On 30.06.22 05:32, SK, SivaSangeetha (Siva Sangeetha) wrote: > [AMD Official Use Only - General] > > +team > > -----Original Message----- > From: Stefano Stabellini > Sent: Thursday, June 30, 2022 1:34 AM > To: Julien Grall > Cc: SK, SivaSangeetha (Siva Sangeetha) ; xen-devel@lists.xenproject.org; Stefano Stabellini ; Bertrand Marquis ; Volodymyr Babchuk ; jgross@suse.com; boris.ostrovsky@oracle.com > Subject: Re: Reg. Tee init fail... > > Adding Juergen and Boris because this is a Linux/x86 issue. > > > As you can see from this Linux driver: > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Flatest%2Fsource%2Fdrivers%2Fcrypto%2Fccp%2Ftee-dev.c%23L132&data=05%7C01%7CSivaSangeetha.SK%40amd.com%7Ce962a907794f4917a80b08da5a0a7b3b%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637921298315828104%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=NxmMUckiDRGLv3qLJrhZKBt2zNTuomEZqYJdV74tXxA%3D&reserved=0 > > Linux as dom0 on x86 is trying to communicate with firmware (TEE). Linux is calling __pa to pass a physical address to firmware. However, __pa returns a "fake" address not an mfn. I imagine that a quick workaround would be to call "virt_to_machine" instead of "__pa" in tee-dev.c. > > Normally, if this was a device, the "right fix" would be to use swiotlb-xen:xen_swiotlb_map_page to get back a real physical address. > > However, xen_swiotlb_map_page is meant to be used as part of the dma_ops API and takes a struct device *dev as input parameter. Maybe xen_swiotlb_map_page can be used for tee-dev as well? > > > Basically tee-dev would need to call dma_map_page before passing addresses to firmware, and dma_unmap_page when it is done. E.g.: > > > cmd_buffer = dma_map_page(dev, virt_to_page(cmd), > cmd & ~PAGE_MASK, > ring_size, > DMA_TO_DEVICE); > > > Juergen, Boris, > what do you think? Yes, I think using the DMA interface is the correct way to handle that. BTW, I did a similar fix for the dcdbas driver recently: https://lore.kernel.org/r/20220318150950.16843-1-jgross@suse.com Juergen