From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from a7-12.smtp-out.eu-west-1.amazonses.com (a7-12.smtp-out.eu-west-1.amazonses.com [54.240.7.12]) by mx.groups.io with SMTP id smtpd.web10.42872.1674127527088580854 for ; Thu, 19 Jan 2023 03:25:27 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@ipxe.org header.s=cphpx6z2rfcgehlykjjh3gknqe3hsoe2 header.b=jcGHWYnp; spf=pass (domain: eu-west-1.amazonses.com, ip: 54.240.7.12, mailfrom: 01020185c9c6c541-8649dfa8-c4d7-4fbb-9e15-98af5177ee6b-000000@eu-west-1.amazonses.com) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=cphpx6z2rfcgehlykjjh3gknqe3hsoe2; d=ipxe.org; t=1674127525; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=YtoH5Fju+sa3yyhj3WDVVEU7Y2Gii4C/nROhIBcnMhU=; b=jcGHWYnp1Q5gq9qwtPCq4RdeD+rVJ9/Sv3kE5lHGRI/k2Gz3NdaEuKBTpDYWubGf zwNlclmMuduiFGGDxyyin/8c2trqlFy2igzbEsRfu/9j09ci0Jpfvco6+M9rJh4k7E6 AVfxn+8CErptDdzlp/Av7DSOlvH+eDQzWvy6xd2OQqop/zSyYmPMpR8r4WD1WdKAHUA OB0U7Pk8XeHKJWId5F8+UM5fiGJ6knuGYhBFQ0pJIJjIJjBlcUqM7HdgMLIefeXpwxd A/Ysy+eBXb5FgUqAZgl1xRBfS2oNdvznMT91pIB1vbKRPcKOSXBpT2ZUc6GSyUqusrv 8wHYNo8ELg== DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=ihchhvubuqgjsxyuhssfvqohv7z3u4hn; d=amazonses.com; t=1674127525; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Feedback-ID; bh=YtoH5Fju+sa3yyhj3WDVVEU7Y2Gii4C/nROhIBcnMhU=; b=NxQPTxj36X/OKGYf/8KE3UCdFY9RL++IC94YY7ZOY50Xjy2to0gVx2iWpjnvpOSs 0nlCoobXg01vR5TeOeVRNlUbYCUUp1x5+gR9ITImKXFQl0iR6cO5hIlB7bNbFR5smla ZMPQGzTamVBLMNt7ZYOmYNHROzHpq0bGqLaqzT+Q= Message-ID: <01020185c9c6c541-8649dfa8-c4d7-4fbb-9e15-98af5177ee6b-000000@eu-west-1.amazonses.com> Date: Thu, 19 Jan 2023 11:25:25 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [edk2-devel] [PATCH v3 0/2] OvmfPkg/PlatformInitLib: catch QEMU's CPU hotplug reg block regression To: devel@edk2.groups.io, lersek@redhat.com Cc: Ard Biesheuvel , Brijesh Singh , Erdem Aktas , Gerd Hoffmann , James Bottomley , Jiewen Yao , Jordan Justen , Min Xu , Oliver Steffen , Sebastien Boeuf , Tom Lendacky References: <20230119110131.91923-1-lersek@redhat.com> From: "Michael Brown" In-Reply-To: <20230119110131.91923-1-lersek@redhat.com> X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00, URIBL_DBL_BLOCKED_OPENDNS,URIBL_ZEN_BLOCKED_OPENDNS autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on blyat.fensystems.co.uk Feedback-ID: 1.eu-west-1.fspj4M/5bzJ9NLRzJP0PaxRwxrpZqiDQJ1IF94CF2TA=:AmazonSES X-SES-Outgoing: 2023.01.19-54.240.7.12 Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 19/01/2023 11:01, Laszlo Ersek wrote: >> PlatformCpuCountBugCheck: Present=0 Possible=1 >> PlatformCpuCountBugCheck: Broken CPU hotplug register block found. Update QEMU to version 8+, or >> PlatformCpuCountBugCheck: to a stable release with commit dab30fbef389 backported. Refer to >> PlatformCpuCountBugCheck: . >> PlatformCpuCountBugCheck: Consequences of the QEMU bug may include, but are not limited to: >> PlatformCpuCountBugCheck: - all firmware logic, dependent on the CPU hotplug register block, >> PlatformCpuCountBugCheck: being confused, for example, multiprocessing-related logic; >> PlatformCpuCountBugCheck: - guest OS data loss, including filesystem corruption, due to crash or >> PlatformCpuCountBugCheck: hang during ACPI S3 resume; >> PlatformCpuCountBugCheck: - SMM privilege escalation, by a malicious guest OS or 3rd partty UEFI >> PlatformCpuCountBugCheck: agent, against the platform firmware. >> PlatformCpuCountBugCheck: These symptoms need not necessarily be limited to the QEMU user >> PlatformCpuCountBugCheck: attempting to hot(un)plug a CPU. >> PlatformCpuCountBugCheck: The firmware will now stop (hang) deliberately, in order to prevent the >> PlatformCpuCountBugCheck: above symptoms. >> PlatformCpuCountBugCheck: You can forcibly override the hang, *at your own risk*, with the >> PlatformCpuCountBugCheck: following *experimental* QEMU command line option: >> PlatformCpuCountBugCheck: -fw_cfg name=opt/org.tianocore/X-Cpuhp-Bugcheck-Override,string=yes >> PlatformCpuCountBugCheck: Please only report such bugs that you can reproduce *without* the >> PlatformCpuCountBugCheck: override. Laszlo: thank you for taking the time to deal with this so thoroughly and to see it through to its conclusion. For what it's worth: Hugely-appreciated-by: Michael Brown Thanks, Michael