kernel.git/drivers/vfio/pci, branch linux-4.5.y

vfio: fix ioctl error handling

2016-02-28T14:38:52Z

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 Signed-off-by: Alex Williamson

vfio: Include No-IOMMU mode

2015-12-21T22:28:11Z

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 Acked-by: Michael S. Tsirkin

Revert: "vfio: Include No-IOMMU mode"

2015-12-04T15:38:42Z

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

vfio-pci: constify pci_error_handlers structures

2015-11-19T23:53:07Z

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 Signed-off-by: Alex Williamson

Merge tag 'vfio-v4.4-rc1' of git://github.com/awilliam/linux-vfio

2015-11-14T01:05:32Z

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 larger

2015-11-09T15:59:11Z

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 Signed-off-by: Alex Williamson

vfio: Include No-IOMMU mode

2015-11-04T16:56:16Z

vfio/pci: Use kernel VPD access functions

2015-10-27T20:53:05Z

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 Acked-by: Mark Rustad

vfio: Register/unregister irq_bypass_producer

2015-10-01T13:06:50Z

This patch adds the registration/unregistration of an irq_bypass_producer for MSI/MSIx on vfio pci devices. Acked-by: Alex Williamson Signed-off-by: Feng Wu Signed-off-by: Paolo Bonzini

vfio/pci: Fix racy vfio_device_get_from_dev() call

2015-06-09T16:08:57Z

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