From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Tue, 01 Mar 2022 11:43:35 +0000 Subject: Re: [PATCH 08/12] x86: centralize setting SWIOTLB_FORCE when guest memory encryption is enabled Message-Id: <20220301114335.GA2881@lst.de> List-Id: References: <20220301105311.885699-1-hch@lst.de> <20220301105311.885699-9-hch@lst.de> <8e623a11-d809-4fab-401c-2ce609a9fc14@citrix.com> In-Reply-To: <8e623a11-d809-4fab-401c-2ce609a9fc14@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Andrew Cooper Cc: Christoph Hellwig , "iommu@lists.linux-foundation.org" , "x86@kernel.org" , Anshuman Khandual , Tom Lendacky , Konrad Rzeszutek Wilk , Stefano Stabellini , Boris Ostrovsky , Juergen Gross , Joerg Roedel , David Woodhouse , Lu Baolu , Robin Murphy , "linux-arm-kernel@lists.infradead.org" , "xen-devel@lists.xenproject.org" , "linux-ia64@vger.kernel.org" , "linux-mips@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-riscv@lists.infradead.org" , "linux-s390@vger.kernel.org" , "linux-hyperv@vger.kernel.org" , "tboot-devel@lists.sourceforge.net" , "linux-pci@vger.kernel.org" On Tue, Mar 01, 2022 at 11:39:29AM +0000, Andrew Cooper wrote: > This isn't really "must".  The guest is perfectly capable of sharing > memory with the hypervisor. > > It's just that for now, bounce buffering is allegedly faster, and the > simple way of getting it working. Yeah, I guess you щould just share/unshare on demand. But given that this isn't implemented it is a must in the current kernel. But if you want a different wording suggest one and I'll put it in.