| Message ID | 20210306161833.4552-1-jgross@suse.com |
|---|---|
| Headers | show |
| Series | xen/events: bug fixes and some diagnostic aids | expand |
On 3/6/21 11:18 AM, Juergen Gross wrote: > An event channel should be kept masked when an eoi is pending for it. > When being migrated to another cpu it might be unmasked, though. > > In order to avoid this keep three different flags for each event channel > to be able to distinguish "normal" masking/unmasking from eoi related > masking/unmasking and temporary masking. The event channel should only > be able to generate an interrupt if all flags are cleared. > > Cc: stable@vger.kernel.org > Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn framework") > Reported-by: Julien Grall <julien@xen.org> > Signed-off-by: Juergen Gross <jgross@suse.com> > Reviewed-by: Julien Grall <jgrall@amazon.com> > --- > V2: > - introduce a lock around masking/unmasking > - merge patch 3 into this one (Jan Beulich) > V4: > - don't set eoi masking flag in lateeoi_mask_ack_dynirq() Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Ross, are you planning to test this? -boris
On 08.03.21 21:33, Boris Ostrovsky wrote: > > On 3/6/21 11:18 AM, Juergen Gross wrote: >> An event channel should be kept masked when an eoi is pending for it. >> When being migrated to another cpu it might be unmasked, though. >> >> In order to avoid this keep three different flags for each event channel >> to be able to distinguish "normal" masking/unmasking from eoi related >> masking/unmasking and temporary masking. The event channel should only >> be able to generate an interrupt if all flags are cleared. >> >> Cc: stable@vger.kernel.org >> Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn framework") >> Reported-by: Julien Grall <julien@xen.org> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> Reviewed-by: Julien Grall <jgrall@amazon.com> >> --- >> V2: >> - introduce a lock around masking/unmasking >> - merge patch 3 into this one (Jan Beulich) >> V4: >> - don't set eoi masking flag in lateeoi_mask_ack_dynirq() > > > Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> > > > Ross, are you planning to test this? Just as another data point: With the previous version of the patches a reboot loop of a guest needed max 33 reboots to loose network in my tests (those were IIRC 6 test runs). With this patch version I stopped the test after about 1300 reboots without having seen any problems. Juergen
On 2021-03-09 05:14, Jürgen Groß wrote: > On 08.03.21 21:33, Boris Ostrovsky wrote: >> >> On 3/6/21 11:18 AM, Juergen Gross wrote: >>> An event channel should be kept masked when an eoi is pending for it. >>> When being migrated to another cpu it might be unmasked, though. >>> >>> In order to avoid this keep three different flags for each event channel >>> to be able to distinguish "normal" masking/unmasking from eoi related >>> masking/unmasking and temporary masking. The event channel should only >>> be able to generate an interrupt if all flags are cleared. >>> >>> Cc: stable@vger.kernel.org >>> Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn framework") >>> Reported-by: Julien Grall <julien@xen.org> >>> Signed-off-by: Juergen Gross <jgross@suse.com> >>> Reviewed-by: Julien Grall <jgrall@amazon.com> >>> --- >>> V2: >>> - introduce a lock around masking/unmasking >>> - merge patch 3 into this one (Jan Beulich) >>> V4: >>> - don't set eoi masking flag in lateeoi_mask_ack_dynirq() >> >> >> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> >> >> >> Ross, are you planning to test this? > > Just as another data point: With the previous version of the patches > a reboot loop of a guest needed max 33 reboots to loose network in > my tests (those were IIRC 6 test runs). With this patch version I > stopped the test after about 1300 reboots without having seen any > problems. > Thanks, I'll test it today and get back to you. Ross
On 2021-03-09 08:57, Ross Lagerwall wrote: > On 2021-03-09 05:14, Jürgen Groß wrote: >> On 08.03.21 21:33, Boris Ostrovsky wrote: >>> >>> On 3/6/21 11:18 AM, Juergen Gross wrote: >>>> An event channel should be kept masked when an eoi is pending for it. >>>> When being migrated to another cpu it might be unmasked, though. >>>> >>>> In order to avoid this keep three different flags for each event channel >>>> to be able to distinguish "normal" masking/unmasking from eoi related >>>> masking/unmasking and temporary masking. The event channel should only >>>> be able to generate an interrupt if all flags are cleared. >>>> >>>> Cc: stable@vger.kernel.org >>>> Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn framework") >>>> Reported-by: Julien Grall <julien@xen.org> >>>> Signed-off-by: Juergen Gross <jgross@suse.com> >>>> Reviewed-by: Julien Grall <jgrall@amazon.com> >>>> --- >>>> V2: >>>> - introduce a lock around masking/unmasking >>>> - merge patch 3 into this one (Jan Beulich) >>>> V4: >>>> - don't set eoi masking flag in lateeoi_mask_ack_dynirq() >>> >>> >>> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> >>> >>> >>> Ross, are you planning to test this? >> >> Just as another data point: With the previous version of the patches >> a reboot loop of a guest needed max 33 reboots to loose network in >> my tests (those were IIRC 6 test runs). With this patch version I >> stopped the test after about 1300 reboots without having seen any >> problems. >> > > Thanks, I'll test it today and get back to you. > Tested-by: Ross Lagerwall <ross.lagerwall@citrix.com> The updated patch seems fine in testing. Thanks Ross
On 3/6/21 11:18 AM, Juergen Gross wrote: > Those are fixes for XSA-332. > > The rest of the V3 patches have been applied already. There is one > additional fix in patch 2 which addresses network outages when a guest > is doing reboot loops. > > Juergen Gross (3): > xen/events: reset affinity of 2-level event when tearing it down > xen/events: don't unmask an event channel when an eoi is pending > xen/events: avoid handling the same event on two cpus at the same time > > drivers/xen/events/events_2l.c | 22 +++-- > drivers/xen/events/events_base.c | 130 ++++++++++++++++++++------- > drivers/xen/events/events_fifo.c | 7 -- > drivers/xen/events/events_internal.h | 14 +-- > 4 files changed, 123 insertions(+), 50 deletions(-) Applied to for-linus-5.12b