Re: [PATCH 5.15 00/11] 5.15.48-rc1 review

Tyler Hicks
2022-06-16T03:27:27Z

On 2022-06-14 20:40:29, Greg Kroah-Hartman wrote:
> This is the start of the stable review cycle for the 5.15.48 release.
> There are 11 patches in this series, all will be posted as a response
> to this one. If anyone has any issues with these being applied, please
> let me know.
>
> Responses should be made by Thu, 16 Jun 2022 18:37:02 +0000.
> Anything received after that time might be too late.
>
> The whole patch series can be found in one patch at:
> https://www.kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.15.48-rc1.gz
> or in the git tree and branch at:
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.15.y
> and the diffstat can be found below.
>
> thanks,
>
> greg k-h

Hi Greg - I successfully tested this release candidate in x86_64 Hyper-V
Azure VMs with speculation controls both enabled and disabled.
Speculation controls are passed through to the guest and, of particular
interest for this release candidate, set the FB_CLEAR bit in the
IA32_ARCH_CAPABILITIES MSR.

The FB_CLEAR bit's presence is accurately conveyed in the kernel log
messages during boot and in the
/sys/devices/system/cpu/vulnerabilities/mmio_stale_data file.

I did a full LTP run in both scenarios (the results were the same) and
also compared the results to a previous run against the v5.15.45 release
(there were no regressions).

Tested-by: Tyler Hicks <tyhicks@linux.microsoft.com>

Tyler