From ff5c186b8b6169bf25a6f30670a75fb9d4c945e3 Mon Sep 17 00:00:00 2001
From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Fri, 21 Jan 2011 21:48:14 +0100
Subject: [PATCH] kvm: x86: Reset paravirtual MSRs
Make sure to write the cleared MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
and MSR_KVM_ASYNC_PF_EN to the kernel state so that a freshly booted
guest cannot be disturbed by old values.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
CC: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
target-i386/kvm.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 454ddb182f..825af428d9 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -845,6 +845,13 @@ static int kvm_put_msrs(CPUState *env, int level)
if (smp_cpus == 1 || env->tsc != 0) {
kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSC, env->tsc);
}
+ }
+ /*
+ * The following paravirtual MSRs have side effects on the guest or are
+ * too heavy for normal writeback. Limit them to reset or full state
+ * updates.
+ */
+ if (level >= KVM_PUT_RESET_STATE) {
kvm_msr_entry_set(&msrs[n++], MSR_KVM_SYSTEM_TIME,
env->system_time_msr);
kvm_msr_entry_set(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
--
2.30.2