Re: [PATCH v3] i386/cpu: fixup number of addressable IDs for processor cores in the physical package

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

On Tue, Jun 11, 2024 at 11:23:14AM +0800, Chuang Xu wrote:
> Date: Tue, 11 Jun 2024 11:23:14 +0800
> From: Chuang Xu <xuchuangxclwt@bytedance.com>
> Subject: [PATCH v3] i386/cpu: fixup number of addressable IDs for processor
>  cores in the physical package
> X-Mailer: git-send-email 2.24.3 (Apple Git-128)
> 
> When QEMU is started with:
> -cpu host,host-cache-info=on,l3-cache=off \
> -smp 2,sockets=1,dies=1,cores=1,threads=2
> Guest can't acquire maximum number of addressable IDs for processor cores in
> the physical package from CPUID[04H].
> 
> When creating a CPU topology of 1 core per package, host-cache-info only
> uses the Host's addressable core IDs field (CPUID.04H.EAX[bits 31-26]),
> resulting in a conflict (on the multicore Host) between the Guest core
> topology information in this field and the Guest's actual cores number.
> 
> Fix it by removing the unnecessary condition to cover 1 core per package
> case. This is safe because cores_per_pkg will not be 0 and will be at
> least 1.
> 
> Fixes: d7caf13b5fcf ("x86: cpu: fixup number of addressable IDs for logical processors sharing cache")
> Signed-off-by: Guixiong Wei <weiguixiong@bytedance.com>
> Signed-off-by: Yipeng Yin <yinyipeng@bytedance.com>
> Signed-off-by: Chuang Xu <xuchuangxclwt@bytedance.com>
> ---
>  target/i386/cpu.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)

Thanks! LGTM,

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>