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[127.0.0.1]) by director1.derp.mail-out.ovh.net (inspect_sender_mail_agent) with SMTP for ; Mon, 21 Sep 2026 13:07:00 +0000 (UTC) Received: from mta3.priv.ovhmail-u1.ea.mail.ovh.net (unknown [10.110.58.168]) by director1.derp.mail-out.ovh.net (Postfix) with ESMTPS id 4hpNmN4r0rz6GrY; Mon, 21 Sep 2026 13:07:00 +0000 (UTC) Received: from mailstore7.priv.ovhmail-u1.ea.mail.ovh.net (unknown [10.1.8.7]) by mta3.priv.ovhmail-u1.ea.mail.ovh.net (Postfix) with ESMTP id C7A14941C53; Mon, 21 Sep 2026 13:06:59 +0000 (UTC) Date: Mon, 21 Sep 2026 13:06:59 +0000 (UTC) From: Support TRINITY To: Thorsten Leemhuis Cc: regressions , linux-acpi , linux-pm , stable , xen-devel , linux-kernel Message-ID: <8375109.285919554.1789996019673.JavaMail.zimbra@trinity-net.com> In-Reply-To: <8aaad113-1952-4655-978d-0cdd8b048064@leemhuis.info> References: <905771062.272724286.1789919301858.JavaMail.zimbra@trinity-net.com> <8aaad113-1952-4655-978d-0cdd8b048064@leemhuis.info> Subject: Re: [REGRESSION] ACPI processor/cpuidle change in 6.18.52 breaks bare-metal Xen dom0 boot Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Authenticated-User: support@trinity-net.com Thread-Topic: ACPI processor/cpuidle change in 6.18.52 breaks bare-metal Xen dom0 boot Thread-Index: xFt9ystRsn0Dmv4s3yH1kJqjVpPWwg== x-ovh-tracer-id: 3167156440896468507 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: 0 X-VR-SPAMCAUSE: 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 DKIM-Signature: a=rsa-sha256; bh=QD4uKSRlS28zp5D1m/z675fqJs3w1celrAPe2tovDvQ=; c=relaxed/relaxed; d=trinity-net.com; h=From; s=ovhmo-selector-1; t=1789996021; v=1; b=vTiMaFm6OJNBaQJZhBE6oZXC6f+0KXjkr0BPkQ0mDJ9O0sKMaJAAUVD8gVPYo2XQXRZHoEVY woIukHkU1/wY4grSFnD1ep7In4CdeKPQfEC8dpZ6xkYSIK0J6RUc3ykHMxt13Hycc7+593qgcxP 9qEwYu6k6BvnPWRAut4BRcVnH32ar2bmS85enSKkK3c36/6nrL0VCyrscLliGcMZ2dkMN8MAokS XCuI+DJ69RWcpSpVD+s+mdNZPBcGXsPloVYNG/Mye6bTjmlx82d2id5VliQG8KYGRjSIi8hX8/u 7kW1WAQKTjB101q9b4AW3pJ3pEM2+GmieCKPhv6F0wsZw== Hello Thorsten, Thanks for the follow-up. I have not tested latest 7.3-rc yet. So far, the regression was only tested= and isolated on the Alpine linux-lts 6.18.51 -> 6.18.52 path. I will now test: latest 7.3-rc as-is on the affected bare-metal Xen dom0 host; latest 7.3-rc with the same partial ACPI processor/cpuidle lifecycle revert= applied. I will report back with the results. Regards, Tony -----Message original----- De: Thorsten Leemhuis =C3=A0: Support TRINITY ; regressions ; linux-acpi ; linux-pm ; stable ; xen-devel ; linux-kernel Envoy=C3=A9: lundi 21 septembre 2026 12:01 CEST Sujet : Re: [REGRESSION] ACPI processor/cpuidle change in 6.18.52 breaks ba= re-metal Xen dom0 boot On 9/20/26 17:48, Support TRINITY wrote: > > I am reporting a bare-metal *Xen* dom0 boot regression seen with *Linux > 6.18.52.* Thx for the report. There is one somewhat important detail that was missing (hope I didn't miss it): Is latest 7.3-rc also affected? And if it is: does that partial revert help there, too? Ciao, Thorsten > On affected systems, Linux 6.18.51 boots successfully as Xen dom0 on > bare metal, while Linux 6.18.52 *consistently black-screens before dom0 > userspace/networking comes up.* >=20 > #regzbot introduced: v6.18.51..v6.18.52 > #regzbot title: ACPI processor/cpuidle lifecycle change breaks bare- > metal Xen dom0 boot > #regzbot link: https://gitlab.alpinelinux.org/alpine/aports/-/ > work_items/18447 work_items/18447> >=20 > Tested results: >=20 > * Linux 6.18.51-r0, Xen dom0, bare metal: boots > * Linux 6.18.52-r0, Xen dom0, bare metal: black screen before > userspace/network > * Linux 6.18.52-r0, Xen domU: boots > * Linux 6.18.52-r0 with Xenbus notifier change reverted: still fails > * Linux 6.18.52-r0 with only ACPI processor/cpuidle changes reverted: > boots > * Linux 6.18.52-r0 with refined ACPI idle lifecycle patch: boots >=20 > Affected hardware tested: >=20 > * Intel Core i7-4785T thin mini-ITX, 16 GB DDR3 > * Intel N305 thin mini-ITX, 16 GB DDR5 > * Supermicro / Intel Xeon E5-1650, 32 GB DDR3 >=20 > The successful boot used the regular Xen command line: >=20 > multiboot2 /boot/xen.gz cpufreq=3Dxen:performance > module2 /boot/vmlinuz-lts modules=3Dloop,squashfs,sd-mod,usb-storage,xfs = quiet > module2 /boot/initramfs-lts >=20 > No IOMMU workaround, serial console parameter, debug parameter, storage > workaround, or Xen command-line change was required. >=20 > The regression was narrowed to *ACPI processor/cpuidle* changes between > 6.18.51 and 6.18.52, specifically the idle-driver registration lifecycle. >=20 > The working 6.18.51-style behavior registers the ACPI idle driver from > *acpi_processor_power_init()* and unregisters it from > *acpi_processor_power_exit().* >=20 > The failing 6.18.52 behavior registers the ACPI idle driver globally > from *acpi_processor_driver_init()* before *driver_register().* >=20 > A first ACPI-only revert confirmed the regression source. A refined > candidate patch was then prepared to preserve the working ACPI idle > lifecycle while keeping unrelated 6.18.52 safety fixes, including: >=20 > * _LPI bounds checks > * cpufreq notifier cleanup on *acpi_processor_driver_init()* failure >=20 > The refined candidate patch modifies only: >=20 > * *drivers/acpi/processor_driver.c* > * *drivers/acpi/processor_idle.c* > * *include/acpi/processor.h* >=20 > It does not modify Xen, Xenbus, IOMMU, APIC, PCI/ASPM, intel_idle, > syscore, USB, storage, XFS, networking, printk, or the cpuidle core API. >=20 > The earlier cpuidle_disabled() workaround is not included. >=20 > The refined patch has been rebuilt and boot-tested successfully as Xen > dom0 on bare metal on TRINITY-EDGE. >=20 > This issue is currently visible to *Alpine* users because the *Alpine > v3.24 *stable repository contains: >=20 > alpine-release 3.24.2-r0 > *linux-lts 6.18.52-r0* >=20 > Systems tracking Alpine 3.24 stable / latest-stable may therefore > receive Linux 6.18.52 as the default LTS kernel. >=20 > Attachments: >=20 > * revert-acpi-idle-registration-lifecycle.patch > * APKBUILD >=20 > The original Alpine report is here: >=20 > https://gitlab.alpinelinux.org/alpine/aports/-/work_items/18447 > >=20 > Please let me know if this should be submitted as a formal patch with > Signed-off-by, or if there is a better upstream fix/dependency that > should be backported instead. >=20 > Regards, >=20 > *Tony BONNIN* >=20 #regzbot introduced: 6cffb59ee50ea4