From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>, Keir Fraser <keir@xen.org>
Subject: Re: [PATCH 3/3] x86/HVM: make hvm_efer_valid() honor guest features
Date: Fri, 9 Jan 2015 15:36:50 +0000 [thread overview]
Message-ID: <54AFF592.9070308@citrix.com> (raw)
In-Reply-To: <54B002E40200007800053372@mail.emea.novell.com>
On 09/01/15 15:33, Jan Beulich wrote:
>>>> On 09.01.15 at 16:09, <andrew.cooper3@citrix.com> wrote:
>> On 09/01/15 11:20, Jan Beulich wrote:
>>>>>> On 08.01.15 at 19:49, <andrew.cooper3@citrix.com> wrote:
>>>> I think hvm_efer_valid() also needs the current EFER and CR0 to work out
>>>> what the current LMA should be, and reject any attempt to change it.
>>> I.e. this would be needed only for the restore path (and it not being
>>> done hasn't caused problems for me because guests don't normally
>>> get migrated before they fully enabled long mode).
>> Urgh. In the restore case we don't have a current EFER to use. In this
>> case I think it is acceptable to check that new_lma is (new_lme &&
>> !cr4.pg), which allows us to declare that the restore state is
>> consistent (presuming we have already validated cr4).
> I suppose you mean cr0 here, and also new_lma == new_lme && cr0.pg?
Oops yes - I do on both counts.
~Andrew
next prev parent reply other threads:[~2015-01-09 15:36 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-08 15:15 [PATCH 0/3] x86: XSA-111 follow-ups Jan Beulich
2015-01-08 15:22 ` [PATCH 1/3] x86: streamline hypercall_create_continuation() Jan Beulich
2015-01-08 16:01 ` Andrew Cooper
2015-01-08 16:11 ` Jan Beulich
2015-01-08 15:22 ` [PATCH 2/3] x86/HVM: clobber hypercall arguments just like for PV Jan Beulich
2015-01-08 17:20 ` Andrew Cooper
2015-01-08 15:23 ` [PATCH 3/3] x86/HVM: make hvm_efer_valid() honor guest features Jan Beulich
2015-01-08 15:56 ` Tim Deegan
2015-01-08 16:04 ` Jan Beulich
2015-01-08 18:57 ` Andrew Cooper
2015-01-08 18:49 ` Andrew Cooper
2015-01-09 11:20 ` Jan Beulich
2015-01-09 15:09 ` Andrew Cooper
2015-01-09 15:33 ` Jan Beulich
2015-01-09 15:36 ` Andrew Cooper [this message]
2015-01-08 15:53 ` [PATCH 0/3] x86: XSA-111 follow-ups Tim Deegan
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