Alex Williamson bc93b9ae01 vfio-pci: Avoid recursive read-lock usage ... A down_read on memory_lock is held when performing read/write accesses to MMIO BAR space, including across the copy_to/from_user() callouts which may fault. If the user buffer for these copies resides in an mmap of device MMIO space, the mmap fault handler will acquire a recursive read-lock on memory_lock. Avoid this by reducing the lock granularity. Sequential accesses requiring multiple ioread/iowrite cycles are expected to be rare, therefore typical accesses should not see additional overhead. VGA MMIO accesses are expected to be non-fatal regardless of the PCI memory enable bit to allow legacy probing, this behavior remains with a comment added. ioeventfds are now included in memory access testing, with writes dropped while memory space is disabled. Fixes: abafbc551f ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Reported-by: Zhiyi Guo <zhguo@redhat.com> Tested-by: Zhiyi Guo <zhguo@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>		2020-08-17 11:08:18 -06:00
..
mdev	vfio/mdev: Fix reference count leak in add_mdev_supported_type	2020-05-29 16:07:18 -06:00
pci	vfio-pci: Avoid recursive read-lock usage	2020-08-17 11:08:18 -06:00
platform	vfio: platform: Switch to platform_get_irq_optional()	2020-03-24 09:26:30 -06:00
Kconfig	docs: driver-api: add a series of orphaned documents	2019-07-15 11:03:02 -03:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
vfio.c	vfio: Cleanup allowed driver naming	2020-07-27 13:43:36 -06:00
vfio_iommu_spapr_tce.c	vfio/spapr_tce: convert get_user_pages() --> pin_user_pages()	2020-07-27 13:43:38 -06:00
vfio_iommu_type1.c	VFIO updates for v5.9-rc1	2020-08-12 12:09:36 -07:00
vfio_spapr_eeh.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
virqfd.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00