From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH v6 25/34] swiotlb: Add warnings for use of bounce buffers with SME Date: Thu, 8 Jun 2017 00:58:29 -0700 Message-ID: <20170608075829.GA2446@infradead.org> References: <20170607191309.28645.15241.stgit@tlendack-t1.amdoffice.net> <20170607191732.28645.42876.stgit@tlendack-t1.amdoffice.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170607191732.28645.42876.stgit@tlendack-t1.amdoffice.net> Sender: linux-doc-owner@vger.kernel.org To: Tom Lendacky Cc: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Rik van Riel , Radim =?utf-8?B?S3LEjW3DocWZ?= , Toshimitsu Kani , Arnd Bergmann , Jonathan Corbet , Matt Fleming , "Michael S. Tsirkin" , Joerg Roedel , Konrad Rzeszutek Wilk , Paolo Bonzini , Larry Woodman , Brijesh Singh , Ingo Molnar List-Id: iommu@lists.linux-foundation.org On Wed, Jun 07, 2017 at 02:17:32PM -0500, Tom Lendacky wrote: > Add warnings to let the user know when bounce buffers are being used for > DMA when SME is active. Since the bounce buffers are not in encrypted > memory, these notifications are to allow the user to determine some > appropriate action - if necessary. And what would the action be? Do we need a boot or other option to disallow this fallback for people who care deeply?