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From:   Stefano Garzarella <sgarzare@redhat.com>
To:     virtualization@lists.linux-foundation.org
Cc:     Stefan Hajnoczi <stefanha@redhat.com>,
        Laurent Vivier <lvivier@redhat.com>,
        linux-kernel@vger.kernel.org, Eli Cohen <elic@nvidia.com>,
        Jason Wang <jasowang@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Max Gurtovoy <mgurtovoy@nvidia.com>
Subject: [PATCH RFC 03/12] vdpa_sim: remove hard-coded virtq count
Date:   Fri, 13 Nov 2020 14:47:03 +0100
Message-Id: <20201113134712.69744-4-sgarzare@redhat.com>
In-Reply-To: <20201113134712.69744-1-sgarzare@redhat.com>
References: <20201113134712.69744-1-sgarzare@redhat.com>
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From: Max Gurtovoy <mgurtovoy@nvidia.com>

Add a new attribute that will define the number of virt queues to be
created for the vdpasim device.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
[sgarzare: replace kmalloc_array() with kcalloc()]
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v1:
- use kcalloc() instead of kmalloc_array() since some function expects
  variables initialized to zero
---
 drivers/vdpa/vdpa_sim/vdpa_sim.h     |  5 +++--
 drivers/vdpa/vdpa_sim/vdpa_sim.c     | 14 +++++++++++---
 drivers/vdpa/vdpa_sim/vdpa_sim_net.c |  3 +++
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h
index 33613c49888c..6a1267c40d5e 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.h
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h
@@ -20,7 +20,6 @@
 #define VDPASIM_QUEUE_ALIGN PAGE_SIZE
 #define VDPASIM_QUEUE_MAX 256
 #define VDPASIM_VENDOR_ID 0
-#define VDPASIM_VQ_NUM 0x2
 
 #define VDPASIM_FEATURES	((1ULL << VIRTIO_F_ANY_LAYOUT) | \
 				 (1ULL << VIRTIO_F_VERSION_1)  | \
@@ -46,12 +45,13 @@ struct vdpasim_init_attr {
 	u64		features;
 	work_func_t	work_fn;
 	int		batch_mapping;
+	int		nvqs;
 };
 
 /* State of each vdpasim device */
 struct vdpasim {
 	struct vdpa_device vdpa;
-	struct vdpasim_virtqueue vqs[VDPASIM_VQ_NUM];
+	struct vdpasim_virtqueue *vqs;
 	struct work_struct work;
 	/* spinlock to synchronize virtqueue state */
 	spinlock_t lock;
@@ -64,6 +64,7 @@ struct vdpasim {
 	u32 generation;
 	u64 features;
 	u64 supported_features;
+	int nvqs;
 	/* spinlock to synchronize iommu table */
 	spinlock_t iommu_lock;
 };
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 04f9dc9ce8c8..2b4fea354413 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -54,7 +54,7 @@ static void vdpasim_reset(struct vdpasim *vdpasim)
 {
 	int i;
 
-	for (i = 0; i < VDPASIM_VQ_NUM; i++)
+	for (i = 0; i < vdpasim->nvqs; i++)
 		vdpasim_vq_reset(vdpasim, &vdpasim->vqs[i]);
 
 	spin_lock(&vdpasim->iommu_lock);
@@ -199,7 +199,8 @@ struct vdpasim *vdpasim_create(struct vdpasim_init_attr *attr)
 	else
 		ops = &vdpasim_config_ops;
 
-	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops, VDPASIM_VQ_NUM);
+	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
+				    attr->nvqs);
 	if (!vdpasim)
 		goto err_alloc;
 
@@ -211,8 +212,14 @@ struct vdpasim *vdpasim_create(struct vdpasim_init_attr *attr)
 	if (!vdpasim->config)
 		goto err_iommu;
 
+	vdpasim->vqs = kcalloc(attr->nvqs, sizeof(struct vdpasim_virtqueue),
+			       GFP_KERNEL);
+	if (!vdpasim->vqs)
+		goto err_iommu;
+
 	vdpasim->device_id = device_id;
 	vdpasim->supported_features = attr->features;
+	vdpasim->nvqs = attr->nvqs;
 	INIT_WORK(&vdpasim->work, attr->work_fn);
 	spin_lock_init(&vdpasim->lock);
 	spin_lock_init(&vdpasim->iommu_lock);
@@ -231,7 +238,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_init_attr *attr)
 	if (!vdpasim->buffer)
 		goto err_iommu;
 
-	for (i = 0; i < VDPASIM_VQ_NUM; i++)
+	for (i = 0; i < vdpasim->nvqs; i++)
 		vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu);
 
 	vdpasim->vdpa.dma_dev = dev;
@@ -511,6 +518,7 @@ static void vdpasim_free(struct vdpa_device *vdpa)
 	kfree(vdpasim->buffer);
 	if (vdpasim->iommu)
 		vhost_iotlb_free(vdpasim->iommu);
+	kfree(vdpasim->vqs);
 	kfree(vdpasim->config);
 }
 
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
index c68d5488ab54..e1e57c52b108 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
@@ -14,6 +14,8 @@
 
 #define VDPASIM_NET_FEATURES	(1ULL << VIRTIO_NET_F_MAC)
 
+#define VDPASIM_NET_VQ_NUM 2
+
 static int batch_mapping = 1;
 module_param(batch_mapping, int, 0444);
 MODULE_PARM_DESC(batch_mapping, "Batched mapping 1 - Enable; 0 - Disable");
@@ -105,6 +107,7 @@ static int __init vdpasim_net_init(void)
 
 	attr.device_id = VIRTIO_ID_NET;
 	attr.features = VDPASIM_FEATURES | VDPASIM_NET_FEATURES;
+	attr.nvqs = VDPASIM_NET_VQ_NUM;
 	attr.work_fn = vdpasim_net_work;
 	attr.batch_mapping = batch_mapping;
 	vdpasim_net_dev = vdpasim_create(&attr);
-- 
2.26.2