From nobody Mon Feb 9 13:57:46 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 9065F14830F for ; Tue, 27 Feb 2024 18:17:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709057822; cv=none; b=DsDOTcbW2mBUA3LL+noJRyf3z5+8FxpQUgsIzkxzEA7dceGmcPYom9cAZZVyW8NiGXYiYQcNGgIug2zHw2WKVRpNrrCMu0by9E3HYD0lj+D98d0GM83tnRrAy5wi154fJEi4+ByILc1EQjx4xTHcBf29xtg/z/Va5Ge+zKaMZ7A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709057822; c=relaxed/simple; bh=9DcFlB+EMYNkp2N6OZv2c5TmDu3Stsj7JMO1CUBiP2Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UK4QMKvxnSQZfMqH1eIpPxfnFhSpvgMFG3oE5eKun7ptTwW5q4K/1u0DekiXAGQQfD6B+DPjpVJ2somEoMtSREOno3GN9h6CTV0B6thOdwdOkt5IR0csguexo9QbTTrwdJMTw1HFIKnaN53MX4tO80DCWSI2zKH4Y1lXUOg+jaY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.helo=mgamail.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=QrnLl6wo; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.helo=mgamail.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="QrnLl6wo" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1709057820; x=1740593820; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9DcFlB+EMYNkp2N6OZv2c5TmDu3Stsj7JMO1CUBiP2Q=; b=QrnLl6wo/nWJVEO3+WyG7XtARE55HsfWFKBZ/IAyJa5jlFKaghK8O46a RdoHtm94wuMVe4e86J5V92r2tgTvuagdHsZJdpV3VwAqGxfpVKejLtCBU st/wAlczEHfI4AbVSyMc2JgcPUrgyGclLbslbLyppYa7Hp5S2IoyyBlAh /SMR3fTwh1xtb1ZT1uIUjyPUmCU3GCc+GzxAHGQGfkodsuSjUxvze/g+b Kln8P0hRKBbAYK2PKlMAKncRCm4qFXc36rK8Zw6yNqu4gX2Jih5zQFXe9 wbOXXy3AGmy/TEwoJh6szwtb0klEpDuMtCQ1XxLD87FhbWgjarJe30Cdu w==; X-IronPort-AV: E=McAfee;i="6600,9927,10996"; a="20966113" X-IronPort-AV: E=Sophos;i="6.06,188,1705392000"; d="scan'208";a="20966113" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Feb 2024 10:16:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10996"; a="937032729" X-IronPort-AV: E=Sophos;i="6.06,188,1705392000"; d="scan'208";a="937032729" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 27 Feb 2024 10:16:26 -0800 Received: by black.fi.intel.com (Postfix, from userid 1000) id CBF8D9DB; Tue, 27 Feb 2024 20:16:19 +0200 (EET) From: "Kirill A. Shutemov" To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "Huang, Kai" , Baoquan He , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv8 11/16] x86/mm: Make e820_end_ram_pfn() cover E820_TYPE_ACPI ranges Date: Tue, 27 Feb 2024 20:16:11 +0200 Message-ID: <20240227181616.3032032-12-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240227181616.3032032-1-kirill.shutemov@linux.intel.com> References: <20240227181616.3032032-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" e820__end_of_ram_pfn() is used to calculate max_pfn which, among other things, guides where direct mapping ends. Any memory above max_pfn is not going to be present in the direct mapping. e820__end_of_ram_pfn() finds the end of the ram based on the highest E820_TYPE_RAM range. But it doesn't includes E820_TYPE_ACPI ranges into calculation. Despite the name, E820_TYPE_ACPI covers not only ACPI data, but also EFI tables and might be required by kernel to function properly. Usually the problem is hidden because there is some E820_TYPE_RAM memory above E820_TYPE_ACPI. But crashkernel only presents pre-allocated crash memory as E820_TYPE_RAM on boot. If the preallocated range is small, it can fit under the last E820_TYPE_ACPI range. Modify e820__end_of_ram_pfn() and e820__end_of_low_ram_pfn() to cover E820_TYPE_ACPI memory. The problem was discovered during debugging kexec for TDX guest. TDX guest uses E820_TYPE_ACPI to store the unaccepted memory bitmap and pass it between the kernels on kexec. Signed-off-by: Kirill A. Shutemov --- arch/x86/kernel/e820.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index fb8cf953380d..99c80680dc9e 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -827,7 +827,7 @@ u64 __init e820__memblock_alloc_reserved(u64 size, u64 = align) /* * Find the highest page frame number we have available */ -static unsigned long __init e820_end_pfn(unsigned long limit_pfn, enum e82= 0_type type) +static unsigned long __init e820_end_ram_pfn(unsigned long limit_pfn) { int i; unsigned long last_pfn =3D 0; @@ -838,7 +838,8 @@ static unsigned long __init e820_end_pfn(unsigned long = limit_pfn, enum e820_type unsigned long start_pfn; unsigned long end_pfn; =20 - if (entry->type !=3D type) + if (entry->type !=3D E820_TYPE_RAM && + entry->type !=3D E820_TYPE_ACPI) continue; =20 start_pfn =3D entry->addr >> PAGE_SHIFT; @@ -864,12 +865,12 @@ static unsigned long __init e820_end_pfn(unsigned lon= g limit_pfn, enum e820_type =20 unsigned long __init e820__end_of_ram_pfn(void) { - return e820_end_pfn(MAX_ARCH_PFN, E820_TYPE_RAM); + return e820_end_ram_pfn(MAX_ARCH_PFN); } =20 unsigned long __init e820__end_of_low_ram_pfn(void) { - return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_TYPE_RAM); + return e820_end_ram_pfn(1UL << (32 - PAGE_SHIFT)); } =20 static void __init early_panic(char *msg) --=20 2.43.0