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 07:07:57 -0600 [thread overview]
Message-ID: <CABfawhnQcpBF0dB17YDet+PP3ER7e9RdeROknzb-4oNZqsG4dA@mail.gmail.com> (raw)
In-Reply-To: <f6b6fbe0-b917-2e25-de32-999671101928@suse.com>
On Tue, Jun 2, 2020 at 7:04 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 02.06.2020 15:01, Roger Pau Monné wrote:
> > On Tue, Jun 02, 2020 at 06:40:12AM -0600, 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:
> >>>> --- a/xen/arch/x86/hvm/hvm.c
> >>>> +++ b/xen/arch/x86/hvm/hvm.c
> >>>> @@ -2263,7 +2263,8 @@ int hvm_set_cr0(unsigned long value, bool may_defer)
> >>>> {
> >>>> ASSERT(v->arch.vm_event);
> >>>>
> >>>> - if ( hvm_monitor_crX(CR0, value, old_value) )
> >>>> + if ( hvm_monitor_crX(CR0, value, old_value) &&
> >>>> + v->domain->arch.monitor.control_register_values )
> >>>> {
> >>>> /* The actual write will occur in hvm_do_resume(), if permitted. */
> >>>> v->arch.vm_event->write_data.do_write.cr0 = 1;
> >>>> @@ -2362,7 +2363,8 @@ int hvm_set_cr3(unsigned long value, bool may_defer)
> >>>> {
> >>>> ASSERT(v->arch.vm_event);
> >>>>
> >>>> - if ( hvm_monitor_crX(CR3, value, old) )
> >>>> + if ( hvm_monitor_crX(CR3, value, old) &&
> >>>> + v->domain->arch.monitor.control_register_values )
> >>>> {
> >>>> /* The actual write will occur in hvm_do_resume(), if permitted. */
> >>>> v->arch.vm_event->write_data.do_write.cr3 = 1;
> >>>> @@ -2443,7 +2445,8 @@ int hvm_set_cr4(unsigned long value, bool may_defer)
> >>>> {
> >>>> ASSERT(v->arch.vm_event);
> >>>>
> >>>> - if ( hvm_monitor_crX(CR4, value, old_cr) )
> >>>> + if ( hvm_monitor_crX(CR4, value, old_cr) &&
> >>>> + v->domain->arch.monitor.control_register_values )
> >>>
> >>> I think you could return control_register_values in hvm_monitor_crX
> >>> instead of having to add the check to each caller?
> >>
> >> We could, but this way the code is more consistent.
> >
> > OK, I guess it's a matter of taste. I would rather prefer those checks
> > to be confined to hvm_monitor_crX because then the generic code is not
> > polluted with monitor checks, but that's likely just my taste.
>
> +1
OK.
next prev parent reply other threads:[~2020-06-02 13:08 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
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 [this message]
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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