[V4,0/5] fixes for virtual address update

Message

Steven Sistare Dec. 15, 2022, 9:53 p.m. UTC

Fix bugs in the interfaces that allow the underlying memory object of an
iova range to be mapped in a new address space.  They allow userland to
indefinitely block vfio mediated device kernel threads, and do not
propagate the locked_vm count to a new mm.

The fixes impose restrictions that eliminate waiting conditions, so
revert the dead code:
  commit 898b9eaeb3fe ("vfio/type1: block on invalid vaddr")
  commit 487ace134053 ("vfio/type1: implement notify callback")
  commit ec5e32940cc9 ("vfio: iommu driver notify callback")

Changes in V2 (thanks Alex):
  * do not allow group attach while vaddrs are invalid
  * add patches to delete dead code
  * add WARN_ON for never-should-happen conditions
  * check for changed mm in unmap.
  * check for vfio_lock_acct failure in remap

Changes in V3 (ditto!):
  * return errno at WARN_ON sites, and make it unique
  * correctly check for dma task mm change
  * change dma owner to current when vaddr is updated
  * add Fixes to commit messages
  * refactored new code in vfio_dma_do_map

Changes in V4:
  * misc cosmetic changes

Steve Sistare (5):
  vfio/type1: exclude mdevs from VFIO_UPDATE_VADDR
  vfio/type1: prevent locked_vm underflow
  vfio/type1: revert "block on invalid vaddr"
  vfio/type1: revert "implement notify callback"
  vfio: revert "iommu driver notify callback"

 drivers/vfio/container.c        |   5 -
 drivers/vfio/vfio.h             |   7 --
 drivers/vfio/vfio_iommu_type1.c | 199 +++++++++++++++++++---------------------
 include/uapi/linux/vfio.h       |  15 +--
 4 files changed, 103 insertions(+), 123 deletions(-)

Comments

Steven Sistare Dec. 15, 2022, 9:56 p.m. UTC | #1

PLEASE IGNORE this resend of V4, I sent the wrong directory - steve

On 12/15/2022 4:53 PM, Steve Sistare wrote:
> Fix bugs in the interfaces that allow the underlying memory object of an
> iova range to be mapped in a new address space.  They allow userland to
> indefinitely block vfio mediated device kernel threads, and do not
> propagate the locked_vm count to a new mm.
> 
> The fixes impose restrictions that eliminate waiting conditions, so
> revert the dead code:
>   commit 898b9eaeb3fe ("vfio/type1: block on invalid vaddr")
>   commit 487ace134053 ("vfio/type1: implement notify callback")
>   commit ec5e32940cc9 ("vfio: iommu driver notify callback")
> 
> Changes in V2 (thanks Alex):
>   * do not allow group attach while vaddrs are invalid
>   * add patches to delete dead code
>   * add WARN_ON for never-should-happen conditions
>   * check for changed mm in unmap.
>   * check for vfio_lock_acct failure in remap
> 
> Changes in V3 (ditto!):
>   * return errno at WARN_ON sites, and make it unique
>   * correctly check for dma task mm change
>   * change dma owner to current when vaddr is updated
>   * add Fixes to commit messages
>   * refactored new code in vfio_dma_do_map
> 
> Changes in V4:
>   * misc cosmetic changes
> 
> Steve Sistare (5):
>   vfio/type1: exclude mdevs from VFIO_UPDATE_VADDR
>   vfio/type1: prevent locked_vm underflow
>   vfio/type1: revert "block on invalid vaddr"
>   vfio/type1: revert "implement notify callback"
>   vfio: revert "iommu driver notify callback"
> 
>  drivers/vfio/container.c        |   5 -
>  drivers/vfio/vfio.h             |   7 --
>  drivers/vfio/vfio_iommu_type1.c | 199 +++++++++++++++++++---------------------
>  include/uapi/linux/vfio.h       |  15 +--
>  4 files changed, 103 insertions(+), 123 deletions(-)
>