Commit Graph

4 Commits

Author SHA1 Message Date
Michael S. Tsirkin
cd98639f67 vhost-user: minor cleanups
assert to verify cast does not discard information
minor style fixup.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-07-18 02:22:24 +03:00
Nikolay Nikolaev
f69a28051f vhost-user: Fix VHOST_SET_MEM_TABLE processing
qemu_get_ram_fd doesn't accept a guest physical address. ram_addr_t are
opaque values that are assigned in qemu_ram_alloc.

Find the ram_addr_t corresponding to the userspace_addr using qemu_ram_addr_from_host,
and then call qemu_get_ram_fd on it.

Thanks to Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-18 02:14:15 +03:00
Damjan Marion
3fd74b8407 vhost-user: fix regions provied with VHOST_USER_SET_MEM_TABLE message
Old code was affected by memory gaps which resulted in buffer pointers
pointing to address outside of the mapped regions.

Here we are introducing following changes:
 - new function qemu_get_ram_block_host_ptr() returns host pointer
   to the ram block, it is needed to calculate offset of specific
   region in the host memory
 - new field mmap_offset is added to the VhostUserMemoryRegion. It
   contains offset where specific region starts in the mapped memory.
   As there is stil no wider adoption of vhost-user agreement was made
   that we will not bump version number due to this change
 - other fileds in VhostUserMemoryRegion struct are not changed, as
   they are all needed for usermode app implementation
 - region data is not taken from ram_list.blocks anymore, instead we
   use region data which is alredy calculated for use in vhost-net
 - Now multiple regions can have same FD and user applicaton can call
   mmap() multiple times with the same FD but with different offset
   (user needs to take care for offset page alignment)

Signed-off-by: Damjan Marion <damarion@cisco.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Damjan Marion <damarion@cisco.com>
2014-06-29 19:39:40 +03:00
Nikolay Nikolaev
5f6f6664bf Add vhost-user as a vhost backend.
The initialization takes a chardev backed by a unix domain socket.
It should implement qemu_fe_set_msgfds in order to be able to pass
file descriptors to the remote process.

Each ioctl request of vhost-kernel has a vhost-user message equivalent,
which is sent over the control socket.

The general approach is to copy the data from the supplied argument
pointer to a designated field in the message. If a file descriptor is
to be passed it will be placed in the fds array for inclusion in
the sendmsg control header.

VHOST_SET_MEM_TABLE ignores the supplied vhost_memory structure and scans
the global ram_list for ram blocks with a valid fd field set. This would
be set when the '-object memory-file' option with share=on property is used.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-19 16:41:56 +03:00