From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (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 38E91BE73 for ; Mon, 15 Jan 2024 09:02:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="SAOPBhxw" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id AD92740E01B0; Mon, 15 Jan 2024 09:02:12 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id SUKdvpsWbZhK; Mon, 15 Jan 2024 09:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1705309330; bh=StldW18DJW9RHvhpFLIMw8/y8Xdlf7u+BI435bxm9gE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SAOPBhxwbXpACDVHP9Vgo+tBOgk6enmMbPub2YjCJOSM2Toof/rV7Tf6Q7KI0mS1g ZEBocmEh81odQ2fQbDeCt9YY3bAHX7XPTnpw7Un7NF9qjc3oa1yXKaibzSuoQDj/x3 evyCIOERFXEiSoe5cyAhmDl1c1pRyM8HLcaLyzQMdOF72dHMjbbRjLv0doHYVPOaCh hlygnPuXr/lh3jKPd04u9kqpmeR2RvvB11xD0OZbMX98qSlIrtzWdjd/EJwIPPXF/e 3B4uJK5neFbWsFBfVhuCn823FkTrBaGCd/C4SUl+MIBS8hD67NvSqMRUxA5BhQzE5Z olACYu2A9zCwGqxAR/dxdJtbefC0pED2yvzcvoMizdVumW2bIrH2gaqeVecKt5LeEE kvQxK5TJeeXq+Xc+DaFxh0DsavN4p3n6NNrZ2GYRoMMaOelAuNsYdoTKSLlPViMhxn so7gePgLsENHGpjy+x/C1Wi41H+Rl5T+SVHS7jKFXTVmIhciNEDlSkcfMY61sFbJI/ o7VSoCVXWZv8qrKkhvxKf8e3Yh2FnNPraaEj7B872YIPUs96dShqtLXjHEgZWG9QqR 6jgVxJglFNO/ETzSN4Oz4a+qpYt6yB52z6q81wpRVsI+ElPGIVMbmNf/lhjYS9V2T+ oygAXEbBHHh/kshvJixLCzlI= Received: from zn.tnic (pd9530f8c.dip0.t-ipconnect.de [217.83.15.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 008B940E01A9; Mon, 15 Jan 2024 09:01:31 +0000 (UTC) Date: Mon, 15 Jan 2024 10:01:26 +0100 From: Borislav Petkov To: Michael Roth Cc: x86@kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com, ardb@kernel.org, pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com, jmattson@google.com, luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com, pgonda@google.com, peterz@infradead.org, srinivas.pandruvada@linux.intel.com, rientjes@google.com, tobin@ibm.com, vbabka@suse.cz, kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com, jarkko@kernel.org, ashish.kalra@amd.com, nikunj.dadhania@amd.com, pankaj.gupta@amd.com, liam.merwick@oracle.com, zhi.a.wang@intel.com, Brijesh Singh Subject: Re: [PATCH v1 11/26] x86/sev: Invalidate pages from the direct map when adding them to the RMP table Message-ID: <20240115090126.GEZaT0ZnSPIPsnUiyt@fat_crate.local> References: <20231230161954.569267-1-michael.roth@amd.com> <20231230161954.569267-12-michael.roth@amd.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20231230161954.569267-12-michael.roth@amd.com> On Sat, Dec 30, 2023 at 10:19:39AM -0600, Michael Roth wrote: > + /* > + * If the kernel uses a 2MB directmap mapping to write to an address, > + * and that 2MB range happens to contain a 4KB page that set to private > + * in the RMP table, an RMP #PF will trigger and cause a host crash. Also: diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c index 7d294d1a620b..2ad83e7fb2da 100644 --- a/arch/x86/virt/svm/sev.c +++ b/arch/x86/virt/svm/sev.c @@ -415,8 +415,9 @@ static int rmpupdate(u64 pfn, struct rmp_state *state) /* * If the kernel uses a 2MB directmap mapping to write to an address, - * and that 2MB range happens to contain a 4KB page that set to private - * in the RMP table, an RMP #PF will trigger and cause a host crash. + * and that 2MB range happens to contain a 4KB page that has been set + * to private in the RMP table, an RMP #PF will trigger and cause a + * host crash. * * Prevent this by removing pages from the directmap prior to setting * them as private in the RMP table. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette