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From: Tamas K Lengyel <tamas@tklengyel.com>
To: Adrian Pop <apop@bitdefender.com>
Cc: Wei Liu <wei.liu2@citrix.com>,
	Razvan Cojocaru <rcojocaru@bitdefender.com>,
	George Dunlap <george.dunlap@eu.citrix.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Ian Jackson <ian.jackson@eu.citrix.com>,
	Vlad Ioan Topan <itopan@bitdefender.com>,
	Jan Beulich <jbeulich@suse.com>,
	Xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH v3 1/2] x86/mm: Change default value for suppress #VE in set_mem_access()
Date: Tue, 18 Jul 2017 11:26:45 -0600	[thread overview]
Message-ID: <CABfawhnZmKOPNKeyg2ibjKUMsGcOXb540twZ8voGz2_73NwAsg@mail.gmail.com> (raw)
In-Reply-To: <20170718152547.14006-2-apop@bitdefender.com>

On Tue, Jul 18, 2017 at 9:25 AM, Adrian Pop <apop@bitdefender.com> wrote:
> From: Vlad Ioan Topan <itopan@bitdefender.com>
>
> The default value for the "suppress #VE" bit set by set_mem_access()
> currently depends on whether the call is made from the same domain (the
> bit is set when called from another domain and cleared if called from
> the same domain). This patch changes that behavior to inherit the old
> suppress #VE bit value if it is already set and to set it to 1
> otherwise, which is safer and more reliable.

With the way things are currently if the in-guest tool calls
set_mem_access for an altp2m view, it implies it wants to receive #VE
for it. Wouldn't this change in this patch effectively make it
impossible for an in-guest tool to decide which pages it wants to
receive #VE for? The new HVMOP you are introducing is only accessible
from a privileged domain..

Tamas

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  reply	other threads:[~2017-07-18 17:27 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-18 15:25 [PATCH v3 0/2] Add a hvmop for setting the #VE suppress bit Adrian Pop
2017-07-18 15:25 ` [PATCH v3 1/2] x86/mm: Change default value for suppress #VE in set_mem_access() Adrian Pop
2017-07-18 17:26   ` Tamas K Lengyel [this message]
2017-07-19 11:47     ` Adrian Pop
2017-07-19 18:24       ` Tamas K Lengyel
2017-07-20 16:43         ` George Dunlap
2017-07-20 16:46           ` Tamas K Lengyel
2017-07-20 16:57             ` George Dunlap
2017-07-20 17:03               ` Tamas K Lengyel
2017-07-20 17:36                 ` Tamas K Lengyel
2017-07-20 18:25             ` Razvan Cojocaru
2017-07-20 18:52               ` Tamas K Lengyel
2017-07-20 19:13                 ` Razvan Cojocaru
2017-07-18 15:25 ` [PATCH v3 2/2] x86/altp2m: Add a hvmop for setting the suppress #VE bit Adrian Pop
2017-07-18 17:19   ` Tamas K Lengyel
2017-07-19 11:47     ` Adrian Pop

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