Michael S. Tsirkin
2023-Feb-17 10:12 UTC
[PATCH v2] vhost/vdpa: Add MSI translation tables to iommu for software-managed MSI
On Thu, Feb 16, 2023 at 08:14:50PM -0400, Jason Gunthorpe wrote:> On Tue, Feb 07, 2023 at 08:08:43PM +0800, Nanyong Sun wrote: > > From: Rong Wang <wangrong68 at huawei.com> > > > > Once enable iommu domain for one device, the MSI > > translation tables have to be there for software-managed MSI. > > Otherwise, platform with software-managed MSI without an > > irq bypass function, can not get a correct memory write event > > from pcie, will not get irqs. > > The solution is to obtain the MSI phy base address from > > iommu reserved region, and set it to iommu MSI cookie, > > then translation tables will be created while request irq. > > Probably not what anyone wants to hear, but I would prefer we not add > more uses of this stuff. It looks like we have to get rid of > iommu_get_msi_cookie() :\ > > I'd like it if vdpa could move to iommufd not keep copying stuff from > it..Absolutely but when is that happening?> Also the iommu_group_has_isolated_msi() check is missing on the vdpa > path, and it is missing the iommu ownership mechanism. > > Also which in-tree VDPA driver that uses the iommu runs on ARM? Please > don't propose core changes for unmerged drivers. :( > > Jason