block: add -drive copy-on-read=on|off

This patch adds the -drive copy-on-read=on|off command-line option:

  copy-on-read=on|off
  copy-on-read is "on" or "off" and enables whether to copy read backing
  file sectors into the image file.  Copy-on-read avoids accessing the
  same backing file sectors repeatedly and is useful when the backing
  file is over a slow network.  By default copy-on-read is off.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2011-11-17 13:40:32 +00:00 committed by Kevin Wolf
parent ab1859218a
commit fb0490f69f
4 changed files with 21 additions and 3 deletions

View file

@ -860,9 +860,10 @@ ETEXI
.args_type = "pci_addr:s,opts:s",
.params = "[[<domain>:]<bus>:]<slot>\n"
"[file=file][,if=type][,bus=n]\n"
"[,unit=m][,media=d][index=i]\n"
"[,unit=m][,media=d][,index=i]\n"
"[,cyls=c,heads=h,secs=s[,trans=t]]\n"
"[snapshot=on|off][,cache=on|off]",
"[,snapshot=on|off][,cache=on|off]\n"
"[,readonly=on|off][,copy-on-read=on|off]",
.help = "add drive to PCI storage controller",
.mhandler.cmd = drive_hot_add,
},