Current implementation in hw/virtio/vhost.c accesses the log by 32-bit wide chunks in host native bit and byte endianness. Accessing the log by 8-bit wide chunks, as the spec suggests, will be broken on big-endian hosts.
This commit changes the spec to match the implementation. Signed-off-by: Victor Kaplansky <vict...@redhat.com> --- docs/specs/vhost-user.txt | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index e0d71e2..3d18771 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -177,9 +177,11 @@ addresses. The log covers from address 0 to the maximum of guest regions. In pseudo-code, to mark page at "addr" as dirty: page = addr / VHOST_LOG_PAGE -log[page / 8] |= 1 << page % 8 +log[page / 32] |= 1 << page % 32 -Use atomic operations, as the log may be concurrently manipulated. +Use atomic operations, as the log may be concurrently +manipulated, and access the log by atomic 32-bit wide elements in +host native bit-level endianness. VHOST_USER_SET_LOG_FD is an optional message with an eventfd in ancillary data, it may be used to inform the master that the log has -- --Victor
