f4eef1b652
By simply re-attaching to shared rings during connect_ring() rather than assuming they are freshly allocated (i.e assuming the counters are zero) it is possible for vbd instances to be unbound and re-bound from and to (respectively) a running guest. This has been tested by running: while true; do fio --name=randwrite --ioengine=libaio --iodepth=16 \ --rw=randwrite --bs=4k --direct=1 --size=1G --verify=crc32; done in a PV guest whilst running: while true; do echo vbd-$DOMID-$VBD >unbind; echo unbound; sleep 5; echo vbd-$DOMID-$VBD >bind; echo bound; sleep 3; done in dom0 from /sys/bus/xen-backend/drivers/vbd to continuously unbind and re-bind its system disk image. This is a highly useful feature for a backend module as it allows it to be unloaded and re-loaded (i.e. updated) without requiring domUs to be halted. This was also tested by running: while true; do echo vbd-$DOMID-$VBD >unbind; echo unbound; sleep 5; rmmod xen-blkback; echo unloaded; sleep 1; modprobe xen-blkback; echo bound; cd $(pwd); sleep 3; done in dom0 whilst running the same loop as above in the (single) PV guest. Some (less stressful) testing has also been done using a Windows HVM guest with the latest 9.0 PV drivers installed. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com> |
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.. | ||
aoe | ||
drbd | ||
mtip32xx | ||
paride | ||
rsxx | ||
xen-blkback | ||
zram | ||
amiflop.c | ||
ataflop.c | ||
brd.c | ||
cryptoloop.c | ||
floppy.c | ||
Kconfig | ||
loop.c | ||
loop.h | ||
Makefile | ||
nbd.c | ||
null_blk_main.c | ||
null_blk_zoned.c | ||
null_blk.h | ||
pktcdvd.c | ||
ps3disk.c | ||
ps3vram.c | ||
rbd_types.h | ||
rbd.c | ||
skd_main.c | ||
skd_s1120.h | ||
sunvdc.c | ||
swim3.c | ||
swim_asm.S | ||
swim.c | ||
sx8.c | ||
umem.c | ||
umem.h | ||
virtio_blk.c | ||
xen-blkfront.c | ||
xsysace.c | ||
z2ram.c |