From: "Moger, Babu" <bmoger@amd.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>,
"Michael Tokarev" <mjt@tls.msk.ru>
Cc: Babu Moger <babu.moger@amd.com>,
pbonzini@redhat.com, richard.henderson@linaro.org,
weijiang.yang@intel.com, philmd@linaro.org, dwmw@amazon.co.uk,
paul@xen.org, joao.m.martins@oracle.com, qemu-devel@nongnu.org,
mtosatti@redhat.com, kvm@vger.kernel.org, mst@redhat.com,
marcel.apfelbaum@gmail.com, yang.zhong@intel.com,
jing2.liu@intel.com, vkuznets@redhat.com, michael.roth@amd.com,
wei.huang2@amd.com, bdas@redhat.com, eduardo@habkost.net,
qemu-stable <qemu-stable@nongnu.org>
Subject: Re: [PATCH v3] target/i386: Fix CPUID encoding of Fn8000001E_ECX
Date: Fri, 10 May 2024 15:03:55 -0500 [thread overview]
Message-ID: <531146c2-9a9e-f84d-1301-8e069785248a@amd.com> (raw)
In-Reply-To: <Zj3WhjDW9YBW7LP8@redhat.com>
Hi Daniel,
On 5/10/2024 3:10 AM, Daniel P. Berrangé wrote:
> On Fri, May 10, 2024 at 11:05:44AM +0300, Michael Tokarev wrote:
>> 09.05.2024 17:11, Daniel P. Berrangé wrote:
>>> On Thu, May 09, 2024 at 04:54:16PM +0300, Michael Tokarev wrote:
>>>> 03.05.2024 20:46, Babu Moger wrote:
>>
>>>>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>>>>> index 08c7de416f..46235466d7 100644
>>>>> --- a/hw/i386/pc.c
>>>>> +++ b/hw/i386/pc.c
>>>>> @@ -81,6 +81,7 @@
>>>>> GlobalProperty pc_compat_9_0[] = {
>>>>> { TYPE_X86_CPU, "guest-phys-bits", "0" },
>>>>> { "sev-guest", "legacy-vm-type", "true" },
>>>>> + { TYPE_X86_CPU, "legacy-multi-node", "on" },
>>>>> };
>>>>
>>>> Should this legacy-multi-node property be added to previous
>>>> machine types when applying to stable? How about stable-8.2
>>>> and stable-7.2?
>>>
>>> machine types are considered to express a fixed guest ABI
>>> once part of a QEMU release. Given that we should not be
>>> changing existing machine types in stable branches.
>>
>> Yes, I understand this, and this is exactly why I asked.
>> The change in question has been Cc'ed to stable. And I'm
>> trying to understand what should I do with it :)
>>
>>> In theory we could create new "bug fix" machine types in stable
>>> branches. To support live migration, we would then need to also
>>> add those same stable branch "bug fix" machine type versions in
>>> all future QEMU versions. This is generally not worth the hassle
>>> of exploding the number of machine types.
>>>
>>> If you backport the patch, minus the machine type, then users
>>> can still get the fix but they'll need to manually set the
>>> property to enable it.
>>
>> I don't think this makes big sense. But maybe for someone who
>> actually hits this issue such backport will let to fix it.
>> Hence, again, I'm asking if it really a good idea to pick this
>> up for stable (any version of, - currently there are 2 active
>> series, 7.2, 8.2 and 9.0).
>
> Hmm, the description says
>
> "Observed the following failure while booting the SEV-SNP guest"
>
> and yet the patches for SEV-SNP are *not* merged in QEMU yet. So this
> does not look relevant for stable unless I'm missing something.
I have not thought thru about stable tag. This is not critical for
stable release.
If required I will send a separate patch for stable later. It is not
required right now. Sorry about the noise.
--
- Babu Moger
prev parent reply other threads:[~2024-05-10 20:04 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-02 23:17 [PATCH v2] target/i386: Fix CPUID encoding of Fn8000001E_ECX Babu Moger
2024-03-22 19:18 ` Moger, Babu
2024-05-03 17:46 ` [PATCH v3] " Babu Moger
2024-05-04 11:58 ` Paolo Bonzini
2024-05-09 13:54 ` Michael Tokarev
2024-05-09 14:11 ` Daniel P. Berrangé
2024-05-10 8:05 ` Michael Tokarev
2024-05-10 8:10 ` Daniel P. Berrangé
2024-05-10 20:03 ` Moger, Babu [this message]
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=531146c2-9a9e-f84d-1301-8e069785248a@amd.com \
--to=bmoger@amd.com \
--cc=babu.moger@amd.com \
--cc=bdas@redhat.com \
--cc=berrange@redhat.com \
--cc=dwmw@amazon.co.uk \
--cc=eduardo@habkost.net \
--cc=jing2.liu@intel.com \
--cc=joao.m.martins@oracle.com \
--cc=kvm@vger.kernel.org \
--cc=marcel.apfelbaum@gmail.com \
--cc=michael.roth@amd.com \
--cc=mjt@tls.msk.ru \
--cc=mst@redhat.com \
--cc=mtosatti@redhat.com \
--cc=paul@xen.org \
--cc=pbonzini@redhat.com \
--cc=philmd@linaro.org \
--cc=qemu-devel@nongnu.org \
--cc=qemu-stable@nongnu.org \
--cc=richard.henderson@linaro.org \
--cc=vkuznets@redhat.com \
--cc=wei.huang2@amd.com \
--cc=weijiang.yang@intel.com \
--cc=yang.zhong@intel.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).