adapt to VFIO live migration v2 (#782)

This commit adapts the vfio-user protocol specification and the libvfio-user
implementation to v2 of the VFIO live migration interface, as used in the kernel
and QEMU.

The differences between v1 and v2 are discussed in this email thread [1], and we
slightly differ from upstream VFIO v2 in that instead of transferring data over
a new FD, we use the existing UNIX socket with new commands
VFIO_USER_MIG_DATA_READ/WRITE. We also don't yet use P2P states.

The updated spec was submitted to qemu-devel [2].

[1] https://lore.kernel.org/all/20220130160826.32449-9-yishaih@nvidia.com/
[2] https://lore.kernel.org/all/20230718094150.110183-1-william.henderson@nutanix.com/

Signed-off-by: William Henderson <william.henderson@nutanix.com>

1 files changed, 0 insertions, 14 deletions

diff --git a/lib/private.h b/lib/private.h
index fdd804f..6e0170e 100644
--- a/lib/private.h
+++ b/lib/private.h
@@ -195,20 +195,6 @@ typedef struct ioeventfd {
     LIST_ENTRY(ioeventfd) entry;
 } ioeventfd_t;
 
-static inline int
-ERROR_INT(int err)
-{
-    errno = err;
-    return -1;
-}
-
-static inline void *
-ERROR_PTR(int err)
-{
-    errno = err;
-    return NULL;
-}
-
 int
 consume_fd(int *fds, size_t nr_fds, size_t index);