Re: [PATCH 29/36] qemu: block: Add support for passing FDs of disk images

On Thu, Jan 05, 2023 at 05:30:18PM +0100, Peter Krempa wrote: > Prepare the internal data for passing FDs instead of having qemu open > the file internally. > > Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; > --- > 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. */ What happens if users passes multiple FDs but none of them are read-only? Otherwise looks good so if this is not an issue