Re: [PATCH v4] target/i386: Fix model number of Zhaoxin YongFeng vCPU template

[Zhao Liu <zhao1.liu@intel.com>]

On Wed, May 07, 2025 at 02:30:50PM +0300, Michael Tokarev wrote:
> Date: Wed, 7 May 2025 14:30:50 +0300
> From: Michael Tokarev <mjt@tls.msk.ru>
> Subject: Re: [PATCH v4] target/i386: Fix model number of Zhaoxin YongFeng
>  vCPU template
> 
> On 25.04.2025 14:14, Ewan Hai wrote:
> > On 4/24/25 3:25 PM, Michael Tokarev wrote:
> > > 
> > > On 15.04.2025 05:45, Ewan Hai wrote:
> > > > The model number was mistakenly set to 0x0b (11) in commit ff04bc1ac4.
> > > > The correct value is 0x5b. This mistake occurred because the extended
> > > > model bits in cpuid[eax=0x1].eax were overlooked, and only the base
> > > > model was used.
> > > > 
> > > > Using the wrong model number can affect guest behavior. One known issue
> > > > is that vPMU (which relies on the model number) may fail to operate
> > > > correctly.
> > > > 
> > > > This patch corrects the model field by introducing a new vCPU version.
> > > > 
> > > > Additionally, it adds a "Preferred CPU models for Zhaoxin x86 hosts"
> > > > section in docs/system/cpu-models-x86.rst.inc to recommend the
> > > > appropriate Zhaoxin CPU model(s).
> > > > 
> > > > Fixes: ff04bc1ac4 ("target/i386: Introduce Zhaoxin Yongfeng CPU model")
> > > > Signed-off-by: Ewan Hai <ewanhai-oc@zhaoxin.com>
> > > > Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
> > > 
> > > Is it a qemu-stable material (for 10.0.x)?
> > > 
> > > I'm picking this one up, please let me know if I should not.
> > 
> > I'm not sure if this should go into qemu-stable. Maybe Paolo Bonzini or
> > Zhao can answer?
> 
> Ping?  Paolo, Zhao, - can you comment please?

Sorry for late. Though I didn't find the similar case, without this
patch, the original model can't support vPMU function correctly.

Therefore I think it makes sense to include this patch into stable QEMU,
so that the Zhaoxin user could have a normal CPU model.

Thanks,
Zhao