On Mon, Dec 07, 2020 at 01:29:17PM +0800, Jason Wang wrote:
On 2020/12/4 上午1:05, Stefano Garzarella wrote:
The get_config callback can be used by the device to fill the
config structure.
The callback will be invoked in vdpasim_get_config() before copying
bytes into caller buffer.
Move vDPA-net config updates from vdpasim_set_features() in the
new vdpasim_net_get_config() callback.
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
v3:
- checked if get_config callback is set before call it
---
drivers/vdpa/vdpa_sim/vdpa_sim.c | 35 +++++++++++++++++++-------------
1 file changed, 21 insertions(+), 14 deletions(-)
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index fe71ed7890e1..f935ade0806b 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -60,6 +60,8 @@ struct vdpasim_virtqueue {
#define VDPASIM_NET_FEATURES (VDPASIM_FEATURES | \
(1ULL << VIRTIO_NET_F_MAC))
+struct vdpasim;
+
struct vdpasim_dev_attr {
u64 supported_features;
size_t config_size;
@@ -67,6 +69,7 @@ struct vdpasim_dev_attr {
u32 id;
work_func_t work_fn;
+ void (*get_config)(struct vdpasim *vdpasim, void *config);
};
/* State of each vdpasim device */
@@ -522,8 +525,6 @@ static u64 vdpasim_get_features(struct vdpa_device *vdpa)
static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
- struct virtio_net_config *config =
- (struct virtio_net_config *)vdpasim->config;
/* DMA mapping must be done by driver */
if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
@@ -531,16 +532,6 @@ static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
vdpasim->features = features & vdpasim->dev_attr.supported_features;
- /* We generally only know whether guest is using the legacy interface
- * here, so generally that's the earliest we can set config fields.
- * Note: We actually require VIRTIO_F_ACCESS_PLATFORM above which
- * implies VIRTIO_F_VERSION_1, but let's not try to be clever here.
- */
-
- config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
- config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
- memcpy(config->mac, macaddr_buf, ETH_ALEN);
Patch looks good to me.
But we need Michael to confirm whether doing moving like this is safe.
I guess what has been done were trying to make sure get_config() fail
before set_features(), but it's not clear to me whether it's useful.
IIUC, also looking the QEMU code, the set_features() should be called
every time before get_config(), but to be sure, in get_config(), I can
check for example if 'vdpasim->features' is not zero (we require
VIRTIO_F_ACCESS_PLATFORM set).
@Michael any suggestion?
Thanks,
Stefano
Thanks
-
return 0;
}
@@ -595,8 +586,13 @@ static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
- if (offset + len < vdpasim->dev_attr.config_size)
- memcpy(buf, vdpasim->config + offset, len);
+ if (offset + len > vdpasim->dev_attr.config_size)
+ return;
+
+ if (vdpasim->dev_attr.get_config)
+ vdpasim->dev_attr.get_config(vdpasim, vdpasim->config);
+
+ memcpy(buf, vdpasim->config + offset, len);
}
static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,
@@ -739,6 +735,16 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
.free = vdpasim_free,
};
+static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
+{
+ struct virtio_net_config *net_config =
+ (struct virtio_net_config *)config;
+
+ net_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
+ net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
+ memcpy(net_config->mac, macaddr_buf, ETH_ALEN);
+}
+
static int __init vdpasim_dev_init(void)
{
struct vdpasim_dev_attr dev_attr = {};
@@ -747,6 +753,7 @@ static int __init vdpasim_dev_init(void)
dev_attr.supported_features = VDPASIM_NET_FEATURES;
dev_attr.nvqs = VDPASIM_VQ_NUM;
dev_attr.config_size = sizeof(struct virtio_net_config);
+ dev_attr.get_config = vdpasim_net_get_config;
dev_attr.work_fn = vdpasim_net_work;
vdpasim_dev = vdpasim_create(&dev_attr);
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