[libvirt] [PATCH v2 4/5] domain: Define explicit flags for saved image xml

[John Ferlan]

On 2/14/19 4:29 PM, Eric Blake wrote:
> Commit d2a929d4 (0.9.4) defined virDomainSaveImageGetXMLDesc()'s use
> of @flags as a subset of virDomainXMLFlags, documenting that 2 of the
> 3 flags defined at the time would never be valid.  Later, commit
> 28f8dfdc (1.0.0) introduced a new flag, VIR_DOMAIN_XML_MIGRATABLE, but
> did not adjust the save image documentation to declare it as invalid.
> Later, commit a67e3872 (3.7.0) blindly copied and pasted the same text
> into virDomainManagedSaveGetXMLDesc.
> 
> However, since the flag is not accepted as valid by any of the
> drivers (remote is just passthrough; and qemu is the only supporting
> driver for either API, with support for just VIR_DOMAIN_XML_SECURE),
> it is easier to just define an explicit set of supported flags
> directly related to the save image API rather than trying to borrow
> from live domain API, and risking confusion if even more domain flags
> are added later (in fact, I have an upcoming patch that plans to add
> a new flag to virDomainGetXMLDesc that makes no sense for saved
> images).  We may someday decide that saved images need to support the
> _MIGRATABLE flag, as it is possible to load a saved image with a
> different version of libvirt than the one that created it, but that
> can be a separate patch if it is ever needed.  Meanwhile, it DOES make
> sense to reuse the same flags for SaveImage and for ManagedSave (since
> ManagedSave is really just sugar for creating a normal SaveImage in a
> location controlled by libvirt instead of by the user).
> 
> There is no API or ABI impact (since we purposefully used unsigned int
> rather than an enum type in public API, and since the new flag name
> carries the same value as the old reused name).
> 
> Signed-off-by: Eric Blake <eblake at redhat.com>
> ---
>  include/libvirt/libvirt-domain.h |  5 +++++
>  src/libvirt-domain.c             | 14 ++++++--------
>  src/qemu/qemu_driver.c           |  4 ++--
>  src/remote/remote_protocol.x     |  4 ++--
>  4 files changed, 15 insertions(+), 12 deletions(-)
> 

mea culpa and missa something that the subsequent patch points out ;-)

The virDomainSaveImageGetXMLDesc and virDomainManagedSaveGetXMLDesc
source code should use:

if ((conn->flags & VIR_CONNECT_RO) && (flags &
VIR_DOMAIN_SAVE_IMAGE_XML_SECURE)) {

and not

if ((conn->flags & VIR_CONNECT_RO) && (flags & VIR_DOMAIN_XML_SECURE)) {

<sigh>,

John