Re: [PATCH v3 13/19] vdpa_sim: add get_config callback in vdpasim_dev_attr

2020-12-15 Thread Stefano Garzarella

On Wed, Dec 9, 2020 at 12:07 PM Stefano Garzarella  wrote:
> 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 
> >>---
> >>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).

Working on this I just realized that we already check in 
vdpa_get_config() that set_features() is called, so I think the moving 
is safe.

I'll put these considerations in the commit message.

Thanks,
Stefano

>
> @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 = 

Re: [PATCH v3 13/19] vdpa_sim: add get_config callback in vdpasim_dev_attr

2020-12-06 Thread Jason Wang


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 
---
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.


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(_attr);


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[PATCH v3 13/19] vdpa_sim: add get_config callback in vdpasim_dev_attr

2020-12-03 Thread Stefano Garzarella
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 
---
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);
-
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(_attr);
-- 
2.26.2

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