linux/drivers/vfio, branch v4.8

vfio/pci: Fix NULL pointer oops in error interrupt setup handling

2016-08-08T22:16:23Z

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 Reported-by: Chris Thompson Cc: stable@vger.kernel.org Reviewed-by: Eric Auger

vfio: platform: check reset call return code during release

2016-07-19T16:54:45Z

Release call is ignoring the return code from reset call and can potentially continue even though reset call failed. If reset_required module parameter is set, this patch is going to validate the return code and will cause stack dump with WARN_ON and warn the user of failure. Signed-off-by: Sinan Kaya Reviewed-by: Eric Auger Reviewed-by: Baptiste Reynal Signed-off-by: Alex Williamson

vfio: platform: check reset call return code during open

2016-07-19T16:54:45Z

Open call is ignoring the return code from reset call and can potentially continue even though reset call failed. If reset_required module parameter is set, this patch is going to validate the return code and will abort open if reset fails. Signed-off-by: Sinan Kaya Reviewed-by: Baptiste Reynal Reviewed-by: Eric Auger Signed-off-by: Alex Williamson

vfio, platform: make reset driver a requirement by default

2016-07-19T16:26:46Z

The code was allowing platform devices to be used without a supporting VFIO reset driver. The hardware can be left in some inconsistent state after a guest machine abort. The reset driver will put the hardware back to safe state and disable interrupts before returning the control back to the host machine. Adding a new reset_required kernel module option to platform VFIO drivers. The default value is true for the DT and ACPI based drivers. The reset requirement value for AMBA drivers is set to false and is unchangeable to maintain the existing functionality. New requirements are: 1. A reset function needs to be implemented by the corresponding driver via DT/ACPI. 2. The reset function needs to be discovered via DT/ACPI. The probe of the driver will fail if any of the above conditions are not satisfied. Signed-off-by: Sinan Kaya Signed-off-by: Alex Williamson

vfio: platform: call _RST method when using ACPI

2016-07-19T16:26:44Z

The device tree code checks for the presence of a reset driver and calls the of_reset function pointer by looking up the reset driver as a module. ACPI defines _RST method to perform device level reset. After the _RST method is executed, the OS can resume using the device. _RST method is expected to stop DMA transfers and IRQs. This patch introduces two functions as vfio_platform_acpi_has_reset and vfio_platform_acpi_call_reset. The has reset method is used to declare reset capability via the ioctl flag VFIO_DEVICE_FLAGS_RESET. The call reset function is used to execute the _RST ACPI method. Signed-off-by: Sinan Kaya Signed-off-by: Alex Williamson

vfio: platform: add extra debug info argument to call reset

2016-07-19T16:26:43Z

Getting ready to bring out extra debug information to the caller so that more verbose information can be printed when an error is observed. Signed-off-by: Sinan Kaya Reviewed-by: Baptiste Reynal Signed-off-by: Alex Williamson

vfio: platform: add support for ACPI probe

2016-07-19T16:26:41Z

The code is using the compatible DT string to associate a reset driver with the actual device itself. The compatible string does not exist on ACPI based systems. HID is the unique identifier for a device driver instead. Signed-off-by: Sinan Kaya Signed-off-by: Alex Williamson

vfio: platform: determine reset capability

2016-07-19T16:26:40Z

Creating a new function to determine if this driver supports reset function or not. This is an attempt to abstract device tree calls from the rest of the code. Signed-off-by: Sinan Kaya Reviewed-by: Eric Auger Reviewed-by: Baptiste Reynal Signed-off-by: Alex Williamson

vfio: platform: move reset call to a common function

2016-07-19T16:26:38Z

The reset call sequence seems to replicate itself multiple times across the file. Grouping them together for maintenance reasons. Signed-off-by: Sinan Kaya Reviewed-by: Eric Auger Reviewed-by: Baptiste Reynal Signed-off-by: Alex Williamson

vfio: platform: rename reset function

2016-07-19T16:26:36Z

Renaming the reset function to of_reset as it is only used by the device tree based platforms. Signed-off-by: Sinan Kaya Reviewed-by: Eric Auger Reviewed-by: Baptiste Reynal Signed-off-by: Alex Williamson