[2/2] KVM: PPC: Book3S: PR: No isync in slbie path

Submitted by Alexander Graf on April 25, 2012, 12:38 p.m.


Message ID 1335357502-30113-2-git-send-email-agraf@suse.de
State New
Headers show

Commit Message

Alexander Graf April 25, 2012, 12:38 p.m.
While messing around with the SLBs we're running in real mode. The
entry to guest space goes through rfid, which is context synchronizing,
so there's no need to manually synchronize anything through isync.

With this patch and a simple priviledged SPR access loop guest, I get
a speed bump from 2035607 to 2181301 exits per second.

Signed-off-by: Alexander Graf <agraf@suse.de>
 arch/powerpc/kvm/book3s_64_slb.S |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

Patch hide | download patch | download mbox

diff --git a/arch/powerpc/kvm/book3s_64_slb.S b/arch/powerpc/kvm/book3s_64_slb.S
index f2e6e48..56b983e 100644
--- a/arch/powerpc/kvm/book3s_64_slb.S
+++ b/arch/powerpc/kvm/book3s_64_slb.S
@@ -90,8 +90,6 @@  slb_exit_skip_ ## num:
 	or      r10, r10, r12
 	slbie	r10
-	isync
 	/* Fill SLB with our shadow */
 	lbz	r12, SVCPU_SLB_MAX(r3)