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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 git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds1-2/+0
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>
2016-08-08vfio/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>
2016-05-31vfio/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>
2016-05-19vfio_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>
2016-02-25vfio/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>
2016-02-22vfio/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>
2016-02-22vfio/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>
2016-02-22vfio/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>
2016-02-22vfio/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>
2016-02-22vfio/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>
2016-02-22vfio/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>
2016-02-22vfio/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>
2015-12-21vfio: Include No-IOMMU modeAlex Williamson1-4/+4
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>
2015-12-04Revert: "vfio: Include No-IOMMU mode"Alex Williamson1-4/+4
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>
2015-11-19vfio-pci: constify pci_error_handlers structuresJulia Lawall1-1/+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>
2015-11-13Merge tag 'vfio-v4.4-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds2-7/+75
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
2015-11-09vfio/pci: make an array largerDan Carpenter1-2/+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>
2015-11-04vfio: Include No-IOMMU modeAlex Williamson1-4/+4
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>
2015-10-27vfio/pci: Use kernel VPD access functionsAlex Williamson1-1/+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>
2015-10-01vfio: Register/unregister irq_bypass_producerFeng Wu3-0/+12
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>
2015-06-09vfio/pci: Fix racy vfio_device_get_from_dev() callAlex Williamson1-7/+9
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>
2015-05-01vfio-pci: Log device requests more verboselyAlex Williamson1-1/+7
Log some clues indicating whether the user is receiving device request interfaces or not listening. This can help indicate why a driver unbind is blocked or explain why QEMU automatically unplugged a device from the VM. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-08vfio-pci: Fix use after freeAlex Williamson1-0/+1
Reported by 0-day test infrastructure. Fixes: ecaa1f6a0154 ("vfio-pci: Add VGA arbiter client") Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07vfio-pci: Move idle devices to D3hot power stateAlex Williamson1-3/+33
We can save some power by putting devices that are bound to vfio-pci but not in use by the user in the D3hot power state. Devices get woken into D0 when opened by the user. Resets return the device to D0, so we need to re-apply the low power state after a bus reset. It's tempting to try to use D3cold, but we have no reason to inhibit hotplug of idle devices and we might get into a loop of having the device disappear before we have a chance to try to use it. A new module parameter allows this feature to be disabled if there are devices that misbehave as a result of this change. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07vfio-pci: Remove warning if try-reset failsAlex Williamson1-8/+2
As indicated in the comment, this is not entirely uncommon and causes user concern for no reason. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07vfio-pci: Allow PCI IDs to be specified as module optionsAlex Williamson1-0/+49
This copies the same support from pci-stub for exactly the same purpose, enabling a set of PCI IDs to be automatically added to the driver's dynamic ID table at module load time. The code here is pretty simple and both vfio-pci and pci-stub are fairly unique in being meta drivers, capable of attaching to any device, so there's no attempt made to generalize the code into pci-core. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07vfio-pci: Add VGA arbiter clientAlex Williamson1-4/+63
If VFIO VGA access is disabled for the user, either by CONFIG option or module parameter, we can often opt-out of VGA arbitration. We can do this when PCI bridge control of VGA routing is possible. This means that we must have a parent bridge and there must only be a single VGA device below that bridge. Fortunately this is the typical case for discrete GPUs. Doing this allows us to minimize the impact of additional GPUs, in terms of VGA arbitration, when they are only used via vfio-pci for non-VGA applications. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07vfio-pci: Add module option to disable VGA region accessAlex Williamson1-3/+16
Add a module option so that we don't require a CONFIG change and kernel rebuild to disable VGA support. Not only can VGA support be troublesome in itself, but by disabling it we can reduce the impact to host devices by doing a VGA arbitration opt-out. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-17vfio: Split virqfd into a separate module for vfio bus driversAlex Williamson1-0/+1
An unintended consequence of commit 42ac9bd18d4f ("vfio: initialize the virqfd workqueue in VFIO generic code") is that the vfio module is renamed to vfio_core so that it can include both vfio and virqfd. That's a user visible change that may break module loading scritps and it imposes eventfd support as a dependency on the core vfio code, which it's really not. virqfd is intended to be provided as a service to vfio bus drivers, so instead of wrapping it into vfio.ko, we can make it a stand-alone module toggled by vfio bus drivers. This has the additional benefit of removing initialization and exit from the core vfio code. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-16vfio: initialize the virqfd workqueue in VFIO generic codeAntonios Motakis2-10/+1
Now we have finally completely decoupled virqfd from VFIO_PCI. We can initialize it from the VFIO generic code, in order to safely use it from multiple independent VFIO bus drivers. Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com> Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com> 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>
2015-03-16vfio: move eventfd support code for VFIO_PCI to a separate fileAntonios Motakis3-219/+2
The virqfd functionality that is used by VFIO_PCI to implement interrupt masking and unmasking via an eventfd, is generic enough and can be reused by another driver. Move it to a separate file in order to allow the code to be shared. Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com> Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com> 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>
2015-03-16vfio: pass an opaque pointer on virqfd initializationAntonios Motakis1-14/+16
VFIO_PCI passes the VFIO device structure *vdev via eventfd to the handler that implements masking/unmasking of IRQs via an eventfd. We can replace it in the virqfd infrastructure with an opaque type so we can make use of the mechanism from other VFIO bus drivers. Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com> Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com> 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>
2015-03-16vfio: add local lock for virqfd instead of depending on VFIO PCIAntonios Motakis1-15/+16
The Virqfd code needs to keep accesses to any struct *virqfd safe, but this comes into play only when creating or destroying eventfds, so sharing the same spinlock with the VFIO bus driver is not necessary. Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com> Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com> 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>