From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (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 E317912D212 for ; Tue, 9 Apr 2024 11:30:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712662232; cv=none; b=Ume/u6pPwZggVSMXU4dvNS+3gzRBK8Y3XX4T5IUoWz0QY4GsT19rbgKVafqZbeRPrir2cXTqmBKrjVf3EvNur0suGVpBmEz8BIvS1tfZfVGUpjdHclLQUKJJFpHfBDVeB5FLr9OSeVPlHAgYHCWAYcgXvmhJdRU2FxUSfO4fXfc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712662232; c=relaxed/simple; bh=ggOF5UziCfkAXFWyu9AjZBbe749R0vOnMDQfmgr6Dec=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Z8IxHiz9zaW3xTzRwT8qOq119d+xM61+CQwMySxmnPpeE1P/ZVLFDHXWBTvc1CMCSsywJ1II4x7z2VawfM4yeAyLpZQ6tYpwR8yg8PPWPvV/gtYL5Q8hA9FoFwnnWaWWSwxPSYNodQNbnJbqz4ZOt3CTUV7RgLKhIElJMzNY7/Q= 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=ZWR0zNhC; arc=none smtp.client-ip=198.175.65.9 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="ZWR0zNhC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712662231; x=1744198231; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ggOF5UziCfkAXFWyu9AjZBbe749R0vOnMDQfmgr6Dec=; b=ZWR0zNhC5BzSBqZjqUIKXaeoWCBmO8sy6lUEHUFXDXl89FzRCT0mOVxj z3ac0Q0kvQ5nHEp98cj1umg/ItNq7KZl9IZLqLutA8V6HYLZMwvIv3imv eZ3PA3jiD4tkYrRki1aF788ljfEljdL5JuN56IjxjiDVCdrLE+UFK0VAX YD+m/D22l1eBjBV29loFvB86JMaSPZ78MzSNrmQjkrV+QC6GG4xwPfY0Y bRp97TStf6rSFXA9fvuLR4Ild294MEyYXP2YI+6n2NmRKumXT97hYUZvm hkxqmndK3n2v2TSGTICrap47Qzo54BqPUMxf23DQTVNytBn6cqrjjGpDU Q==; X-CSE-ConnectionGUID: PpptHi8SQJys/5v8ThBn1w== X-CSE-MsgGUID: Y1S2Oo1ST+2LrM9oM+KNTw== X-IronPort-AV: E=McAfee;i="6600,9927,11038"; a="30460387" X-IronPort-AV: E=Sophos;i="6.07,189,1708416000"; d="scan'208";a="30460387" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Apr 2024 04:30:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,11038"; a="937093333" X-IronPort-AV: E=Sophos;i="6.07,189,1708416000"; d="scan'208";a="937093333" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 09 Apr 2024 04:30:24 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id CD2B92E9; Tue, 9 Apr 2024 14:30:17 +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" , Baoquan He , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Tao Liu Subject: [PATCHv10 08/18] x86/tdx: Account shared memory Date: Tue, 9 Apr 2024 14:30:00 +0300 Message-ID: <20240409113010.465412-9-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240409113010.465412-1-kirill.shutemov@linux.intel.com> References: <20240409113010.465412-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The kernel will convert all shared memory back to private during kexec. The direct mapping page tables will provide information on which memory is shared. It is extremely important to convert all shared memory. If a page is missed, it will cause the second kernel to crash when it accesses it. Keep track of the number of shared pages. This will allow for cross-checking against the shared information in the direct mapping and reporting if the shared bit is lost. Signed-off-by: Kirill A. Shutemov Reviewed-by: Kai Huang Tested-by: Tao Liu --- arch/x86/coco/tdx/tdx.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 26fa47db5782..979891e97d83 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -38,6 +38,8 @@ #define TDREPORT_SUBTYPE_0 0 +static atomic_long_t nr_shared; + /* Called from __tdx_hypercall() for unrecoverable failure */ noinstr void __noreturn __tdx_hypercall_failed(void) { @@ -821,6 +823,11 @@ static int tdx_enc_status_change_finish(unsigned long vaddr, int numpages, if (!enc && !tdx_enc_status_changed(vaddr, numpages, enc)) return -EIO; + if (enc) + atomic_long_sub(numpages, &nr_shared); + else + atomic_long_add(numpages, &nr_shared); + return 0; } -- 2.43.0