[v4,0/3] drop writes to read-only ram device & vfio regions

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Yan Zhao April 17, 2020, 7:44 a.m. UTC

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patch 1 modifies handler of ram device memory regions to drop guest writes
to read-only ram device memory regions

patch 2 modifies handler of non-mmap'd read-only vfio regions to drop guest
writes to those regions 

patch 3 set read-only flag to mmap'd read-only vfio regions, so that guest
writes to those regions would be trapped.
without patch 1, host qemu would then crash on guest write to those
read-only regions.
with patch 1, host qemu would drop the writes.

Changelog:
v4:
-instead of modifying tracing log, added qemu_log_mask(LOG_GUEST_ERROR...)
to log guest writes to read-only regions (Philippe)

for
v3:
-refreshed and Cc Stefan for reviewing of tracing part

v2:
-split one big patches into smaller ones (Philippe)
-modify existing trace to record guest writes to read-only memory (Alex)
-modify vfio_region_write() to drop guest writes to non-mmap'd read-only
 region (Alex)


Yan Zhao (3):
  memory: drop guest writes to read-only ram device regions
  hw/vfio: drop guest writes to ro regions
  hw/vfio: let read-only flag take effect for mmap'd regions

 hw/vfio/common.c | 16 ++++++++++++++--
 memory.c         |  7 +++++++
 2 files changed, 21 insertions(+), 2 deletions(-)