guest writes to read-only memory regions need to be dropped. 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: v5: -changed write handler of ram device memory region from .write to .write_with_attrs in patch 1 (Paolo) (for vfio region in patch 2, I still keep the operations as .read & .write. the reasons are: 1. vfio_region_ops are for mmio/pio regions. the top level read/write dispatcher in kvm just ignores their return values. (the return value of address_space_rw() is just ignored) 2. there are a lot of callers to vfio_region_read() and vfio_region_write(), who actually do not care about the return values ) -minor changes on text format in error logs. 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 | 17 +++++++++++++++-- memory.c | 15 ++++++++++++--- 2 files changed, 27 insertions(+), 5 deletions(-) -- 2.17.1
