From 4cb2ea28c55cf5e5ef83aec535099ffce3c583df Mon Sep 17 00:00:00 2001 From: john cooper Date: Thu, 25 Mar 2010 01:33:33 -0400 Subject: Add virtio disk identification support Add virtio-blk device id (s/n) support via virtio request. Signed-off-by: john cooper Signed-off-by: Rusty Russell --- include/linux/virtio_blk.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index e52029e98919..167720d695ed 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -17,6 +17,8 @@ #define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */ #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ +#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ + struct virtio_blk_config { /* The capacity (in 512-byte sectors). */ __u64 capacity; @@ -67,6 +69,9 @@ struct virtio_blk_config { /* Cache flush command */ #define VIRTIO_BLK_T_FLUSH 4 +/* Get device ID command */ +#define VIRTIO_BLK_T_GET_ID 8 + /* Barrier before this op. */ #define VIRTIO_BLK_T_BARRIER 0x80000000 -- cgit v1.2.3 From 316f25f5b3d547ce892d370f99f08a27276896ff Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 12 Apr 2010 16:18:25 +0300 Subject: virtio: add virtqueue_ vq_ops wrappers Add inline functions that wrap vq->vq_ops-> calls Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- include/linux/virtio.h | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) (limited to 'include/linux') diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 40d1709bdbf4..18ccc686a429 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -77,6 +77,40 @@ struct virtqueue_ops { void *(*detach_unused_buf)(struct virtqueue *vq); }; +static inline int virtqueue_add_buf(struct virtqueue *vq, + struct scatterlist sg[], + unsigned int out_num, + unsigned int in_num, + void *data) +{ + return vq->vq_ops->add_buf(vq, sg, out_num, in_num, data); +} + +static inline int void virtqueue_kick(struct virtqueue *vq) +{ + return vq->vq_ops->kick(vq); +} + +static inline void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len) +{ + return vq->vq_ops->get_buf(vq, len); +} + +static inline void virtqueue_disable_cb(struct virtqueue *vq) +{ + vq->vq_ops->disable_cb(vq); +} + +static inline bool virtqueue_enable_cb(struct virtqueue *vq) +{ + return vq->vq_ops->enable_cb(vq); +} + +static inline void *virtqueue_detach_unused_buf(struct virtqueue *vq) +{ + return vq->vq_ops->detach_unused_buf(vq); +} + /** * virtio_device - representation of a device using virtio * @index: unique position on the virtio bus -- cgit v1.2.3 From 7c5e9ed0c84e7d70d887878574590638d5572659 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 12 Apr 2010 16:19:07 +0300 Subject: virtio_ring: remove a level of indirection We have a single virtqueue_ops implementation, and it seems unlikely we'll get another one at this point. So let's remove an unnecessary level of indirection: it would be very easy to re-add it if another implementation surfaces. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_ring.c | 36 ++++++++++------------ include/linux/virtio.h | 71 +++++++++++--------------------------------- 2 files changed, 34 insertions(+), 73 deletions(-) (limited to 'include/linux') diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 0f90634bcb85..0717b5b000bb 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -155,11 +155,11 @@ static int vring_add_indirect(struct vring_virtqueue *vq, return head; } -static int vring_add_buf(struct virtqueue *_vq, - struct scatterlist sg[], - unsigned int out, - unsigned int in, - void *data) +int virtqueue_add_buf(struct virtqueue *_vq, + struct scatterlist sg[], + unsigned int out, + unsigned int in, + void *data) { struct vring_virtqueue *vq = to_vvq(_vq); unsigned int i, avail, head, uninitialized_var(prev); @@ -232,8 +232,9 @@ add_head: return vq->num_free ? vq->vring.num : 0; return vq->num_free; } +EXPORT_SYMBOL_GPL(virtqueue_add_buf); -static void vring_kick(struct virtqueue *_vq) +void virtqueue_kick(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); START_USE(vq); @@ -253,6 +254,7 @@ static void vring_kick(struct virtqueue *_vq) END_USE(vq); } +EXPORT_SYMBOL_GPL(virtqueue_kick); static void detach_buf(struct vring_virtqueue *vq, unsigned int head) { @@ -284,7 +286,7 @@ static inline bool more_used(const struct vring_virtqueue *vq) return vq->last_used_idx != vq->vring.used->idx; } -static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len) +void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len) { struct vring_virtqueue *vq = to_vvq(_vq); void *ret; @@ -325,15 +327,17 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len) END_USE(vq); return ret; } +EXPORT_SYMBOL_GPL(virtqueue_get_buf); -static void vring_disable_cb(struct virtqueue *_vq) +void virtqueue_disable_cb(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; } +EXPORT_SYMBOL_GPL(virtqueue_disable_cb); -static bool vring_enable_cb(struct virtqueue *_vq) +bool virtqueue_enable_cb(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); @@ -351,8 +355,9 @@ static bool vring_enable_cb(struct virtqueue *_vq) END_USE(vq); return true; } +EXPORT_SYMBOL_GPL(virtqueue_enable_cb); -static void *vring_detach_unused_buf(struct virtqueue *_vq) +void *virtqueue_detach_unused_buf(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); unsigned int i; @@ -375,6 +380,7 @@ static void *vring_detach_unused_buf(struct virtqueue *_vq) END_USE(vq); return NULL; } +EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf); irqreturn_t vring_interrupt(int irq, void *_vq) { @@ -396,15 +402,6 @@ irqreturn_t vring_interrupt(int irq, void *_vq) } EXPORT_SYMBOL_GPL(vring_interrupt); -static struct virtqueue_ops vring_vq_ops = { - .add_buf = vring_add_buf, - .get_buf = vring_get_buf, - .kick = vring_kick, - .disable_cb = vring_disable_cb, - .enable_cb = vring_enable_cb, - .detach_unused_buf = vring_detach_unused_buf, -}; - struct virtqueue *vring_new_virtqueue(unsigned int num, unsigned int vring_align, struct virtio_device *vdev, @@ -429,7 +426,6 @@ struct virtqueue *vring_new_virtqueue(unsigned int num, vring_init(&vq->vring, num, pages, vring_align); vq->vq.callback = callback; vq->vq.vdev = vdev; - vq->vq.vq_ops = &vring_vq_ops; vq->vq.name = name; vq->notify = notify; vq->broken = false; diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 18ccc686a429..5b0fce0d2aa2 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -14,7 +14,6 @@ * @callback: the function to call when buffers are consumed (can be NULL). * @name: the name of this virtqueue (mainly for debugging) * @vdev: the virtio device this queue was created for. - * @vq_ops: the operations for this virtqueue (see below). * @priv: a pointer for the virtqueue implementation to use. */ struct virtqueue { @@ -22,94 +21,60 @@ struct virtqueue { void (*callback)(struct virtqueue *vq); const char *name; struct virtio_device *vdev; - struct virtqueue_ops *vq_ops; void *priv; }; /** - * virtqueue_ops - operations for virtqueue abstraction layer - * @add_buf: expose buffer to other end + * operations for virtqueue + * virtqueue_add_buf: expose buffer to other end * vq: the struct virtqueue we're talking about. * sg: the description of the buffer(s). * out_num: the number of sg readable by other side * in_num: the number of sg which are writable (after readable ones) * data: the token identifying the buffer. * Returns remaining capacity of queue (sg segments) or a negative error. - * @kick: update after add_buf + * virtqueue_kick: update after add_buf * vq: the struct virtqueue * After one or more add_buf calls, invoke this to kick the other side. - * @get_buf: get the next used buffer + * virtqueue_get_buf: get the next used buffer * vq: the struct virtqueue we're talking about. * len: the length written into the buffer * Returns NULL or the "data" token handed to add_buf. - * @disable_cb: disable callbacks + * virtqueue_disable_cb: disable callbacks * vq: the struct virtqueue we're talking about. * Note that this is not necessarily synchronous, hence unreliable and only * useful as an optimization. - * @enable_cb: restart callbacks after disable_cb. + * virtqueue_enable_cb: restart callbacks after disable_cb. * vq: the struct virtqueue we're talking about. * This re-enables callbacks; it returns "false" if there are pending * buffers in the queue, to detect a possible race between the driver * checking for more work, and enabling callbacks. - * @detach_unused_buf: detach first unused buffer + * virtqueue_detach_unused_buf: detach first unused buffer * vq: the struct virtqueue we're talking about. * Returns NULL or the "data" token handed to add_buf * * Locking rules are straightforward: the driver is responsible for * locking. No two operations may be invoked simultaneously, with the exception - * of @disable_cb. + * of virtqueue_disable_cb. * * All operations can be called in any context. */ -struct virtqueue_ops { - int (*add_buf)(struct virtqueue *vq, - struct scatterlist sg[], - unsigned int out_num, - unsigned int in_num, - void *data); - void (*kick)(struct virtqueue *vq); +int virtqueue_add_buf(struct virtqueue *vq, + struct scatterlist sg[], + unsigned int out_num, + unsigned int in_num, + void *data); - void *(*get_buf)(struct virtqueue *vq, unsigned int *len); +void virtqueue_kick(struct virtqueue *vq); - void (*disable_cb)(struct virtqueue *vq); - bool (*enable_cb)(struct virtqueue *vq); - void *(*detach_unused_buf)(struct virtqueue *vq); -}; - -static inline int virtqueue_add_buf(struct virtqueue *vq, - struct scatterlist sg[], - unsigned int out_num, - unsigned int in_num, - void *data) -{ - return vq->vq_ops->add_buf(vq, sg, out_num, in_num, data); -} - -static inline int void virtqueue_kick(struct virtqueue *vq) -{ - return vq->vq_ops->kick(vq); -} - -static inline void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len) -{ - return vq->vq_ops->get_buf(vq, len); -} +void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); -static inline void virtqueue_disable_cb(struct virtqueue *vq) -{ - vq->vq_ops->disable_cb(vq); -} +void virtqueue_disable_cb(struct virtqueue *vq); -static inline bool virtqueue_enable_cb(struct virtqueue *vq) -{ - return vq->vq_ops->enable_cb(vq); -} +bool virtqueue_enable_cb(struct virtqueue *vq); -static inline void *virtqueue_detach_unused_buf(struct virtqueue *vq) -{ - return vq->vq_ops->detach_unused_buf(vq); -} +void *virtqueue_detach_unused_buf(struct virtqueue *vq); /** * virtio_device - representation of a device using virtio -- cgit v1.2.3 From bbd603efb4238cf78083c00f0a81adfa8994aa33 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 29 Apr 2010 17:26:37 +0300 Subject: virtio: add_buf_gfp Add an add_buf variant that gets gfp parameter. Use that to allocate indirect buffers. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_ring.c | 20 +++++++++++--------- include/linux/virtio.h | 22 +++++++++++++++++----- 2 files changed, 28 insertions(+), 14 deletions(-) (limited to 'include/linux') diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 0717b5b000bb..1ca88908723b 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -110,13 +110,14 @@ struct vring_virtqueue static int vring_add_indirect(struct vring_virtqueue *vq, struct scatterlist sg[], unsigned int out, - unsigned int in) + unsigned int in, + gfp_t gfp) { struct vring_desc *desc; unsigned head; int i; - desc = kmalloc((out + in) * sizeof(struct vring_desc), GFP_ATOMIC); + desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp); if (!desc) return vq->vring.num; @@ -155,11 +156,12 @@ static int vring_add_indirect(struct vring_virtqueue *vq, return head; } -int virtqueue_add_buf(struct virtqueue *_vq, - struct scatterlist sg[], - unsigned int out, - unsigned int in, - void *data) +int virtqueue_add_buf_gfp(struct virtqueue *_vq, + struct scatterlist sg[], + unsigned int out, + unsigned int in, + void *data, + gfp_t gfp) { struct vring_virtqueue *vq = to_vvq(_vq); unsigned int i, avail, head, uninitialized_var(prev); @@ -171,7 +173,7 @@ int virtqueue_add_buf(struct virtqueue *_vq, /* If the host supports indirect descriptor tables, and we have multiple * buffers, then go indirect. FIXME: tune this threshold */ if (vq->indirect && (out + in) > 1 && vq->num_free) { - head = vring_add_indirect(vq, sg, out, in); + head = vring_add_indirect(vq, sg, out, in, gfp); if (head != vq->vring.num) goto add_head; } @@ -232,7 +234,7 @@ add_head: return vq->num_free ? vq->vring.num : 0; return vq->num_free; } -EXPORT_SYMBOL_GPL(virtqueue_add_buf); +EXPORT_SYMBOL_GPL(virtqueue_add_buf_gfp); void virtqueue_kick(struct virtqueue *_vq) { diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 5b0fce0d2aa2..aff5b4f74041 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -7,6 +7,7 @@ #include #include #include +#include /** * virtqueue - a queue to register buffers for sending or receiving. @@ -32,6 +33,7 @@ struct virtqueue { * out_num: the number of sg readable by other side * in_num: the number of sg which are writable (after readable ones) * data: the token identifying the buffer. + * gfp: how to do memory allocations (if necessary). * Returns remaining capacity of queue (sg segments) or a negative error. * virtqueue_kick: update after add_buf * vq: the struct virtqueue @@ -60,11 +62,21 @@ struct virtqueue { * All operations can be called in any context. */ -int virtqueue_add_buf(struct virtqueue *vq, - struct scatterlist sg[], - unsigned int out_num, - unsigned int in_num, - void *data); +int virtqueue_add_buf_gfp(struct virtqueue *vq, + struct scatterlist sg[], + unsigned int out_num, + unsigned int in_num, + void *data, + gfp_t gfp); + +static inline int virtqueue_add_buf(struct virtqueue *vq, + struct scatterlist sg[], + unsigned int out_num, + unsigned int in_num, + void *data) +{ + return virtqueue_add_buf_gfp(vq, sg, out_num, in_num, data, GFP_ATOMIC); +} void virtqueue_kick(struct virtqueue *vq); -- cgit v1.2.3 From b99fa815d71023b2e330d63cd7f47d6247ffa321 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Wed, 19 May 2010 22:15:46 -0600 Subject: virtio: Revert "virtio: disable multiport console support." This reverts commit b7a413015d2986edf020fba765c906cc9cbcbfc9. Multiport support was disabled for 2.6.34 because we wanted to introduce a new ABI and since we didn't have any released kernel with the older ABI and were out of the merge window, it didn't make sense keeping the older ABI around. Now we revert the patch disabling multiport and rework the ABI in the following patches. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell --- drivers/char/virtio_console.c | 49 +++++++----------------------------------- include/linux/virtio_console.h | 23 ++++++++++++++++++++ 2 files changed, 31 insertions(+), 41 deletions(-) (limited to 'include/linux') diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 48ce834306b5..e53c52b904fb 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -33,35 +33,6 @@ #include #include "hvc_console.h" -/* Moved here from .h file in order to disable MULTIPORT. */ -#define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */ - -struct virtio_console_multiport_conf { - struct virtio_console_config config; - /* max. number of ports this device can hold */ - __u32 max_nr_ports; - /* number of ports added so far */ - __u32 nr_ports; -} __attribute__((packed)); - -/* - * A message that's passed between the Host and the Guest for a - * particular port. - */ -struct virtio_console_control { - __u32 id; /* Port number */ - __u16 event; /* The kind of control event (see below) */ - __u16 value; /* Extra information for the key */ -}; - -/* Some events for control messages */ -#define VIRTIO_CONSOLE_PORT_READY 0 -#define VIRTIO_CONSOLE_CONSOLE_PORT 1 -#define VIRTIO_CONSOLE_RESIZE 2 -#define VIRTIO_CONSOLE_PORT_OPEN 3 -#define VIRTIO_CONSOLE_PORT_NAME 4 -#define VIRTIO_CONSOLE_PORT_REMOVE 5 - /* * This is a global struct for storing common data for all the devices * this driver handles. @@ -150,7 +121,7 @@ struct ports_device { spinlock_t cvq_lock; /* The current config space is stored here */ - struct virtio_console_multiport_conf config; + struct virtio_console_config config; /* The virtio device we're associated with */ struct virtio_device *vdev; @@ -1243,7 +1214,7 @@ fail: */ static void config_work_handler(struct work_struct *work) { - struct virtio_console_multiport_conf virtconconf; + struct virtio_console_config virtconconf; struct ports_device *portdev; struct virtio_device *vdev; int err; @@ -1252,8 +1223,7 @@ static void config_work_handler(struct work_struct *work) vdev = portdev->vdev; vdev->config->get(vdev, - offsetof(struct virtio_console_multiport_conf, - nr_ports), + offsetof(struct virtio_console_config, nr_ports), &virtconconf.nr_ports, sizeof(virtconconf.nr_ports)); @@ -1445,19 +1415,16 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) multiport = false; portdev->config.nr_ports = 1; portdev->config.max_nr_ports = 1; -#if 0 /* Multiport is not quite ready yet --RR */ if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) { multiport = true; vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT; - vdev->config->get(vdev, - offsetof(struct virtio_console_multiport_conf, - nr_ports), + vdev->config->get(vdev, offsetof(struct virtio_console_config, + nr_ports), &portdev->config.nr_ports, sizeof(portdev->config.nr_ports)); - vdev->config->get(vdev, - offsetof(struct virtio_console_multiport_conf, - max_nr_ports), + vdev->config->get(vdev, offsetof(struct virtio_console_config, + max_nr_ports), &portdev->config.max_nr_ports, sizeof(portdev->config.max_nr_ports)); if (portdev->config.nr_ports > portdev->config.max_nr_ports) { @@ -1473,7 +1440,6 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) /* Let the Host know we support multiple ports.*/ vdev->config->finalize_features(vdev); -#endif err = init_vqs(portdev); if (err < 0) { @@ -1556,6 +1522,7 @@ static struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTIO_CONSOLE_F_SIZE, + VIRTIO_CONSOLE_F_MULTIPORT, }; static struct virtio_driver virtio_console = { diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h index 92228a8fbcbc..ae4f039515b4 100644 --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -12,14 +12,37 @@ /* Feature bits */ #define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */ +#define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */ struct virtio_console_config { /* colums of the screens */ __u16 cols; /* rows of the screens */ __u16 rows; + /* max. number of ports this device can hold */ + __u32 max_nr_ports; + /* number of ports added so far */ + __u32 nr_ports; } __attribute__((packed)); +/* + * A message that's passed between the Host and the Guest for a + * particular port. + */ +struct virtio_console_control { + __u32 id; /* Port number */ + __u16 event; /* The kind of control event (see below) */ + __u16 value; /* Extra information for the key */ +}; + +/* Some events for control messages */ +#define VIRTIO_CONSOLE_PORT_READY 0 +#define VIRTIO_CONSOLE_CONSOLE_PORT 1 +#define VIRTIO_CONSOLE_RESIZE 2 +#define VIRTIO_CONSOLE_PORT_OPEN 3 +#define VIRTIO_CONSOLE_PORT_NAME 4 +#define VIRTIO_CONSOLE_PORT_REMOVE 5 + #ifdef __KERNEL__ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)); #endif /* __KERNEL__ */ -- cgit v1.2.3 From eaeff9608a8cf43a676b6f4b6235ea9d76192230 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Wed, 19 May 2010 22:15:47 -0600 Subject: virtio: console: Let host know of port or device add failures The host may want to know and let management apps notify of port or device add failures. Send a control message saying the device or port is not ready in this case. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell --- drivers/char/virtio_console.c | 5 +++++ include/linux/virtio_console.h | 3 +++ 2 files changed, 8 insertions(+) (limited to 'include/linux') diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 8c24b86aadc9..f63bf77a4825 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1210,6 +1210,8 @@ free_cdev: free_port: kfree(port); fail: + /* The host might want to notify management sw about port add failure */ + send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 0); return err; } @@ -1488,6 +1490,9 @@ free_chrdev: free: kfree(portdev); fail: + /* The host might want to notify mgmt sw about device add failure */ + __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, + VIRTIO_CONSOLE_DEVICE_READY, 0); return err; } diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h index ae4f039515b4..015736113c25 100644 --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -14,6 +14,8 @@ #define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */ #define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */ +#define VIRTIO_CONSOLE_BAD_ID (~(u32)0) + struct virtio_console_config { /* colums of the screens */ __u16 cols; @@ -42,6 +44,7 @@ struct virtio_console_control { #define VIRTIO_CONSOLE_PORT_OPEN 3 #define VIRTIO_CONSOLE_PORT_NAME 4 #define VIRTIO_CONSOLE_PORT_REMOVE 5 +#define VIRTIO_CONSOLE_DEVICE_READY 6 #ifdef __KERNEL__ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)); -- cgit v1.2.3 From f909f850d666e3dbac1ee7c9d5d83416bd02f84e Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Wed, 19 May 2010 22:15:48 -0600 Subject: virtio: console: Use a control message to add ports Instead of the host and guest independently enumerating ports, switch to a control message to add ports where the host supplies the port number so there's no ambiguity or a possibility of a race between the host and the guest port numbers. We now no longer need the 'nr_ports' config value. Since no kernel has been released with the MULTIPORT changes yet, we have a chance to fiddle with the config space without adding compatibility features. This is beneficial for management software, which would now be able to instantiate ports at known locations and avoid problems that arise with implicit numbering in the host and the guest. This removes the 'guessing game' part of it, and management software can now actually indicate which id to spawn a particular port on. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell --- drivers/char/virtio_console.c | 77 ++++++++++++++++++------------------------ include/linux/virtio_console.h | 17 +++++----- 2 files changed, 41 insertions(+), 53 deletions(-) (limited to 'include/linux') diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 237eee26fbc3..7671914be172 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1048,7 +1048,7 @@ static void handle_control_message(struct ports_device *portdev, cpkt = (struct virtio_console_control *)(buf->buf + buf->offset); port = find_port_by_id(portdev, cpkt->id); - if (!port) { + if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) { /* No valid header at start of buffer. Drop it. */ dev_dbg(&portdev->vdev->dev, "Invalid index %u in control packet\n", cpkt->id); @@ -1056,6 +1056,30 @@ static void handle_control_message(struct ports_device *portdev, } switch (cpkt->event) { + case VIRTIO_CONSOLE_PORT_ADD: + if (port) { + /* + * This can happen for port 0: we have to + * create a console port during probe() as was + * the behaviour before the MULTIPORT feature. + * On a newer host, when the host tells us + * that a port 0 is available, we should just + * say we have the port all set up. + */ + send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); + break; + } + if (cpkt->id >= portdev->config.max_nr_ports) { + dev_warn(&portdev->vdev->dev, + "Request for adding port with out-of-bound id %u, max. supported id: %u\n", + cpkt->id, portdev->config.max_nr_ports - 1); + break; + } + add_port(portdev, cpkt->id); + break; + case VIRTIO_CONSOLE_PORT_REMOVE: + remove_port(port); + break; case VIRTIO_CONSOLE_CONSOLE_PORT: if (!cpkt->value) break; @@ -1114,32 +1138,6 @@ static void handle_control_message(struct ports_device *portdev, kobject_uevent(&port->dev->kobj, KOBJ_CHANGE); } break; - case VIRTIO_CONSOLE_PORT_REMOVE: - /* - * Hot unplug the port. We don't decrement nr_ports - * since we don't want to deal with extra complexities - * of using the lowest-available port id: We can just - * pick up the nr_ports number as the id and not have - * userspace send it to us. This helps us in two - * ways: - * - * - We don't need to have a 'port_id' field in the - * config space when a port is hot-added. This is a - * good thing as we might queue up multiple hotplug - * requests issued in our workqueue. - * - * - Another way to deal with this would have been to - * use a bitmap of the active ports and select the - * lowest non-active port from that map. That - * bloats the already tight config space and we - * would end up artificially limiting the - * max. number of ports to sizeof(bitmap). Right - * now we can support 2^32 ports (as the port id is - * stored in a u32 type). - * - */ - remove_port(port); - break; } } @@ -1347,7 +1345,6 @@ static const struct file_operations portdev_fops = { static int __devinit virtcons_probe(struct virtio_device *vdev) { struct ports_device *portdev; - u32 i; int err; bool multiport; @@ -1376,29 +1373,15 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) } multiport = false; - portdev->config.nr_ports = 1; portdev->config.max_nr_ports = 1; if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) { multiport = true; vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT; - vdev->config->get(vdev, offsetof(struct virtio_console_config, - nr_ports), - &portdev->config.nr_ports, - sizeof(portdev->config.nr_ports)); vdev->config->get(vdev, offsetof(struct virtio_console_config, max_nr_ports), &portdev->config.max_nr_ports, sizeof(portdev->config.max_nr_ports)); - if (portdev->config.nr_ports > portdev->config.max_nr_ports) { - dev_warn(&vdev->dev, - "More ports (%u) specified than allowed (%u). Will init %u ports.", - portdev->config.nr_ports, - portdev->config.max_nr_ports, - portdev->config.max_nr_ports); - - portdev->config.nr_ports = portdev->config.max_nr_ports; - } } /* Let the Host know we support multiple ports.*/ @@ -1428,11 +1411,17 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) } } - for (i = 0; i < portdev->config.nr_ports; i++) - add_port(portdev, i); + /* + * For backward compatibility: if we're running on an older + * host, we always want to create a console port. + */ + add_port(portdev, 0); /* Start using the new console output. */ early_put_chars = NULL; + + __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, + VIRTIO_CONSOLE_DEVICE_READY, 1); return 0; free_vqs: diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h index 015736113c25..a85064db8f94 100644 --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -23,8 +23,6 @@ struct virtio_console_config { __u16 rows; /* max. number of ports this device can hold */ __u32 max_nr_ports; - /* number of ports added so far */ - __u32 nr_ports; } __attribute__((packed)); /* @@ -38,13 +36,14 @@ struct virtio_console_control { }; /* Some events for control messages */ -#define VIRTIO_CONSOLE_PORT_READY 0 -#define VIRTIO_CONSOLE_CONSOLE_PORT 1 -#define VIRTIO_CONSOLE_RESIZE 2 -#define VIRTIO_CONSOLE_PORT_OPEN 3 -#define VIRTIO_CONSOLE_PORT_NAME 4 -#define VIRTIO_CONSOLE_PORT_REMOVE 5 -#define VIRTIO_CONSOLE_DEVICE_READY 6 +#define VIRTIO_CONSOLE_DEVICE_READY 0 +#define VIRTIO_CONSOLE_PORT_ADD 1 +#define VIRTIO_CONSOLE_PORT_REMOVE 2 +#define VIRTIO_CONSOLE_PORT_READY 3 +#define VIRTIO_CONSOLE_CONSOLE_PORT 4 +#define VIRTIO_CONSOLE_RESIZE 5 +#define VIRTIO_CONSOLE_PORT_OPEN 6 +#define VIRTIO_CONSOLE_PORT_NAME 7 #ifdef __KERNEL__ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)); -- cgit v1.2.3