From: "Roger Pau Monné" <roger.pau@citrix.com>
To: Alexandru Stefan ISAILA <aisaila@bitdefender.com>
Cc: "kevin.tian@intel.com" <kevin.tian@intel.com>,
"tamas@tklengyel.com" <tamas@tklengyel.com>,
"wei.liu2@citrix.com" <wei.liu2@citrix.com>,
"jun.nakajima@intel.com" <jun.nakajima@intel.com>,
"Razvan Cojocaru" <rcojocaru@bitdefender.com>,
"george.dunlap@eu.citrix.com" <george.dunlap@eu.citrix.com>,
"andrew.cooper3@citrix.com" <andrew.cooper3@citrix.com>,
"Mihai Donțu" <mdontu@bitdefender.com>,
"Andrei Vlad LUTAS" <vlutas@bitdefender.com>,
"jbeulich@suse.com" <jbeulich@suse.com>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
"Anshul Makkar" <anshul.makkar@citrix.com>
Subject: Re: [PATCH v1] x86/hvm: Generic instruction re-execution mechanism for execute faults
Date: Thu, 22 Nov 2018 11:07:39 +0100 [thread overview]
Message-ID: <20181122100739.li2fcsaquq6rens7@mac> (raw)
In-Reply-To: <e5dcca5e-6f19-f2d6-05f1-8659ea1dd2bb@bitdefender.com>
On Thu, Nov 22, 2018 at 09:50:28AM +0000, Alexandru Stefan ISAILA wrote:
>
> On 21.11.2018 20:55, Razvan Cojocaru wrote:
> >> + if ( a == v )
> >> + continue;
> >> +
> >> + /* Pause, synced. */
> >> + while ( !a->arch.in_host )
> > Why not use a->is_running as a way to know whether the vCPU is
> > running?
> >
> > I think the logic of using vcpu_pause and expecting the running vcpu
> > to take a vmexit and thus set in_host is wrong because a vcpu that
> > wasn't running when vcpu_pause_nosync is called won't get scheduled
> > anymore, thus not taking a vmexit and this function will lockup.
>
> We can resolve this by using while ( !vcpu_runnable(a) &&
> !a->arch.in_host ), if this is suitable.
I'm afraid that without a reason why the generic vcpu_pause is not
suitable here adding more code to it is just papering over the real
issue.
Thanks, Roger.
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next prev parent reply other threads:[~2018-11-22 10:08 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-16 10:06 [PATCH v1] x86/hvm: Generic instruction re-execution mechanism for execute faults Alexandru Stefan ISAILA
2018-11-16 17:04 ` Roger Pau Monné
2018-11-19 13:30 ` Alexandru Stefan ISAILA
2018-11-19 14:26 ` Jan Beulich
2018-11-19 15:08 ` Roger Pau Monné
2018-11-19 15:56 ` Alexandru Stefan ISAILA
2018-11-21 9:56 ` Roger Pau Monné
2018-11-21 10:28 ` Alexandru Stefan ISAILA
2018-11-21 11:41 ` Roger Pau Monné
2018-11-21 12:00 ` Alexandru Stefan ISAILA
2018-11-19 13:33 ` Jan Beulich
2018-11-21 18:55 ` Razvan Cojocaru
2018-11-22 9:50 ` Alexandru Stefan ISAILA
2018-11-22 10:00 ` Jan Beulich
2018-11-22 10:07 ` Roger Pau Monné [this message]
2018-11-22 10:05 ` Roger Pau Monné
2018-11-22 10:14 ` Razvan Cojocaru
2018-11-22 10:58 ` Roger Pau Monné
2018-11-22 12:48 ` Razvan Cojocaru
2018-11-22 14:49 ` Roger Pau Monné
2018-11-22 15:25 ` Razvan Cojocaru
2018-11-22 15:37 ` Roger Pau Monné
2018-11-22 16:52 ` Razvan Cojocaru
2018-11-22 17:08 ` Roger Pau Monné
2018-11-22 18:24 ` Razvan Cojocaru
2018-11-23 8:54 ` Roger Pau Monné
[not found] ` <59739FBC020000C234861ACF@prv1-mh.provo.novell.com>
[not found] ` <F553A58C020000AB0063616D@prv1-mh.provo.novell.com>
[not found] ` <4D445A680200003E34861ACF@prv1-mh.provo.novell.com>
[not found] ` <DAD49D5A020000780063616D@prv1-mh.provo.novell.com>
[not found] ` <5400A6CB0200003634861ACF@prv1-mh.provo.novell.com>
[not found] ` <203C1A92020000400063616D@prv1-mh.provo.novell.com>
[not found] ` <0DF3BC62020000E934861ACF@prv1-mh.provo.novell.com>
[not found] ` <C6A2E442020000640063616D@prv1-mh.provo.novell.com>
[not found] ` <6EEA58AB020000EA34861ACF@prv1-mh.provo.novell.com>
2018-11-27 10:31 ` Razvan Cojocaru
2018-11-27 11:32 ` Roger Pau Monné
2018-11-27 11:45 ` Razvan Cojocaru
2018-11-27 11:59 ` Andrew Cooper
2018-11-27 12:12 ` Razvan Cojocaru
2018-12-19 16:49 ` Alexandru Stefan ISAILA
2018-12-19 17:40 ` Roger Pau Monné
2018-12-20 14:37 ` Alexandru Stefan ISAILA
[not found] ` <838191050200006B34861ACF@prv1-mh.provo.novell.com>
2018-11-23 9:07 ` Jan Beulich
2018-11-27 10:49 ` Razvan Cojocaru
2018-11-27 11:28 ` Jan Beulich
2018-11-27 11:44 ` Razvan Cojocaru
2019-05-13 13:58 ` Razvan Cojocaru
2019-05-13 13:58 ` [Xen-devel] " Razvan Cojocaru
2019-05-13 14:06 ` Jan Beulich
2019-05-13 14:06 ` [Xen-devel] " Jan Beulich
2019-05-13 14:15 ` Razvan Cojocaru
2019-05-13 14:15 ` [Xen-devel] " Razvan Cojocaru
2019-05-14 13:47 ` Razvan Cojocaru
2019-05-14 13:47 ` [Xen-devel] " Razvan Cojocaru
2019-05-14 14:16 ` Jan Beulich
2019-05-14 14:16 ` [Xen-devel] " Jan Beulich
2019-05-14 14:20 ` Razvan Cojocaru
2019-05-14 14:20 ` [Xen-devel] " Razvan Cojocaru
[not found] ` <A31948D30200007D0063616D@prv1-mh.provo.novell.com>
2018-11-23 9:10 ` Jan Beulich
[not found] ` <9B05ED9E020000C434861ACF@prv1-mh.provo.novell.com>
[not found] ` <626A217B020000C50063616D@prv1-mh.provo.novell.com>
[not found] ` <0D3C56BA0200004834861ACF@prv1-mh.provo.novell.com>
2018-12-20 9:07 ` Jan Beulich
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