add hyper-v enlightments for windows guests

This add special hyper-v cpu flags for windows guests.

This improve performance and avoid some bsod related to timer.

(I currently disable the hv_vapic flag because I can't get it working).

I have tested all theses flags with: win2003, win2008R2, winxp, linux debian 64bit, on intel and amd physicals processor

It doesn't break live migration, because new cpu flags are not see by guests until a vm reset.

Signed-off-by: Alexandre Derumier <aderumier@odiso.com>

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index ff5760f9138af9637bb62d8942706a6826b12670..62c74cc61136812a53ee420076a138f32d45ad3e 100644 (file)
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -2371,6 +2371,12 @@ sub config_to_command {
            $ost eq 'wvista') {
            push @$globalFlags, 'kvm-pit.lost_tick_policy=discard';
            push @$cmd, '-no-hpet';
+           #push @$cpuFlags , 'hv_vapic" if !$nokvm;  #fixme, my win2008R2 hang at boot with this
+           push @$cpuFlags , 'hv_spinlocks=0xffff' if !$nokvm;
+       }
+
+       if ($ost eq 'win7' || $ost eq 'win8') {
+           push @$cpuFlags , 'hv_relaxed' if !$nokvm;
        }
     }