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{ "id": 2234272, "url": "http://patchwork.ozlabs.org/api/1.2/covers/2234272/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/cover/20260507040153.14565-1-matthew@pq.io/", "project": { "id": 14, "url": "http://patchwork.ozlabs.org/api/1.2/projects/14/?format=api", "name": "QEMU Development", "link_name": "qemu-devel", "list_id": "qemu-devel.nongnu.org", "list_email": "qemu-devel@nongnu.org", "web_url": "", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260507040153.14565-1-matthew@pq.io>", "list_archive_url": null, "date": "2026-05-07T04:01:51", "name": "[0/2] hw/misc/applesmc: fix GET_KEY_BY_INDEX iteration and populate Apple SMC key set", "submitter": { "id": 93356, "url": "http://patchwork.ozlabs.org/api/1.2/people/93356/?format=api", "name": "Matthew Jackson", "email": "matthew@pq.io" }, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/cover/20260507040153.14565-1-matthew@pq.io/mbox/", "series": [ { "id": 503191, "url": "http://patchwork.ozlabs.org/api/1.2/series/503191/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=503191", "date": "2026-05-07T04:01:53", "name": "hw/misc/applesmc: fix GET_KEY_BY_INDEX iteration and populate Apple SMC key set", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/503191/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2234272/comments/", "headers": { "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=pq.io header.i=@pq.io header.a=rsa-sha256\n header.s=protonmail3 header.b=cvk5XdPD;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4gBDlf3l6Zz1y04\n\tfor <incoming@patchwork.ozlabs.org>; Fri, 08 May 2026 00:14:38 +1000 (AEST)", "from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists1p.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from <qemu-devel-bounces@nongnu.org>)\n\tid 1wKzU5-00077k-14; Thu, 07 May 2026 10:13:49 -0400", "from eggs.gnu.org ([2001:470:142:3::10])\n by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <matthew@pq.io>) id 1wKpwG-0005nf-L3\n for qemu-devel@nongnu.org; Thu, 07 May 2026 00:02:16 -0400", "from mail-07.mail-europe.com ([188.165.51.139])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <matthew@pq.io>) id 1wKpwE-0004lS-5R\n for qemu-devel@nongnu.org; Thu, 07 May 2026 00:02:16 -0400" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=pq.io;\n s=protonmail3; t=1778126518; x=1778385718;\n bh=n5bvQTa+HhPEB+e9FnWjsqkmI3WPI9djj3iISzogovg=;\n h=From:To:Cc:Subject:Date:Message-ID:From:To:Cc:Date:Subject:\n Reply-To:Feedback-ID:Message-ID:BIMI-Selector;\n b=cvk5XdPDJY8GMljfeqYmwahxdQ41zrU5/xbabwRxdxEy9o+AWi8jJZN8ptSeqOG9x\n YZdEWO6IwFDC3sqcXqRPCbOz96d3I4Im3O2S2LS+1nxmMVBmMgpxMSSRSWUBR0i7AW\n F+6eSxn+0zk+Yeb339iLsyY9bVERpjmcnOVApfqa10v7/rAky6cAPUx+1BQ83ZPusk\n 1Z2YG9Rs/uY/vZtkjTEJwCoBJw4+SBU24E7LdGX3Z1zLlT2gwb3inhCSiCJmPGhPeR\n 6RpAC6rnxfpz3poR5BYgOV0ZyY9HH20ghFiRrm/4X0H6N5OlVC4cuTRLbdAL5+t/qS\n MzE07CHmiM73g==", "X-Pm-Submission-Id": "4g9z8j2rWhz1DF77", "From": "Matthew Jackson <matthew@pq.io>", "To": "qemu-devel@nongnu.org", "Cc": "stefanha@redhat.com", "Subject": "[PATCH 0/2] hw/misc/applesmc: fix GET_KEY_BY_INDEX iteration and\n populate Apple SMC key set", "Date": "Wed, 6 May 2026 21:01:51 -0700", "Message-ID": "<20260507040153.14565-1-matthew@pq.io>", "X-Mailer": "git-send-email 2.50.1", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "Received-SPF": "pass client-ip=188.165.51.139; envelope-from=matthew@pq.io;\n helo=mail-07.mail-europe.com", "X-Spam_score_int": "-27", "X-Spam_score": "-2.8", "X-Spam_bar": "--", "X-Spam_report": "(-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,\n DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=0.001, SPF_HELO_NONE=0.001,\n SPF_PASS=-0.001 autolearn=ham autolearn_force=no", "X-Spam_action": "no action", "X-Mailman-Approved-At": "Thu, 07 May 2026 10:13:40 -0400", "X-BeenThere": "qemu-devel@nongnu.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "qemu development <qemu-devel.nongnu.org>", "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>", "List-Archive": "<https://lists.nongnu.org/archive/html/qemu-devel>", "List-Post": "<mailto:qemu-devel@nongnu.org>", "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>", "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=subscribe>", "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org", "Sender": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org" }, "content": "The QEMU applesmc device implements just enough of the Apple SMC PMIO\nprotocol to satisfy the OSK boot check on older macOS versions. On\nmodern macOS guests (x86 10.14+, all of the 15.x series) the real\nAppleSMC kext enumerates the SMC key space at boot via\nAPPLESMC_GET_KEY_BY_INDEX_CMD (0x12). The current device only\nacknowledges APPLESMC_READ_CMD (0x10) at the command port; every\nother command falls through to the default arm of the switch and\nsets ST_1E_BAD_CMD.\n\nThe macOS driver interprets the resulting 0x82 reply as \"spurious\ndata\" and enters a retry loop that floods the kernel log with\nkSMCSpuriousData (0x81) / kSMCKeyNotFound errors at roughly 1800\nevents per second, pegging kernel_task at ~70% CPU and WindowServer\nat ~509% CPU. This reproduces reliably on any recent macOS 15 guest\nbooted with -device isa-applesmc,osk=<valid-OSK>.\n\nThis two-patch series fixes the protocol-level bug and rounds out\nthe SMC key table to a complete iMac20,1 profile.\n\n Patch 1: protocol-level fix\n - Accept WRITE_CMD, GET_KEY_BY_INDEX_CMD, GET_KEY_TYPE_CMD at the\n command port (in addition to READ_CMD).\n - Implement the indexed-iteration walker (returns real key names\n from s->data_def, or APPLESMC_ST_1E_BAD_INDEX 0xb8 once the\n index is past the end so the guest stops iterating).\n - Implement GET_KEY_TYPE returning a 6-byte type/size/attr\n response matching VirtualSMC's kern_pmio.cpp behaviour.\n - Accept and log WRITE_CMD silently.\n - Replace the unknown-key NOEXIST (0x84) reply with a zeroed\n payload of the requested length, logged at LOG_UNIMP.\n - Route the BAD_CMD path through qemu_log_mask(LOG_GUEST_ERROR).\n - Fix MSSD initialiser typo (\"\\0x3\" -> \"\\x03\"). The original\n literal was three bytes ('\\0', 'x', '3') truncated to one\n ('\\0') by the size argument, so MSSD has been silently\n returning 0 since the device was introduced; the corrected\n value matches what a real iMac20,1 SMC reports.\n\n Patch 2: populate the key table\n - Add 94 keys covering the categories macOS queries on a Sequoia\n 15.7.5 guest: 28 temperature sensors (sp78), 4 fan keys (fpe2),\n 12 power-rail keys, 6 DIMM keys, 11 SMC-internal bookkeeping,\n 13 motion-sensor / wireless, 3 write targets (HE0N/MSDW/NTOK),\n 2 power-management gates (HE2N/WDTC), 8 platform-identity /\n probe keys, plus the Apple-canonical #KEY total-count.\n - Sensor values match a real iMac20,1 idle probe published at\n https://linux-hardware.org/?probe=999fc708a4&log=sensors:\n CPU 40-51 C, GPU 36-42 C, fan at 1200 RPM (= F0Mn idle), etc.\n\nMeasured impact (macOS 15.7.5 guest, iMac20,1 profile):\n\n Metric | Before | After\n -----------------|---------:|------:\n SMC errors / 5s | 9,225 | 2\n kernel_task CPU | 70 % | ~2 %\n WindowServer CPU | 509 % | ~6 %\n\nA note for review on the zero-valued keys in patch 2: the 26 keys\ncovering DIMM / SMC bookkeeping / motion-sensor / wireless rails are\nregistered with present-with-zero values rather than omitted. macOS\ndistinguishes \"absent\" (NOEXIST reply, retry-poll) from \"broken\"\n(present, value 0, accepted-and-ignored). Registering these keys\npresent-with-zero stops the retry-poll behaviour without asserting\nany specific value. If the maintainer prefers a tighter scope for\nthis series I am happy to drop any subset and follow up; the\npresent-with-zero approach was driven by which keys macOS observed\nquerying during boot.\n\nBackwards compatibility: legacy macOS guests (10.11-10.13) which do\nnot iterate the key space via GET_KEY_BY_INDEX boot unchanged. The\noriginal six keys (REV/OSK0/OSK1/NATJ/MSSP/MSSD) are still present\nand respond with the same values, modulo the MSSD typo fix in patch\n1 which corrects MSSD to the value a real iMac20,1 SMC reports.\n\nTested against current master (post v11.0.0). Builds clean on\ngcc-13 / clang-17 with --enable-werror. Sequoia 15.7.5 guest boots\nto login screen with the SMC retry storm absent from the kernel\nlog; smoke test recipe in TESTING.md alongside the series.\n\nMatthew Jackson (2):\n hw/misc/applesmc: fix GET_KEY_BY_INDEX to return real keys, accept\n WRITE/TYPE commands\n hw/misc/applesmc: populate Apple SMC key table\n\n hw/misc/applesmc.c | 344 ++++++++++++++++++++++++++++++++++++++++++++-\n 1 file changed, 337 insertions(+), 7 deletions(-)" }