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![]() For block host devices, I/O can happen through either the kernel file descriptor I/O system calls (preadv/pwritev, io_submit, io_uring) or the SCSI passthrough ioctl SG_IO. In the latter case, the size of each transfer can be limited by the HBA, while for file descriptor I/O the kernel is able to split and merge I/O in smaller pieces as needed. Applying the HBA limits to file descriptor I/O results in more system calls and suboptimal performance, so this patch splits the max_transfer limit in two: max_transfer remains valid and is used in general, while max_hw_transfer is limited to the maximum hardware size. max_hw_transfer can then be included by the scsi-generic driver in the block limits page, to ensure that the stricter hardware limit is used. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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.. | ||
emulation.c | ||
esp-pci.c | ||
esp.c | ||
Kconfig | ||
lsi53c895a.c | ||
megasas.c | ||
meson.build | ||
mfi.h | ||
mpi.h | ||
mptconfig.c | ||
mptendian.c | ||
mptsas.c | ||
mptsas.h | ||
scsi-bus.c | ||
scsi-disk.c | ||
scsi-generic.c | ||
spapr_vscsi.c | ||
srp.h | ||
trace-events | ||
trace.h | ||
vhost-scsi-common.c | ||
vhost-scsi.c | ||
vhost-user-scsi.c | ||
viosrp.h | ||
virtio-scsi-dataplane.c | ||
virtio-scsi.c | ||
vmw_pvscsi.c | ||
vmw_pvscsi.h |