On Tue, Mar 5, 2019 at 8:33 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > On Tue, Mar 05, 2019 at 08:17:03PM +0800, Kairui Song wrote: > > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > > index 7abb09e2eeb8..34aa1e953dfc 100644 > > --- a/arch/x86/hyperv/hv_init.c > > +++ b/arch/x86/hyperv/hv_init.c > > @@ -406,6 +406,12 @@ void hyperv_cleanup(void) > > /* Reset our OS id */ > > wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0); > > > > + /* Cleanup hypercall page reference before reset the page */ > > + hv_hypercall_pg = NULL; > > + > > + /* Make sure page reference is cleared before wrmsr */ > > This comment forgets to tell us who cares about this. And why the wrmsr > itself isn't serializing enough. > > > + wmb(); > > + > > /* Reset the hypercall page */ > > hypercall_msr.as_uint64 = 0; > > wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); > > That looks like a fake MSR; and you're telling me that VMEXIT doesn't > serialize? Thanks for the review, seem I being a bit paranoid on this. Will drop it and send a v3 if no one has any other complaint. -- Best Regards, Kairui Song _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
