From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 42F0D25B085 for ; Sun, 20 Sep 2026 09:14:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789895684; cv=none; b=fVFqcNPYNy3/s7EW/v6Z7YfTG0nr6bilSOBhXrTPbMi0sXnNrQCt3NzCIpwKI2MhAjr1LZ4VnhaomSuXADZjavBbxdbIqrqagLc7aUhd0iSWqY4W7Hi+WB/tm5ZH1eu1K64BSz/6Iy6ipCEnlJBwdynyeeGg1Q8RGzqVIG2VYG8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789895684; c=relaxed/simple; bh=wQEzCUSivGHJ8c3rd7iLCcihTRKZrEeJA/Gr+Ea5/sI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qIPGSRRb4ZVcGwYAZnYZK9tiqnSBRCSHEsY4MTsUDMEJFyaDC0Mvmjb/tZ34tEaw68N3MaJfSWMmsfouwwB33LVHzmd+UzxKKj174J0+5/Z3TSmmonOlXoNRe5A4TgqCwyJa4h2U2Tucp8Gkx7/c+kQc3U3eul/oZ/OFmWq+3TM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=kZHBy0+b; arc=none smtp.client-ip=192.198.163.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="kZHBy0+b" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789895683; x=1821431683; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=wQEzCUSivGHJ8c3rd7iLCcihTRKZrEeJA/Gr+Ea5/sI=; b=kZHBy0+b1gPGwkMZACLD3tmaF6CUaNXS/HfnItbc0wL391NVWiTSqleH Ejm67BzWMHVonjV0dPUa9l2NcPUhctuFY1tLBW/J4wCV7JFDDMSvz6ve0 Yn0tgp8391FP68Ti7Uz3mV/C65cFXbJ2o2G72ocjZCft0OIUZmPkxW7TL vo2qvL8APZq1P9hULRyDO9I5NZL5HVaoDNi3a618UGq+PaGdtQ+KqTLHr mcx/B+C5WX0BiZ9CdZIaRKpiPQJAJH6OV6bPpDPW1JAS7aEVdmrA9ZP4C 9j0SSCggqH2jhOWV6rkZBtN/ThDpWFIU1EvCY+lSiqHBfT0VatSOov2Jd Q==; X-CSE-ConnectionGUID: d+MSlQbLQmGeXF4ezxXojw== X-CSE-MsgGUID: VKmdeTNJQq+XjV28iUzGRQ== X-IronPort-AV: E=McAfee;i="6800,10657,11910"; a="905967" X-IronPort-AV: E=Sophos;i="6.27,111,1787036400"; d="scan'208";a="905967" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by fmvoesa115.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2026 02:14:42 -0700 X-CSE-ConnectionGUID: 86mLZJSiR/W+KT04aN9mQA== X-CSE-MsgGUID: Zmx9090hSaSO9by6HGQ/Zw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,111,1787036400"; d="scan'208";a="271357757" Received: from junjie-desk-dev.bj.intel.com ([10.238.152.71]) by fmviesa010-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2026 02:14:36 -0700 From: Junjie Cao To: Manish Honap Cc: alex@shazbot.org, ankita@nvidia.com, jic23@kernel.org, dave.jiang@intel.com, alejandro.lucero-palau@amd.com, smadhavan@nvidia.com, pierrick.bouvier@oss.qualcomm.com, mst@redhat.com, imammedo@redhat.com, anisinha@redhat.com, pbonzini@redhat.com, eric.auger@redhat.com, peter.maydell@linaro.org, richard.henderson@linaro.org, clg@redhat.com, cohuck@redhat.com, kjaju@nvidia.com, vsethi@nvidia.com, zhiw@nvidia.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, linux-cxl@vger.kernel.org, skolothumtho@nvidia.com Subject: Re: [PATCH v2 10/10] hw/pci-host: Emit a _DSM on pxb-cxl to preserve firmware PCI config Date: Sun, 20 Sep 2026 17:14:29 +0800 Message-ID: <20260920091429.717003-1-junjie.cao@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260916184412.3825713-11-mhonap@nvidia.com> References: <20260916184412.3825713-11-mhonap@nvidia.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 17 Sep 2026 00:14:12 +0530, Manish Honap wrote: > under preserve_config, the _DSM. Gate the _DSM on preserve_config: x86 q35 > passes false as it does not use the accelerated SMMU, so it emits no _DSM > and its ACPI tables stay byte for byte what they were. Confirmed: on 28e7aad522 plus the series bios-tables-test passes on x86_64 (q35/cxl and q35/acpihmat-genericx, the v1 failures, included), aarch64, riscv64 and loongarch64. accel=on is out of reach under TCG, so I forced preserve_config on virt locally and booted an arm64 guest (7.3-rc1 based, defconfig) with a cxl-type3 behind a cxl-rp. With this patch Linux keeps the firmware BARs and bridge window under the pxb-cxl; on 09/10 with the same hack it releases and reassigns them. No ACPI errors either way. Tested-by: Junjie Cao 08/10 still says the x86 bridge "still emits the ``_DSM`` method, but its function 0 returns an empty support mask"; that was v1. Junjie