« Previous | Next » 

Revision 74b41e56

ID74b41e5676568e6560474267bbf1a5a32d3e2c41

Added by David Gibson over 12 years ago

pseries: Allow writes to KVM accelerated TCE table

Sufficiently recent kernels include a KVM call to accelerate use of
PAPR TCE tables (IOMMU), which are used by PAPR virtual IO devices.
This involves qemu mapping the TCE table in from a kernel obtained fd,
which currently we do with PROT_READ only. This is a hangover from
early (never released) versions of this kernel interface which only
permitted read-only mappings and required us to destroy and recreate
the table when we needed to clear it from qemu.

Now, the kernel permits read-write mappings, and we rely on this to
clear the table in spapr_vio_quiesce_one(). However, due to
insufficient testing, I forgot to update the actual mapping of the
table in kvmppc_create_spapr_tce() to add PROT_WRITE to the mmap().

This patch corrects the oversight.

Signed-off-by: David Gibson <>
Signed-off-by: Alexander Graf <>

Files

  • added
  • modified
  • copied
  • renamed
  • deleted

View differences