Re: [PATCH 0/3] target/i386/cpu: Misc Cleanup on host-cache-info

[Zhao Liu]

Hi Igor,

Just a gentle poke and what do you think about this minor series?

Thanks,
Zhao

On Wed, Jun 19, 2024 at 10:42:12PM +0800, Zhao Liu wrote:
> Date: Wed, 19 Jun 2024 22:42:12 +0800
> From: Zhao Liu <zhao1.liu@intel.com>
> Subject: [PATCH 0/3] target/i386/cpu: Misc Cleanup on host-cache-info
> X-Mailer: git-send-email 2.34.1
> 
> Hi,
> 
> This series is mainly to addresss Igor's comment about if one check in
> host-cache-info could be removed [1], i.e., whether Guest's cache
> topology should be self-consistent (able to correspond to Guest's CPU
> topology level, as we currently do with the Guest cache topo).
> 
> I originally thought (in the mail thread with Igor) that host-cache-info
> should allow Guest and Host to have the same topology level information,
> e.g. if Host shares cache on core level, then via host-cache-info, Guest
> should also share on core level.
> 
> But in practice, I gave up on this idea, because in the cache info
> passthrough case, it should be possible for Guest to get the original
> Host cache info (including the original threads sharing cache) without
> further modifying the info to Guest.
> 
> Therefore, I simply added the comment in PATCH 3 to hopefully illustrate
> the need for such a check.
> 
> Hope my explanation is clear enough so that my poor English doesn't
> bother you!
> 
> [1]: 
> https://lore.kernel.org/qemu-devel/20240527170317.14520a2f@imammedo.users.ipa.redhat.com/
> 
> Thanks and Best Regards,
> Zhao
> ---
> Zhao Liu (3):
>   target/i386/cpu: Use hex mask to check for valid cache CPUID leaf
>   target/i386/cpu: Check guest_thread_ids_per_pkg for host-cache-info
>     case
>   target/i386/cpu: Add comment about adjusting the Guest cache topo for
>     host-cache-info
> 
>  target/i386/cpu.c | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)
> 
> -- 
> 2.34.1
> 
>