From: Jan Beulich <jbeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Xen-devel <xen-devel@lists.xenproject.org>,
"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH v2 1/3] x86/pv: Options to disable and/or compile out 32bit PV support
Date: Wed, 29 Apr 2020 15:55:39 +0200 [thread overview]
Message-ID: <6f629cab-e729-5201-3315-130b0a1d3082@suse.com> (raw)
In-Reply-To: <20200429130631.6018-1-andrew.cooper3@citrix.com>
On 29.04.2020 15:06, Andrew Cooper wrote:
> This is the start of some performance and security-hardening improvements,
> based on the fact that 32bit PV guests are few and far between these days.
>
> Ring1 is full of architectural corner cases, such as counting as supervisor
> from a paging point of view. This accounts for a substantial performance hit
> on processors from the last 8 years (adjusting SMEP/SMAP on every privilege
> transition), and the gap is only going to get bigger with new hardware
> features.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> Reviewed-by: Wei Liu <wl@xen.org>
> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
next prev parent reply other threads:[~2020-04-29 13:55 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-17 15:50 [PATCH 0/3] x86/pv: Start to trim 32bit support Andrew Cooper
2020-04-17 15:50 ` [PATCH 1/3] x86/pv: Options to disable and/or compile out 32bit PV support Andrew Cooper
2020-04-20 13:47 ` Roger Pau Monné
2020-04-20 17:31 ` Andrew Cooper
2020-04-20 14:05 ` Jan Beulich
2020-04-20 18:05 ` Andrew Cooper
2020-04-21 6:02 ` Jan Beulich
2020-04-23 17:35 ` Andrew Cooper
2020-04-24 5:28 ` Jürgen Groß
2020-04-27 20:02 ` Andrew Cooper
2020-04-24 6:11 ` Jan Beulich
2020-04-20 14:15 ` Jan Beulich
2020-04-29 13:06 ` [PATCH v2 " Andrew Cooper
2020-04-29 13:55 ` Jan Beulich [this message]
2020-04-17 15:50 ` [PATCH 2/3] x86/pv: Short-circuit is_pv_{32, 64}bit_domain() in !CONFIG_PV32 builds Andrew Cooper
2020-04-20 14:09 ` [PATCH 2/3] x86/pv: Short-circuit is_pv_{32,64}bit_domain() " Jan Beulich
2020-04-29 13:13 ` Andrew Cooper
2020-04-29 13:29 ` Jan Beulich
2020-04-29 13:30 ` Andrew Cooper
2020-04-29 13:37 ` Jan Beulich
2020-04-17 15:50 ` [PATCH 3/3] x86/pv: Compile out compat_gdt in !CONFIG_PV builds Andrew Cooper
2020-04-20 14:12 ` Jan Beulich
2020-04-20 14:39 ` Andrew Cooper
2020-04-20 15:47 ` Jan Beulich
2020-04-20 17:08 ` Andrew Cooper
2020-04-21 6:09 ` Jan Beulich
2020-04-18 13:46 ` [PATCH 0/3] x86/pv: Start to trim 32bit support Wei Liu
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