9a51c9ee6c
There is at least one guest (OS) such that although it does not rely on the guarantees provided by ORB 1 word 9 bit (aka unlimited prefetch, aka P bit) not being set, it fails to tell this to the machine. Usually this ain't a big deal, as the original purpose of the P bit is to allow for performance optimizations. vfio-ccw however can not provide the guarantees required if the bit is not set. It is not possible to implement support for the P bit not set without transitioning to lower level protocols for vfio-ccw. So let's give the user the opportunity to force setting the P bit, if the user knows this is safe. For self modifying channel programs forcing the P bit is not safe. If the P bit is forced for a self modifying channel program things are expected to break in strange ways. Let's also avoid warning multiple about P bit not set in the ORB in case P bit is not told to be forced, and designate the affected vfio-ccw device. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Suggested-by: Dong Jia Shi <bjsdjshi@linux.ibm.com> Acked-by: Jason J. Herne <jjherne@linux.ibm.com> Tested-by: Jason J. Herne <jjherne@linux.ibm.com> Message-Id: <20180524175828.3143-2-pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> |
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| .. | ||
| Makefile.objs | ||
| amd-xgbe.c | ||
| calxeda-xgmac.c | ||
| ccw.c | ||
| common.c | ||
| display.c | ||
| pci-quirks.c | ||
| pci.c | ||
| pci.h | ||
| platform.c | ||
| spapr.c | ||
| trace-events | ||