kvmclock: count total_sleep_time when updating guest clock

commit 923de3cf5bf12049628019010e36623fca5ef6d1 upstream.

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.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 145741c979bf2754974ab5ac273bea6c93d4174c..e78d9907e0eef7719b4b52be2bb37217e2ab8f45 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -583,7 +583,7 @@ 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;
@@ -598,9 +598,7 @@ 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;
@@ -675,6 +673,7 @@ 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 */