On Fri, Oct 15, 2010 at 10:52:05AM +0900, Hidetoshi Seto wrote: > (2010/10/15 10:06), Marcelo Tosatti wrote: > > On Thu, Oct 14, 2010 at 05:55:28PM +0900, Jin Dongming wrote: > >> There is no reason why SRAO event received by the main thread > >> is the only one that being broadcasted. > >> > >> According to the x86 ASDM vol.3A 15.10.4.1, > >> MCE signal is broadcast on processor version 06H_EH or later. > >> > >> This change is required to handle SRAR in the guest. > >> > >> Signed-off-by: Hidetoshi Seto <seto.hideto...@jp.fujitsu.com> > >> Tested-by: Jin Dongming <jin.dongm...@np.css.fujitsu.com> > >> --- > >> qemu-kvm.c | 63 > >> +++++++++++++++++++++++++++++------------------------------ > >> 1 files changed, 31 insertions(+), 32 deletions(-) > > > > Why is this necessary? _AO SIGBUS should be sent to all vcpu threads and > > main thread. > > Humm? If you are right, vcpu threads will receive same SRAO event twice, > one is that received by itself and another is that received by main thread > and forwarded by the broadcast. > > My understanding is (Jin, please correct me if something wrong): > - _AO SIGBUS is sent to main thread only, and then SRAO event is > broadcasted to all vcpu threads. > - _AR SIGBUS is sent to a vcpu thread that tried to touch the > unmapped poisoned page, and SRAR event is posted to the vcpu. > > One problem here is that SRAR is not broadcasted. > The guest might observe the event differently, like "some cpus > don't enter machine check."
Right. > > Please separate bug fixes from cleanups. Very nice, thanks. > > Maybe this set is considered as 10 cleanups + 1 fix. > I think this fix will be complicated one without preceding cleanups. Why? All you need is to broadcast from vcpu context. Please do a minimal fix separately so it can be backported, and the cleanups can be done later once its merged upstream. Thanks.
