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virtio-pci: Introduce admin command sending function

Add support for sending admin command through admin virtqueue interface. Abort any inflight admin commands once device reset completes. Activate admin queue when device becomes ready; deactivate on device reset. To comply to the below specification statement [1], the admin virtqueue is activated for upper layer users only after setting DRIVER_OK status. [1] The driver MUST NOT send any buffer available notifications to the device before setting DRIVER_OK.

Feng Liu committed 2 years ago

Commit 92792ac1 parent fd27ef64 files · +177 −2Browse files

Unified · Split

4 files
  1. drivers/virtio/virtio_pci_common.h +6 −0
  2. drivers/virtio/virtio_pci_modern.c +141 −2
  3. include/linux/virtio.h +8 −0
  4. include/uapi/linux/virtio_pci.h +22 −0
drivers/virtio/virtio_pci_common.h+6−0
@@ -29,6 +29,7 @@ · 28 unmodified lines
2929 #include <linux/virtio_pci_modern.h>
3030 #include <linux/highmem.h>
3131 #include <linux/spinlock.h>
32+#include <linux/mutex.h>
3233
3334 struct virtio_pci_vq_info {
3435 /* the actual virtqueue */
@@ -44,6 +45,8 @@ struct virtio_pci_vq_info { · 9 unmodified lines
4445 struct virtio_pci_admin_vq {
4546 /* Virtqueue info associated with this admin queue. */
4647 struct virtio_pci_vq_info info;
48+ /* serializing admin commands execution and virtqueue deletion */
49+ struct mutex cmd_lock;
4750 /* Name of the admin queue: avq.$vq_index. */
4851 char name[10];
4952 u16 vq_index;
@@ -152,4 +155,7 @@ static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) · 102 unmodified lines
152155 int virtio_pci_modern_probe(struct virtio_pci_device *);
153156 void virtio_pci_modern_remove(struct virtio_pci_device *);
154157
158+int vp_modern_admin_cmd_exec(struct virtio_device *vdev,
159+ struct virtio_admin_cmd *cmd);
160+
155161 #endif
drivers/virtio/virtio_pci_modern.c+141−2
@@ -38,6 +38,132 @@ static bool vp_is_avq(struct virtio_device *vdev, unsigned int index) · 37 unmodified lines
3838 return index == vp_dev->admin_vq.vq_index;
3939 }
4040
41+static int virtqueue_exec_admin_cmd(struct virtio_pci_admin_vq *admin_vq,
42+ struct scatterlist **sgs,
43+ unsigned int out_num,
44+ unsigned int in_num,
45+ void *data)
46+{
47+ struct virtqueue *vq;
48+ int ret, len;
49+
50+ vq = admin_vq->info.vq;
51+ if (!vq)
52+ return -EIO;
53+
54+ ret = virtqueue_add_sgs(vq, sgs, out_num, in_num, data, GFP_KERNEL);
55+ if (ret < 0)
56+ return -EIO;
57+
58+ if (unlikely(!virtqueue_kick(vq)))
59+ return -EIO;
60+
61+ while (!virtqueue_get_buf(vq, &len) &&
62+ !virtqueue_is_broken(vq))
63+ cpu_relax();
64+
65+ if (virtqueue_is_broken(vq))
66+ return -EIO;
67+
68+ return 0;
69+}
70+
71+int vp_modern_admin_cmd_exec(struct virtio_device *vdev,
72+ struct virtio_admin_cmd *cmd)
73+{
74+ struct scatterlist *sgs[VIRTIO_AVQ_SGS_MAX], hdr, stat;
75+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
76+ struct virtio_admin_cmd_status *va_status;
77+ unsigned int out_num = 0, in_num = 0;
78+ struct virtio_admin_cmd_hdr *va_hdr;
79+ u16 status;
80+ int ret;
81+
82+ if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
83+ return -EOPNOTSUPP;
84+
85+ va_status = kzalloc(sizeof(*va_status), GFP_KERNEL);
86+ if (!va_status)
87+ return -ENOMEM;
88+
89+ va_hdr = kzalloc(sizeof(*va_hdr), GFP_KERNEL);
90+ if (!va_hdr) {
91+ ret = -ENOMEM;
92+ goto err_alloc;
93+ }
94+
95+ va_hdr->opcode = cmd->opcode;
96+ va_hdr->group_type = cmd->group_type;
97+ va_hdr->group_member_id = cmd->group_member_id;
98+
99+ /* Add header */
100+ sg_init_one(&hdr, va_hdr, sizeof(*va_hdr));
101+ sgs[out_num] = &hdr;
102+ out_num++;
103+
104+ if (cmd->data_sg) {
105+ sgs[out_num] = cmd->data_sg;
106+ out_num++;
107+ }
108+
109+ /* Add return status */
110+ sg_init_one(&stat, va_status, sizeof(*va_status));
111+ sgs[out_num + in_num] = &stat;
112+ in_num++;
113+
114+ if (cmd->result_sg) {
115+ sgs[out_num + in_num] = cmd->result_sg;
116+ in_num++;
117+ }
118+
119+ mutex_lock(&vp_dev->admin_vq.cmd_lock);
120+ ret = virtqueue_exec_admin_cmd(&vp_dev->admin_vq, sgs,
121+ out_num, in_num, sgs);
122+ mutex_unlock(&vp_dev->admin_vq.cmd_lock);
123+
124+ if (ret) {
125+ dev_err(&vdev->dev,
126+ "Failed to execute command on admin vq: %d\n.", ret);
127+ goto err_cmd_exec;
128+ }
129+
130+ status = le16_to_cpu(va_status->status);
131+ if (status != VIRTIO_ADMIN_STATUS_OK) {
132+ dev_err(&vdev->dev,
133+ "admin command error: status(%#x) qualifier(%#x)\n",
134+ status, le16_to_cpu(va_status->status_qualifier));
135+ ret = -status;
136+ }
137+
138+err_cmd_exec:
139+ kfree(va_hdr);
140+err_alloc:
141+ kfree(va_status);
142+ return ret;
143+}
144+
145+static void vp_modern_avq_activate(struct virtio_device *vdev)
146+{
147+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
148+ struct virtio_pci_admin_vq *admin_vq = &vp_dev->admin_vq;
149+
150+ if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
151+ return;
152+
153+ __virtqueue_unbreak(admin_vq->info.vq);
154+}
155+
156+static void vp_modern_avq_deactivate(struct virtio_device *vdev)
157+{
158+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
159+ struct virtio_pci_admin_vq *admin_vq = &vp_dev->admin_vq;
160+
161+ if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
162+ return;
163+
164+ __virtqueue_break(admin_vq->info.vq);
165+}
166+
41167 static void vp_transport_features(struct virtio_device *vdev, u64 features)
42168 {
43169 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
@@ -213,6 +339,8 @@ static void vp_set_status(struct virtio_device *vdev, u8 status) · 169 unmodified lines
213339 /* We should never be setting status to 0. */
214340 BUG_ON(status == 0);
215341 vp_modern_set_status(&vp_dev->mdev, status);
342+ if (status & VIRTIO_CONFIG_S_DRIVER_OK)
343+ vp_modern_avq_activate(vdev);
216344 }
217345
218346 static void vp_reset(struct virtio_device *vdev)
@@ -229,6 +357,9 @@ static void vp_reset(struct virtio_device *vdev) · 10 unmodified lines
229357 */
230358 while (vp_modern_get_status(mdev))
231359 msleep(1);
360+
361+ vp_modern_avq_deactivate(vdev);
362+
232363 /* Flush pending VQ/configuration callbacks. */
233364 vp_synchronize_vectors(vdev);
234365 }
@@ -404,8 +535,11 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, · 169 unmodified lines
404535 goto err;
405536 }
406537
407− if (is_avq)
538+ if (is_avq) {
539+ mutex_lock(&vp_dev->admin_vq.cmd_lock);
408540 vp_dev->admin_vq.info.vq = vq;
541+ mutex_unlock(&vp_dev->admin_vq.cmd_lock);
542+ }
409543
410544 return vq;
411545
@@ -442,8 +576,11 @@ static void del_vq(struct virtio_pci_vq_info *info) · 30 unmodified lines
442576 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
443577 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
444578
445− if (vp_is_avq(&vp_dev->vdev, vq->index))
579+ if (vp_is_avq(&vp_dev->vdev, vq->index)) {
580+ mutex_lock(&vp_dev->admin_vq.cmd_lock);
446581 vp_dev->admin_vq.info.vq = NULL;
582+ mutex_unlock(&vp_dev->admin_vq.cmd_lock);
583+ }
447584
448585 if (vp_dev->msix_enabled)
449586 vp_modern_queue_vector(mdev, vq->index,
@@ -662,6 +799,7 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev) · 212 unmodified lines
662799 vp_dev->isr = mdev->isr;
663800 vp_dev->vdev.id = mdev->id;
664801
802+ mutex_init(&vp_dev->admin_vq.cmd_lock);
665803 return 0;
666804 }
667805
@@ -669,5 +807,6 @@ void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev) · 1 unmodified line
669807 {
670808 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
671809
810+ mutex_destroy(&vp_dev->admin_vq.cmd_lock);
672811 vp_modern_remove(mdev);
673812 }
include/linux/virtio.h+8−0
@@ -103,6 +103,14 @@ int virtqueue_resize(struct virtqueue *vq, u32 num, · 102 unmodified lines
103103 int virtqueue_reset(struct virtqueue *vq,
104104 void (*recycle)(struct virtqueue *vq, void *buf));
105105
106+struct virtio_admin_cmd {
107+ __le16 opcode;
108+ __le16 group_type;
109+ __le64 group_member_id;
110+ struct scatterlist *data_sg;
111+ struct scatterlist *result_sg;
112+};
113+
106114 /**
107115 * struct virtio_device - representation of a device using virtio
108116 * @index: unique position on the virtio bus
include/uapi/linux/virtio_pci.h+22−0
@@ -223,4 +223,26 @@ struct virtio_pci_cfg_cap { · 222 unmodified lines
223223
224224 #endif /* VIRTIO_PCI_NO_MODERN */
225225
226+/* Admin command status. */
227+#define VIRTIO_ADMIN_STATUS_OK 0
228+
229+struct __packed virtio_admin_cmd_hdr {
230+ __le16 opcode;
231+ /*
232+ * 1 - SR-IOV
233+ * 2-65535 - reserved
234+ */
235+ __le16 group_type;
236+ /* Unused, reserved for future extensions. */
237+ __u8 reserved1[12];
238+ __le64 group_member_id;
239+};
240+
241+struct __packed virtio_admin_cmd_status {
242+ __le16 status;
243+ __le16 status_qualifier;
244+ /* Unused, reserved for future extensions. */
245+ __u8 reserved2[4];
246+};
247+
226248 #endif

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