68d01b80642fbf6a4c0977
parent 2345df8c555ecb92c0c36172c07d5ac321a92dc7
author Avi Kivity <avi@qumranet.com> 1176978168 +0300
committer Avi Kivity <avi@qumranet.com> 1178178750 +0300

KVM: VMX: Don't switch 64-bit msrs for 32-bit guests

Some msrs are only used by x86_64 instructions, and are therefore
not needed when the guest is legacy mode.  By not bothering to switch
them, we reduce vmexit latency by 2400 cycles (from about 8800) when
running a 32-bt guest on a 64-bit host.

Signed-off-by: Avi Kivity <avi@qumranet.com>