Currently we allocate one vhost log per vhost device. This is sub
optimal when:
- Guest has several device with vhost as backend
- Guest has multiqueue devices
In the above cases, we can avoid the memory allocation by sharing a
single vhost log among all the vhost devices. This is done through:
- Introducing a new vhost_log structure with refcnt inside.
- Using a global pointer to vhost_log structure that will be used. And
introduce helper to get the log with expected log size and helper to
- drop the refcnt to the old log.
- Each vhost device still keep track of a pointer to the log that was
used.
With above, if no resize happens, all vhost device will share a single
vhost log. During resize, a new vhost_log structure will be allocated
and made for the global pointer. And each vhost devices will drop the
refcnt to the old log.
Tested by doing scp during migration for a 2 queues virtio-net-pci.
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
vhost user does not support LOG_ALL feature bit.
Generally, we should not try to set this bit without
checking that backend can support it first.
Detect and block migration.
Signed-off-by: Michael S. Tsirkin <mst@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>
Use vhost_set_backend_type to initialise a proper vhost_ops structure.
In vhost_net_init and vhost_net_start_one call conditionally TAP related
initialisation depending on the vhost backend type.
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>
Decouple vhost from the Linux kernel by introducing vhost_ops. The
intention is to provide different backends - a 'kernel' backend based on
the ioctl interface, and an 'user' backend based on a UNIX domain socket
and shared memory interface.
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>
vhost_dev_init will replace devfd and devpath with a single opaque argument.
This is initialised with a file descriptor. When TAP is used (through
vhost_net), open /dev/vhost-net and pass the fd as an opaque parameter in
VhostNetOptions. The same applies to vhost-scsi - open /dev/vhost-scsi and
pass the fd.
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>
Generalize the features get/ack to be used for both vhost-net and vhost-scsi.
In vhost-net add vhost_net_get_feature_bits to select the feature bit set
depending on the NetClient kind.
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>
This patch follows MST's recommendation to move checks for
vhost_verify_ring_mappings() -> cpu_physical_memory_map() operations
from MemoryListener->region_[add,del]() -> vhost_set_memory() into
final MemoryListener->commit() -> vhost_commit() callback.
It addresses the case where virtio-scsi vq ioport RAM re-mapping
to read-only SeaBIOS ROM triggers a cpu_physical_memory_map()
NIL MemoryRegionSection pointer failure.
Also save vhost_dev->mem_changed_[start,end]_addr values in
vhost_set_memory() for final ranges_overlap checks. (Thanks Paolo!)
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Many of these should be cleaned up with proper qdev-/QOM-ification.
Right now there are many catch-all headers in include/hw/ARCH depending
on cpu.h, and this makes it necessary to compile these files per-target.
However, fixing this does not belong in these patches.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
