From: Tamas K Lengyel <tamas@tklengyel.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: "Petre Pircalabu" <ppircalabu@bitdefender.com>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Julien Grall" <julien@xen.org>, "Wei Liu" <wl@xen.org>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Ian Jackson" <ian.jackson@eu.citrix.com>,
"George Dunlap" <george.dunlap@citrix.com>,
"Alexandru Isaila" <aisaila@bitdefender.com>,
Xen-devel <xen-devel@lists.xenproject.org>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH v2 for-4.14 1/3] xen/monitor: Control register values
Date: Tue, 2 Jun 2020 07:10:07 -0600 [thread overview]
Message-ID: <CABfawhkB1u2M8RCO0v8uwsur4ZUSThwy_1Uhj=k0UjUdyNZi3Q@mail.gmail.com> (raw)
In-Reply-To: <c7091857-2613-303e-416e-a4778278e428@suse.com>
On Tue, Jun 2, 2020 at 7:00 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 02.06.2020 14:51, Tamas K Lengyel wrote:
> > On Tue, Jun 2, 2020 at 6:47 AM Jan Beulich <jbeulich@suse.com> wrote:
> >>
> >> On 02.06.2020 14:40, Tamas K Lengyel wrote:
> >>> On Tue, Jun 2, 2020 at 5:08 AM Roger Pau Monné <roger.pau@citrix.com> wrote:
> >>>>
> >>>> On Wed, May 20, 2020 at 08:31:52PM -0600, Tamas K Lengyel wrote:
> >>>>> Extend the monitor_op domctl to include option that enables
> >>>>> controlling what values certain registers are permitted to hold
> >>>>> by a monitor subscriber.
> >>>>
> >>>> I think the change could benefit for some more detail commit message
> >>>> here. Why is this useful?
> >>>
> >>> You would have to ask the Bitdefender folks who made the feature. I
> >>> don't use it. Here we are just making it optional as it is buggy so it
> >>> is disabled by default.
> >>
> >> Now that's exactly the opposite of what I had derived from the
> >> description here so far. Perhaps an at least weak indication
> >> that you want to reword this. For example, from your reply to
> >> Roger I understand it's rather that the new flag allows to
> >> "suppress" the controlling (since presumably you don't change
> >> default behavior), rather then "enabling" it.
> >
> > What we are adding is a domctl you need to call that enables this
> > feature. It's not an option to suppress it. It shouldn't have been
> > enabled by default to begin with. That was a mistake when the feature
> > was contributed and it is buggy.
>
> Okay, in this case it's important to point out that you alter
> default behavior. The BitDefender folks may not like this, yet
> they've been surprisingly silent so far.
Well, it was Bitdefender who altered the default behavior. We are
reverting their mistake and making it optional. But I can certainly
make that more clear.
Tamas
next prev parent reply other threads:[~2020-06-02 13:10 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-21 2:31 [PATCH v2 for-4.14 0/3] vm_event: fix race-condition when disabling monitor events Tamas K Lengyel
2020-05-21 2:31 ` [PATCH v2 for-4.14 1/3] xen/monitor: Control register values Tamas K Lengyel
2020-06-02 11:08 ` Roger Pau Monné
2020-06-02 12:40 ` Tamas K Lengyel
2020-06-02 12:47 ` Jan Beulich
2020-06-02 12:51 ` Tamas K Lengyel
2020-06-02 13:00 ` Jan Beulich
2020-06-02 13:10 ` Tamas K Lengyel [this message]
2020-06-03 8:04 ` Roger Pau Monné
2020-06-02 13:01 ` Roger Pau Monné
2020-06-02 13:04 ` Jan Beulich
2020-06-02 13:07 ` Tamas K Lengyel
2020-06-02 13:09 ` Tamas K Lengyel
2020-05-21 2:31 ` [PATCH v2 for-4.14 2/3] xen/vm_event: add vm_event_check_pending_op Tamas K Lengyel
2020-06-02 11:47 ` Roger Pau Monné
2020-06-02 11:50 ` Jan Beulich
2020-06-02 12:43 ` Tamas K Lengyel
2020-05-21 2:31 ` [PATCH v2 for-4.14 3/3] xen/vm_event: Add safe to disable vm_event Tamas K Lengyel
2020-06-02 12:54 ` Roger Pau Monné
2020-06-02 13:06 ` Tamas K Lengyel
2020-06-01 18:58 ` [PATCH v2 for-4.14 0/3] vm_event: fix race-condition when disabling monitor events Tamas K Lengyel
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