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* vfio/pci: use correct format charactersLouis Taylor2019-05-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 426b046b748d1f47e096e05bdcc6fb4172791307 ] When compiling with -Wformat, clang emits the following warnings: drivers/vfio/pci/vfio_pci.c:1601:5: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1601:13: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1601:21: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1601:32: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1605:5: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1605:13: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1605:21: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1605:32: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ The types of these arguments are unconditionally defined, so this patch updates the format character to the correct ones for unsigned ints. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Signed-off-by: Louis Taylor <louis@kragniz.eu> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* vfio/type1: Limit DMA mappings per containerAlex Williamson2019-05-161-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 492855939bdb59c6f947b0b5b44af9ad82b7e38c upstream. Memory backed DMA mappings are accounted against a user's locked memory limit, including multiple mappings of the same memory. This accounting bounds the number of such mappings that a user can create. However, DMA mappings that are not backed by memory, such as DMA mappings of device MMIO via mmaps, do not make use of page pinning and therefore do not count against the user's locked memory limit. These mappings still consume memory, but the memory is not well associated to the process for the purpose of oom killing a task. To add bounding on this use case, we introduce a limit to the total number of concurrent DMA mappings that a user is allowed to create. This limit is exposed as a tunable module option where the default value of 64K is expected to be well in excess of any reasonable use case (a large virtual machine configuration would typically only make use of tens of concurrent mappings). This fixes CVE-2019-3882. Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [groeck: Adjust for missing upstream commit] Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio/pci: Virtualize Maximum Read Request SizeAlex Williamson2018-04-241-3/+26
| | | | | | | | | | | | | | | | | | 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 <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio/pci: Virtualize Maximum Payload SizeAlex Williamson2018-04-241-2/+4
| | | | | | | | | | | | | | | | | | | | 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 <alex.williamson@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio-pci: Virtualize PCIe & AF FLRAlex Williamson2018-04-241-5/+77
| | | | | | | | | | | | | | | | | | | | | | | | | 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 <alex.williamson@redhat.com> Reviewed-by: Greg Rose <grose@lightfleet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio-pci: Handle error from pci_iomapArvind Yadav2017-08-061-0/+4
| | | | | | | | | | | | [ Upstream commit e19f32da5ded958238eac1bbe001192acef191a2 ] Here, pci_iomap can fail, handle this case release selected pci regions and return -ENOMEM. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio-pci: use 32-bit comparisons for register address for gcc-4.5Arnd Bergmann2017-08-061-1/+4
| | | | | | | | | | | | | | | | | | [ 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 <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio: New external user group/file matchAlex Williamson2017-07-271-0/+9
| | | | | | | | | | | | | | | | | | | | 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 <alex.williamson@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio: Fix group release deadlockAlex Williamson2017-07-271-1/+36
| | | | | | | | | | | | | | | | 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 <alex.williamson@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio/spapr: fail tce_iommu_attach_group() when iommu_data is nullGreg Kurz2017-07-051-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ 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 <SF,HV,EE,ME,IR,DR,RI,LE> [ 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 <e93e0030> 2fa90000 419e0114 e9090020 [ 116.298914] ---[ end trace 1e10b0ced08b9120 ]--- This patch fixes the oops. Reported-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Greg Kurz <groug@kaod.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio/type1: Remove locked page accounting workqueueAlex Williamson2017-05-201-59/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <peterx@redhat.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio/pci: Fix integer overflows, bitmask checkVlad Tsyrklevich2017-04-302-13/+22
| | | | | | | | | | | | | | | | | | | | | | | 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 <vlad@tsyrklevich.net> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio/spapr: Postpone allocation of userspace version of TCE tableSumit Semwal2017-03-301-13/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From: Alexey Kardashevskiy <aik@ozlabs.ru> [ Upstream commit 39701e56f5f16ea0cf8fc9e8472e645f8de91d23 ] The iommu_table struct manages a hardware TCE table and a vmalloc'd table with corresponding userspace addresses. Both are allocated when the default DMA window is created and this happens when the very first group is attached to a container. As we are going to allow the userspace to configure container in one memory context and pas container fd to another, we have to postpones such allocations till a container fd is passed to the destination user process so we would account locked memory limit against the actual container user constrainsts. This postpones the it_userspace array allocation till it is used first time for mapping. The unmapping patch already checks if the array is allocated. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio/pci: Fix NULL pointer oops in error interrupt setup handlingAlex Williamson2016-09-071-36/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | commit c8952a707556e04374d7b2fdb3a079d63ddf6f2f upstream. There are multiple cases in vfio_pci_set_ctx_trigger_single() where we assume we can safely read from our data pointer without actually checking whether the user has passed any data via the count field. VFIO_IRQ_SET_DATA_NONE in particular is entirely broken since we attempt to pull an int32_t file descriptor out before even checking the data type. The other data types assume the data pointer contains one element of their type as well. In part this is good news because we were previously restricted from doing much sanitization of parameters because it was missed in the past and we didn't want to break existing users. Clearly DATA_NONE is completely broken, so it must not have any users and we can fix it up completely. For DATA_BOOL and DATA_EVENTFD, we'll just protect ourselves, returning error when count is zero since we previously would have oopsed. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reported-by: Chris Thompson <the_cartographer@hotmail.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfio: fix ioctl error handlingMichael S. Tsirkin2016-03-093-8/+16
| | | | | | | | | | | | | | | | | | | | commit 8160c4e455820d5008a1116d2dca35f0363bb062 upstream. Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up vfio to do return copy_to_user(...)) ? -EFAULT : 0; everywhere. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert: "vfio: Include No-IOMMU mode"Alex Williamson2015-12-043-199/+10
| | | | | | | | | Revert commit 033291eccbdb ("vfio: Include No-IOMMU mode") due to lack of a user. This was originally intended to fill a need for the DPDK driver, but uptake has been slow so rather than support an unproven kernel interface revert it and revisit when userspace catches up. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* vfio: fix a warning messageDan Carpenter2015-11-211-1/+1
| | | | | | | | | The first argument to the WARN() macro has to be a condition. I'm sort of disappointed that this code doesn't generate a compiler warning. I guess -Wformat-extra-args doesn't work in the kernel. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* vfio: platform: remove needless stack usageKees Cook2015-11-201-4/+1
| | | | | | | | request_module already takes format strings, so no need to duplicate the effort. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* vfio-pci: constify pci_error_handlers structuresJulia Lawall2015-11-191-1/+1
| | | | | | | | | | This pci_error_handlers structure is never modified, like all the other pci_error_handlers structures, so declare it as const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* vfio: Drop owner assignment from platform_driverKrzysztof Kozlowski2015-11-191-1/+0
| | | | | | | | | platform_driver does not need to set an owner because platform_driver_register() will set it. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* Merge tag 'vfio-v4.4-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds2015-11-1315-90/+606
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull VFIO updates from Alex Williamson: - Use kernel interfaces for VPD emulation (Alex Williamson) - Platform fix for releasing IRQs (Eric Auger) - Type1 IOMMU always advertises PAGE_SIZE support when smaller mapping sizes are available (Eric Auger) - Platform fixes for incorrectly using copies of structures rather than pointers to structures (James Morse) - Rework platform reset modules, fix leak, and add AMD xgbe reset module (Eric Auger) - Fix vfio_device_get_from_name() return value (Joerg Roedel) - No-IOMMU interface (Alex Williamson) - Fix potential out of bounds array access in PCI config handling (Dan Carpenter) * tag 'vfio-v4.4-rc1' of git://github.com/awilliam/linux-vfio: vfio/pci: make an array larger vfio: Include No-IOMMU mode vfio: Fix bug in vfio_device_get_from_name() VFIO: platform: reset: AMD xgbe reset module vfio: platform: reset: calxedaxgmac: fix ioaddr leak vfio: platform: add dev_info on device reset vfio: platform: use list of registered reset function vfio: platform: add compat in vfio_platform_device vfio: platform: reset: calxedaxgmac: add reset function registration vfio: platform: introduce module_vfio_reset_handler macro vfio: platform: add capability to register a reset function vfio: platform: introduce vfio-platform-base module vfio/platform: store mapped memory in region, instead of an on-stack copy vfio/type1: handle case where IOMMU does not support PAGE_SIZE size VFIO: platform: clear IRQ_NOAUTOEN when de-assigning the IRQ vfio/pci: Use kernel VPD access functions vfio: Whitelist PCI bridges
| * vfio/pci: make an array largerDan Carpenter2015-11-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Smatch complains about a possible out of bounds error: drivers/vfio/pci/vfio_pci_config.c:1241 vfio_cap_init() error: buffer overflow 'pci_cap_length' 20 <= 20 The problem is that pci_cap_length[] was defined as large enough to hold "PCI_CAP_ID_AF + 1" elements. The code in vfio_cap_init() assumes it has PCI_CAP_ID_MAX + 1 elements. Originally, PCI_CAP_ID_AF and PCI_CAP_ID_MAX were the same but then we introduced PCI_CAP_ID_EA in commit f80b0ba95964 ("PCI: Add Enhanced Allocation register entries") so now the array is too small. Let's fix this by making the array size PCI_CAP_ID_MAX + 1. And let's make a similar change to pci_ext_cap_length[] for consistency. Also both these arrays can be made const. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: Include No-IOMMU modeAlex Williamson2015-11-043-10/+199
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is really no way to safely give a user full access to a DMA capable device without an IOMMU to protect the host system. There is also no way to provide DMA translation, for use cases such as device assignment to virtual machines. However, there are still those users that want userspace drivers even under those conditions. The UIO driver exists for this use case, but does not provide the degree of device access and programming that VFIO has. In an effort to avoid code duplication, this introduces a No-IOMMU mode for VFIO. This mode requires building VFIO with CONFIG_VFIO_NOIOMMU and enabling the "enable_unsafe_noiommu_mode" option on the vfio driver. This should make it very clear that this mode is not safe. Additionally, CAP_SYS_RAWIO privileges are necessary to work with groups and containers using this mode. Groups making use of this support are named /dev/vfio/noiommu-$GROUP and can only make use of the special VFIO_NOIOMMU_IOMMU for the container. Use of this mode, specifically binding a device without a native IOMMU group to a VFIO bus driver will taint the kernel and should therefore not be considered supported. This patch includes no-iommu support for the vfio-pci bus driver only. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com>
| * vfio: Fix bug in vfio_device_get_from_name()Joerg Roedel2015-11-041-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vfio_device_get_from_name() function might return a non-NULL pointer, when called with a device name that is not found in the list. This causes undefined behavior, in my case calling an invalid function pointer later on: kernel tried to execute NX-protected page - exploit attempt? (uid: 0) BUG: unable to handle kernel paging request at ffff8800cb3ddc08 [...] Call Trace: [<ffffffffa03bd733>] ? vfio_group_fops_unl_ioctl+0x253/0x410 [vfio] [<ffffffff811efc4d>] do_vfs_ioctl+0x2cd/0x4c0 [<ffffffff811f9657>] ? __fget+0x77/0xb0 [<ffffffff811efeb9>] SyS_ioctl+0x79/0x90 [<ffffffff81001bb0>] ? syscall_return_slowpath+0x50/0x130 [<ffffffff8167f776>] entry_SYSCALL_64_fastpath+0x16/0x75 Fix the issue by returning NULL when there is no device with the requested name in the list. Cc: stable@vger.kernel.org # v4.2+ Fixes: 4bc94d5dc95d ("vfio: Fix lockdep issue") Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * VFIO: platform: reset: AMD xgbe reset moduleEric Auger2015-11-033-0/+137
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a module that registers and implements a low-level reset function for the AMD XGBE device. it performs the following actions: - reset the PHY - disable auto-negotiation - disable & clear auto-negotiation IRQ - soft-reset the MAC Those tiny pieces of code are inherited from the native xgbe driver. Signed-off-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: reset: calxedaxgmac: fix ioaddr leakEric Auger2015-11-031-7/+7
| | | | | | | | | | | | | | | | | | | | In the current code the vfio_platform_region is copied on the stack. As a consequence the ioaddr address is not iounmapped in the vfio platform driver (vfio_platform_regions_cleanup). The patch uses the pointer to the region instead. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: add dev_info on device resetEric Auger2015-11-032-2/+13
| | | | | | | | | | | | | | | | | | | | | | It might be helpful for the end-user to check the device reset function was found by the vfio platform reset framework. Lets store a pointer to the struct device in vfio_platform_device and trace when the reset function is called or not found. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: use list of registered reset functionEric Auger2015-11-033-30/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the static lookup table and use the dynamic list of registered reset functions instead. Also load the reset module through its alias. The reset struct module pointer is stored in vfio_platform_device. We also remove the useless struct device pointer parameter in vfio_platform_get_reset. This patch fixes the issue related to the usage of __symbol_get, which besides from being moot, prevented compilation with CONFIG_MODULES disabled. Also usage of MODULE_ALIAS makes possible to add a new reset module without needing to update the framework. This was suggested by Arnd. Signed-off-by: Eric Auger <eric.auger@linaro.org> Reported-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: add compat in vfio_platform_deviceEric Auger2015-11-032-7/+9
| | | | | | | | | | | | | | | | Let's retrieve the compatibility string on probe and store it in the vfio_platform_device struct Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: reset: calxedaxgmac: add reset function registrationEric Auger2015-11-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | This patch adds the reset function registration/unregistration. This is handled through the module_vfio_reset_handler macro. This latter also defines a MODULE_ALIAS which simplifies the load from vfio-platform. Signed-off-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: introduce module_vfio_reset_handler macroEric Auger2015-11-031-0/+14
| | | | | | | | | | | | | | | | | | | | | | The module_vfio_reset_handler macro - define a module alias - implement module init/exit function which respectively registers and unregisters the reset function. Signed-off-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: add capability to register a reset functionEric Auger2015-11-032-0/+47
| | | | | | | | | | | | | | | | | | | | | | | | In preparation for subsequent changes in reset function lookup, lets introduce a dynamic list of reset combos (compat string, reset module, reset function). The list can be populated/voided with vfio_platform_register/unregister_reset. Those are not yet used in this patch. Signed-off-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio: platform: introduce vfio-platform-base moduleEric Auger2015-11-035-4/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To prepare for vfio platform reset rework let's build vfio_platform_common.c and vfio_platform_irq.c in a separate module from vfio-platform and vfio-amba. This makes possible to have separate module inits and works around a race between platform driver init and vfio reset module init: that way we make sure symbols exported by base are available when vfio-platform driver gets probed. The open/release being implemented in the base module, the ref count is applied to the parent module instead. Signed-off-by: Eric Auger <eric.auger@linaro.org> Suggested-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio/platform: store mapped memory in region, instead of an on-stack copyJames Morse2015-11-031-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vfio_platform_{read,write}_mmio() call ioremap_nocache() to map a region of io memory, which they store in struct vfio_platform_region to be eventually re-used, or unmapped by vfio_platform_regions_cleanup(). These functions receive a copy of their struct vfio_platform_region argument on the stack - so these mapped areas are always allocated, and always leaked. Pass this argument as a pointer instead. Fixes: 6e3f26456009 "vfio/platform: read and write support for the device fd" Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio/type1: handle case where IOMMU does not support PAGE_SIZE sizeEric Auger2015-11-031-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current vfio_pgsize_bitmap code hides the supported IOMMU page sizes smaller than PAGE_SIZE. As a result, in case the IOMMU does not support PAGE_SIZE page, the alignment check on map/unmap is done with larger page sizes, if any. This can fail although mapping could be done with pages smaller than PAGE_SIZE. This patch modifies vfio_pgsize_bitmap implementation so that, in case the IOMMU supports page sizes smaller than PAGE_SIZE we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes. That way the user will be able to map/unmap buffers whose size/ start address is aligned with PAGE_SIZE. Pinning code uses that granularity while iommu driver can use the sub-PAGE_SIZE size to map the buffer. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * VFIO: platform: clear IRQ_NOAUTOEN when de-assigning the IRQEric Auger2015-10-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | The vfio platform driver currently sets the IRQ_NOAUTOEN before doing the request_irq to properly handle the user masking. However it does not clear it when de-assigning the IRQ. This brings issues when loading the native driver again which may not explicitly enable the IRQ. This problem was observed with xgbe driver. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio/pci: Use kernel VPD access functionsAlex Williamson2015-10-271-1/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PCI VPD capability operates on a set of window registers in PCI config space. Writing to the address register triggers either a read or write, depending on the setting of the PCI_VPD_ADDR_F bit within the address register. The data register provides either the source for writes or the target for reads. This model is susceptible to being broken by concurrent access, for which the kernel has adopted a set of access functions to serialize these registers. Additionally, commits like 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0") and 7aa6ca4d39ed ("PCI: Add VPD function 0 quirk for Intel Ethernet devices") indicate that VPD registers can be shared between functions on multifunction devices creating dependencies between otherwise independent devices. Fortunately it's quite easy to emulate the VPD registers, simply storing copies of the address and data registers in memory and triggering a VPD read or write on writes to the address register. This allows vfio users to avoid seeing spurious register changes from accesses on other devices and enables the use of shared quirks in the host kernel. We can theoretically still race with access through sysfs, but the window of opportunity is much smaller. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Mark Rustad <mark.d.rustad@intel.com>
| * vfio: Whitelist PCI bridgesAlex Williamson2015-10-271-6/+25
| | | | | | | | | | | | | | When determining whether a group is viable, we already allow devices bound to pcieport. Generalize this to include any PCI bridge device. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* | vfio: Register/unregister irq_bypass_producerFeng Wu2015-10-014-0/+13
|/ | | | | | | | | This patch adds the registration/unregistration of an irq_bypass_producer for MSI/MSIx on vfio pci devices. Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Feng Wu <feng.wu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* vfio: Fix lockdep issueAlex Williamson2015-07-241-37/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we open a device file descriptor, we currently have the following: vfio_group_get_device_fd() mutex_lock(&group->device_lock); open() ... if (ret) release() If we hit that error case, we call the backend driver release path, which for vfio-pci looks like this: vfio_pci_release() vfio_pci_disable() vfio_pci_try_bus_reset() vfio_pci_get_devs() vfio_device_get_from_dev() vfio_group_get_device() mutex_lock(&group->device_lock); Whoops, we've stumbled back onto group.device_lock and created a deadlock. There's a low likelihood of ever seeing this play out, but obviously it needs to be fixed. To do that we can use a reference to the vfio_device for vfio_group_get_device_fd() rather than holding the lock. There was a loop in this function, theoretically allowing multiple devices with the same name, but in practice we don't expect such a thing to happen and the code is already aborting from the loop with break on any sort of error rather than continuing and only parsing the first match anyway, so the loop was effectively unused already. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Fixes: 20f300175a1e ("vfio/pci: Fix racy vfio_device_get_from_dev() call") Reported-by: Joerg Roedel <joro@8bytes.org> Tested-by: Joerg Roedel <jroedel@suse.de>
* Merge tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds2015-06-289-19/+195
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull VFIO updates from Alex Williamson: - fix race with device reference versus driver release (Alex Williamson) - add reset hooks and Calxeda xgmac reset for vfio-platform (Eric Auger) - enable vfio-platform for ARM64 (Eric Auger) - tag Baptiste Reynal as vfio-platform sub-maintainer (Alex Williamson) * tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfio: MAINTAINERS: Add vfio-platform sub-maintainer VFIO: platform: enable ARM64 build VFIO: platform: Calxeda xgmac reset module VFIO: platform: populate the reset function on probe VFIO: platform: add reset callback VFIO: platform: add reset struct and lookup table vfio/pci: Fix racy vfio_device_get_from_dev() call
| * VFIO: platform: enable ARM64 buildEric Auger2015-06-221-1/+1
| | | | | | | | | | | | | | | | | | This patch enables building VFIO platform and derivatives on ARM64. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * VFIO: platform: Calxeda xgmac reset moduleEric Auger2015-06-226-0/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a module that registers and implements a basic reset function for the Calxeda xgmac device. This latter basically disables interrupts and stops DMA transfers. The reset function code is inherited from the native calxeda xgmac driver. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * VFIO: platform: populate the reset function on probeEric Auger2015-06-221-1/+36
| | | | | | | | | | | | | | | | | | | | | | The reset function lookup happens on vfio-platform probe. The reset module load is requested and a reference to the function symbol is hold. The reference is released on vfio-platform remove. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * VFIO: platform: add reset callbackEric Auger2015-06-222-2/+14
| | | | | | | | | | | | | | | | | | | | | | A new reset callback is introduced. If this callback is populated, the reset is invoked on device first open/last close or upon userspace ioctl. The modality is exposed on VFIO_DEVICE_GET_INFO. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * VFIO: platform: add reset struct and lookup tableEric Auger2015-06-172-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces the vfio_platform_reset_combo struct that stores all the information useful to handle the reset modality: compat string, name of the reset function, name of the module that implements the reset function. A lookup table of such structures is added, currently void. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| * vfio/pci: Fix racy vfio_device_get_from_dev() callAlex Williamson2015-06-092-15/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Testing the driver for a PCI device is racy, it can be all but complete in the release path and still report the driver as ours. Therefore we can't trust drvdata to be valid. This race can sometimes be seen when one port of a multifunction device is being unbound from the vfio-pci driver while another function is being released by the user and attempting a bus reset. The device in the remove path is found as a dependent device for the bus reset of the release path device, the driver is still set to vfio-pci, but the drvdata has already been cleared, resulting in a null pointer dereference. To resolve this, fix vfio_device_get_from_dev() to not take the dev_get_drvdata() shortcut and instead traverse through the iommu_group, vfio_group, vfio_device path to get a reference we can trust. Once we have that reference, we know the device isn't in transition and we can test to make sure the driver is still what we expect, so that we don't interfere with devices we don't own. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* | Merge tag 'powerpc-4.2-1' of ↵Linus Torvalds2015-06-242-101/+1010
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux Pull powerpc updates from Michael Ellerman: - disable the 32-bit vdso when building LE, so we can build with a 64-bit only toolchain. - EEH fixes from Gavin & Richard. - enable the sys_kcmp syscall from Laurent. - sysfs control for fastsleep workaround from Shreyas. - expose OPAL events as an irq chip by Alistair. - MSI ops moved to pci_controller_ops by Daniel. - fix for kernel to userspace backtraces for perf from Anton. - merge pseries and pseries_le defconfigs from Cyril. - CXL in-kernel API from Mikey. - OPAL prd driver from Jeremy. - fix for DSCR handling & tests from Anshuman. - Powernv flash mtd driver from Cyril. - dynamic DMA Window support on powernv from Alexey. - LLVM clang fixes & workarounds from Anton. - reworked version of the patch to abort syscalls when transactional. - fix the swap encoding to support 4TB, from Aneesh. - various fixes as usual. - Freescale updates from Scott: Highlights include more 8xx optimizations, an e6500 hugetlb optimization, QMan device tree nodes, t1024/t1023 support, and various fixes and cleanup. * tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (180 commits) cxl: Fix typo in debug print cxl: Add CXL_KERNEL_API config option powerpc/powernv: Fix wrong IOMMU table in pnv_ioda_setup_bus_dma() powerpc/mm: Change the swap encoding in pte. powerpc/mm: PTE_RPN_MAX is not used, remove the same powerpc/tm: Abort syscalls in active transactions powerpc/iommu/ioda2: Enable compile with IOV=on and IOMMU_API=off powerpc/include: Add opal-prd to installed uapi headers powerpc/powernv: fix construction of opal PRD messages powerpc/powernv: Increase opal-irqchip initcall priority powerpc: Make doorbell check preemption safe powerpc/powernv: pnv_init_idle_states() should only run on powernv macintosh/nvram: Remove as unused powerpc: Don't use gcc specific options on clang powerpc: Don't use -mno-strict-align on clang powerpc: Only use -mtraceback=no, -mno-string and -msoft-float if toolchain supports it powerpc: Only use -mabi=altivec if toolchain supports it powerpc: Fix duplicate const clang warning in user access code vfio: powerpc/spapr: Support Dynamic DMA windows vfio: powerpc/spapr: Register memory and define IOMMU v2 ...
| * | vfio: powerpc/spapr: Support Dynamic DMA windowsAlexey Kardashevskiy2015-06-111-1/+195
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds create/remove window ioctls to create and remove DMA windows. sPAPR defines a Dynamic DMA windows capability which allows para-virtualized guests to create additional DMA windows on a PCI bus. The existing linux kernels use this new window to map the entire guest memory and switch to the direct DMA operations saving time on map/unmap requests which would normally happen in a big amounts. This adds 2 ioctl handlers - VFIO_IOMMU_SPAPR_TCE_CREATE and VFIO_IOMMU_SPAPR_TCE_REMOVE - to create and remove windows. Up to 2 windows are supported now by the hardware and by this driver. This changes VFIO_IOMMU_SPAPR_TCE_GET_INFO handler to return additional information such as a number of supported windows and maximum number levels of TCE tables. DDW is added as a capability, not as a SPAPR TCE IOMMU v2 unique feature as we still want to support v2 on platforms which cannot do DDW for the sake of TCE acceleration in KVM (coming soon). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | vfio: powerpc/spapr: Register memory and define IOMMU v2Alexey Kardashevskiy2015-06-111-80/+421
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing implementation accounts the whole DMA window in the locked_vm counter. This is going to be worse with multiple containers and huge DMA windows. Also, real-time accounting would requite additional tracking of accounted pages due to the page size difference - IOMMU uses 4K pages and system uses 4K or 64K pages. Another issue is that actual pages pinning/unpinning happens on every DMA map/unmap request. This does not affect the performance much now as we spend way too much time now on switching context between guest/userspace/host but this will start to matter when we add in-kernel DMA map/unmap acceleration. This introduces a new IOMMU type for SPAPR - VFIO_SPAPR_TCE_v2_IOMMU. New IOMMU deprecates VFIO_IOMMU_ENABLE/VFIO_IOMMU_DISABLE and introduces 2 new ioctls to register/unregister DMA memory - VFIO_IOMMU_SPAPR_REGISTER_MEMORY and VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY - which receive user space address and size of a memory region which needs to be pinned/unpinned and counted in locked_vm. New IOMMU splits physical pages pinning and TCE table update into 2 different operations. It requires: 1) guest pages to be registered first 2) consequent map/unmap requests to work only with pre-registered memory. For the default single window case this means that the entire guest (instead of 2GB) needs to be pinned before using VFIO. When a huge DMA window is added, no additional pinning will be required, otherwise it would be guest RAM + 2GB. The new memory registration ioctls are not supported by VFIO_SPAPR_TCE_IOMMU. Dynamic DMA window and in-kernel acceleration will require memory to be preregistered in order to work. The accounting is done per the user process. This advertises v2 SPAPR TCE IOMMU and restricts what the userspace can do with v1 or v2 IOMMUs. In order to support memory pre-registration, we need a way to track the use of every registered memory region and only allow unregistration if a region is not in use anymore. So we need a way to tell from what region the just cleared TCE was from. This adds a userspace view of the TCE table into iommu_table struct. It contains userspace address, one per TCE entry. The table is only allocated when the ownership over an IOMMU group is taken which means it is only used from outside of the powernv code (such as VFIO). As v2 IOMMU supports IODA2 and pre-IODA2 IOMMUs (which do not support DDW API), this creates a default DMA window for IODA2 for consistency. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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