[PATCH RFC 00/12] vdpa: generalize vdpa simulator and add block device

Stefano Garzarella
2020-11-13T13:47:33Z

Thanks to Max that started this work!
I took his patches, and extended the block simulator a bit.

This series moves the network device simulator in a new module
(vdpa_sim_net) and leaves the generic functions in the vdpa_sim core
module, allowing the possibility to add new vDPA device simulators.
Then we added a new vdpa_sim_blk module to simulate a block device.

I'm not sure about patch 11 ("vringh: allow vringh_iov_xfer() to skip
bytes when ptr is NULL"), maybe we can add a new functions instead of
modify vringh_iov_xfer().

As Max reported, I'm also seeing errors with vdpa_sim_blk related to
iotlb and vringh when there is high load, these are some of the error
messages I can see randomly:

vringh: Failed to access avail idx at 00000000e8deb2cc
vringh: Failed to read head: idx 6289 address 00000000e1ad1d50
vringh: Failed to get flags at 000000006635d7a3

virtio_vdpa vdpa0: vringh_iov_push_iotlb() error: -14 offset: 0x2840000 len: 0x20000
virtio_vdpa vdpa0: vringh_iov_pull_iotlb() error: -14 offset: 0x58ee000 len: 0x3000

These errors should all be related to the fact that iotlb_translate()
fails with -EINVAL, so it seems that we miss some mapping.

I'll debug more carefully, in the meantime can you give a first review?

Thanks,
Stefano

Max Gurtovoy (4):
vhost-vdpa: add support for vDPA blk devices
vdpa: split vdpasim to core and net modules
vdpa_sim: remove hard-coded virtq count
vdpa: add vdpa simulator for block device

Stefano Garzarella (8):
vdpa_sim: remove the limit of IOTLB entries
vdpa_sim: add struct vdpasim_device to store device properties
vdpa_sim: move config management outside of the core
vdpa_sim: use kvmalloc to allocate vdpasim->buffer
vdpa_sim: make vdpasim->buffer size configurable
vdpa_sim: split vdpasim_virtqueue's iov field in riov and wiov
vringh: allow vringh_iov_xfer() to skip bytes when ptr is NULL
vdpa_sim_blk: implement ramdisk behaviour

drivers/vdpa/vdpa_sim/vdpa_sim.h | 117 +++++++++++
drivers/vdpa/vdpa_sim/vdpa_sim.c | 283 +++++----------------------
drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 251 ++++++++++++++++++++++++
drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 172 ++++++++++++++++
drivers/vhost/vdpa.c | 11 +-
drivers/vhost/vringh.c | 16 +-
drivers/vdpa/Kconfig | 16 +-
drivers/vdpa/vdpa_sim/Makefile | 2 +
8 files changed, 628 insertions(+), 240 deletions(-)
create mode 100644 drivers/vdpa/vdpa_sim/vdpa_sim.h
create mode 100644 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
create mode 100644 drivers/vdpa/vdpa_sim/vdpa_sim_net.c

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2.26.2