From: Jason Wang <jasowang@redhat.com> To: Stefano Garzarella <sgarzare@redhat.com> Cc: virtualization@lists.linux-foundation.org, Stefan Hajnoczi <stefanha@redhat.com>, linux-kernel@vger.kernel.org, Laurent Vivier <lvivier@redhat.com>, Max Gurtovoy <mgurtovoy@nvidia.com>, "Michael S. Tsirkin" <mst@redhat.com>, Eli Cohen <elic@nvidia.com> Subject: Re: [PATCH v2 12/17] vdpa_sim: add get_config callback in vdpasim_dev_attr Date: Tue, 1 Dec 2020 11:44:19 +0800 [thread overview] Message-ID: <c2158059-6509-7702-f52a-e497ce899293@redhat.com> (raw) In-Reply-To: <20201130141453.jobe76loyfy4qrdw@steredhat> On 2020/11/30 下午10:14, Stefano Garzarella wrote: > On Mon, Nov 30, 2020 at 11:25:31AM +0800, Jason Wang wrote: >> >> On 2020/11/26 下午10:49, 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@redhat.com> >>> --- >>> drivers/vdpa/vdpa_sim/vdpa_sim.c | 33 +++++++++++++++++++------------- >>> 1 file changed, 20 insertions(+), 13 deletions(-) >>> >>> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> b/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> index c07ddf6af720..8b87ce0485b6 100644 >>> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> @@ -58,6 +58,8 @@ 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; >>> @@ -65,6 +67,7 @@ struct vdpasim_dev_attr { >>> u32 id; >>> work_func_t work_fn; >>> + void (*get_config)(struct vdpasim *vdpasim, void *config); >>> }; >>> /* State of each vdpasim device */ >>> @@ -520,8 +523,6 @@ 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))) >>> @@ -529,15 +530,6 @@ 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; >>> } >>> @@ -593,8 +585,12 @@ 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; >>> + >>> + vdpasim->dev_attr.get_config(vdpasim, vdpasim->config); >>> + >>> + memcpy(buf, vdpasim->config + offset, len); >>> } >> >> >> I wonder how much value we can get from vdpasim->config consider >> we've already had get_config() method. >> >> Is it possible to copy to the buffer directly here? > > I had thought of eliminating it too, but then I wanted to do something > similar to what we do in QEMU (hw/virtio/virtio.c), leaving in the > simulator core the buffer, the memory copy (handling offset and len), > and the boundary checks. > > In this way each device should simply fill the entire configuration > and we can avoid code duplication. > > Storing the configuration in the core may also be useful if some > device needs to support config writes. I think in that way we need should provide config_write(). > > Do you think it makes sense, or is it better to move everything in the > device? I prefer to do that in the device but it's also fine keep what the patch has done. Thanks > > Thanks, > Stefano >
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com> To: Stefano Garzarella <sgarzare@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com>, Max Gurtovoy <mgurtovoy@nvidia.com>, "Michael S. Tsirkin" <mst@redhat.com>, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Stefan Hajnoczi <stefanha@redhat.com>, Eli Cohen <elic@nvidia.com> Subject: Re: [PATCH v2 12/17] vdpa_sim: add get_config callback in vdpasim_dev_attr Date: Tue, 1 Dec 2020 11:44:19 +0800 [thread overview] Message-ID: <c2158059-6509-7702-f52a-e497ce899293@redhat.com> (raw) In-Reply-To: <20201130141453.jobe76loyfy4qrdw@steredhat> On 2020/11/30 下午10:14, Stefano Garzarella wrote: > On Mon, Nov 30, 2020 at 11:25:31AM +0800, Jason Wang wrote: >> >> On 2020/11/26 下午10:49, 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@redhat.com> >>> --- >>> drivers/vdpa/vdpa_sim/vdpa_sim.c | 33 +++++++++++++++++++------------- >>> 1 file changed, 20 insertions(+), 13 deletions(-) >>> >>> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> b/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> index c07ddf6af720..8b87ce0485b6 100644 >>> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c >>> @@ -58,6 +58,8 @@ 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; >>> @@ -65,6 +67,7 @@ struct vdpasim_dev_attr { >>> u32 id; >>> work_func_t work_fn; >>> + void (*get_config)(struct vdpasim *vdpasim, void *config); >>> }; >>> /* State of each vdpasim device */ >>> @@ -520,8 +523,6 @@ 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))) >>> @@ -529,15 +530,6 @@ 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; >>> } >>> @@ -593,8 +585,12 @@ 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; >>> + >>> + vdpasim->dev_attr.get_config(vdpasim, vdpasim->config); >>> + >>> + memcpy(buf, vdpasim->config + offset, len); >>> } >> >> >> I wonder how much value we can get from vdpasim->config consider >> we've already had get_config() method. >> >> Is it possible to copy to the buffer directly here? > > I had thought of eliminating it too, but then I wanted to do something > similar to what we do in QEMU (hw/virtio/virtio.c), leaving in the > simulator core the buffer, the memory copy (handling offset and len), > and the boundary checks. > > In this way each device should simply fill the entire configuration > and we can avoid code duplication. > > Storing the configuration in the core may also be useful if some > device needs to support config writes. I think in that way we need should provide config_write(). > > Do you think it makes sense, or is it better to move everything in the > device? I prefer to do that in the device but it's also fine keep what the patch has done. Thanks > > Thanks, > Stefano > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2020-12-01 3:46 UTC|newest] Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-26 14:49 [PATCH v2 00/17] vdpa: generalize vdpa simulator Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 01/17] vdpa: remove unnecessary 'default n' in Kconfig entries Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:01 ` Jason Wang 2020-11-30 3:01 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 02/17] vdpa_sim: remove unnecessary headers inclusion Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:04 ` Jason Wang 2020-11-30 3:04 ` Jason Wang 2020-11-30 11:10 ` Stefano Garzarella 2020-11-30 11:10 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 03/17] vdpa_sim: remove hard-coded virtq count Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:05 ` Jason Wang 2020-11-30 3:05 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 04/17] vdpa_sim: remove the limit of IOTLB entries Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:07 ` Jason Wang 2020-11-30 3:07 ` Jason Wang 2020-11-30 11:24 ` Stefano Garzarella 2020-11-30 11:24 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 05/17] vdpa_sim: rename vdpasim_config_ops variables Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:07 ` Jason Wang 2020-11-30 3:07 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 06/17] vdpa_sim: add struct vdpasim_dev_attr for device attributes Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:09 ` Jason Wang 2020-11-30 3:09 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 07/17] vdpa_sim: add device id field in vdpasim_dev_attr Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:10 ` Jason Wang 2020-11-30 3:10 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 08/17] vdpa_sim: add supported_features " Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:14 ` Jason Wang 2020-11-30 3:14 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 09/17] vdpa_sim: add work_fn " Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:16 ` Jason Wang 2020-11-30 3:16 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 10/17] vdpa_sim: store parsed MAC address in a buffer Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:20 ` Jason Wang 2020-11-30 3:20 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 11/17] vdpa_sim: make 'config' generic and usable for any device type Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 12/17] vdpa_sim: add get_config callback in vdpasim_dev_attr Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:25 ` Jason Wang 2020-11-30 3:25 ` Jason Wang 2020-11-30 14:14 ` Stefano Garzarella 2020-11-30 14:14 ` Stefano Garzarella 2020-12-01 3:44 ` Jason Wang [this message] 2020-12-01 3:44 ` Jason Wang 2020-12-01 10:52 ` Stefano Garzarella 2020-12-01 10:52 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 13/17] vdpa_sim: set vringh notify callback Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:27 ` Jason Wang 2020-11-30 3:27 ` Jason Wang 2020-11-30 14:16 ` Stefano Garzarella 2020-11-30 14:16 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 14/17] vdpa_sim: use kvmalloc to allocate vdpasim->buffer Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 15/17] vdpa_sim: make vdpasim->buffer size configurable Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-26 14:49 ` [PATCH v2 16/17] vdpa_sim: split vdpasim_virtqueue's iov field in out_iov and in_iov Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:29 ` Jason Wang 2020-11-30 3:29 ` Jason Wang 2020-11-26 14:49 ` [PATCH v2 17/17] vdpa: split vdpasim to core and net modules Stefano Garzarella 2020-11-26 14:49 ` Stefano Garzarella 2020-11-30 3:31 ` Jason Wang 2020-11-30 3:31 ` Jason Wang 2020-11-30 14:17 ` Stefano Garzarella 2020-11-30 14:17 ` Stefano Garzarella 2020-11-26 15:12 ` [PATCH v2 00/17] vdpa: generalize vdpa simulator Max Gurtovoy 2020-11-26 15:24 ` Stefano Garzarella 2020-11-26 15:24 ` Stefano Garzarella
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