commit 60a01f558a upstream.
This patch addresses a long-standing bug where the get_user_pages_fast()
write parameter used for setting the underlying page table entry permission
bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().
However, this parameter is intended to signal WRITEs to pinned userspace
PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.
This bug would manifest itself as random process segmentation faults on
KVM host after repeated vhost starts + stops and/or with lots of vhost
endpoints + LUNs.
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It was disabled as a workaround. Now userspace bits work fine with it.
The broken version was not ever committed to QEMU, I guess the same is
true for nlkt.
So, let's enable it.
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Rename module and update Kconfig and Makefile.
Add alias for compatibility with old userspace
scripts if any.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Asias He <asias@redhat.com>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
move uapi parts to vhost.h
move .c private parts to .c itself
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Asias He <asias@redhat.com>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
