Alex Williamson 4e1a635552 vfio/pci: Use kernel VPD access functions ... 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 932c435cab ("PCI: Add dev_flags bit to access VPD through function 0") and 7aa6ca4d39 ("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>		2015-10-27 14:53:05 -06:00
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Kconfig	vfio: Split virqfd into a separate module for vfio bus drivers	2015-03-17 08:33:38 -06:00
Makefile	vfio: initialize the virqfd workqueue in VFIO generic code	2015-03-16 14:08:54 -06:00
vfio_pci_config.c	vfio/pci: Use kernel VPD access functions	2015-10-27 14:53:05 -06:00
vfio_pci_intrs.c	vfio: move eventfd support code for VFIO_PCI to a separate file	2015-03-16 14:08:54 -06:00
vfio_pci_private.h	vfio: move eventfd support code for VFIO_PCI to a separate file	2015-03-16 14:08:54 -06:00
vfio_pci_rdwr.c	vfio-pci: Add support for VGA region access	2013-02-18 10:11:13 -07:00
vfio_pci.c	vfio/pci: Fix racy vfio_device_get_from_dev() call	2015-06-09 10:08:57 -06:00