e6db5df7e2
With the introduction of the batch hinting, meaningless batches can be
created with no IOTLB updates if the memory region was skipped by
vhost_vdpa_listener_skipped_section. This is the case of host notifiers
memory regions, device un/realize, and others. This causes the vdpa
device to receive dma mapping settings with no changes, a possibly
expensive operation for nothing.
To avoid that, VHOST_IOTLB_BATCH_BEGIN hint is delayed until we have a
meaningful (not skipped section) mapping or unmapping operation, and
VHOST_IOTLB_BATCH_END is not written unless at least one of _UPDATE /
_INVALIDATE has been issued.
v3:
* Use a bool instead of a counter avoiding potential number wrapping
* Fix bad check on _commit
* Move VHOST_BACKEND_F_IOTLB_BATCH check to
vhost_vdpa_iotlb_batch_begin_once
v2 (from RFC):
* Rename misleading name
* Abstract start batching function for listener_add/del
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20210812140933.226288-1-eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
32 lines
672 B
C
32 lines
672 B
C
/*
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* vhost-vdpa.h
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*
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* Copyright(c) 2017-2018 Intel Corporation.
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* Copyright(c) 2020 Red Hat, Inc.
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#ifndef HW_VIRTIO_VHOST_VDPA_H
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#define HW_VIRTIO_VHOST_VDPA_H
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#include "hw/virtio/virtio.h"
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typedef struct VhostVDPAHostNotifier {
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MemoryRegion mr;
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void *addr;
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} VhostVDPAHostNotifier;
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typedef struct vhost_vdpa {
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int device_fd;
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uint32_t msg_type;
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bool iotlb_batch_begin_sent;
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MemoryListener listener;
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struct vhost_dev *dev;
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VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
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} VhostVDPA;
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#endif
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