> From: Roger Pau Monné <roger....@citrix.com> > Sent: Tuesday, March 24, 2020 8:19 PM > > On Tue, Mar 24, 2020 at 11:33:00AM +0000, Tian, Kevin wrote: > > > From: Roger Pau Monné <roger....@citrix.com> > > > Sent: Tuesday, March 24, 2020 7:23 PM > > > > > > On Tue, Mar 24, 2020 at 10:11:15AM +0000, Tian, Kevin wrote: > > > > > From: Roger Pau Monné <roger....@citrix.com> > > > > > Sent: Tuesday, March 24, 2020 5:51 PM > > > > > > > > > > On Tue, Mar 24, 2020 at 06:03:28AM +0000, Tian, Kevin wrote: > > > > > > > From: Roger Pau Monne <roger....@citrix.com> > > > > > > > Sent: Saturday, March 21, 2020 3:08 AM > > > > > > > > > > > > > > The current usage of nvmx_update_apicv is not clear: it is deeply > > > > > > > intertwined with the Ack interrupt on exit VMEXIT control. > > > > > > > > > > > > > > The code in nvmx_update_apicv should update the SVI (in service > > > > > interrupt) > > > > > > > field of the guest interrupt status only when the Ack interrupt on > > > > > > > exit is set, as it is used to record that the interrupt being > > > > > > > serviced is signaled in a vmcs field, and hence hasn't been > > > > > > > injected > > > > > > > as on native. It's important to record the current in service > > > > > > > interrupt on the guest interrupt status field, or else further > > > > > > > interrupts won't respect the priority of the in service one. > > > > > > > > > > > > > > While clarifying the usage make sure that the SVI is only updated > > > when > > > > > > > Ack on exit is set and the nested vmcs interrupt info field is > > > > > > > valid. > Or > > > > > > > else a guest not using the Ack on exit feature would loose > interrupts > > > as > > > > > > > they would be signaled as being in service on the guest interrupt > > > > > > > status field but won't actually be recorded on the interrupt info > vmcs > > > > > > > field, neither injected in any other way. > > > > > > > > > > > > It is insufficient. You also need to update RVI to enable virtual > injection > > > > > > when Ack on exit is cleared. > > > > > > > > > > But RVI should be updated in vmx_intr_assist in that case, since > > > > > nvmx_intr_intercept shouldn't intercept the interrupt, as it should be > > > > > handled normally. > > > > > > > > As we discussed before, vmx_intr_assist is invoked before > > > nvmx_switch_guest. > > > > > > > > It is incorrectly to update RVI at that time since it might be still > > > > vmcs02 > > > being > > > > active (if no pending softirq to make it invoked again). > > > > > > > > Also nvmx_intr_intercept does intercept Ack-on-exit=0 case: > > > > > > > > if ( intack.source == hvm_intsrc_pic || > > > > intack.source == hvm_intsrc_lapic ) > > I've realized that nvmx_intr_intercept will return 1 for interrupts > originating from the lapic or the pic, while nvmx_update_apicv will > only update GUEST_INTR_STATUS for interrupts originating from the > lapic. Is this correct?
Isn't apicv for virtual lapic instead of virtual pic? > > Shouldn't both be in sync and handle the same interrupt sources? > But I do realize one potential issue about 67f9d0b9, which may break vpic delivery when ack-on-exit is off. We should always use interrupt window to handle that situation for vpic. Sorry I didn't catch it when proposing that change... Thanks Kevin
