We have a policy of avoiding enum types in structs in our public API, because it is possible for a client to choose compiler options that can change the in-memory ABI of that struct based on whether the enum value occupies an int or a minimal size. But we missed this for virDomainBlockJobInfo. We got lucky on little-endian machines - if the enum fits minimal size (a char), we still end up padding to the next long before the next field; but on big-endian, a client interpreting the enum as a char would always see 0 when the server supplies contents as an int. While at it, I noticed that the web page lacked documentation: http://libvirt.org/html/libvirt-libvirt.html#virDomainBlockJobType not only for the recently added active commit, but also for all the other job types. * include/libvirt/libvirt.h.in (virDomainBlockJobInfo): Enforce particular sizing. (virDomainBlockJobType): Document recent addition. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- include/libvirt/libvirt.h.in | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index 127de11..dc88c40 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -2501,19 +2501,26 @@ int virDomainUpdateDeviceFlags(virDomainPtr domain, /** * virDomainBlockJobType: * - * VIR_DOMAIN_BLOCK_JOB_TYPE_PULL: Block Pull (virDomainBlockPull, or - * virDomainBlockRebase without flags), job ends on completion - * VIR_DOMAIN_BLOCK_JOB_TYPE_COPY: Block Copy (virDomainBlockRebase with - * flags), job exists as long as mirroring is active - * VIR_DOMAIN_BLOCK_JOB_TYPE_COMMIT: Block Commit (virDomainBlockCommit), - * job ends on completion + * Describes various possible block jobs. */ typedef enum { - VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN = 0, + VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN = 0, /* Placeholder */ + VIR_DOMAIN_BLOCK_JOB_TYPE_PULL = 1, + /* Block Pull (virDomainBlockPull, or virDomainBlockRebase without + * flags), job ends on completion */ + VIR_DOMAIN_BLOCK_JOB_TYPE_COPY = 2, + /* Block Copy (virDomainBlockRebase with flags), job exists as + * long as mirroring is active */ + VIR_DOMAIN_BLOCK_JOB_TYPE_COMMIT = 3, + /* Block Commit (virDomainBlockCommit without flags), job ends on + * completion */ + VIR_DOMAIN_BLOCK_JOB_TYPE_ACTIVE_COMMIT = 4, + /* Active Block Commit (virDomainBlockCommit with flags), job + * exists as long as sync is active */ #ifdef VIR_ENUM_SENTINELS VIR_DOMAIN_BLOCK_JOB_TYPE_LAST @@ -2537,7 +2544,7 @@ typedef unsigned long long virDomainBlockJobCursor; typedef struct _virDomainBlockJobInfo virDomainBlockJobInfo; struct _virDomainBlockJobInfo { - virDomainBlockJobType type; + int type; /* virDomainBlockJobType */ unsigned long bandwidth; /* * The following fields provide an indication of block job progress. @cur -- 1.9.3