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From: "Roger Pau Monné" <roger.pau@citrix.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>, Wei Liu <wl@xen.org>,
	Ian Jackson <iwj@xenproject.org>
Subject: Re: [PATCH][4.15] x86: mirror compat argument translation area for 32-bit PV
Date: Mon, 22 Feb 2021 12:35:21 +0100	[thread overview]
Message-ID: <YDOW+ftkNsG2RH3C@Air-de-Roger> (raw)
In-Reply-To: <bdedf018-b6c4-d0da-fb4b-8cf2d048c3b1@suse.com>

On Mon, Feb 22, 2021 at 11:27:07AM +0100, Jan Beulich wrote:
> Now that we guard the entire Xen VA space against speculative abuse
> through hypervisor accesses to guest memory, the argument translation
> area's VA also needs to live outside this range, at least for 32-bit PV
> guests. To avoid extra is_hvm_*() conditionals, use the alternative VA
> uniformly.

Since you are double mapping the per-domain virtual area, won't it
make more sense to map it just once outside of the Xen virtual space
area? (so it's always using PML4_ADDR(511))

Is there anything concerning in the per-domain area that should be
protected against speculative accesses?

Thanks, Roger.


  parent reply	other threads:[~2021-02-22 11:35 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-22 10:27 [PATCH][4.15] x86: mirror compat argument translation area for 32-bit PV Jan Beulich
2021-02-22 11:26 ` Ian Jackson
2021-02-22 11:35 ` Roger Pau Monné [this message]
2021-02-22 14:12   ` Jan Beulich
2021-02-22 14:13   ` Roger Pau Monné
2021-02-22 14:20     ` Jan Beulich
2021-02-22 14:46       ` Roger Pau Monné
2021-02-22 14:14 ` Andrew Cooper
2021-02-22 14:22   ` Jan Beulich
2021-02-22 16:47     ` Andrew Cooper
2021-02-22 19:36       ` Roger Pau Monné
2021-02-23  7:13       ` Jan Beulich
2021-02-24 19:04         ` Andrew Cooper

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