kernel/linux.git/drivers/vfio, branch v4.4.171

vfio/pci: Virtualize Maximum Read Request Size

2018-04-24T07:32:09+00:00

commit cf0d53ba4947aad6e471491d5b20a567cbe92e56 upstream. MRRS defines the maximum read request size a device is allowed to make. Drivers will often increase this to allow more data transfer with a single request. Completions to this request are bound by the MPS setting for the bus. Aside from device quirks (none known), it doesn't seem to make sense to set an MRRS value less than MPS, yet this is a likely scenario given that user drivers do not have a system-wide view of the PCI topology. Virtualize MRRS such that the user can set MRRS >= MPS, but use MPS as the floor value that we'll write to hardware. Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

vfio/pci: Virtualize Maximum Payload Size

2018-04-24T07:32:09+00:00

commit 523184972b282cd9ca17a76f6ca4742394856818 upstream. With virtual PCI-Express chipsets, we now see userspace/guest drivers trying to match the physical MPS setting to a virtual downstream port. Of course a lone physical device surrounded by virtual interconnects cannot make a correct decision for a proper MPS setting. Instead, let's virtualize the MPS control register so that writes through to hardware are disallowed. Userspace drivers like QEMU assume they can write anything to the device and we'll filter out anything dangerous. Since mismatched MPS can lead to AER and other faults, let's add it to the kernel side rather than relying on userspace virtualization to handle it. Signed-off-by: Alex Williamson Reviewed-by: Eric Auger Signed-off-by: Greg Kroah-Hartman

vfio-pci: Virtualize PCIe & AF FLR

2018-04-24T07:32:09+00:00

commit ddf9dc0eb5314d6dac8b19b1cc37c739c6896e7e upstream. We use a BAR restore trick to try to detect when a user has performed a device reset, possibly through FLR or other backdoors, to put things back into a working state. This is important for backdoor resets, but we can actually just virtualize the "front door" resets provided via PCIe and AF FLR. Set these bits as virtualized + writable, allowing the default write to set them in vconfig, then we can simply check the bit, perform an FLR of our own, and clear the bit. We don't actually have the granularity in PCI to specify the type of reset we want to do, but generally devices don't implement both PCIe and AF FLR and we'll favor these over other types of reset, so we should generally lineup. We do test whether the device provides the requested FLR type to stay consistent with hardware capabilities though. This seems to fix several instance of devices getting into bad states with userspace drivers, like dpdk, running inside a VM. Signed-off-by: Alex Williamson Reviewed-by: Greg Rose Signed-off-by: Greg Kroah-Hartman

vfio-pci: Handle error from pci_iomap

2017-08-07T02:19:46+00:00

[ Upstream commit e19f32da5ded958238eac1bbe001192acef191a2 ] Here, pci_iomap can fail, handle this case release selected pci regions and return -ENOMEM. Signed-off-by: Arvind Yadav Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

vfio-pci: use 32-bit comparisons for register address for gcc-4.5

2017-08-07T02:19:44+00:00

[ Upstream commit 45e869714489431625c569d21fc952428d761476 ] Using ancient compilers (gcc-4.5 or older) on ARM, we get a link failure with the vfio-pci driver: ERROR: "__aeabi_lcmp" [drivers/vfio/pci/vfio-pci.ko] undefined! The reason is that the compiler tries to do a comparison of a 64-bit range. This changes it to convert to a 32-bit number explicitly first, as newer compilers do for themselves. Signed-off-by: Arnd Bergmann Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

vfio: New external user group/file match

2017-07-27T22:06:07+00:00

commit 5d6dee80a1e94cc284d03e06d930e60e8d3ecf7d upstream. At the point where the kvm-vfio pseudo device wants to release its vfio group reference, we can't always acquire a new reference to make that happen. The group can be in a state where we wouldn't allow a new reference to be added. This new helper function allows a caller to match a file to a group to facilitate this. Given a file and group, report if they match. Thus the caller needs to already have a group reference to match to the file. This allows the deletion of a group without acquiring a new reference. Signed-off-by: Alex Williamson Reviewed-by: Eric Auger Reviewed-by: Paolo Bonzini Tested-by: Eric Auger Signed-off-by: Greg Kroah-Hartman

vfio: Fix group release deadlock

2017-07-27T22:06:07+00:00

commit 811642d8d8a82c0cce8dc2debfdaf23c5a144839 upstream. If vfio_iommu_group_notifier() acquires a group reference and that reference becomes the last reference to the group, then vfio_group_put introduces a deadlock code path where we're trying to unregister from the iommu notifier chain from within a callout of that chain. Use a work_struct to release this reference asynchronously. Signed-off-by: Alex Williamson Reviewed-by: Eric Auger Tested-by: Eric Auger Signed-off-by: Greg Kroah-Hartman

vfio/spapr: fail tce_iommu_attach_group() when iommu_data is null

2017-07-05T12:37:19+00:00

[ Upstream commit bd00fdf198e2da475a2f4265a83686ab42d998a8 ] The recently added mediated VFIO driver doesn't know about powerpc iommu. It thus doesn't register a struct iommu_table_group in the iommu group upon device creation. The iommu_data pointer hence remains null. This causes a kernel oops when userspace tries to set the iommu type of a container associated with a mediated device to VFIO_SPAPR_TCE_v2_IOMMU. [ 82.585440] mtty mtty: MDEV: Registered [ 87.655522] iommu: Adding device 83b8f4f2-509f-382f-3c1e-e6bfe0fa1001 to group 10 [ 87.655527] vfio_mdev 83b8f4f2-509f-382f-3c1e-e6bfe0fa1001: MDEV: group_id = 10 [ 116.297184] Unable to handle kernel paging request for data at address 0x00000030 [ 116.297389] Faulting instruction address: 0xd000000007870524 [ 116.297465] Oops: Kernel access of bad area, sig: 11 [#1] [ 116.297611] SMP NR_CPUS=2048 [ 116.297611] NUMA [ 116.297627] PowerNV ... [ 116.297954] CPU: 33 PID: 7067 Comm: qemu-system-ppc Not tainted 4.10.0-rc5-mdev-test #8 [ 116.297993] task: c000000e7718b680 task.stack: c000000e77214000 [ 116.298025] NIP: d000000007870524 LR: d000000007870518 CTR: 0000000000000000 [ 116.298064] REGS: c000000e77217990 TRAP: 0300 Not tainted (4.10.0-rc5-mdev-test) [ 116.298103] MSR: 9000000000009033 [ 116.298107] CR: 84004444 XER: 00000000 [ 116.298154] CFAR: c00000000000888c DAR: 0000000000000030 DSISR: 40000000 SOFTE: 1 GPR00: d000000007870518 c000000e77217c10 d00000000787b0ed c000000eed2103c0 GPR04: 0000000000000000 0000000000000000 c000000eed2103e0 0000000f24320000 GPR08: 0000000000000104 0000000000000001 0000000000000000 d0000000078729b0 GPR12: c00000000025b7e0 c00000000fe08400 0000000000000001 000001002d31d100 GPR16: 000001002c22c850 00003ffff315c750 0000000043145680 0000000043141bc0 GPR20: ffffffffffffffed fffffffffffff000 0000000020003b65 d000000007706018 GPR24: c000000f16cf0d98 d000000007706000 c000000003f42980 c000000003f42980 GPR28: c000000f1575ac00 c000000003f429c8 0000000000000000 c000000eed2103c0 [ 116.298504] NIP [d000000007870524] tce_iommu_attach_group+0x10c/0x360 [vfio_iommu_spapr_tce] [ 116.298555] LR [d000000007870518] tce_iommu_attach_group+0x100/0x360 [vfio_iommu_spapr_tce] [ 116.298601] Call Trace: [ 116.298610] [c000000e77217c10] [d000000007870518] tce_iommu_attach_group+0x100/0x360 [vfio_iommu_spapr_tce] (unreliable) [ 116.298671] [c000000e77217cb0] [d0000000077033a0] vfio_fops_unl_ioctl+0x278/0x3e0 [vfio] [ 116.298713] [c000000e77217d40] [c0000000002a3ebc] do_vfs_ioctl+0xcc/0x8b0 [ 116.298745] [c000000e77217de0] [c0000000002a4700] SyS_ioctl+0x60/0xc0 [ 116.298782] [c000000e77217e30] [c00000000000b220] system_call+0x38/0xfc [ 116.298812] Instruction dump: [ 116.298828] 7d3f4b78 409effc8 3d220000 e9298020 3c800140 38a00018 608480c0 e8690028 [ 116.298869] 4800249d e8410018 7c7f1b79 41820230 2fa90000 419e0114 e9090020 [ 116.298914] ---[ end trace 1e10b0ced08b9120 ]--- This patch fixes the oops. Reported-by: Vaibhav Jain Signed-off-by: Greg Kurz Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

vfio/type1: Remove locked page accounting workqueue

2017-05-20T12:27:00+00:00

commit 0cfef2b7410b64d7a430947e0b533314c4f97153 upstream. If the mmap_sem is contented then the vfio type1 IOMMU backend will defer locked page accounting updates to a workqueue task. This has a few problems and depending on which side the user tries to play, they might be over-penalized for unmaps that haven't yet been accounted or race the workqueue to enter more mappings than they're allowed. The original intent of this workqueue mechanism seems to be focused on reducing latency through the ioctl, but we cannot do so at the cost of correctness. Remove this workqueue mechanism and update the callers to allow for failure. We can also now recheck the limit under write lock to make sure we don't exceed it. vfio_pin_pages_remote() also now necessarily includes an unwind path which we can jump to directly if the consecutive page pinning finds that we're exceeding the user's memory limits. This avoids the current lazy approach which does accounting and mapping up to the fault, only to return an error on the next iteration to unwind the entire vfio_dma. Cc: stable@vger.kernel.org Reviewed-by: Peter Xu Reviewed-by: Kirti Wankhede Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

vfio/pci: Fix integer overflows, bitmask check

2017-04-30T03:49:29+00:00

commit 05692d7005a364add85c6e25a6c4447ce08f913a upstream. The VFIO_DEVICE_SET_IRQS ioctl did not sufficiently sanitize user-supplied integers, potentially allowing memory corruption. This patch adds appropriate integer overflow checks, checks the range bounds for VFIO_IRQ_SET_DATA_NONE, and also verifies that only single element in the VFIO_IRQ_SET_DATA_TYPE_MASK bitmask is set. VFIO_IRQ_SET_ACTION_TYPE_MASK is already correctly checked later in vfio_pci_set_irqs_ioctl(). Furthermore, a kzalloc is changed to a kcalloc because the use of a kzalloc with an integer multiplication allowed an integer overflow condition to be reached without this patch. kcalloc checks for overflow and should prevent a similar occurrence. Signed-off-by: Vlad Tsyrklevich Signed-off-by: Alex Williamson Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman