linux/drivers/vfio, branch v4.5

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/noiommu: Don't use iommu_present() to track fake groups

2016-01-27T18:22:25Z

Using iommu_present() to determine whether an IOMMU group is real or fake has some problems. First, apparently Power systems don't register an IOMMU on the device bus, so the groups and containers get marked as noiommu and then won't bind to their actual IOMMU driver. Second, I expect we'll run into the same issue as we try to support vGPUs through vfio, since they're likely to emulate this behavior of creating an IOMMU group on a virtual device and then providing a vfio IOMMU backend tailored to the sort of isolation they provide, which won't necessarily be fully compatible with the IOMMU API. The solution here is to use the existing iommudata interface to IOMMU groups, which allows us to easily identify the fake groups we've created for noiommu purposes. The iommudata we set is purely arbitrary since we're only comparing the address, so we use the address of the noiommu switch itself. Reported-by: Alexey Kardashevskiy Reviewed-by: Alexey Kardashevskiy Tested-by: Alexey Kardashevskiy Tested-by: Anatoly Burakov Tested-by: Santosh Shukla Fixes: 03a76b60f8ba ("vfio: Include No-IOMMU mode") Signed-off-by: Alex Williamson

vfio/iommu_type1: make use of info.flags

2016-01-04T19:55:44Z

The flags entry is there to tell the user that some optional information is available. Since we report the iova_pgsizes signal it to the user by setting the flags to VFIO_IOMMU_INFO_PGSIZES. Signed-off-by: Pierre Morel 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

VFIO: platform: reset: fix a warning message condition

2015-12-21T22:28:11Z

This loop ends with count set to -1 and not zero so the warning message isn't printed when it should be. I've fixed this by change the postop to a preop. Fixes: 0990822c9866 ('VFIO: platform: reset: AMD xgbe reset module') Signed-off-by: Dan Carpenter Reviewed-by: Eric Auger Signed-off-by: Alex Williamson

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: fix a warning message

2015-11-21T13:55:58Z

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 Signed-off-by: Alex Williamson

vfio: platform: remove needless stack usage

2015-11-20T16:00:10Z

request_module already takes format strings, so no need to duplicate the effort. Signed-off-by: Kees Cook 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

vfio: Drop owner assignment from platform_driver

2015-11-19T22:52:08Z

platform_driver does not need to set an owner because platform_driver_register() will set it. Signed-off-by: Krzysztof Kozlowski Acked-by: Baptiste Reynal Signed-off-by: Alex Williamson