[Xen-changelog] Attached patch for svm will enable a tlb flush for each vmrun.

[Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 65127e18d821fccb6df97e573e5cd70d2310dfb5
# Parent  974ed9f7364198b2f3be194847e3b0538f88d5d8
Attached patch for svm will enable a tlb flush for each vmrun.

Setting the tbl_control flag to 1 in the vmcb, causes a complete tlb
flush on this core.  We have seen issues (blue screens) when utilizing
ASID granularity with WinxpSP1 running on cores>0.  we have found that
flushing the TLBs each vmrun alleviates winxpsp1 crashes.  We have also
sometimes seen a substantial performance improvement(!) when flushing
each vmrun, which was completely unexpected.  We are continuing to
investigate root cause, but for the moment, we would like to just flush
each vmrun. Digging around in the SPT code might be necessary here also.

Signed-off-by: Tom Woller <thomas.woller@xxxxxxx>

diff -r 974ed9f73641 -r 65127e18d821 xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c        Wed Feb  8 16:27:32 2006
+++ b/xen/arch/x86/hvm/svm/svm.c        Wed Feb  8 23:13:46 2006
@@ -2317,7 +2317,7 @@
     save_svm_cpu_user_regs(v, &regs);
     v->arch.hvm_svm.injecting_event = 0;
 
-    vmcb->tlb_control = 0;
+    vmcb->tlb_control = 1;
 
 #ifdef SVM_EXTRA_DEBUG
 {

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