On Fri, May 26, 2017 at 03:25:22PM +0300, Denis Plotnikov wrote: > Do an update of system_time_msr address every time before reading > the value of tsc_timestamp from guest's kvmclock page. > > There is no other code paths which ensure that qemu has an up-to-date > value of system_time_msr. So, force this update on guest's tsc_timestamp > reading. > > This bug causes effect on those nested setups which turn off TPR access > interception for L2 guests and that access being intercepted by L0 doesn't > show up in L1. > Linux bootstrap initiate kvmclock before APIC initializing causing TPR access. > That's why on L1 guests, having TPR interception turned on for L2, the effect > of the bug is not revealed. > > This patch fixes this problem by making sure it knows the correct > system_time_msr address every time it is needed. > > Signed-off-by: Denis Plotnikov <dplotni...@virtuozzo.com> > --- > hw/i386/kvm/clock.c | 2 ++ > 1 file changed, 2 insertions(+)
Reviewed-by: Roman Kagan <rka...@virtuozzo.com>
