On 3/24/2015 7:07 AM, Manish Jaggi wrote: > > On Monday 23 March 2015 07:16 PM, Robbie VanVossen wrote: >> If multiple devices are being passed through to the same domain and they >> share a single SMMU, then they only require a single iommu_domain. >> >> In arm_smmu_assign_dev, before a new iommu_domain is created, the >> xen_domain->contexts is checked for any iommu_domains that are already >> assigned to device that uses the same SMMU as the current device. If one >> is found, attach the device to that iommu_domain. If a new one isn't >> found, create a new iommu_domain just like before. >> >> The arm_smmu_deassign_dev function assumes that there is a single >> device per iommu_domain. This meant that when the first device was >> deassigned, the iommu_domain was freed and when another device was >> deassigned a crash occured in xen. >> >> To fix this, a reference counter was added to the iommu_domain struct. >> When an arm_smmu_xen_device references an iommu_domain, the >> iommu_domains ref is incremented. When that reference is removed, the >> iommu_domains ref is decremented. The iommu_domain will only be freed >> when the ref is 0. >> >> Signed-off-by: Robbie VanVossen <robert.vanvos...@dornerworks.com> > Hi, > Are you adding a PCI passthrough support to Xen ?. I am in process of > sending smmu driver patches based on juliens latest code. >
Nope, I am just working on what this patch describes Thanks, Robbie VanVossen DornerWorks _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
