On 9/28/25 12:41, Paolo Bonzini wrote:
On 9/25/25 18:17, Zhao Liu wrote:
On Tue, Sep 23, 2025 at 12:41:34PM +0200, Paolo Bonzini wrote:
Date: Tue, 23 Sep 2025 12:41:34 +0200
From: Paolo Bonzini <[email protected]>
Subject: [RFT PATCH v2 0/2] Fix cross migration issue with missing
features: pdcm, arch-capabilities
X-Mailer: git-send-email 2.51.0
Add two compatibility properties to restore legacy behavior of
machine types
prior to QEMU 10.1. Each of them addresses the two changes to CPUID:
...>> I found the previous 2 fixes were merged into stable 10.0:
24778b1c7ee7aca9721ed4757b0e0df0c16390f7
3d26cb65c27190e57637644ecf6c96b8c3d246a3
Yes, thanks for noticing it Zhao. Because we cannot apply the machine
type changes to 10.0, those two patches have to be reverted.
Hmm. And I missed this message too, noticed it just now
(right after tagging 10.0.5, - what a shame on me!).
What's the problem with these patches in 10.0.x?
IIRC, 24778b1c7e "target/i386: do not expose ARCH_CAPABILITIES on AMD
CPU" fixed a real issue we've hit, but I don't remember the details
off my head anymore. It can be easily reverted, with the bug it fixed,
returned.
3d26cb65c2 "i386/cpu: Move adjustment of CPUID_EXT_PDCM before
feature_dependencies[] check" seemed innocent enough to me, and it
was on the way of other changes in this same area (notable 53f100eeec
"i386/cpu: Fix number of addressable IDs field.." and its subsequent
fixup). Reverting this one requires some editing.
BTW, I'm Cc'in all involved people when I pick a path to each of
the stable series, - please let me know if I can make this process
more obvious. Also, 10.0.x supposed to be a long-term series.
Thanks!
/mjt
