From: "Jan Beulich" <JBeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
Wei Liu <wei.liu2@citrix.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [PATCH] libx86: Elide more empty CPUID leaves when serialising a policy
Date: Thu, 23 May 2019 02:33:52 -0600 [thread overview]
Message-ID: <5CE65AF002000078002319A7@prv1-mh.provo.novell.com> (raw)
In-Reply-To: <1558540230-26612-1-git-send-email-andrew.cooper3@citrix.com>
>>> On 22.05.19 at 17:50, <andrew.cooper3@citrix.com> wrote:
> x86_cpuid_copy_to_buffer() currently serialises the full content of the
> various subleaf unions. While leaves 4, 0xb and 0xd don't have a concrete
> max_subleaf field, they do have well defined upper bounds.
>
> Diffing the results of `xen-cpuid -p` shows the resutling saving:
>
> @@ -1,5 +1,5 @@
> Xen reports there are maximum 114 leaves and 1 MSRs
> -Raw policy: 93 leaves, 1 MSRs
> +Raw policy: 38 leaves, 1 MSRs
> CPUID:
> leaf subleaf -> eax ebx ecx edx
> 00000000:ffffffff -> 00000016:756e6547:6c65746e:49656e69
> @@ -32,7 +32,7 @@ Raw policy: 93 leaves, 1 MSRs
> MSRs:
> index -> value
> 000000ce -> 0000000080000000
> -Host policy: 93 leaves, 1 MSRs
> +Host policy: 33 leaves, 1 MSRs
> CPUID:
> leaf subleaf -> eax ebx ecx edx
> 00000000:ffffffff -> 0000000d:756e6547:6c65746e:49656e69
>
> which is mostly due to no longer writing out 64 leaves for xstate when (on
> this CoffeeLake system) 8 will do.
>
> Extend the unit tests to cover empty and partially filled subleaf unions.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
For the lib/x86/ part
Reviewed-by: Jan Beulich <jbeulich@suse.com>
For the test harness part
Acked-by: Jan Beulich <jbeulich@suse.com>
No idea how else I should represent that I didn't look overly closely
at the harness additions.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
WARNING: multiple messages have this Message-ID (diff)
From: "Jan Beulich" <JBeulich@suse.com>
To: "Andrew Cooper" <andrew.cooper3@citrix.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
Wei Liu <wei.liu2@citrix.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH] libx86: Elide more empty CPUID leaves when serialising a policy
Date: Thu, 23 May 2019 02:33:52 -0600 [thread overview]
Message-ID: <5CE65AF002000078002319A7@prv1-mh.provo.novell.com> (raw)
Message-ID: <20190523083352.vkbeUUqWuS5bxY_svCIY0xFBFVGRcxRz94rCB3mFutA@z> (raw)
In-Reply-To: <1558540230-26612-1-git-send-email-andrew.cooper3@citrix.com>
>>> On 22.05.19 at 17:50, <andrew.cooper3@citrix.com> wrote:
> x86_cpuid_copy_to_buffer() currently serialises the full content of the
> various subleaf unions. While leaves 4, 0xb and 0xd don't have a concrete
> max_subleaf field, they do have well defined upper bounds.
>
> Diffing the results of `xen-cpuid -p` shows the resutling saving:
>
> @@ -1,5 +1,5 @@
> Xen reports there are maximum 114 leaves and 1 MSRs
> -Raw policy: 93 leaves, 1 MSRs
> +Raw policy: 38 leaves, 1 MSRs
> CPUID:
> leaf subleaf -> eax ebx ecx edx
> 00000000:ffffffff -> 00000016:756e6547:6c65746e:49656e69
> @@ -32,7 +32,7 @@ Raw policy: 93 leaves, 1 MSRs
> MSRs:
> index -> value
> 000000ce -> 0000000080000000
> -Host policy: 93 leaves, 1 MSRs
> +Host policy: 33 leaves, 1 MSRs
> CPUID:
> leaf subleaf -> eax ebx ecx edx
> 00000000:ffffffff -> 0000000d:756e6547:6c65746e:49656e69
>
> which is mostly due to no longer writing out 64 leaves for xstate when (on
> this CoffeeLake system) 8 will do.
>
> Extend the unit tests to cover empty and partially filled subleaf unions.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
For the lib/x86/ part
Reviewed-by: Jan Beulich <jbeulich@suse.com>
For the test harness part
Acked-by: Jan Beulich <jbeulich@suse.com>
No idea how else I should represent that I didn't look overly closely
at the harness additions.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2019-05-23 8:33 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 15:50 [PATCH] libx86: Elide more empty CPUID leaves when serialising a policy Andrew Cooper
2019-05-22 15:50 ` [Xen-devel] " Andrew Cooper
2019-05-23 8:33 ` Jan Beulich [this message]
2019-05-23 8:33 ` Jan Beulich
2019-05-23 10:38 ` Andrew Cooper
2019-05-23 10:38 ` [Xen-devel] " Andrew Cooper
2019-05-23 10:27 ` [PATCH] libx86: Introduce wrappers for extracting XCR0/XSS from a cpuid policy Andrew Cooper
2019-05-23 10:27 ` [Xen-devel] " Andrew Cooper
2019-05-23 11:52 ` Jan Beulich
2019-05-23 11:52 ` [Xen-devel] " Jan Beulich
2019-05-23 11:59 ` Andrew Cooper
2019-05-23 11:59 ` [Xen-devel] " Andrew Cooper
2019-05-23 12:08 ` Jan Beulich
2019-05-23 12:08 ` [Xen-devel] " Jan Beulich
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5CE65AF002000078002319A7@prv1-mh.provo.novell.com \
--to=jbeulich@suse.com \
--cc=andrew.cooper3@citrix.com \
--cc=roger.pau@citrix.com \
--cc=wei.liu2@citrix.com \
--cc=xen-devel@lists.xenproject.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).