From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Joerg Roedel" Subject: Re: [PATCH 1/8] KVM: PVDMA Host: Handle reqeusts for guest DMA mappings Date: Mon, 12 Nov 2007 16:55:22 +0100 Message-ID: <20071112155522.GF6466@amd.com> References: <1194445269752-git-send-email-amit.shah@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Amit Shah" Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Wed, Nov 07, 2007 at 04:21:02PM +0200, Amit Shah wrote: > @@ -1649,6 +1913,15 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) > } > > switch (nr) { > + case KVM_PV_DMA_MAP: > + ret = pv_map_hypercall(vcpu, a0, a1); > + break; > + case KVM_PV_DMA_UNMAP: > + ret = pv_unmap_hypercall(vcpu, a0); > + break; > + case KVM_PV_PCI_DEVICE: > + ret = pv_mapped_pci_device_hypercall(vcpu, a0); > + break; > default: > ret = -KVM_ENOSYS; > break; How does synchronization work with that design? I don't see a hypercall to synchronize de DMA buffers. It will only work if GART is used as the dma_ops backend on the host side and not with SWIOTLB. But GART can be configured away. Or do I miss something? Joerg -- | AMD Saxony Limited Liability Company & Co. KG Operating | Wilschdorfer Landstr. 101, 01109 Dresden, Germany System | Register Court Dresden: HRA 4896 Research | General Partner authorized to represent: Center | AMD Saxony LLC (Wilmington, Delaware, US) | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/