@@ -1967,8 +1967,10 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
* new memory, it will not yet set ram_block_discard_set_required() and
* therefore, neither stops us here or deals with the sudden memory
* consumption of inflated memory.
+ *
+ * We do support discarding of memory coordinated via the RamDiscardMgr.
*/
- ret = ram_block_discard_disable(true);
+ ret = ram_block_uncoordinated_discard_disable(true);
if (ret) {
error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
return ret;
@@ -2144,7 +2146,7 @@ close_fd_exit:
close(fd);
put_space_exit:
- ram_block_discard_disable(false);
+ ram_block_uncoordinated_discard_disable(false);
vfio_put_address_space(space);
return ret;
@@ -2266,7 +2268,7 @@ void vfio_put_group(VFIOGroup *group)
}
if (!group->ram_block_discard_allowed) {
- ram_block_discard_disable(false);
+ ram_block_uncoordinated_discard_disable(false);
}
vfio_kvm_device_del_group(group);
vfio_disconnect_container(group);
@@ -2320,7 +2322,7 @@ int vfio_get_device(VFIOGroup *group, const char *name,
if (!group->ram_block_discard_allowed) {
group->ram_block_discard_allowed = true;
- ram_block_discard_disable(false);
+ ram_block_uncoordinated_discard_disable(false);
}
}
We support coordinated discarding of RAM using the RamDiscardMgr. Let's unlock support for coordinated discards, keeping uncoordinated discards (e.g., via virtio-balloon) disabled. This unlocks virtio-mem + vfio. Note that vfio used via "nvme://" by the block layer has to be implemented/unlocked separately. For now, virtio-mem only supports x86-64 - spapr IOMMUs are not tested/affected. Note: The block size of a virtio-mem device has to be set to sane sizes, depending on the maximum hotplug size - to not run out of vfio mappings. The default virtio-mem block size is usually in the range of a couple of MBs. The maximum number of mapping is 64k, shared with other users. Assume you want to hotplug 256GB using virtio-mem - the block size would have to be set to at least 8 MiB (resulting in 32768 separate mappings). Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Auger Eric <eric.auger@redhat.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Marek Kedzierski <mkedzier@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> --- hw/vfio/common.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)