From nobody Wed Dec 17 01:00:05 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) (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 AA518225A57; Mon, 17 Feb 2025 16:42:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739810561; cv=none; b=BGzvfXOe0SdEfFtq+jlGIVT2CTgcNXx2DOI4L9u53qYde/QBb3z4L8RTIVINxLnplvB6zGBPmkuW9BBIl+c5o62x2JbN2dyK1+xHH6N0JjWGViTrGnmxqRxfUzIq9+ymyP1kHT/4z3z3WcznWugsYdSsCUAvkSl0oyyXR3wlrIg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739810561; c=relaxed/simple; bh=Q/y2Ura+ZZ4aJJSpOsP2M0RlMQFJRNDUTUtpYBZlPro=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X8L9r2JBeEIZuNv3usyf9ogpkVtTMllUzkn9igw9xdSuEaQnqPK784ufZ7Ng0fG1aIivfiu8soWP9Oa0MxuxlfDkQNL2KZolKkGexYtX/oiIakVmYC1fKVn+SPLlBhe9S2YEW0lll/ezqfA/STVaSt/Dq1U4S1MSfevrmpk1jZg= 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=c1SWIqM7; arc=none smtp.client-ip=192.198.163.12 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="c1SWIqM7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1739810560; x=1771346560; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Q/y2Ura+ZZ4aJJSpOsP2M0RlMQFJRNDUTUtpYBZlPro=; b=c1SWIqM7gHfLQ6x+cmRUSV/pE+5v8a4csJ7jO+uhm7By3gNM9EB7MgDb rkQASHkeKx+ARY3Ag0KoWhu7WCuEcBgLzlarc1fmCeFrW5qFIDC0a7pYq V5XX39ZX+x7e4T6zlTExIFifOZ9tWfvzY4iEkxZAkeGjwTQUO34Ckpr6V Wag3MwmlK0nk/9A8MRCoFsflF6BReQhVsewvrRQsJzarqSufmBUrDBend C0cichzBD3NTiZ9lbxveqRUDUKHO2GgneHF0yFZbArI+j5jOzSh66qB9/ Yldr74jpKmF008mQdZSaKAfZf4TbvuP5ZtOnk45mf0XG7mUOuaKHD3rfE g==; X-CSE-ConnectionGUID: NndbcaRYT2GC5v/RGdMzDA== X-CSE-MsgGUID: UEVzFiioRzWH+nqvn64S6w== X-IronPort-AV: E=McAfee;i="6700,10204,11348"; a="44426586" X-IronPort-AV: E=Sophos;i="6.13,293,1732608000"; d="scan'208";a="44426586" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Feb 2025 08:42:38 -0800 X-CSE-ConnectionGUID: DLaoWa/wSWS1Bb+Zkbv1Tw== X-CSE-MsgGUID: X50OseD7Tkq0w6139d7UYg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,199,1725346800"; d="scan'208";a="119092112" Received: from black.fi.intel.com ([10.237.72.28]) by orviesa003.jf.intel.com with ESMTP; 17 Feb 2025 08:42:31 -0800 Received: by black.fi.intel.com (Postfix, from userid 1000) id 98D08139; Mon, 17 Feb 2025 18:42:29 +0200 (EET) From: "Kirill A. Shutemov" To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andy Lutomirski , Tom Lendacky Cc: Albert Ou , Alexei Starovoitov , Andrea Parri , Arnd Bergmann , Daniel Borkmann , Eric Chan , Jason Gunthorpe , Kai Huang , Kefeng Wang , Kent Overstreet , Palmer Dabbelt , Paul Walmsley , Russell King , Samuel Holland , Suren Baghdasaryan , Yuntao Wang , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, "Kirill A. Shutemov" , stable@vger.kernel.org, Ashish Kalra , "Maciej W. Rozycki" Subject: [PATCHv4 2/2] x86/mm: Make memremap(MEMREMAP_WB) map memory as encrypted by default Date: Mon, 17 Feb 2025 18:38:21 +0200 Message-ID: <20250217163822.343400-3-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250217163822.343400-1-kirill.shutemov@linux.intel.com> References: <20250217163822.343400-1-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" Currently memremap(MEMREMAP_WB) can produce decrypted/shared mapping: memremap(MEMREMAP_WB) arch_memremap_wb() ioremap_cache() __ioremap_caller(.encrytped =3D false) In such cases, the IORES_MAP_ENCRYPTED flag on the memory will determine if the resulting mapping is encrypted or decrypted. Creating a decrypted mapping without explicit request from the caller is risky: - It can inadvertently expose the guest's data and compromise the guest. - Accessing private memory via shared/decrypted mapping on TDX will either trigger implicit conversion to shared or #VE (depending on VMM implementation). Implicit conversion is destructive: subsequent access to the same memory via private mapping will trigger a hard-to-debug #VE crash. The kernel already provides a way to request decrypted mapping explicitly via the MEMREMAP_DEC flag. Modify memremap(MEMREMAP_WB) to produce encrypted/private mapping by default unless MEMREMAP_DEC is specified or if the kernel runs on a machine with SME enabled. It fixes the crash due to #VE on kexec in TDX guests if CONFIG_EISA is enabled. Signed-off-by: Kirill A. Shutemov Cc: stable@vger.kernel.org # 6.11+ Cc: Tom Lendacky Cc: Ashish Kalra Cc: "Maciej W. Rozycki" --- arch/x86/include/asm/io.h | 3 +++ arch/x86/mm/ioremap.c | 8 ++++++++ 2 files changed, 11 insertions(+) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index ed580c7f9d0a..1a0dc2b2bf5b 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -175,6 +175,9 @@ extern void __iomem *ioremap_prot(resource_size_t offse= t, unsigned long size, un extern void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned= long size); #define ioremap_encrypted ioremap_encrypted =20 +void *arch_memremap_wb(phys_addr_t phys_addr, size_t size, unsigned long f= lags); +#define arch_memremap_wb arch_memremap_wb + /** * ioremap - map bus memory into CPU space * @offset: bus address of the memory diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 8d29163568a7..a4b23d2e92d2 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -503,6 +503,14 @@ void iounmap(volatile void __iomem *addr) } EXPORT_SYMBOL(iounmap); =20 +void *arch_memremap_wb(phys_addr_t phys_addr, size_t size, unsigned long f= lags) +{ + if ((flags & MEMREMAP_DEC) || cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) + return (void __force *)ioremap_cache(phys_addr, size); + + return (void __force *)ioremap_encrypted(phys_addr, size); +} + /* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access --=20 2.47.2