[PATCH 29/36] qemu: block: Add support for passing FDs of disk images
Prepare the internal data for passing FDs instead of having qemu open
the file internally.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_block.c | 31 ++++++++++++++++++++++++++++---
src/qemu/qemu_command.c | 22 ++++++++++++++++++++++
2 files changed, 50 insertions(+), 3 deletions(-)
diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 8a6f601b29..a672ad6f54 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -673,22 +673,47 @@ qemuBlockStorageSourceGetSshProps(virStorageSource *src)
static virJSONValue *
qemuBlockStorageSourceGetFileProps(virStorageSource *src,
- bool onlytarget)
+ bool onlytarget,
+ virTristateBool *autoReadOnly,
+ virTristateBool *readOnly)
{
+ const char *path = src->path;
const char *iomode = NULL;
const char *prManagerAlias = NULL;
virJSONValue *ret = NULL;
if (!onlytarget) {
+ qemuDomainStorageSourcePrivate *srcpriv =
QEMU_DOMAIN_STORAGE_SOURCE_PRIVATE(src);
+
if (src->pr)
prManagerAlias = src->pr->mgralias;
if (src->iomode != VIR_DOMAIN_DISK_IO_DEFAULT)
iomode = virDomainDiskIoTypeToString(src->iomode);
+
+ if (srcpriv && srcpriv->fdpass) {
+ path = qemuFDPassGetPath(srcpriv->fdpass);
+
+ /* when passing a FD to qemu via the /dev/fdset mechanism qemu
+ * fetches the appropriate FD from the fdset by checking that it has
+ * the correct accessmode. Now with 'auto-read-only' in effect qemu
+ * wants to use a read-only FD first. If the user didn't pass multiple
+ * FDs the feature will not work regardless, so we'll disable it. */
+ if (src->fdtuple->nfds == 1) {
+ *autoReadOnly = VIR_TRISTATE_BOOL_ABSENT;
+
+ /* now we setup the normal readonly flag. If user requested write
+ * access honour it */
+ if (src->fdtuple->writable)
+ *readOnly = VIR_TRISTATE_BOOL_NO;
+ else
+ *readOnly = virTristateBoolFromBool(src->readonly);
+ }
+ }
}
ignore_value(virJSONValueObjectAdd(&ret,
- "s:filename", src->path,
+ "s:filename", path,
"S:aio", iomode,
"S:pr-manager", prManagerAlias,
NULL) < 0);
@@ -818,7 +843,7 @@ qemuBlockStorageSourceGetBackendProps(virStorageSource *src,
driver = "file";
}
- if (!(fileprops = qemuBlockStorageSourceGetFileProps(src, onlytarget)))
+ if (!(fileprops = qemuBlockStorageSourceGetFileProps(src, onlytarget, &aro,
&ro)))
return NULL;
break;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 06e29ff8ae..ed159bc8b1 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2146,6 +2146,25 @@ qemuBuildBlockStorageSourceAttachDataCommandline(virCommand *cmd,
}
+static int
+qemuBuildDiskSourceCommandLineFDs(virCommand *cmd,
+ virDomainDiskDef *disk)
+{
+ virStorageSource *n;
+
+ for (n = disk->src; virStorageSourceIsBacking(n); n = n->backingStore) {
+ qemuDomainStorageSourcePrivate *srcpriv = QEMU_DOMAIN_STORAGE_SOURCE_PRIVATE(n);
+
+ if (!srcpriv || !srcpriv->fdpass)
+ continue;
+
+ qemuFDPassTransferCommand(srcpriv->fdpass, cmd);
+ }
+
+ return 0;
+}
+
+
static int
qemuBuildDiskSourceCommandLine(virCommand *cmd,
virDomainDiskDef *disk,
@@ -2163,6 +2182,9 @@ qemuBuildDiskSourceCommandLine(virCommand *cmd,
if (virStorageSourceIsEmpty(disk->src))
return 0;
+ if (qemuBuildDiskSourceCommandLineFDs(cmd, disk) < 0)
+ return -1;
+
if (!(data = qemuBuildStorageSourceChainAttachPrepareBlockdev(disk->src)))
return -1;
--
2.38.1