On 1/5/24 10:59, Eugenio Perez Martin wrote:
On Fri, Jan 5, 2024 at 9:12 AM Maxime Coquelin
<maxime.coquelin@xxxxxxxxxx> wrote:
On 1/5/24 03:45, Jason Wang wrote:
On Thu, Jan 4, 2024 at 11:38 PM Maxime Coquelin
<maxime.coquelin@xxxxxxxxxx> wrote:
Virtio-net driver control queue implementation is not safe
when used with VDUSE. If the VDUSE application does not
reply to control queue messages, it currently ends up
hanging the kernel thread sending this command.
Some work is on-going to make the control queue
implementation robust with VDUSE. Until it is completed,
let's fail features check if any control-queue related
feature is requested.
Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx>
---
drivers/vdpa/vdpa_user/vduse_dev.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 0486ff672408..94f54ea2eb06 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -28,6 +28,7 @@
#include <uapi/linux/virtio_config.h>
#include <uapi/linux/virtio_ids.h>
#include <uapi/linux/virtio_blk.h>
+#include <uapi/linux/virtio_ring.h>
#include <linux/mod_devicetable.h>
#include "iova_domain.h"
@@ -46,6 +47,15 @@
#define IRQ_UNBOUND -1
+#define VDUSE_NET_INVALID_FEATURES_MASK \
+ (BIT_ULL(VIRTIO_NET_F_CTRL_VQ) | \
+ BIT_ULL(VIRTIO_NET_F_CTRL_RX) | \
+ BIT_ULL(VIRTIO_NET_F_CTRL_VLAN) | \
+ BIT_ULL(VIRTIO_NET_F_GUEST_ANNOUNCE) | \
+ BIT_ULL(VIRTIO_NET_F_MQ) | \
+ BIT_ULL(VIRTIO_NET_F_CTRL_MAC_ADDR) | \
+ BIT_ULL(VIRTIO_NET_F_RSS))
We need to make this as well:
VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
I missed it, and see others have been added in the Virtio spec
repository (BTW, I see this specific one is missing in the dependency
list [0], I will submit a patch).
I wonder if it is not just simpler to just check for
VIRTIO_NET_F_CTRL_VQ is requested. As we fail instead of masking out,
the VDUSE driver won't be the one violating the spec so it should be
good?
It will avoid having to update the mask if new features depending on it
are added (or forgetting to update it).
WDYT?
I think it is safer to work with a whitelist, instead of a blacklist.
As any new feature might require code changes in QEMU. Is that
possible?
Well, that's how it was done in previous revision. :)
I changed to a blacklist for consistency with block device's WCE feature
check after Jason's comment.
I'm not sure moving back to a whitelist brings much advantages when
compared to the effort of keeping it up to date. Just blacklisting
VIRTIO_NET_F_CTRL_VQ is enough in my opinion.
Thanks,
Maxime
Thanks,
Maxime
[0]:
https://github.com/oasis-tcs/virtio-spec/blob/5fc35a7efb903fc352da81a6d2be5c01810b68d3/device-types/net/description.tex#L129
Other than this,
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
+
struct vduse_virtqueue {
u16 index;
u16 num_max;
@@ -1680,6 +1690,9 @@ static bool features_is_valid(struct vduse_dev_config *config)
if ((config->device_id == VIRTIO_ID_BLOCK) &&
(config->features & (1ULL << VIRTIO_BLK_F_CONFIG_WCE)))
return false;
+ else if ((config->device_id == VIRTIO_ID_NET) &&
+ (config->features & VDUSE_NET_INVALID_FEATURES_MASK))
+ return false;
return true;
}
--
2.43.0
