[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH] doc: Describe missing generic -blockdev options
From: |
Kevin Wolf |
Subject: |
[PATCH] doc: Describe missing generic -blockdev options |
Date: |
Tue, 15 Oct 2019 14:38:54 +0200 |
We added more generic options after introducing -blockdev and forgot to
update the documentation (man page and --help output) accordingly. Do
that now.
Signed-off-by: Kevin Wolf <address@hidden>
---
qemu-options.hx | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/qemu-options.hx b/qemu-options.hx
index 793d70ff93..9f6aa3dde3 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -849,7 +849,8 @@ ETEXI
DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
"-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
" [,cache.direct=on|off][,cache.no-flush=on|off]\n"
- " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
+ " [,read-only=on|off][,auto-read-only=on|off]\n"
+ " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n"
" [,driver specific parameters...]\n"
" configure a block backend\n", QEMU_ARCH_ALL)
STEXI
@@ -885,6 +886,22 @@ name is not intended to be predictable and changes between
QEMU invocations.
For the top level, an explicit node name must be specified.
@item read-only
Open the node read-only. Guest write attempts will fail.
+
+Note that some block drivers support only read-only access, either generally or
+in certain configurations. In this case, the default value
+@option{read-only=off} does not work and the option must be specified
+explicitly.
+@item auto-read-only
+If @option{auto-read-only=on} is set, QEMU is allowed not to open the image
+read-write even if @option{read-only=off} is requested, but fall back to
+read-only instead (and switch between the modes later), e.g. depending on
+whether the image file is writable or whether a writing user is attached to the
+node.
+@item force-share
+Override the image locking system of QEMU and force the node to allowing
+sharing all permissions with other uses.
+
+Enabling @option{force-share=on} requires @option{read-only=on}.
@item cache.direct
The host page cache can be avoided with @option{cache.direct=on}. This will
attempt to do disk IO directly to the guest's memory. QEMU may still perform an
--
2.20.1
- [PATCH] doc: Describe missing generic -blockdev options,
Kevin Wolf <=