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>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1ddcad452add0808b3c3aac39c291db32c3e620a..a1e1bc9d412dadca87e4a7be6c7903ab0768a8a8 100644 (file)
--- 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 */