4 * Copyright IBM, Corp. 2007
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
19 /* The alignment to use between consumer and producer parts of vring.
20 * x86 pagesize again. */
21 #define VIRTIO_PCI_VRING_ALIGN 4096
23 /* QEMU doesn't strictly need write barriers since everything runs in
24 * lock-step. We'll leave the calls to wmb() in though to make it obvious for
25 * KVM or if kqemu gets SMP support.
26 * In any case, we must prevent the compiler from reordering the code.
27 * TODO: we likely need some rmb()/mb() as well.
30 #define wmb() __asm__ __volatile__("": : :"memory")
32 typedef struct VRingDesc
40 typedef struct VRingAvail
47 typedef struct VRingUsedElem
53 typedef struct VRingUsed
57 VRingUsedElem ring
[0];
63 target_phys_addr_t desc
;
64 target_phys_addr_t avail
;
65 target_phys_addr_t used
;
71 target_phys_addr_t pa
;
72 uint16_t last_avail_idx
;
75 void (*handle_output
)(VirtIODevice
*vdev
, VirtQueue
*vq
);
78 /* virt queue functions */
79 static void virtqueue_init(VirtQueue
*vq
)
81 target_phys_addr_t pa
= vq
->pa
;
84 vq
->vring
.avail
= pa
+ vq
->vring
.num
* sizeof(VRingDesc
);
85 vq
->vring
.used
= vring_align(vq
->vring
.avail
+
86 offsetof(VRingAvail
, ring
[vq
->vring
.num
]),
87 VIRTIO_PCI_VRING_ALIGN
);
90 static inline uint64_t vring_desc_addr(target_phys_addr_t desc_pa
, int i
)
92 target_phys_addr_t pa
;
93 pa
= desc_pa
+ sizeof(VRingDesc
) * i
+ offsetof(VRingDesc
, addr
);
97 static inline uint32_t vring_desc_len(target_phys_addr_t desc_pa
, int i
)
99 target_phys_addr_t pa
;
100 pa
= desc_pa
+ sizeof(VRingDesc
) * i
+ offsetof(VRingDesc
, len
);
104 static inline uint16_t vring_desc_flags(target_phys_addr_t desc_pa
, int i
)
106 target_phys_addr_t pa
;
107 pa
= desc_pa
+ sizeof(VRingDesc
) * i
+ offsetof(VRingDesc
, flags
);
108 return lduw_phys(pa
);
111 static inline uint16_t vring_desc_next(target_phys_addr_t desc_pa
, int i
)
113 target_phys_addr_t pa
;
114 pa
= desc_pa
+ sizeof(VRingDesc
) * i
+ offsetof(VRingDesc
, next
);
115 return lduw_phys(pa
);
118 static inline uint16_t vring_avail_flags(VirtQueue
*vq
)
120 target_phys_addr_t pa
;
121 pa
= vq
->vring
.avail
+ offsetof(VRingAvail
, flags
);
122 return lduw_phys(pa
);
125 static inline uint16_t vring_avail_idx(VirtQueue
*vq
)
127 target_phys_addr_t pa
;
128 pa
= vq
->vring
.avail
+ offsetof(VRingAvail
, idx
);
129 return lduw_phys(pa
);
132 static inline uint16_t vring_avail_ring(VirtQueue
*vq
, int i
)
134 target_phys_addr_t pa
;
135 pa
= vq
->vring
.avail
+ offsetof(VRingAvail
, ring
[i
]);
136 return lduw_phys(pa
);
139 static inline void vring_used_ring_id(VirtQueue
*vq
, int i
, uint32_t val
)
141 target_phys_addr_t pa
;
142 pa
= vq
->vring
.used
+ offsetof(VRingUsed
, ring
[i
].id
);
146 static inline void vring_used_ring_len(VirtQueue
*vq
, int i
, uint32_t val
)
148 target_phys_addr_t pa
;
149 pa
= vq
->vring
.used
+ offsetof(VRingUsed
, ring
[i
].len
);
153 static uint16_t vring_used_idx(VirtQueue
*vq
)
155 target_phys_addr_t pa
;
156 pa
= vq
->vring
.used
+ offsetof(VRingUsed
, idx
);
157 return lduw_phys(pa
);
160 static inline void vring_used_idx_increment(VirtQueue
*vq
, uint16_t val
)
162 target_phys_addr_t pa
;
163 pa
= vq
->vring
.used
+ offsetof(VRingUsed
, idx
);
164 stw_phys(pa
, vring_used_idx(vq
) + val
);
167 static inline void vring_used_flags_set_bit(VirtQueue
*vq
, int mask
)
169 target_phys_addr_t pa
;
170 pa
= vq
->vring
.used
+ offsetof(VRingUsed
, flags
);
171 stw_phys(pa
, lduw_phys(pa
) | mask
);
174 static inline void vring_used_flags_unset_bit(VirtQueue
*vq
, int mask
)
176 target_phys_addr_t pa
;
177 pa
= vq
->vring
.used
+ offsetof(VRingUsed
, flags
);
178 stw_phys(pa
, lduw_phys(pa
) & ~mask
);
181 void virtio_queue_set_notification(VirtQueue
*vq
, int enable
)
184 vring_used_flags_unset_bit(vq
, VRING_USED_F_NO_NOTIFY
);
186 vring_used_flags_set_bit(vq
, VRING_USED_F_NO_NOTIFY
);
189 int virtio_queue_ready(VirtQueue
*vq
)
191 return vq
->vring
.avail
!= 0;
194 int virtio_queue_empty(VirtQueue
*vq
)
196 return vring_avail_idx(vq
) == vq
->last_avail_idx
;
199 void virtqueue_fill(VirtQueue
*vq
, const VirtQueueElement
*elem
,
200 unsigned int len
, unsigned int idx
)
206 for (i
= 0; i
< elem
->in_num
; i
++) {
207 size_t size
= MIN(len
- offset
, elem
->in_sg
[i
].iov_len
);
209 cpu_physical_memory_unmap(elem
->in_sg
[i
].iov_base
,
210 elem
->in_sg
[i
].iov_len
,
213 offset
+= elem
->in_sg
[i
].iov_len
;
216 for (i
= 0; i
< elem
->out_num
; i
++)
217 cpu_physical_memory_unmap(elem
->out_sg
[i
].iov_base
,
218 elem
->out_sg
[i
].iov_len
,
219 0, elem
->out_sg
[i
].iov_len
);
221 idx
= (idx
+ vring_used_idx(vq
)) % vq
->vring
.num
;
223 /* Get a pointer to the next entry in the used ring. */
224 vring_used_ring_id(vq
, idx
, elem
->index
);
225 vring_used_ring_len(vq
, idx
, len
);
228 void virtqueue_flush(VirtQueue
*vq
, unsigned int count
)
230 /* Make sure buffer is written before we update index. */
232 vring_used_idx_increment(vq
, count
);
236 void virtqueue_push(VirtQueue
*vq
, const VirtQueueElement
*elem
,
239 virtqueue_fill(vq
, elem
, len
, 0);
240 virtqueue_flush(vq
, 1);
243 static int virtqueue_num_heads(VirtQueue
*vq
, unsigned int idx
)
245 uint16_t num_heads
= vring_avail_idx(vq
) - idx
;
247 /* Check it isn't doing very strange things with descriptor numbers. */
248 if (num_heads
> vq
->vring
.num
) {
249 fprintf(stderr
, "Guest moved used index from %u to %u",
250 idx
, vring_avail_idx(vq
));
257 static unsigned int virtqueue_get_head(VirtQueue
*vq
, unsigned int idx
)
261 /* Grab the next descriptor number they're advertising, and increment
262 * the index we've seen. */
263 head
= vring_avail_ring(vq
, idx
% vq
->vring
.num
);
265 /* If their number is silly, that's a fatal mistake. */
266 if (head
>= vq
->vring
.num
) {
267 fprintf(stderr
, "Guest says index %u is available", head
);
274 static unsigned virtqueue_next_desc(target_phys_addr_t desc_pa
,
275 unsigned int i
, unsigned int max
)
279 /* If this descriptor says it doesn't chain, we're done. */
280 if (!(vring_desc_flags(desc_pa
, i
) & VRING_DESC_F_NEXT
))
283 /* Check they're not leading us off end of descriptors. */
284 next
= vring_desc_next(desc_pa
, i
);
285 /* Make sure compiler knows to grab that: we don't want it changing! */
289 fprintf(stderr
, "Desc next is %u", next
);
296 int virtqueue_avail_bytes(VirtQueue
*vq
, int in_bytes
, int out_bytes
)
299 int total_bufs
, in_total
, out_total
;
301 idx
= vq
->last_avail_idx
;
303 total_bufs
= in_total
= out_total
= 0;
304 while (virtqueue_num_heads(vq
, idx
)) {
305 unsigned int max
, num_bufs
, indirect
= 0;
306 target_phys_addr_t desc_pa
;
310 num_bufs
= total_bufs
;
311 i
= virtqueue_get_head(vq
, idx
++);
312 desc_pa
= vq
->vring
.desc
;
314 if (vring_desc_flags(desc_pa
, i
) & VRING_DESC_F_INDIRECT
) {
315 if (vring_desc_len(desc_pa
, i
) % sizeof(VRingDesc
)) {
316 fprintf(stderr
, "Invalid size for indirect buffer table\n");
320 /* If we've got too many, that implies a descriptor loop. */
321 if (num_bufs
>= max
) {
322 fprintf(stderr
, "Looped descriptor");
326 /* loop over the indirect descriptor table */
328 max
= vring_desc_len(desc_pa
, i
) / sizeof(VRingDesc
);
330 desc_pa
= vring_desc_addr(desc_pa
, i
);
334 /* If we've got too many, that implies a descriptor loop. */
335 if (++num_bufs
> max
) {
336 fprintf(stderr
, "Looped descriptor");
340 if (vring_desc_flags(desc_pa
, i
) & VRING_DESC_F_WRITE
) {
342 (in_total
+= vring_desc_len(desc_pa
, i
)) >= in_bytes
)
346 (out_total
+= vring_desc_len(desc_pa
, i
)) >= out_bytes
)
349 } while ((i
= virtqueue_next_desc(desc_pa
, i
, max
)) != max
);
352 total_bufs
= num_bufs
;
360 int virtqueue_pop(VirtQueue
*vq
, VirtQueueElement
*elem
)
362 unsigned int i
, head
, max
;
363 target_phys_addr_t desc_pa
= vq
->vring
.desc
;
364 target_phys_addr_t len
;
366 if (!virtqueue_num_heads(vq
, vq
->last_avail_idx
))
369 /* When we start there are none of either input nor output. */
370 elem
->out_num
= elem
->in_num
= 0;
374 i
= head
= virtqueue_get_head(vq
, vq
->last_avail_idx
++);
376 if (vring_desc_flags(desc_pa
, i
) & VRING_DESC_F_INDIRECT
) {
377 if (vring_desc_len(desc_pa
, i
) % sizeof(VRingDesc
)) {
378 fprintf(stderr
, "Invalid size for indirect buffer table\n");
382 /* loop over the indirect descriptor table */
383 max
= vring_desc_len(desc_pa
, i
) / sizeof(VRingDesc
);
384 desc_pa
= vring_desc_addr(desc_pa
, i
);
392 if (vring_desc_flags(desc_pa
, i
) & VRING_DESC_F_WRITE
) {
393 elem
->in_addr
[elem
->in_num
] = vring_desc_addr(desc_pa
, i
);
394 sg
= &elem
->in_sg
[elem
->in_num
++];
397 sg
= &elem
->out_sg
[elem
->out_num
++];
399 /* Grab the first descriptor, and check it's OK. */
400 sg
->iov_len
= vring_desc_len(desc_pa
, i
);
403 sg
->iov_base
= cpu_physical_memory_map(vring_desc_addr(desc_pa
, i
),
406 if (sg
->iov_base
== NULL
|| len
!= sg
->iov_len
) {
407 fprintf(stderr
, "virtio: trying to map MMIO memory\n");
411 /* If we've got too many, that implies a descriptor loop. */
412 if ((elem
->in_num
+ elem
->out_num
) > max
) {
413 fprintf(stderr
, "Looped descriptor");
416 } while ((i
= virtqueue_next_desc(desc_pa
, i
, max
)) != max
);
422 return elem
->in_num
+ elem
->out_num
;
426 static void virtio_notify_vector(VirtIODevice
*vdev
, uint16_t vector
)
428 if (vdev
->binding
->notify
) {
429 vdev
->binding
->notify(vdev
->binding_opaque
, vector
);
433 void virtio_update_irq(VirtIODevice
*vdev
)
435 virtio_notify_vector(vdev
, VIRTIO_NO_VECTOR
);
438 void virtio_reset(void *opaque
)
440 VirtIODevice
*vdev
= opaque
;
446 vdev
->guest_features
= 0;
450 vdev
->config_vector
= VIRTIO_NO_VECTOR
;
451 virtio_notify_vector(vdev
, vdev
->config_vector
);
453 for(i
= 0; i
< VIRTIO_PCI_QUEUE_MAX
; i
++) {
454 vdev
->vq
[i
].vring
.desc
= 0;
455 vdev
->vq
[i
].vring
.avail
= 0;
456 vdev
->vq
[i
].vring
.used
= 0;
457 vdev
->vq
[i
].last_avail_idx
= 0;
459 vdev
->vq
[i
].vector
= VIRTIO_NO_VECTOR
;
463 uint32_t virtio_config_readb(VirtIODevice
*vdev
, uint32_t addr
)
467 vdev
->get_config(vdev
, vdev
->config
);
469 if (addr
> (vdev
->config_len
- sizeof(val
)))
472 memcpy(&val
, vdev
->config
+ addr
, sizeof(val
));
476 uint32_t virtio_config_readw(VirtIODevice
*vdev
, uint32_t addr
)
480 vdev
->get_config(vdev
, vdev
->config
);
482 if (addr
> (vdev
->config_len
- sizeof(val
)))
485 memcpy(&val
, vdev
->config
+ addr
, sizeof(val
));
489 uint32_t virtio_config_readl(VirtIODevice
*vdev
, uint32_t addr
)
493 vdev
->get_config(vdev
, vdev
->config
);
495 if (addr
> (vdev
->config_len
- sizeof(val
)))
498 memcpy(&val
, vdev
->config
+ addr
, sizeof(val
));
502 void virtio_config_writeb(VirtIODevice
*vdev
, uint32_t addr
, uint32_t data
)
506 if (addr
> (vdev
->config_len
- sizeof(val
)))
509 memcpy(vdev
->config
+ addr
, &val
, sizeof(val
));
511 if (vdev
->set_config
)
512 vdev
->set_config(vdev
, vdev
->config
);
515 void virtio_config_writew(VirtIODevice
*vdev
, uint32_t addr
, uint32_t data
)
519 if (addr
> (vdev
->config_len
- sizeof(val
)))
522 memcpy(vdev
->config
+ addr
, &val
, sizeof(val
));
524 if (vdev
->set_config
)
525 vdev
->set_config(vdev
, vdev
->config
);
528 void virtio_config_writel(VirtIODevice
*vdev
, uint32_t addr
, uint32_t data
)
532 if (addr
> (vdev
->config_len
- sizeof(val
)))
535 memcpy(vdev
->config
+ addr
, &val
, sizeof(val
));
537 if (vdev
->set_config
)
538 vdev
->set_config(vdev
, vdev
->config
);
541 void virtio_queue_set_addr(VirtIODevice
*vdev
, int n
, target_phys_addr_t addr
)
543 vdev
->vq
[n
].pa
= addr
;
544 virtqueue_init(&vdev
->vq
[n
]);
547 target_phys_addr_t
virtio_queue_get_addr(VirtIODevice
*vdev
, int n
)
549 return vdev
->vq
[n
].pa
;
552 int virtio_queue_get_num(VirtIODevice
*vdev
, int n
)
554 return vdev
->vq
[n
].vring
.num
;
557 void virtio_queue_notify(VirtIODevice
*vdev
, int n
)
559 if (n
< VIRTIO_PCI_QUEUE_MAX
&& vdev
->vq
[n
].vring
.desc
) {
560 vdev
->vq
[n
].handle_output(vdev
, &vdev
->vq
[n
]);
564 uint16_t virtio_queue_vector(VirtIODevice
*vdev
, int n
)
566 return n
< VIRTIO_PCI_QUEUE_MAX
? vdev
->vq
[n
].vector
:
570 void virtio_queue_set_vector(VirtIODevice
*vdev
, int n
, uint16_t vector
)
572 if (n
< VIRTIO_PCI_QUEUE_MAX
)
573 vdev
->vq
[n
].vector
= vector
;
576 VirtQueue
*virtio_add_queue(VirtIODevice
*vdev
, int queue_size
,
577 void (*handle_output
)(VirtIODevice
*, VirtQueue
*))
581 for (i
= 0; i
< VIRTIO_PCI_QUEUE_MAX
; i
++) {
582 if (vdev
->vq
[i
].vring
.num
== 0)
586 if (i
== VIRTIO_PCI_QUEUE_MAX
|| queue_size
> VIRTQUEUE_MAX_SIZE
)
589 vdev
->vq
[i
].vring
.num
= queue_size
;
590 vdev
->vq
[i
].handle_output
= handle_output
;
595 void virtio_notify(VirtIODevice
*vdev
, VirtQueue
*vq
)
597 /* Always notify when queue is empty (when feature acknowledge) */
598 if ((vring_avail_flags(vq
) & VRING_AVAIL_F_NO_INTERRUPT
) &&
599 (!(vdev
->guest_features
& (1 << VIRTIO_F_NOTIFY_ON_EMPTY
)) ||
600 (vq
->inuse
|| vring_avail_idx(vq
) != vq
->last_avail_idx
)))
604 virtio_notify_vector(vdev
, vq
->vector
);
607 void virtio_notify_config(VirtIODevice
*vdev
)
609 if (!(vdev
->status
& VIRTIO_CONFIG_S_DRIVER_OK
))
613 virtio_notify_vector(vdev
, vdev
->config_vector
);
616 void virtio_save(VirtIODevice
*vdev
, QEMUFile
*f
)
620 if (vdev
->binding
->save_config
)
621 vdev
->binding
->save_config(vdev
->binding_opaque
, f
);
623 qemu_put_8s(f
, &vdev
->status
);
624 qemu_put_8s(f
, &vdev
->isr
);
625 qemu_put_be16s(f
, &vdev
->queue_sel
);
626 qemu_put_be32s(f
, &vdev
->guest_features
);
627 qemu_put_be32(f
, vdev
->config_len
);
628 qemu_put_buffer(f
, vdev
->config
, vdev
->config_len
);
630 for (i
= 0; i
< VIRTIO_PCI_QUEUE_MAX
; i
++) {
631 if (vdev
->vq
[i
].vring
.num
== 0)
637 for (i
= 0; i
< VIRTIO_PCI_QUEUE_MAX
; i
++) {
638 if (vdev
->vq
[i
].vring
.num
== 0)
641 qemu_put_be32(f
, vdev
->vq
[i
].vring
.num
);
642 qemu_put_be64(f
, vdev
->vq
[i
].pa
);
643 qemu_put_be16s(f
, &vdev
->vq
[i
].last_avail_idx
);
644 if (vdev
->binding
->save_queue
)
645 vdev
->binding
->save_queue(vdev
->binding_opaque
, i
, f
);
649 int virtio_load(VirtIODevice
*vdev
, QEMUFile
*f
)
653 uint32_t supported_features
=
654 vdev
->binding
->get_features(vdev
->binding_opaque
);
656 if (vdev
->binding
->load_config
) {
657 ret
= vdev
->binding
->load_config(vdev
->binding_opaque
, f
);
662 qemu_get_8s(f
, &vdev
->status
);
663 qemu_get_8s(f
, &vdev
->isr
);
664 qemu_get_be16s(f
, &vdev
->queue_sel
);
665 qemu_get_be32s(f
, &features
);
666 if (features
& ~supported_features
) {
667 fprintf(stderr
, "Features 0x%x unsupported. Allowed features: 0x%x\n",
668 features
, supported_features
);
671 vdev
->guest_features
= features
;
672 vdev
->config_len
= qemu_get_be32(f
);
673 qemu_get_buffer(f
, vdev
->config
, vdev
->config_len
);
675 num
= qemu_get_be32(f
);
677 for (i
= 0; i
< num
; i
++) {
678 vdev
->vq
[i
].vring
.num
= qemu_get_be32(f
);
679 vdev
->vq
[i
].pa
= qemu_get_be64(f
);
680 qemu_get_be16s(f
, &vdev
->vq
[i
].last_avail_idx
);
682 if (vdev
->vq
[i
].pa
) {
683 virtqueue_init(&vdev
->vq
[i
]);
685 if (vdev
->binding
->load_queue
) {
686 ret
= vdev
->binding
->load_queue(vdev
->binding_opaque
, i
, f
);
692 virtio_notify_vector(vdev
, VIRTIO_NO_VECTOR
);
696 void virtio_cleanup(VirtIODevice
*vdev
)
699 qemu_free(vdev
->config
);
703 VirtIODevice
*virtio_common_init(const char *name
, uint16_t device_id
,
704 size_t config_size
, size_t struct_size
)
709 vdev
= qemu_mallocz(struct_size
);
711 vdev
->device_id
= device_id
;
715 vdev
->config_vector
= VIRTIO_NO_VECTOR
;
716 vdev
->vq
= qemu_mallocz(sizeof(VirtQueue
) * VIRTIO_PCI_QUEUE_MAX
);
717 for(i
= 0; i
< VIRTIO_PCI_QUEUE_MAX
; i
++)
718 vdev
->vq
[i
].vector
= VIRTIO_NO_VECTOR
;
721 vdev
->config_len
= config_size
;
722 if (vdev
->config_len
)
723 vdev
->config
= qemu_mallocz(config_size
);
730 void virtio_bind_device(VirtIODevice
*vdev
, const VirtIOBindings
*binding
,
733 vdev
->binding
= binding
;
734 vdev
->binding_opaque
= opaque
;