On 27/03/17 16:58, Shameerali Kolothum Thodi wrote: > > >> -----Original Message----- >> From: Shameerali Kolothum Thodi >> Sent: Monday, March 27, 2017 3:53 PM >> To: 'Robin Murphy'; Sricharan R; Wangzhou (B); will.deacon@xxxxxxx; >> joro@xxxxxxxxxx; lorenzo.pieralisi@xxxxxxx; iommu@lists.linux- >> foundation.org; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-arm- >> msm@xxxxxxxxxxxxxxx; m.szyprowski@xxxxxxxxxxx; >> bhelgaas@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux- >> acpi@xxxxxxxxxxxxxxx; tn@xxxxxxxxxxxx; hanjun.guo@xxxxxxxxxx; >> okaya@xxxxxxxxxxxxxx >> Subject: RE: [PATCH V9 00/11] IOMMU probe deferral support >> >> >>> -----Original Message----- >>> From: Robin Murphy [mailto:robin.murphy@xxxxxxx] >>> Sent: Friday, March 24, 2017 6:39 PM >>> To: Shameerali Kolothum Thodi; Sricharan R; Wangzhou (B); >>> will.deacon@xxxxxxx; joro@xxxxxxxxxx; lorenzo.pieralisi@xxxxxxx; >>> iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; >>> linux-arm-msm@xxxxxxxxxxxxxxx; m.szyprowski@xxxxxxxxxxx; >>> bhelgaas@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux- >>> acpi@xxxxxxxxxxxxxxx; tn@xxxxxxxxxxxx; hanjun.guo@xxxxxxxxxx; >>> okaya@xxxxxxxxxxxxxx >>> Subject: Re: [PATCH V9 00/11] IOMMU probe deferral support >>> >>> On 24/03/17 09:27, Shameerali Kolothum Thodi wrote: >>>> Hi Sricharan, >>>> >>>>> -----Original Message----- >>>>> From: Sricharan R [mailto:sricharan@xxxxxxxxxxxxxx] >> [...] >>>>> Looks like this triggers the start of the bug. >>>>> So the below check in iommu_dma_init_domain fails, >>>>> >>>>> if (domain->geometry.force_aperture) { >>>>> if (base > domain->geometry.aperture_end || >>>>> base + size <= domain->geometry.aperture_start) { >>>>> >>>>> and the rest goes out of sync after that. Can you print out the base, >>>>> aperture_start and end values to see why the check fails ? >>>> >>>> dev_info(dev, "0x%llx 0x%llx, 0x%llx 0x%llx, 0x%llx 0x%llx\n", base, size, >>> domain->geometry.aperture_start, domain->geometry.aperture_end, >>> *dev->dma_mask, dev->coherent_dma_mask); >>>> >>>> [ 183.752100] ixgbevf 0000:81:10.0: 0x0 0x100000000, 0x0 0xffffffffffff, >>> 0xffffffff 0xffffffff >>>> ..... >>>> [ 319.508037] vfio-pci 0000:81:10.0: 0x0 0x0, 0x0 0xffffffffffff, >>> 0xffffffffffffffff 0xffffffffffffffff >>>> >>>> Yes, size seems to be the problem here. When the VF device gets >> attached >>> to vfio-pci, >>>> somehow the dev->coherent_dma_mask is set to 64 bits and size >> become >>> zero. >>> >>> AFAICS, this is either down to patch 3 (which should apply on its own >>> easily enough for testing), or patch 6, implying that somehow the >>> vfio-pci device gets its DMA mask widened to 64 bits somewhere between >>> very soon after after creation (where we originally called >>> of_dma_configure()) and immediately before probe (where we now call >> it). >>> >>> Either way I guess this is yet more motivation to write that "change the >>> arch_setup_dma_ops() interface to take a mask instead of a size" patch... >> >> Just applying the patch 3 and binding the device into vfio-pci is fine. Please >> find the >> log below (with dev_info debug added to iommu_dma_init_domain ). >> ... >> [ 142.851906] iommu: Adding device 0000:81:10.0 to group 6 >> [ 142.852063] ixgbevf 0000:81:10.0: 0x0 0x100000000, 0x0 0xffffffffffff, >> 0xffffffff 0xffffffff ---->dev_info() >> [ 142.852836] ixgbevf 0000:81:10.0: enabling device (0000 -> 0002) >> [ 142.852962] ixgbe 0000:81:00.0 eth0: VF Reset msg received from vf 0 >> [ 142.853833] ixgbe 0000:81:00.0: VF 0 has no MAC address assigned, you >> may have to assign one manually >> [ 142.863956] ixgbevf 0000:81:10.0: MAC address not assigned by >> administrator. >> [ 142.863960] ixgbevf 0000:81:10.0: Assigning random MAC address >> [ 142.865689] ixgbevf 0000:81:10.0: da:9f:f8:1e:57:3a >> [ 142.865692] ixgbevf 0000:81:10.0: MAC: 1 >> [ 142.865693] ixgbevf 0000:81:10.0: Intel(R) 82599 Virtual Function >> [ 142.939145] ixgbe 0000:81:00.0 eth0: NIC Link is Up 1 Gbps, Flow Control: >> None >> [ 152.902894] nfs: server 172.18.45.166 not responding, still trying >> [ 188.980933] nfs: server 172.18.45.166 not responding, still trying >> [ 188.981298] nfs: server 172.18.45.166 OK >> [ 188.981593] nfs: server 172.18.45.166 OK >> [ 221.755626] VFIO - User Level meta-driver version: 0.3 >> ... >> >> Applied up to patch 6, and the issue appeared, >> >> [ 145.212351] iommu: Adding device 0000:81:10.0 to group 5 >> [ 145.212367] ixgbevf 0000:81:10.0: 0x0 0x100000000, 0x0 0xffffffffffff, >> 0xffffffff 0xffffffff >> [ 145.213261] ixgbevf 0000:81:10.0: enabling device (0000 -> 0002) >> [ 145.213394] ixgbe 0000:81:00.0 eth0: VF Reset msg received from vf 0 >> [ 145.214272] ixgbe 0000:81:00.0: VF 0 has no MAC address assigned, you >> may have to assign one manually >> [ 145.224379] ixgbevf 0000:81:10.0: MAC address not assigned by >> administrator. >> [ 145.224384] ixgbevf 0000:81:10.0: Assigning random MAC address >> [ 145.225941] ixgbevf 0000:81:10.0: 1a:85:06:48:a7:19 >> [ 145.225944] ixgbevf 0000:81:10.0: MAC: 1 >> [ 145.225946] ixgbevf 0000:81:10.0: Intel(R) 82599 Virtual Function >> [ 145.299961] ixgbe 0000:81:00.0 eth0: NIC Link is Up 1 Gbps, Flow Control: >> None >> [ 154.947742] nfs: server 172.18.45.166 not responding, still trying >> [ 191.025780] nfs: server 172.18.45.166 not responding, still trying >> [ 191.026122] nfs: server 172.18.45.166 OK >> [ 191.026317] nfs: server 172.18.45.166 OK >> [ 263.706402] VFIO - User Level meta-driver version: 0.3 >> [ 269.757613] vfio-pci 0000:81:10.0: 0x0 0x0, 0x0 0xffffffffffff, 0xffffffffffffffff >> 0xffffffffffffffff >> [ 269.757617] specified DMA range outside IOMMU capability >> [ 269.757618] Failed to set up IOMMU for device 0000:81:10.0; retaining >> platform DMA ops >> >> From the logs its clear that when ixgbevf driver originally probes and adds >> the device >> to smmu the dma mask is 32, but when it binds to vfio-pci, it becomes 64 bit. > > Just to add to that, the mask is set to 64 bit in the ixgebvf driver probe[1] Aha, but of course it's still the same struct device getting bound to VFIO later, so whatever mask the first driver set is still in there when we go through of_dma_configure() the second time (and the fact that we go through more than once being the new behaviour). So yes, this is a legitimate problem and we really do need to be robust against size overflow. I reckon the below tweak of your fix is probably the way to go; cleaning up the arch_setup_dma_ops() interface can happen later. Robin. -----8<----- diff --git a/drivers/of/device.c b/drivers/of/device.c index 9933077df7b7..77d080bde52d 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -107,7 +107,7 @@ void of_dma_configure(struct device *dev, struct device_node *np) ret = of_dma_get_range(np, &dma_addr, &paddr, &size); if (ret < 0) { dma_addr = offset = 0; - size = dev->coherent_dma_mask + 1; + size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); } else { offset = PFN_DOWN(paddr - dma_addr); ----->8----- > [ 127.914001] ixgbe 0000:81:00.0 eth0: SR-IOV enabled with 1 VFs > [ 127.914106] ixgbe 0000:81:00.0: removed PHC on eth0 > [ 128.125166] ixgbe 0000:81:00.0: Multiqueue Enabled: Rx Queue count = 4, Tx Queue count = 4 > [ 128.143857] ixgbe 0000:81:00.0: registered PHC device on eth0 > [ 128.314754] ixgbe 0000:81:00.0 eth0: detected SFP+: 11 > [ 128.357878] pci 0000:81:10.0: [8086:10ed] type 00 class 0x020000 > [ 128.358416] iommu: Adding device 0000:81:10.0 to group 5 > [ 128.358443] ixgbevf 0000:81:10.0: 0x0 0x100000000, 0x0 0xffffffffffff, 0xffffffff 0xffffffff > [ 128.359326] ixgbevf 0000:81:10.0: enabling device (0000 -> 0002) > [ 128.359333] Shameer: ixgbevf_probe, 64 bit ------------->mask set to 64 bit > [ 128.359462] ixgbe 0000:81:00.0 eth0: VF Reset msg received from vf 0 > [ 128.360331] ixgbe 0000:81:00.0: VF 0 has no MAC address assigned, you may have to assign one manually > [ 128.370470] ixgbevf 0000:81:10.0: MAC address not assigned by administrator. > [ 128.370474] ixgbevf 0000:81:10.0: Assigning random MAC address > [ 128.372172] ixgbevf 0000:81:10.0: ea:40:b9:e9:cb:04 > [ 128.372176] ixgbevf 0000:81:10.0: MAC: 1 > [ 128.372178] ixgbevf 0000:81:10.0: Intel(R) 82599 Virtual Function > [ 128.445551] ixgbe 0000:81:00.0 eth0: NIC Link is Up 1 Gbps, Flow Control: None > [ 138.089869] nfs: server 172.18.45.166 not responding, still trying > [ 174.697868] nfs: server 172.18.45.166 not responding, still trying > [ 174.698359] nfs: server 172.18.45.166 OK > [ 174.698582] nfs: server 172.18.45.166 OK > [ 465.942259] VFIO - User Level meta-driver version: 0.3 > [ 472.754074] vfio-pci 0000:81:10.0: 0x0 0x0, 0x0 0xffffffffffff, 0xffffffffffffffff 0xffffffffffffffff > [ 472.754075] specified DMA range outside IOMMU capability > [ 472.754077] Failed to set up IOMMU for device 0000:81:10.0; retaining platform DMA ops > > 1. http://lxr.free-electrons.com/source/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c#L3996 > > > >
