From patchwork Tue May 28 09:55:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 799931 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 E87DE16C694; Tue, 28 May 2024 09:55:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716890144; cv=none; b=E1O+qOXXzUVlPVDjpxuuRkD1wjnXnxiSQSHd9qFbOakV+Y+H8eDCAdveiTHgxsO8XowN3jKaqCU0ShXOkGmVVUEz4mz8Rsrym/UM18SSX3u98FNqKqpW9JuBJH0JrhQrogEQlWBpE0sQIpfu07MoX4FImfZeXuzNIkuF7g3HQ0A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716890144; c=relaxed/simple; bh=DBcJsWV4nfgk/8fw3M6vcKnfFbP1zoB1PzLmLNRfgyE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f0i9SKnXkPjd61s1Uw9Ivd+MhjVHG7PcQyBddeou/ufRN7bXnkS0vcWc/BIJIb/2dvMFzleohD0URpdWZp2IqE5dWthNGx0p0w/zsDI3ebfVC8e7K6ZG6k8nQZ3gebydMMUBRT6iGCdbwi+Fak3rFnSRMsbKMxl5qB1+KAcXT/I= 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=Z3GjFks9; arc=none smtp.client-ip=192.198.163.17 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="Z3GjFks9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1716890143; x=1748426143; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DBcJsWV4nfgk/8fw3M6vcKnfFbP1zoB1PzLmLNRfgyE=; b=Z3GjFks9ZVzeYgFOk9IQ0Tc+Jw3lmIFU8mMT2phjI/USTUBwIwTY4Qqo M/faOhzQiVpDHACdYVgUEtbWu8UfT06HYkZlVlm35sPdWGvhFNCgOlHh+ G6cOSt82PH7KbIjL7S+5XyRAze4CovSr+p+Q4SsjlAIS7i0LFd91fgw1v ZgPYH2yGuY1BKb5b26AzHqn10VzMgodJK7GVJYGPtXoPAr28lG/iicGkP 0XzQDFqZ3beELfSwqrt5Y93GfD3fcbZSdg2pFgmVN0EQ4CJPK7oJH65pN vAXG8BcJkuYqOUSEqiB7s7DpgSkyFjHwVAisoIOQ51CdoEXDTD+9dFqzY g==; X-CSE-ConnectionGUID: 1QBz2EmJQlaAKZtGi6iAvw== X-CSE-MsgGUID: tqMtj6XMRbuBNqCKoZ7GjQ== X-IronPort-AV: E=McAfee;i="6600,9927,11085"; a="13097744" X-IronPort-AV: E=Sophos;i="6.08,194,1712646000"; d="scan'208";a="13097744" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2024 02:55:40 -0700 X-CSE-ConnectionGUID: nYowhn8yRl2agu6ZLQpafw== X-CSE-MsgGUID: K15k1wcAQba0VOJckfd11g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,194,1712646000"; d="scan'208";a="34951742" Received: from black.fi.intel.com ([10.237.72.28]) by fmviesa007.fm.intel.com with ESMTP; 28 May 2024 02:55:34 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id E35768EA; Tue, 28 May 2024 12:55:26 +0300 (EEST) 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" , Ard Biesheuvel , Baoquan He , "H. Peter Anvin" , "Kirill A. Shutemov" , "K. Y. Srinivasan" , Haiyang Zhang , kexec@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-acpi@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCHv11 13/19] x86/mm: Do not zap page table entries mapping unaccepted memory table during kdump. Date: Tue, 28 May 2024 12:55:16 +0300 Message-ID: <20240528095522.509667-14-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240528095522.509667-1-kirill.shutemov@linux.intel.com> References: <20240528095522.509667-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Ashish Kalra During crashkernel boot only pre-allocated crash memory is presented as E820_TYPE_RAM. This can cause page table entries mapping unaccepted memory table to be zapped during phys_pte_init(), phys_pmd_init(), phys_pud_init() and phys_p4d_init() as SNP/TDX guest use E820_TYPE_ACPI to store the unaccepted memory table and pass it between the kernels on kexec/kdump. E820_TYPE_ACPI covers not only ACPI data, but also EFI tables and might be required by kernel to function properly. The problem was discovered during debugging kdump for SNP guest. The unaccepted memory table stored with E820_TYPE_ACPI and passed between the kernels on kdump was getting zapped as the PMD entry mapping this is above the E820_TYPE_RAM range for the reserved crashkernel memory. Signed-off-by: Ashish Kalra Signed-off-by: Kirill A. Shutemov --- arch/x86/mm/init_64.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 7e177856ee4f..28002cc7a37d 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -469,7 +469,9 @@ phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end, !e820__mapped_any(paddr & PAGE_MASK, paddr_next, E820_TYPE_RAM) && !e820__mapped_any(paddr & PAGE_MASK, paddr_next, - E820_TYPE_RESERVED_KERN)) + E820_TYPE_RESERVED_KERN) && + !e820__mapped_any(paddr & PAGE_MASK, paddr_next, + E820_TYPE_ACPI)) set_pte_init(pte, __pte(0), init); continue; } @@ -524,7 +526,9 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end, !e820__mapped_any(paddr & PMD_MASK, paddr_next, E820_TYPE_RAM) && !e820__mapped_any(paddr & PMD_MASK, paddr_next, - E820_TYPE_RESERVED_KERN)) + E820_TYPE_RESERVED_KERN) && + !e820__mapped_any(paddr & PMD_MASK, paddr_next, + E820_TYPE_ACPI)) set_pmd_init(pmd, __pmd(0), init); continue; } @@ -611,7 +615,9 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end, !e820__mapped_any(paddr & PUD_MASK, paddr_next, E820_TYPE_RAM) && !e820__mapped_any(paddr & PUD_MASK, paddr_next, - E820_TYPE_RESERVED_KERN)) + E820_TYPE_RESERVED_KERN) && + !e820__mapped_any(paddr & PUD_MASK, paddr_next, + E820_TYPE_ACPI)) set_pud_init(pud, __pud(0), init); continue; } @@ -698,7 +704,9 @@ phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end, !e820__mapped_any(paddr & P4D_MASK, paddr_next, E820_TYPE_RAM) && !e820__mapped_any(paddr & P4D_MASK, paddr_next, - E820_TYPE_RESERVED_KERN)) + E820_TYPE_RESERVED_KERN) && + !e820__mapped_any(paddr & P4D_MASK, paddr_next, + E820_TYPE_ACPI)) set_p4d_init(p4d, __p4d(0), init); continue; }