kvmclock: count total_sleep_time when updating guest clock

Current kvm wallclock does not consider the total_sleep_time which could cause
wrong wallclock in guest after host suspend/resume. This patch solve
this issue by counting total_sleep_time to get the correct host boot time.

Cc: stable@kernel.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1ddcad452add..a1e1bc9d412d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -670,7 +670,7 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
 {
         static int version;
         struct pvclock_wall_clock wc;
-        struct timespec now, sys, boot;
+        struct timespec boot;
 
         if (!wall_clock)
                 return;
@@ -685,9 +685,7 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
          * wall clock specified here.  guest system time equals host
          * system time for us, thus we must fill in host boot time here.
          */
-        now = current_kernel_time();
-        ktime_get_ts(&sys);
-        boot = ns_to_timespec(timespec_to_ns(&now) - timespec_to_ns(&sys));
+        getboottime(&boot);
 
         wc.sec = boot.tv_sec;
         wc.nsec = boot.tv_nsec;
@@ -762,6 +760,7 @@ static void kvm_write_guest_time(struct kvm_vcpu *v)
         local_irq_save(flags);
         kvm_get_msr(v, MSR_IA32_TSC, &vcpu->hv_clock.tsc_timestamp);
         ktime_get_ts(&ts);
+        monotonic_to_bootbased(&ts);
         local_irq_restore(flags);
 
         /* With all the info we got, fill in the values */