> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > Sent: Friday, September 27, 2019 2:05 AM > To: Dexuan Cui <decui@xxxxxxxxxxxxx> > > Dexuan Cui <decui@xxxxxxxxxxxxx> writes: > ... > > So, I'm pretty sure no IPI can happen between hv_suspend() and > hv_resume(). > > self-IPI is not supposed to happen either, since interrupts are disabled. > > > > IMO TLB flush should not be an issue either, unless the kernel changes page > > tables between hv_suspend() and hv_resume(), which is not the case as I > > checked the related code, but it looks in theory that might happen, say, in > > the future, so if you insist we should save the variable "hv_hypercall_pg" > > to a temporary variable and set the "hv_hypercall_pg" to NULL before we > > disable the hypercall page > > Let's do it as a future proof so we can keep relying on !hv_hypercall_pg > everywhere we need. No need to change this patch IMO, a follow-up would > do. > Vitaly Now I think it would be better to do it in this patch. :-) I'll post a v6 to follow your suggestion. Thanks, -- Dexuan