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2020-10-29vfio/pci: Clear token on bypass registration failureAlex Williamson1-1/+3
[ Upstream commit 852b1beecb6ff9326f7ca4bc0fe69ae860ebdb9e ] The eventfd context is used as our irqbypass token, therefore if an eventfd is re-used, our token is the same. The irqbypass code will return an -EBUSY in this case, but we'll still attempt to unregister the producer, where if that duplicate token still exists, results in removing the wrong object. Clear the token of failed producers so that they harmlessly fall out when unregistered. Fixes: 6d7425f109d2 ("vfio: Register/unregister irq_bypass_producer") Reported-by: guomin chen <guomin_chen@sina.com> Tested-by: guomin chen <guomin_chen@sina.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01vfio/pci: fix racy on error and request eventfd ctxZeng Tao1-0/+5
[ Upstream commit b872d0640840018669032b20b6375a478ed1f923 ] The vfio_pci_release call will free and clear the error and request eventfd ctx while these ctx could be in use at the same time in the function like vfio_pci_request, and it's expected to protect them under the vdev->igate mutex, which is missing in vfio_pci_release. This issue is introduced since commit 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx"),and since commit 5c5866c593bb ("vfio/pci: Clear error and request eventfd ctx after releasing"), it's very easily to trigger the kernel panic like this: [ 9513.904346] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 [ 9513.913091] Mem abort info: [ 9513.915871] ESR = 0x96000006 [ 9513.918912] EC = 0x25: DABT (current EL), IL = 32 bits [ 9513.924198] SET = 0, FnV = 0 [ 9513.927238] EA = 0, S1PTW = 0 [ 9513.930364] Data abort info: [ 9513.933231] ISV = 0, ISS = 0x00000006 [ 9513.937048] CM = 0, WnR = 0 [ 9513.940003] user pgtable: 4k pages, 48-bit VAs, pgdp=0000007ec7d12000 [ 9513.946414] [0000000000000008] pgd=0000007ec7d13003, p4d=0000007ec7d13003, pud=0000007ec728c003, pmd=0000000000000000 [ 9513.956975] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 9513.962521] Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio hclge hns3 hnae3 [last unloaded: vfio_pci] [ 9513.972998] CPU: 4 PID: 1327 Comm: bash Tainted: G W 5.8.0-rc4+ #3 [ 9513.980443] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B270.01 05/08/2020 [ 9513.989274] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) [ 9513.994827] pc : _raw_spin_lock_irqsave+0x48/0x88 [ 9513.999515] lr : eventfd_signal+0x6c/0x1b0 [ 9514.003591] sp : ffff800038a0b960 [ 9514.006889] x29: ffff800038a0b960 x28: ffff007ef7f4da10 [ 9514.012175] x27: ffff207eefbbfc80 x26: ffffbb7903457000 [ 9514.017462] x25: ffffbb7912191000 x24: ffff007ef7f4d400 [ 9514.022747] x23: ffff20be6e0e4c00 x22: 0000000000000008 [ 9514.028033] x21: 0000000000000000 x20: 0000000000000000 [ 9514.033321] x19: 0000000000000008 x18: 0000000000000000 [ 9514.038606] x17: 0000000000000000 x16: ffffbb7910029328 [ 9514.043893] x15: 0000000000000000 x14: 0000000000000001 [ 9514.049179] x13: 0000000000000000 x12: 0000000000000002 [ 9514.054466] x11: 0000000000000000 x10: 0000000000000a00 [ 9514.059752] x9 : ffff800038a0b840 x8 : ffff007ef7f4de60 [ 9514.065038] x7 : ffff007fffc96690 x6 : fffffe01faffb748 [ 9514.070324] x5 : 0000000000000000 x4 : 0000000000000000 [ 9514.075609] x3 : 0000000000000000 x2 : 0000000000000001 [ 9514.080895] x1 : ffff007ef7f4d400 x0 : 0000000000000000 [ 9514.086181] Call trace: [ 9514.088618] _raw_spin_lock_irqsave+0x48/0x88 [ 9514.092954] eventfd_signal+0x6c/0x1b0 [ 9514.096691] vfio_pci_request+0x84/0xd0 [vfio_pci] [ 9514.101464] vfio_del_group_dev+0x150/0x290 [vfio] [ 9514.106234] vfio_pci_remove+0x30/0x128 [vfio_pci] [ 9514.111007] pci_device_remove+0x48/0x108 [ 9514.115001] device_release_driver_internal+0x100/0x1b8 [ 9514.120200] device_release_driver+0x28/0x38 [ 9514.124452] pci_stop_bus_device+0x68/0xa8 [ 9514.128528] pci_stop_and_remove_bus_device+0x20/0x38 [ 9514.133557] pci_iov_remove_virtfn+0xb4/0x128 [ 9514.137893] sriov_disable+0x3c/0x108 [ 9514.141538] pci_disable_sriov+0x28/0x38 [ 9514.145445] hns3_pci_sriov_configure+0x48/0xb8 [hns3] [ 9514.150558] sriov_numvfs_store+0x110/0x198 [ 9514.154724] dev_attr_store+0x44/0x60 [ 9514.158373] sysfs_kf_write+0x5c/0x78 [ 9514.162018] kernfs_fop_write+0x104/0x210 [ 9514.166010] __vfs_write+0x48/0x90 [ 9514.169395] vfs_write+0xbc/0x1c0 [ 9514.172694] ksys_write+0x74/0x100 [ 9514.176079] __arm64_sys_write+0x24/0x30 [ 9514.179987] el0_svc_common.constprop.4+0x110/0x200 [ 9514.184842] do_el0_svc+0x34/0x98 [ 9514.188144] el0_svc+0x14/0x40 [ 9514.191185] el0_sync_handler+0xb0/0x2d0 [ 9514.195088] el0_sync+0x140/0x180 [ 9514.198389] Code: b9001020 d2800000 52800022 f9800271 (885ffe61) [ 9514.204455] ---[ end trace 648de00c8406465f ]--- [ 9514.212308] note: bash[1327] exited with preempt_count 1 Cc: Qian Cai <cai@lca.pw> Cc: Alex Williamson <alex.williamson@redhat.com> Fixes: 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx") Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01vfio/pci: Clear error and request eventfd ctx after releasingAlex Williamson1-2/+6
[ Upstream commit 5c5866c593bbd444d0339ede6a8fb5f14ff66d72 ] The next use of the device will generate an underflow from the stale reference. Cc: Qian Cai <cai@lca.pw> Fixes: 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx") Reported-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Tested-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01vfio/pci: fix memory leaks of eventfd ctxQian Cai1-0/+4
[ Upstream commit 1518ac272e789cae8c555d69951b032a275b7602 ] Finished a qemu-kvm (-device vfio-pci,host=0001:01:00.0) triggers a few memory leaks after a while because vfio_pci_set_ctx_trigger_single() calls eventfd_ctx_fdget() without the matching eventfd_ctx_put() later. Fix it by calling eventfd_ctx_put() for those memory in vfio_pci_release() before vfio_device_release(). unreferenced object 0xebff008981cc2b00 (size 128): comm "qemu-kvm", pid 4043, jiffies 4294994816 (age 9796.310s) hex dump (first 32 bytes): 01 00 00 00 6b 6b 6b 6b 00 00 00 00 ad 4e ad de ....kkkk.....N.. ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ backtrace: [<00000000917e8f8d>] slab_post_alloc_hook+0x74/0x9c [<00000000df0f2aa2>] kmem_cache_alloc_trace+0x2b4/0x3d4 [<000000005fcec025>] do_eventfd+0x54/0x1ac [<0000000082791a69>] __arm64_sys_eventfd2+0x34/0x44 [<00000000b819758c>] do_el0_svc+0x128/0x1dc [<00000000b244e810>] el0_sync_handler+0xd0/0x268 [<00000000d495ef94>] el0_sync+0x164/0x180 unreferenced object 0x29ff008981cc4180 (size 128): comm "qemu-kvm", pid 4043, jiffies 4294994818 (age 9796.290s) hex dump (first 32 bytes): 01 00 00 00 6b 6b 6b 6b 00 00 00 00 ad 4e ad de ....kkkk.....N.. ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ backtrace: [<00000000917e8f8d>] slab_post_alloc_hook+0x74/0x9c [<00000000df0f2aa2>] kmem_cache_alloc_trace+0x2b4/0x3d4 [<000000005fcec025>] do_eventfd+0x54/0x1ac [<0000000082791a69>] __arm64_sys_eventfd2+0x34/0x44 [<00000000b819758c>] do_el0_svc+0x128/0x1dc [<00000000b244e810>] el0_sync_handler+0xd0/0x268 [<00000000d495ef94>] el0_sync+0x164/0x180 Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-12vfio/pci: Fix SR-IOV VF handling with MMIO blockingAlex Williamson1-1/+16
commit ebfa440ce38b7e2e04c3124aa89c8a9f4094cf21 upstream. SR-IOV VFs do not implement the memory enable bit of the command register, therefore this bit is not set in config space after pci_enable_device(). This leads to an unintended difference between PF and VF in hand-off state to the user. We can correct this by setting the initial value of the memory enable bit in our virtualized config space. There's really no need however to ever fault a user on a VF though as this would only indicate an error in the user's management of the enable bit, versus a PF where the same access could trigger hardware faults. Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12vfio-pci: Invalidate mmaps and block MMIO access on disabled memoryAlex Williamson5-48/+334
commit abafbc551fddede3e0a08dee1dcde08fc0eb8476 upstream. Accessing the disabled memory space of a PCI device would typically result in a master abort response on conventional PCI, or an unsupported request on PCI express. The user would generally see these as a -1 response for the read return data and the write would be silently discarded, possibly with an uncorrected, non-fatal AER error triggered on the host. Some systems however take it upon themselves to bring down the entire system when they see something that might indicate a loss of data, such as this discarded write to a disabled memory space. To avoid this, we want to try to block the user from accessing memory spaces while they're disabled. We start with a semaphore around the memory enable bit, where writers modify the memory enable state and must be serialized, while readers make use of the memory region and can access in parallel. Writers include both direct manipulation via the command register, as well as any reset path where the internal mechanics of the reset may both explicitly and implicitly disable memory access, and manipulation of the MSI-X configuration, where the MSI-X vector table resides in MMIO space of the device. Readers include the read and write file ops to access the vfio device fd offsets as well as memory mapped access. In the latter case, we make use of our new vma list support to zap, or invalidate, those memory mappings in order to force them to be faulted back in on access. Our semaphore usage will stall user access to MMIO spaces across internal operations like reset, but the user might experience new behavior when trying to access the MMIO space while disabled via the PCI command register. Access via read or write while disabled will return -EIO and access via memory maps will result in a SIGBUS. This is expected to be compatible with known use cases and potentially provides better error handling capabilities than present in the hardware, while avoiding the more readily accessible and severe platform error responses that might otherwise occur. Fixes: CVE-2020-12888 Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [Ajay: Regenerated the patch for v4.14] Signed-off-by: Ajay Kaher <akaher@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12vfio-pci: Fault mmaps to enable vma trackingAlex Williamson2-2/+81
commit 11c4cd07ba111a09f49625f9e4c851d83daf0a22 upstream. Rather than calling remap_pfn_range() when a region is mmap'd, setup a vm_ops handler to support dynamic faulting of the range on access. This allows us to manage a list of vmas actively mapping the area that we can later use to invalidate those mappings. The open callback invalidates the vma range so that all tracking is inserted in the fault handler and removed in the close handler. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [Ajay: Regenerated the patch for v4.14] Signed-off-by: Ajay Kaher <akaher@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-25vfio-pci: Mask cap zeroAlex Williamson1-1/+6
[ Upstream commit bc138db1b96264b9c1779cf18d5a3b186aa90066 ] The PCI Code and ID Assignment Specification changed capability ID 0 from reserved to a NULL capability in the v1.1 revision. The NULL capability is defined to include only the 16-bit capability header, ie. only the ID and next pointer. Unfortunately vfio-pci creates a map of config space, where ID 0 is used to reserve the standard type 0 header. Finding an actual capability with this ID therefore results in a bogus range marked in that map and conflicts with subsequent capabilities. As this seems to be a dummy capability anyway and we already support dropping capabilities, let's hide this one rather than delving into the potentially subtle dependencies within our map. Seen on an NVIDIA Tesla T4. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25vfio/pci: fix memory leaks in alloc_perm_bits()Qian Cai1-2/+5
[ Upstream commit 3e63b94b6274324ff2e7d8615df31586de827c4e ] vfio_pci_disable() calls vfio_config_free() but forgets to call free_perm_bits() resulting in memory leaks, unreferenced object 0xc000000c4db2dee0 (size 16): comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s) hex dump (first 16 bytes): 00 00 ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................ backtrace: [<00000000a6a4552d>] alloc_perm_bits+0x58/0xe0 [vfio_pci] [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci] init_pci_cap_msi_perm at drivers/vfio/pci/vfio_pci_config.c:1125 (inlined by) vfio_msi_cap_len at drivers/vfio/pci/vfio_pci_config.c:1180 (inlined by) vfio_cap_len at drivers/vfio/pci/vfio_pci_config.c:1241 (inlined by) vfio_cap_init at drivers/vfio/pci/vfio_pci_config.c:1468 (inlined by) vfio_config_init at drivers/vfio/pci/vfio_pci_config.c:1707 [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci] [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio] [<000000009e34c54f>] ksys_ioctl+0xd8/0x130 [<000000006577923d>] sys_ioctl+0x28/0x40 [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0 [<0000000008ea7dd5>] system_call_common+0xf0/0x278 unreferenced object 0xc000000c4db2e330 (size 16): comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s) hex dump (first 16 bytes): 00 ff ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................ backtrace: [<000000004c71914f>] alloc_perm_bits+0x44/0xe0 [vfio_pci] [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci] [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci] [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio] [<000000009e34c54f>] ksys_ioctl+0xd8/0x130 [<000000006577923d>] sys_ioctl+0x28/0x40 [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0 [<0000000008ea7dd5>] system_call_common+0xf0/0x278 Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Qian Cai <cai@lca.pw> [aw: rolled in follow-up patch] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27vfio_pci: Enable memory accesses before calling pci_map_romEric Auger1-5/+14
[ Upstream commit 0cfd027be1d6def4a462cdc180c055143af24069 ] pci_map_rom/pci_get_rom_size() performs memory access in the ROM. In case the Memory Space accesses were disabled, readw() is likely to trigger a synchronous external abort on some platforms. In case memory accesses were disabled, re-enable them before the call and disable them back again just after. Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Eric Auger <eric.auger@redhat.com> Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-21vfio/pci: call irq_bypass_unregister_producer() before freeing irqJiang Yi1-1/+1
commit d567fb8819162099035e546b11a736e29c2af0ea upstream. Since irq_bypass_register_producer() is called after request_irq(), we should do tear-down in reverse order: irq_bypass_unregister_producer() then free_irq(). Specifically free_irq() may release resources required by the irqbypass del_producer() callback. Notably an example provided by Marc Zyngier on arm64 with GICv4 that he indicates has the potential to wedge the hardware: free_irq(irq) __free_irq(irq) irq_domain_deactivate_irq(irq) its_irq_domain_deactivate() [unmap the VLPI from the ITS] kvm_arch_irq_bypass_del_producer(cons, prod) kvm_vgic_v4_unset_forwarding(kvm, irq, ...) its_unmap_vlpi(irq) [Unmap the VLPI from the ITS (again), remap the original LPI] Signed-off-by: Jiang Yi <giangyi@amazon.com> Cc: stable@vger.kernel.org # v4.4+ Fixes: 6d7425f109d26 ("vfio: Register/unregister irq_bypass_producer") Link: https://lore.kernel.org/kvm/20191127164910.15888-1-giangyi@amazon.com Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> [aw: commit log] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-20vfio/pci: Mask buggy SR-IOV VF INTx supportAlex Williamson2-2/+33
[ Upstream commit db04264fe9bc0f2b62e036629f9afb530324b693 ] The SR-IOV spec requires that VFs must report zero for the INTx pin register as VFs are precluded from INTx support. It's much easier for the host kernel to understand whether a device is a VF and therefore whether a non-zero pin register value is bogus than it is to do the same in userspace. Override the INTx count for such devices and virtualize the pin register to provide a consistent view of the device to the user. As this is clearly a spec violation, warn about it to support hardware validation, but also provide a known whitelist as it doesn't do much good to continue complaining if the hardware vendor doesn't plan to fix it. Known devices with this issue: 8086:270c Tested-by: Gage Eads <gage.eads@intel.com> Reviewed-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20vfio/pci: Fix potential memory leak in vfio_msi_cap_lenLi Qiang1-1/+3
[ Upstream commit 30ea32ab1951c80c6113f300fce2c70cd12659e4 ] Free allocated vdev->msi_perm in error path. Signed-off-by: Li Qiang <liq3ea@gmail.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-07vfio_pci: Restore original state on releasehexin1-4/+13
[ Upstream commit 92c8026854c25093946e0d7fe536fd9eac440f06 ] vfio_pci_enable() saves the device's initial configuration information with the intent that it is restored in vfio_pci_disable(). However, the commit referenced in Fixes: below replaced the call to __pci_reset_function_locked(), which is not wrapped in a state save and restore, with pci_try_reset_function(), which overwrites the restored device state with the current state before applying it to the device. Reinstate use of __pci_reset_function_locked() to return to the desired behavior. Fixes: 890ed578df82 ("vfio-pci: Use pci "try" reset interface") Signed-off-by: hexin <hexin15@baidu.com> Signed-off-by: Liu Qi <liuqi16@baidu.com> Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-08vfio/pci: use correct format charactersLouis Taylor1-2/+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>
2018-07-25vfio/pci: Fix potential Spectre v1Gustavo A. R. Silva1-0/+4
commit 0e714d27786ce1fb3efa9aac58abc096e68b1c2a upstream. info.index can be indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/vfio/pci/vfio_pci.c:734 vfio_pci_ioctl() warn: potential spectre issue 'vdev->region' Fix this by sanitizing info.index before indirectly using it to index vdev->region Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-24vfio/pci: Virtualize Maximum Read Request SizeAlex Williamson1-3/+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>
2017-12-25vfio/pci: Virtualize Maximum Payload SizeAlex Williamson1-2/+4
[ Upstream commit 523184972b282cd9ca17a76f6ca4742394856818 ] 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: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27vfio/pci: Fix handling of RC integrated endpoint PCIe capability sizeAlex Williamson1-4/+9
Root complex integrated endpoints do not have a link and therefore may use a smaller PCIe capability in config space than we expect when building our config map. Add a case for these to avoid reporting an erroneous overlap. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-07-26vfio/pci: Use pci_try_reset_function() on initial openAlex Williamson1-1/+8
Device lock bites again; if a device .remove() callback races a user calling ioctl(VFIO_GROUP_GET_DEVICE_FD), the unbind request will hold the device lock, but the user ioctl may have already taken a vfio_device reference. In the case of a PCI device, the initial open will attempt to reset the device, which again attempts to get the device lock, resulting in deadlock. Use the trylock PCI reset interface and return error on the open path if reset fails due to lock contention. Link: https://lkml.org/lkml/2017/7/25/381 Reported-by: Wen Congyang <wencongyang2@huawei.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-06-13vfio/pci: Add Intel XXV710 to hidden INTx devicesAlex Williamson1-2/+2
XXV710 has the same broken INTx behavior as the rest of the X/XL710 series, the interrupt status register is not wired to report pending INTx interrupts, thus we never associate the interrupt to the device. Extend the device IDs to include these so that we hide that the device supports INTx at all to the user. Reported-by: Stefan Assmann <sassmann@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
2017-01-04vfio-pci: Handle error from pci_iomapArvind Yadav1-0/+4
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>
2016-12-30vfio-pci: use 32-bit comparisons for register address for gcc-4.5Arnd Bergmann1-1/+4
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>
2016-12-15Merge tag 'pci-v4.10-changes' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "PCI changes: - add support for PCI on ARM64 boxes with ACPI. We already had this for theoretical spec-compliant hardware; now we're adding quirks for the actual hardware (Cavium, HiSilicon, Qualcomm, X-Gene) - add runtime PM support for hotplug ports - enable runtime suspend for Intel UHCI that uses platform-specific wakeup signaling - add yet another host bridge registration interface. We hope this is extensible enough to subsume the others - expose device revision in sysfs for DRM - to avoid device conflicts, make sure any VF BAR updates are done before enabling the VF - avoid unnecessary link retrains for ASPM - allow INTx masking on Mellanox devices that support it - allow access to non-standard VPD for Chelsio devices - update Broadcom iProc support for PAXB v2, PAXC v2, inbound DMA, etc - update Rockchip support for max-link-speed - add NVIDIA Tegra210 support - add Layerscape LS1046a support - update R-Car compatibility strings - add Qualcomm MSM8996 support - remove some uninformative bootup messages" * tag 'pci-v4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (115 commits) PCI: Enable access to non-standard VPD for Chelsio devices (cxgb3) PCI: Expand "VPD access disabled" quirk message PCI: pciehp: Remove loading message PCI: hotplug: Remove hotplug core message PCI: Remove service driver load/unload messages PCI/AER: Log AER IRQ when claiming Root Port PCI/AER: Log errors with PCI device, not PCIe service device PCI/AER: Remove unused version macros PCI/PME: Log PME IRQ when claiming Root Port PCI/PME: Drop unused support for PMEs from Root Complex Event Collectors PCI: Move config space size macros to pci_regs.h x86/platform/intel-mid: Constify mid_pci_platform_pm PCI/ASPM: Don't retrain link if ASPM not possible PCI: iproc: Skip check for legacy IRQ on PAXC buses PCI: pciehp: Leave power indicator on when enabling already-enabled slot PCI: pciehp: Prioritize data-link event over presence detect PCI: rcar: Add gen3 fallback compatibility string for pcie-rcar PCI: rcar: Use gen2 fallback compatibility last PCI: rcar-gen2: Use gen2 fallback compatibility last PCI: rockchip: Move the deassert of pm/aclk/pclk after phy_init() ..
2016-12-12PCI: Move config space size macros to pci_regs.hWang Sheng-Hui1-2/+0
Move PCI configuration space size macros (PCI_CFG_SPACE_SIZE and PCI_CFG_SPACE_EXP_SIZE) from drivers/pci/pci.h to include/uapi/linux/pci_regs.h so they can be used by more drivers and eliminate duplicate definitions. [bhelgaas: Expand comment to include PCI-X details] Signed-off-by: Wang Sheng-Hui <shhuiw@foxmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-11-18vfio/pci: Drop unnecessary pcibios_err_to_errno()Cao jin1-5/+5
As of commit d97ffe236894 ("PCI: Fix return value from pci_user_{read,write}_config_*()") it's unnecessary to call pcibios_err_to_errno() to fixup the return value from these functions. pcibios_err_to_errno() already does simple passthrough of -errno values, therefore no functional change is expected. [aw: changelog] Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17vfio_pci: Updated to use vfio_set_irqs_validate_and_prepare()Kirti Wankhede1-27/+7
Updated vfio_pci.c file to use vfio_set_irqs_validate_and_prepare() Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17vfio_pci: Update vfio_pci to use vfio_info_add_capability()Kirti Wankhede1-30/+19
Update msix_sparse_mmap_cap() to use vfio_info_add_capability() Update region type capability to use vfio_info_add_capability() Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-10-26vfio/pci: Fix integer overflows, bitmask checkVlad Tsyrklevich2-13/+22
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>
2016-09-29vfio_pci: use pci_alloc_irq_vectorsChristoph Hellwig2-36/+10
Simplify the interrupt setup by using the new PCI layer helpers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-09-26vfio-pci: Disable INTx after MSI/X teardownAlex Williamson1-0/+7
The MSI/X shutdown path can gratuitously enable INTx, which is not something we want to happen if we're dealing with broken INTx device. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-09-26vfio-pci: Virtualize PCIe & AF FLRAlex Williamson1-5/+77
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>
2016-08-29vfio/pci: Fix typos in commentsWei Jiangang1-4/+4
Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-08-09vfio/pci: Fix NULL pointer oops in error interrupt setup handlingAlex Williamson1-36/+49
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> Cc: stable@vger.kernel.org Reviewed-by: Eric Auger <eric.auger@redhat.com>
2016-07-08vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusiveYongji Xie2-6/+90
Current vfio-pci implementation disallows to mmap sub-page(size < PAGE_SIZE) MMIO BARs because these BARs' mmio page may be shared with other BARs. This will cause some performance issues when we passthrough a PCI device with this kind of BARs. Guest will be not able to handle the mmio accesses to the BARs which leads to mmio emulations in host. However, not all sub-page BARs will share page with other BARs. We should allow to mmap the sub-page MMIO BARs which we can make sure will not share page with other BARs. This patch adds support for this case. And we try to add a dummy resource to reserve the remainder of the page which hot-add device's BAR might be assigned into. But it's not necessary to handle the case when the BAR is not page aligned. Because we can't expect the BAR will be assigned into the same location in a page in guest when we passthrough the BAR. And it's hard to access this BAR in userspace because we have no way to get the BAR's location in a page. Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-06-01vfio/pci: Allow VPD short readAlex Williamson1-1/+2
The size of the VPD area is not necessarily 4-byte aligned, so a pci_vpd_read() might return less than 4 bytes. Zero our buffer and accept anything other than an error. Intel X710 NICs exercise this. Fixes: 4e1a635552d3 ("vfio/pci: Use kernel VPD access functions") Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-30vfio/pci: Fix ordering of eventfd vs virqfd shutdownAlex Williamson1-3/+3
Both the INTx and MSI/X disable paths do an eventfd_ctx_put() for the trigger eventfd before calling vfio_virqfd_disable() any potential mask and unmask eventfds. This opens a use-after-free race where an inopportune irqfd can reference the freed signalling eventfd. Reorder to avoid this possibility. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-20vfio_pci: Test for extended capabilities if config space > 256 bytesAlexey Kardashevskiy1-6/+11
PCI-Express spec says that reading 4 bytes at offset 100h should return zero if there is no extended capability so VFIO reads this dword to know if there are extended capabilities. However it is not always possible to access the extended space so generic PCI code in pci_cfg_space_size_ext() checks if pci_read_config_dword() can read beyond 100h and if the check fails, it sets the config space size to 100h. VFIO does its own extended capabilities check by reading at offset 100h which may produce 0xffffffff which VFIO treats as the extended config space presense and calls vfio_ecap_init() which fails to parse capabilities (which is expected) but right before the exit, it writes zero at offset 100h which is beyond the buffer allocated for vdev->vconfig (which is 256 bytes) which leads to random memory corruption. This makes VFIO only check for the extended capabilities if the discovered config size is more than 256 bytes. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-04-28vfio/pci: Add test for BAR restoreAlex Williamson1-1/+19
If a device is reset without the memory or i/o bits enabled in the command register we may not detect it, potentially leaving the device without valid BAR programming. Add an additional test to check the BARs on each write to the command register. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-04-28vfio/pci: Hide broken INTx support from userAlex Williamson3-11/+54
INTx masking has two components, the first is that we need the ability to prevent the device from continuing to assert INTx. This is provided via the DisINTx bit in the command register and is the only thing we can really probe for when testing if INTx masking is supported. The second component is that the device needs to indicate if INTx is asserted via the interrupt status bit in the device status register. With these two features we can generically determine if one of the devices we own is asserting INTx, signal the user, and mask the interrupt while the user services the device. Generally if one or both of these components is broken we resort to APIC level interrupt masking, which requires an exclusive interrupt since we have no way to determine the source of the interrupt in a shared configuration. This often makes it difficult or impossible to configure the system for userspace use of the device, for an interrupt mode that the user may not need. One possible configuration of broken INTx masking is that the DisINTx support is fully functional, but the interrupt status bit never signals interrupt assertion. In this case we do have the ability to prevent the device from asserting INTx, but lack the ability to identify the interrupt source. For this case we can simply pretend that the device lacks INTx support entirely, keeping DisINTx set on the physical device, virtualizing this bit for the user, and virtualizing the interrupt pin register to indicate no INTx support. We already support virtualization of the DisINTx bit and already virtualize the interrupt pin for platforms without INTx support. By tying these components together, setting DisINTx on open and reset, and identifying devices broken in this particular way, we can provide support for them w/o the handicap of APIC level INTx masking. Intel i40e (XL710/X710) 10/20/40GbE NICs have been identified as being broken in this specific way. We leave the vfio-pci.nointxmask option as a mechanism to bypass this support, enabling INTx on the device with all the requirements of APIC level masking. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Cc: John Ronciak <john.ronciak@intel.com> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
2016-03-17Merge tag 'vfio-v4.6-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds8-25/+545
Pull VFIO updates from Alex Williamson: "Various enablers for assignment of Intel graphics devices and future support of vGPU devices (Alex Williamson). This includes - Handling the vfio type1 interface as an API rather than a specific implementation, allowing multiple type1 providers. - Capability chains, similar to PCI device capabilities, that allow extending ioctls. Extensions here include device specific regions and sparse mmap descriptions. The former is used to expose non-PCI regions for IGD, including the OpRegion (particularly the Video BIOS Table), and read only PCI config access to the host and LPC bridge as drivers often depend on identifying those devices. Sparse mmaps here are used to describe the MSIx vector table, which vfio has always protected from mmap, but never had an API to explicitly define that protection. In future vGPU support this is expected to allow the description of PCI BARs that may mix direct access and emulated access within a single region. - The ability to expose the shadow ROM as an option ROM as IGD use cases may rely on the ROM even though the physical device does not make use of a PCI option ROM BAR" * tag 'vfio-v4.6-rc1' of git://github.com/awilliam/linux-vfio: vfio/pci: return -EFAULT if copy_to_user fails vfio/pci: Expose shadow ROM as PCI option ROM vfio/pci: Intel IGD host and LCP bridge config space access vfio/pci: Intel IGD OpRegion support vfio/pci: Enable virtual register in PCI config space vfio/pci: Add infrastructure for additional device specific regions vfio: Define device specific region type capability vfio/pci: Include sparse mmap capability for MSI-X table regions vfio: Define sparse mmap capability for regions vfio: Add capability chain helpers vfio: Define capability chains vfio: If an IOMMU backend fails, keep looking vfio/pci: Fix unsigned comparison overflow
2016-02-28vfio: fix ioctl error handlingMichael S. Tsirkin1-3/+6
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. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-26vfio/pci: return -EFAULT if copy_to_user failsDan Carpenter1-5/+4
The copy_to_user() function returns the number of bytes that were not copied but we want to return -EFAULT on error here. Fixes: 188ad9d6cbbc ('vfio/pci: Include sparse mmap capability for MSI-X table regions') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-23vfio/pci: Expose shadow ROM as PCI option ROMAlex Williamson3-8/+22
Integrated graphics may have their ROM shadowed at 0xc0000 rather than implement a PCI option ROM. Make this ROM appear to the user using the ROM BAR. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-23vfio/pci: Intel IGD host and LCP bridge config space accessAlex Williamson3-7/+183
Provide read-only access to PCI config space of the PCI host bridge and LPC bridge through device specific regions. This may be used to configure a VM with matching register contents to satisfy driver requirements. Providing this through the vfio file descriptor removes an additional userspace requirement for access through pci-sysfs and removes the CAP_SYS_ADMIN requirement that doesn't appear to apply to the specific devices we're accessing. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-23vfio/pci: Intel IGD OpRegion supportAlex Williamson5-0/+131
This is the first consumer of vfio device specific resource support, providing read-only access to the OpRegion for Intel graphics devices. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-23vfio/pci: Enable virtual register in PCI config spaceAlex Williamson2-4/+34
Typically config space for a device is mapped out into capability specific handlers and unassigned space. The latter allows direct read/write access to config space. Sometimes we know about registers living in this void space and would like an easy way to virtualize them, similar to how BAR registers are managed. To do this, create one more pseudo (fake) PCI capability to be handled as purely virtual space. Reads and writes are serviced entirely from virtual config space. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-23vfio/pci: Add infrastructure for additional device specific regionsAlex Williamson2-5/+103
Add support for additional regions with indexes started after the already defined fixed regions. Device specific code can register these regions with the new vfio_pci_register_dev_region() function. The ops structure per region currently only includes read/write access and a release function, allowing automatic cleanup when the device is closed. mmap support is only missing here because it's not needed by the first user queued for this support. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-23vfio/pci: Include sparse mmap capability for MSI-X table regionsAlex Williamson1-1/+72
vfio-pci has never allowed the user to directly mmap the MSI-X vector table, but we've always relied on implicit knowledge of the user that they cannot do this. Now that we have capability chains that we can expose in the region info ioctl and a sparse mmap capability that represents the sub-areas within the region that can be mmap'd, we can make the mmap constraints more explicit. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-23vfio/pci: Fix unsigned comparison overflowAlex Williamson1-8/+9
Signed versus unsigned comparisons are implicitly cast to unsigned, which result in a couple possible overflows. For instance (start + count) might overflow and wrap, getting through our validation test. Also when unwinding setup, -1 being compared as unsigned doesn't produce the intended stop condition. Fix both of these and also fix vfio_msi_set_vector_signal() to validate parameters before using the vector index, though none of the callers should pass bad indexes anymore. Reported-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Eric Auger <eric.auger@linaro.org> Tested-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>