From: "Xu, Quan" <quan.xu@intel.com>
To: Jan Beulich <JBeulich@suse.com>, "Tian, Kevin" <kevin.tian@intel.com>
Cc: "dario.faggioli@citrix.com" <dario.faggioli@citrix.com>,
"Wu, Feng" <feng.wu@intel.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: [PATCH v10 1/3] vt-d: add a timeout parameter for Queued Invalidation
Date: Wed, 18 May 2016 12:53:41 +0000 [thread overview]
Message-ID: <945CA011AD5F084CBEA3E851C0AB28894B8B1F02@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <573AE8CE02000078000EBF88@prv-mh.provo.novell.com>
On May 17, 2016 3:48 PM, Jan Beulich <JBeulich@suse.com> wrote:
> >>> On 17.05.16 at 05:19, <kevin.tian@intel.com> wrote:
> >> From: Xu, Quan
> >> Sent: Monday, May 16, 2016 11:26 PM
> >>
> >> On May 13, 2016 11:28 PM, Jan Beulich <JBeulich@suse.com> wrote:
> >> > >>> On 22.04.16 at 12:54, <quan.xu@intel.com> wrote:
> >> > > --- a/docs/misc/xen-command-line.markdown
> >> > > +++ b/docs/misc/xen-command-line.markdown
> >> > > @@ -1532,6 +1532,16 @@ Note that if **watchdog** option is also
> >> > specified vpmu will be turned off.
> >> > > As the virtualisation is not 100% safe, don't use the vpmu flag
> >> > > on production systems (see http://xenbits.xen.org/xsa/advisory-
> 163.html)!
> >> > >
> >> > > +### vtd\_qi\_timeout (VT-d)
> >> > > +> `= <integer>`
> >> > > +
> >> > > +> Default: `1`
> >> > > +
> >> > > +Specify the timeout of the VT-d Queued Invalidation in milliseconds.
> >> > > +
> >> > > +By default, the timeout is 1ms. When you see error 'Queue
> >> > > +invalidate wait descriptor timed out', try increasing this value.
> >> >
> >> > So when someone enables ATS, will the 1ms timeout apply to the dev
> >> > iotlb invalidations too?
> >>
> >> Yes,
> >> The timeout is the same for IOTLB, Context, IEC and Device-TLB invalidation.
> >>
> >> > If so, that's surely too short, and would ideally be adjusted
> >> > automatically, but the need for a higher timeout in that case
> >> > should in any event be mentioned here.
> >>
> >> I can try to use 1ms for IOTLB, Context and IEC invalidation. As
> >> mentioned, 1 ms is enough for IOTLB, Context and IEC invalidation.
> >> What about 10 ms for Device-TLB (10 ms is just a higher timeout, no
> specific meaning)?
> >
> > I remember in earlier discussion we agreed to use 1ms as the default
> > for both IOMMU-side and device-side flushes. For device-side flushes,
> > we checked internal HW team that 1ms is a reasonable threshold for
> > integrated devices. It's likely insufficient for discrete devices. We
> > may check any automatic adjustment method later when it becomes a real
> > problem. For now, please elaborate above information in the text.
>
> Well, taking care of automation later is fine with me,
> but tying everything to a
> single timeout, when device iotlb invalidation may require a much larger value,
> isn't.
>
A little bit confused. Check it -- could I leave patch 1/3 as is?
btw, I have tested it against the last commit, no conflict.
Quan
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next prev parent reply other threads:[~2016-05-18 12:53 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-22 10:54 [PATCH v10 0/3] VT-d Device-TLB flush issue Quan Xu
2016-04-22 10:54 ` [PATCH v10 1/3] vt-d: add a timeout parameter for Queued Invalidation Quan Xu
2016-05-13 15:27 ` Jan Beulich
2016-05-16 15:25 ` Xu, Quan
2016-05-17 3:19 ` Tian, Kevin
2016-05-17 7:47 ` Jan Beulich
2016-05-18 12:53 ` Xu, Quan [this message]
2016-05-18 15:05 ` Jan Beulich
2016-05-19 0:32 ` Tian, Kevin
2016-05-19 1:35 ` Xu, Quan
2016-05-19 6:13 ` Jan Beulich
2016-05-19 11:26 ` Xu, Quan
2016-05-19 11:35 ` Jan Beulich
2016-05-19 15:14 ` Xu, Quan
2016-04-22 10:54 ` [PATCH v10 2/3] vt-d: synchronize for Device-TLB flush one by one Quan Xu
2016-05-17 12:36 ` Jan Beulich
2016-05-18 8:53 ` Xu, Quan
2016-05-18 9:29 ` Jan Beulich
2016-05-18 12:02 ` Xu, Quan
2016-04-22 10:54 ` [PATCH v10 3/3] vt-d: fix vt-d Device-TLB flush timeout issue Quan Xu
2016-05-17 14:00 ` Jan Beulich
2016-05-18 13:11 ` Xu, Quan
2016-05-20 7:15 ` Xu, Quan
2016-05-20 9:58 ` Jan Beulich
2016-05-23 14:00 ` Xu, Quan
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