On Wed, Nov 11, 2015 at 09:32:17AM -0500, Marc-André Lureau wrote:
> Hi
>
> ----- Original Message -----
> > Unlike the kernel, vhost-user application accesses log table by
> > mmaping it to its user space. This change adds two new fields to
> > VhostUserMsg payload: mmap_size, and mmap_offset and make QEMU to
> > pass the to vhost-user application in VHOST_USER_SET_LOG_BASE
> > request.
> >
> > Signed-off-by: Victor Kaplansky <vict...@redhat.com>
>
> What's the motivation for doing this? The offset is always 0, and the size
> must at least match the size of VM memory.
Remote doesn't know the size though, and offset is only there
in the current implementation.
> >
> > ---
> > hw/virtio/vhost-user.c | 11 +++++++++--
> > tests/vhost-user-test.c | 8 ++++++++
> > docs/specs/vhost-user.txt | 8 +++++++-
> > 3 files changed, 24 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> > index 83c84f1..46c63bc 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -75,6 +75,11 @@ typedef struct VhostUserMemory {
> > VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
> > } VhostUserMemory;
> >
> > +typedef struct VhostUserLog {
> > + uint64_t mmap_size;
> > + uint64_t mmap_offset;
> > +} VhostUserLog;
> > +
> > typedef struct VhostUserMsg {
> > VhostUserRequest request;
> >
> > @@ -89,6 +94,7 @@ typedef struct VhostUserMsg {
> > struct vhost_vring_state state;
> > struct vhost_vring_addr addr;
> > VhostUserMemory memory;
> > + VhostUserLog log;
> > } payload;
> > } QEMU_PACKED VhostUserMsg;
> >
> > @@ -200,8 +206,9 @@ static int vhost_user_set_log_base(struct vhost_dev
> > *dev,
> > uint64_t base,
> > VhostUserMsg msg = {
> > .request = VHOST_USER_SET_LOG_BASE,
> > .flags = VHOST_USER_VERSION,
> > - .payload.u64 = base,
> > - .size = sizeof(msg.payload.u64),
> > + .payload.log.mmap_size = log->size,
> > + .payload.log.mmap_offset = 0,
> > + .size = sizeof(msg.payload.log),
> > };
> >
> > if (shmfd && log->fd != -1) {
> > diff --git a/tests/vhost-user-test.c b/tests/vhost-user-test.c
> > index b6dde75..f005ecf 100644
> > --- a/tests/vhost-user-test.c
> > +++ b/tests/vhost-user-test.c
> > @@ -86,6 +86,11 @@ typedef struct VhostUserMemory {
> > VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
> > } VhostUserMemory;
> >
> > +typedef struct VhostUserLog {
> > + uint64_t mmap_size;
> > + uint64_t mmap_offset;
> > +} VhostUserLog;
> > +
> > typedef struct VhostUserMsg {
> > VhostUserRequest request;
> >
> > @@ -94,10 +99,13 @@ typedef struct VhostUserMsg {
> > uint32_t flags;
> > uint32_t size; /* the following payload size */
> > union {
> > +#define VHOST_USER_VRING_IDX_MASK (0xff)
> > +#define VHOST_USER_VRING_NOFD_MASK (0x1<<8)
> > uint64_t u64;
> > struct vhost_vring_state state;
> > struct vhost_vring_addr addr;
> > VhostUserMemory memory;
> > + VhostUserLog log;
> > } payload;
> > } QEMU_PACKED VhostUserMsg;
> >
> > diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt
> > index e0d71e2..eb8f2b2 100644
> > --- a/docs/specs/vhost-user.txt
> > +++ b/docs/specs/vhost-user.txt
> > @@ -98,6 +98,7 @@ typedef struct VhostUserMsg {
> > struct vhost_vring_state state;
> > struct vhost_vring_addr addr;
> > VhostUserMemory memory;
> > + VhostUserLog log;
> > };
> > } QEMU_PACKED VhostUserMsg;
> >
> > @@ -282,7 +283,12 @@ Message types
> > Master payload: u64
> > Slave payload: N/A
> >
> > - Sets the logging base address.
> > + Sets logging shared memory space.
> > + When slave has VHOST_USER_PROTOCOL_F_LOG_SHMFD protocol
> > + feature, the log memory fd is provided in the ancillary data of
> > + VHOST_USER_SET_LOG_BASE message, the size and offset of shared
> > + memory area provided in the message.
> > +
> >
> > * VHOST_USER_SET_LOG_FD
> >
> > --
> > --Victor
> >
