From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Roger Pau Monne <roger.pau@citrix.com>,
xen-devel <xen-devel@lists.xenproject.org>,
Juergen Gross <jgross@suse.com>,
linux-kernel@vger.kernel.org
Subject: Re: [Xen-devel] [PATCH 4/4] xen/PVH: Remove reserved entry in PVH GDT
Date: Wed, 2 May 2018 11:06:22 -0400 [thread overview]
Message-ID: <ee05bb34-7671-3069-3eb0-f794a2dc68a4@oracle.com> (raw)
In-Reply-To: <5AE9764D02000078001C00BE@prv1-mh.provo.novell.com>
On 05/02/2018 04:26 AM, Jan Beulich wrote:
>>>> On 01.05.18 at 14:34, <boris.ostrovsky@oracle.com> wrote:
>> On 05/01/2018 04:00 AM, Roger Pau Monné wrote:
>>> On Mon, Apr 30, 2018 at 12:23:39PM -0400, Boris Ostrovsky wrote:
>>>> And without it we can't use _BOOT_XX macros any longer so define new ones.
>>> Not being that familiar with Linux internals I'm not sure I see the
>>> benefit of this. Isn't there a risk that some other code is going to
>>> use the __BOOT_XX defines?
>> The startup code we are jumping to loads their own GDT and I don't see
>> any explicit references to segments.
> No explicit references to segments isn't enough: You also need to make
> sure no exceptions at all can occur while loaded selectors and GDT are
> out of sync - in particular NMI might be of concern here (this isn't PV
> after all, where not having a callback registered effectively masks NMI).
How would keeping __BOOT_XX selectors help with NMI? We don't have
anything set up for NMI handling anyway yet, this is all done in x86
startup code later.
-boris
next prev parent reply other threads:[~2018-05-02 15:03 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-30 16:23 [PATCH 0/4] PVH GDT fixes and cleanup Boris Ostrovsky
2018-04-30 16:23 ` [PATCH 1/4] xen/PVH: Replace GDT_ENTRY with explicit constant Boris Ostrovsky
2018-04-30 16:57 ` [Xen-devel] " Roger Pau Monné
2018-04-30 18:07 ` Boris Ostrovsky
2018-05-01 7:53 ` Roger Pau Monné
2018-05-01 12:16 ` Boris Ostrovsky
2018-05-01 11:31 ` David Laight
2018-05-01 12:40 ` Boris Ostrovsky
2018-05-02 8:00 ` [Xen-devel] " Jan Beulich
2018-05-02 14:53 ` Boris Ostrovsky
2018-04-30 16:23 ` [PATCH 2/4] xen/PVH: Use proper CS selector in long mode Boris Ostrovsky
2018-05-02 8:05 ` [Xen-devel] " Jan Beulich
2018-05-02 14:57 ` Boris Ostrovsky
2018-05-02 15:00 ` Jan Beulich
2018-05-02 15:08 ` Boris Ostrovsky
2018-05-02 15:09 ` Jan Beulich
2018-05-02 15:28 ` Andrew Cooper
2018-04-30 16:23 ` [PATCH 3/4] xen/PVH: Set up GS segment for stack canary Boris Ostrovsky
2018-05-02 8:16 ` [Xen-devel] " Jan Beulich
2018-05-02 15:00 ` Boris Ostrovsky
2018-05-02 15:01 ` Jan Beulich
2018-05-02 15:22 ` Boris Ostrovsky
2018-05-02 15:41 ` Jan Beulich
2018-05-02 17:29 ` Boris Ostrovsky
2018-05-03 7:35 ` Jan Beulich
2018-04-30 16:23 ` [PATCH 4/4] xen/PVH: Remove reserved entry in PVH GDT Boris Ostrovsky
2018-05-01 8:00 ` [Xen-devel] " Roger Pau Monné
2018-05-01 12:34 ` Boris Ostrovsky
2018-05-02 8:26 ` Jan Beulich
2018-05-02 15:06 ` Boris Ostrovsky [this message]
2018-05-02 15:07 ` Jan Beulich
2018-05-02 8:19 ` Jan Beulich
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