NACK/Cmt: [SRU][N/J][PATCH 0/1] disable XSAVES workaround

[Thibault Ferrante]

On 03-09-2024 18:55, Bethany Jamison wrote:
> Buglink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2077321

Rejected for the following reasons:
- BugLink has to be in every patch and follow standard format

BugLink: https://bugs.launchpad.net/bugs/<id>

> 
> This patch fixes bug LP#2077321. An older commit (b056346) completely
> disables XSAVES instruction on all AMD ZEN1/2 hardware to avoid a bug
> within that instruction (utilizes XSAVEC instruction instead). This
> method of working around this issue is a bit too broad and causes an
> issue with migrating QEMU VMs from older kernels that use XSAVES to
> newer kernels with XSAVES disabled. This patch implements a commit
> (29ba89f) to improve the workaround. It disables XSAVES only on
> machines that lack a revised piece of microcode that addresses the
> XSAVES bug.
> 
> COMMITS:
> b056346 (x86/CPU/AMD: Disable XSAVES on AMD family 0x17)
> https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/jammy/commit/?id=b0563468eeac88ebc70559d52a0b66efc37e4e9d
> 
> 29ba89f (x86/CPU/AMD: Improve the erratum 1386 workaround)
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=29ba89f1895285f06c333546882e0c5ae9a6df23
> 
> Borislav Petkov (AMD) (1):
>    x86/CPU/AMD: Improve the erratum 1386 workaround
> 
>   arch/x86/include/asm/cpu_device_id.h |  8 ++++++++
>   arch/x86/kernel/cpu/amd.c            | 12 ++++++++++++
>   2 files changed, 20 insertions(+)
> 


--
Thibault