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/*
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* Virtio Support
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*
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* Copyright IBM, Corp. 2007
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#include <inttypes.h> |
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#include "trace.h" |
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#include "qemu/error-report.h" |
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#include "virtio.h" |
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#include "qemu/atomic.h" |
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#include "virtio-bus.h" |
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/* The alignment to use between consumer and producer parts of vring.
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* x86 pagesize again. */
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#define VIRTIO_PCI_VRING_ALIGN 4096 |
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typedef struct VRingDesc |
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{ |
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uint64_t addr; |
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uint32_t len; |
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uint16_t flags; |
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uint16_t next; |
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} VRingDesc; |
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typedef struct VRingAvail |
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{ |
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uint16_t flags; |
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uint16_t idx; |
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uint16_t ring[0];
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} VRingAvail; |
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typedef struct VRingUsedElem |
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{ |
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uint32_t id; |
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uint32_t len; |
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} VRingUsedElem; |
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typedef struct VRingUsed |
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{ |
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uint16_t flags; |
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uint16_t idx; |
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VRingUsedElem ring[0];
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} VRingUsed; |
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typedef struct VRing |
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{ |
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unsigned int num; |
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hwaddr desc; |
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hwaddr avail; |
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hwaddr used; |
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} VRing; |
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struct VirtQueue
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{ |
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VRing vring; |
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hwaddr pa; |
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uint16_t last_avail_idx; |
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/* Last used index value we have signalled on */
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uint16_t signalled_used; |
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/* Last used index value we have signalled on */
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bool signalled_used_valid;
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/* Notification enabled? */
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bool notification;
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int inuse;
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uint16_t vector; |
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void (*handle_output)(VirtIODevice *vdev, VirtQueue *vq);
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VirtIODevice *vdev; |
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EventNotifier guest_notifier; |
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EventNotifier host_notifier; |
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}; |
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/* virt queue functions */
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static void virtqueue_init(VirtQueue *vq) |
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{ |
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hwaddr pa = vq->pa; |
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vq->vring.desc = pa; |
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vq->vring.avail = pa + vq->vring.num * sizeof(VRingDesc);
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vq->vring.used = vring_align(vq->vring.avail + |
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offsetof(VRingAvail, ring[vq->vring.num]), |
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VIRTIO_PCI_VRING_ALIGN); |
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} |
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static inline uint64_t vring_desc_addr(hwaddr desc_pa, int i) |
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{ |
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hwaddr pa; |
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pa = desc_pa + sizeof(VRingDesc) * i + offsetof(VRingDesc, addr);
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return ldq_phys(pa);
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} |
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static inline uint32_t vring_desc_len(hwaddr desc_pa, int i) |
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{ |
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hwaddr pa; |
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pa = desc_pa + sizeof(VRingDesc) * i + offsetof(VRingDesc, len);
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return ldl_phys(pa);
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} |
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static inline uint16_t vring_desc_flags(hwaddr desc_pa, int i) |
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{ |
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hwaddr pa; |
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pa = desc_pa + sizeof(VRingDesc) * i + offsetof(VRingDesc, flags);
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return lduw_phys(pa);
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} |
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static inline uint16_t vring_desc_next(hwaddr desc_pa, int i) |
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{ |
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hwaddr pa; |
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pa = desc_pa + sizeof(VRingDesc) * i + offsetof(VRingDesc, next);
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return lduw_phys(pa);
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} |
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static inline uint16_t vring_avail_flags(VirtQueue *vq) |
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{ |
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hwaddr pa; |
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pa = vq->vring.avail + offsetof(VRingAvail, flags); |
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return lduw_phys(pa);
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} |
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static inline uint16_t vring_avail_idx(VirtQueue *vq) |
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{ |
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hwaddr pa; |
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pa = vq->vring.avail + offsetof(VRingAvail, idx); |
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return lduw_phys(pa);
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} |
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static inline uint16_t vring_avail_ring(VirtQueue *vq, int i) |
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{ |
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hwaddr pa; |
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pa = vq->vring.avail + offsetof(VRingAvail, ring[i]); |
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return lduw_phys(pa);
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} |
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static inline uint16_t vring_used_event(VirtQueue *vq) |
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{ |
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return vring_avail_ring(vq, vq->vring.num);
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} |
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static inline void vring_used_ring_id(VirtQueue *vq, int i, uint32_t val) |
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{ |
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hwaddr pa; |
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pa = vq->vring.used + offsetof(VRingUsed, ring[i].id); |
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stl_phys(pa, val); |
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} |
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static inline void vring_used_ring_len(VirtQueue *vq, int i, uint32_t val) |
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{ |
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hwaddr pa; |
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pa = vq->vring.used + offsetof(VRingUsed, ring[i].len); |
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stl_phys(pa, val); |
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} |
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static uint16_t vring_used_idx(VirtQueue *vq)
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{ |
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hwaddr pa; |
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pa = vq->vring.used + offsetof(VRingUsed, idx); |
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return lduw_phys(pa);
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} |
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static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val) |
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{ |
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hwaddr pa; |
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pa = vq->vring.used + offsetof(VRingUsed, idx); |
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stw_phys(pa, val); |
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} |
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static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask) |
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{ |
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hwaddr pa; |
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pa = vq->vring.used + offsetof(VRingUsed, flags); |
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stw_phys(pa, lduw_phys(pa) | mask); |
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} |
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static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask) |
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{ |
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hwaddr pa; |
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pa = vq->vring.used + offsetof(VRingUsed, flags); |
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stw_phys(pa, lduw_phys(pa) & ~mask); |
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} |
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static inline void vring_avail_event(VirtQueue *vq, uint16_t val) |
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{ |
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hwaddr pa; |
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if (!vq->notification) {
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return;
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} |
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pa = vq->vring.used + offsetof(VRingUsed, ring[vq->vring.num]); |
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stw_phys(pa, val); |
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} |
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void virtio_queue_set_notification(VirtQueue *vq, int enable) |
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{ |
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vq->notification = enable; |
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if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) { |
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vring_avail_event(vq, vring_avail_idx(vq)); |
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} else if (enable) { |
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vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); |
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} else {
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vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); |
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} |
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if (enable) {
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/* Expose avail event/used flags before caller checks the avail idx. */
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smp_mb(); |
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} |
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} |
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int virtio_queue_ready(VirtQueue *vq)
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{ |
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return vq->vring.avail != 0; |
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} |
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int virtio_queue_empty(VirtQueue *vq)
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{ |
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return vring_avail_idx(vq) == vq->last_avail_idx;
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} |
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void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, |
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unsigned int len, unsigned int idx) |
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{ |
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unsigned int offset; |
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int i;
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trace_virtqueue_fill(vq, elem, len, idx); |
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offset = 0;
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for (i = 0; i < elem->in_num; i++) { |
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size_t size = MIN(len - offset, elem->in_sg[i].iov_len); |
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cpu_physical_memory_unmap(elem->in_sg[i].iov_base, |
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elem->in_sg[i].iov_len, |
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1, size);
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offset += size; |
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} |
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for (i = 0; i < elem->out_num; i++) |
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cpu_physical_memory_unmap(elem->out_sg[i].iov_base, |
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elem->out_sg[i].iov_len, |
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0, elem->out_sg[i].iov_len);
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idx = (idx + vring_used_idx(vq)) % vq->vring.num; |
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/* Get a pointer to the next entry in the used ring. */
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vring_used_ring_id(vq, idx, elem->index); |
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vring_used_ring_len(vq, idx, len); |
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} |
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void virtqueue_flush(VirtQueue *vq, unsigned int count) |
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{ |
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uint16_t old, new; |
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/* Make sure buffer is written before we update index. */
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smp_wmb(); |
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trace_virtqueue_flush(vq, count); |
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old = vring_used_idx(vq); |
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new = old + count; |
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vring_used_idx_set(vq, new); |
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vq->inuse -= count; |
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if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old)))
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vq->signalled_used_valid = false;
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} |
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void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, |
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unsigned int len) |
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{ |
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virtqueue_fill(vq, elem, len, 0);
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virtqueue_flush(vq, 1);
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} |
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static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) |
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{ |
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uint16_t num_heads = vring_avail_idx(vq) - idx; |
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/* Check it isn't doing very strange things with descriptor numbers. */
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if (num_heads > vq->vring.num) {
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error_report("Guest moved used index from %u to %u",
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idx, vring_avail_idx(vq)); |
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exit(1);
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} |
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/* On success, callers read a descriptor at vq->last_avail_idx.
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* Make sure descriptor read does not bypass avail index read. */
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if (num_heads) {
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smp_rmb(); |
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} |
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return num_heads;
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} |
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static unsigned int virtqueue_get_head(VirtQueue *vq, unsigned int idx) |
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{ |
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unsigned int head; |
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/* Grab the next descriptor number they're advertising, and increment
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* the index we've seen. */
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head = vring_avail_ring(vq, idx % vq->vring.num); |
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/* If their number is silly, that's a fatal mistake. */
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if (head >= vq->vring.num) {
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error_report("Guest says index %u is available", head);
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exit(1);
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} |
313 |
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return head;
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} |
316 |
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static unsigned virtqueue_next_desc(hwaddr desc_pa, |
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unsigned int i, unsigned int max) |
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{ |
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unsigned int next; |
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/* If this descriptor says it doesn't chain, we're done. */
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if (!(vring_desc_flags(desc_pa, i) & VRING_DESC_F_NEXT))
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return max;
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/* Check they're not leading us off end of descriptors. */
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next = vring_desc_next(desc_pa, i); |
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/* Make sure compiler knows to grab that: we don't want it changing! */
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smp_wmb(); |
330 |
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if (next >= max) {
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error_report("Desc next is %u", next);
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exit(1);
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} |
335 |
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return next;
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} |
338 |
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void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, |
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unsigned int *out_bytes, |
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unsigned max_in_bytes, unsigned max_out_bytes) |
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{ |
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unsigned int idx; |
344 |
unsigned int total_bufs, in_total, out_total; |
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idx = vq->last_avail_idx; |
347 |
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total_bufs = in_total = out_total = 0;
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while (virtqueue_num_heads(vq, idx)) {
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unsigned int max, num_bufs, indirect = 0; |
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hwaddr desc_pa; |
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int i;
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max = vq->vring.num; |
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num_bufs = total_bufs; |
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i = virtqueue_get_head(vq, idx++); |
357 |
desc_pa = vq->vring.desc; |
358 |
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359 |
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_INDIRECT) {
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if (vring_desc_len(desc_pa, i) % sizeof(VRingDesc)) { |
361 |
error_report("Invalid size for indirect buffer table");
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exit(1);
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} |
364 |
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/* If we've got too many, that implies a descriptor loop. */
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if (num_bufs >= max) {
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error_report("Looped descriptor");
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exit(1);
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} |
370 |
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/* loop over the indirect descriptor table */
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indirect = 1;
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max = vring_desc_len(desc_pa, i) / sizeof(VRingDesc);
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num_bufs = i = 0;
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desc_pa = vring_desc_addr(desc_pa, i); |
376 |
} |
377 |
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378 |
do {
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379 |
/* If we've got too many, that implies a descriptor loop. */
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380 |
if (++num_bufs > max) {
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381 |
error_report("Looped descriptor");
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382 |
exit(1);
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383 |
} |
384 |
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385 |
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) {
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386 |
in_total += vring_desc_len(desc_pa, i); |
387 |
} else {
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388 |
out_total += vring_desc_len(desc_pa, i); |
389 |
} |
390 |
if (in_total >= max_in_bytes && out_total >= max_out_bytes) {
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goto done;
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} |
393 |
} while ((i = virtqueue_next_desc(desc_pa, i, max)) != max);
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395 |
if (!indirect)
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total_bufs = num_bufs; |
397 |
else
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total_bufs++; |
399 |
} |
400 |
done:
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401 |
if (in_bytes) {
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402 |
*in_bytes = in_total; |
403 |
} |
404 |
if (out_bytes) {
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*out_bytes = out_total; |
406 |
} |
407 |
} |
408 |
|
409 |
int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, |
410 |
unsigned int out_bytes) |
411 |
{ |
412 |
unsigned int in_total, out_total; |
413 |
|
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virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); |
415 |
return in_bytes <= in_total && out_bytes <= out_total;
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} |
417 |
|
418 |
void virtqueue_map_sg(struct iovec *sg, hwaddr *addr, |
419 |
size_t num_sg, int is_write)
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420 |
{ |
421 |
unsigned int i; |
422 |
hwaddr len; |
423 |
|
424 |
for (i = 0; i < num_sg; i++) { |
425 |
len = sg[i].iov_len; |
426 |
sg[i].iov_base = cpu_physical_memory_map(addr[i], &len, is_write); |
427 |
if (sg[i].iov_base == NULL || len != sg[i].iov_len) { |
428 |
error_report("virtio: trying to map MMIO memory");
|
429 |
exit(1);
|
430 |
} |
431 |
} |
432 |
} |
433 |
|
434 |
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem)
|
435 |
{ |
436 |
unsigned int i, head, max; |
437 |
hwaddr desc_pa = vq->vring.desc; |
438 |
|
439 |
if (!virtqueue_num_heads(vq, vq->last_avail_idx))
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440 |
return 0; |
441 |
|
442 |
/* When we start there are none of either input nor output. */
|
443 |
elem->out_num = elem->in_num = 0;
|
444 |
|
445 |
max = vq->vring.num; |
446 |
|
447 |
i = head = virtqueue_get_head(vq, vq->last_avail_idx++); |
448 |
if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) { |
449 |
vring_avail_event(vq, vring_avail_idx(vq)); |
450 |
} |
451 |
|
452 |
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_INDIRECT) {
|
453 |
if (vring_desc_len(desc_pa, i) % sizeof(VRingDesc)) { |
454 |
error_report("Invalid size for indirect buffer table");
|
455 |
exit(1);
|
456 |
} |
457 |
|
458 |
/* loop over the indirect descriptor table */
|
459 |
max = vring_desc_len(desc_pa, i) / sizeof(VRingDesc);
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460 |
desc_pa = vring_desc_addr(desc_pa, i); |
461 |
i = 0;
|
462 |
} |
463 |
|
464 |
/* Collect all the descriptors */
|
465 |
do {
|
466 |
struct iovec *sg;
|
467 |
|
468 |
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) {
|
469 |
if (elem->in_num >= ARRAY_SIZE(elem->in_sg)) {
|
470 |
error_report("Too many write descriptors in indirect table");
|
471 |
exit(1);
|
472 |
} |
473 |
elem->in_addr[elem->in_num] = vring_desc_addr(desc_pa, i); |
474 |
sg = &elem->in_sg[elem->in_num++]; |
475 |
} else {
|
476 |
if (elem->out_num >= ARRAY_SIZE(elem->out_sg)) {
|
477 |
error_report("Too many read descriptors in indirect table");
|
478 |
exit(1);
|
479 |
} |
480 |
elem->out_addr[elem->out_num] = vring_desc_addr(desc_pa, i); |
481 |
sg = &elem->out_sg[elem->out_num++]; |
482 |
} |
483 |
|
484 |
sg->iov_len = vring_desc_len(desc_pa, i); |
485 |
|
486 |
/* If we've got too many, that implies a descriptor loop. */
|
487 |
if ((elem->in_num + elem->out_num) > max) {
|
488 |
error_report("Looped descriptor");
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489 |
exit(1);
|
490 |
} |
491 |
} while ((i = virtqueue_next_desc(desc_pa, i, max)) != max);
|
492 |
|
493 |
/* Now map what we have collected */
|
494 |
virtqueue_map_sg(elem->in_sg, elem->in_addr, elem->in_num, 1);
|
495 |
virtqueue_map_sg(elem->out_sg, elem->out_addr, elem->out_num, 0);
|
496 |
|
497 |
elem->index = head; |
498 |
|
499 |
vq->inuse++; |
500 |
|
501 |
trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); |
502 |
return elem->in_num + elem->out_num;
|
503 |
} |
504 |
|
505 |
/* virtio device */
|
506 |
static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) |
507 |
{ |
508 |
if (vdev->binding->notify) {
|
509 |
vdev->binding->notify(vdev->binding_opaque, vector); |
510 |
} |
511 |
} |
512 |
|
513 |
void virtio_update_irq(VirtIODevice *vdev)
|
514 |
{ |
515 |
virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); |
516 |
} |
517 |
|
518 |
void virtio_set_status(VirtIODevice *vdev, uint8_t val)
|
519 |
{ |
520 |
trace_virtio_set_status(vdev, val); |
521 |
|
522 |
if (vdev->set_status) {
|
523 |
vdev->set_status(vdev, val); |
524 |
} |
525 |
vdev->status = val; |
526 |
} |
527 |
|
528 |
void virtio_reset(void *opaque) |
529 |
{ |
530 |
VirtIODevice *vdev = opaque; |
531 |
int i;
|
532 |
|
533 |
virtio_set_status(vdev, 0);
|
534 |
|
535 |
if (vdev->reset)
|
536 |
vdev->reset(vdev); |
537 |
|
538 |
vdev->guest_features = 0;
|
539 |
vdev->queue_sel = 0;
|
540 |
vdev->status = 0;
|
541 |
vdev->isr = 0;
|
542 |
vdev->config_vector = VIRTIO_NO_VECTOR; |
543 |
virtio_notify_vector(vdev, vdev->config_vector); |
544 |
|
545 |
for(i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
546 |
vdev->vq[i].vring.desc = 0;
|
547 |
vdev->vq[i].vring.avail = 0;
|
548 |
vdev->vq[i].vring.used = 0;
|
549 |
vdev->vq[i].last_avail_idx = 0;
|
550 |
vdev->vq[i].pa = 0;
|
551 |
vdev->vq[i].vector = VIRTIO_NO_VECTOR; |
552 |
vdev->vq[i].signalled_used = 0;
|
553 |
vdev->vq[i].signalled_used_valid = false;
|
554 |
vdev->vq[i].notification = true;
|
555 |
} |
556 |
} |
557 |
|
558 |
uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) |
559 |
{ |
560 |
uint8_t val; |
561 |
|
562 |
vdev->get_config(vdev, vdev->config); |
563 |
|
564 |
if (addr > (vdev->config_len - sizeof(val))) |
565 |
return (uint32_t)-1; |
566 |
|
567 |
val = ldub_p(vdev->config + addr); |
568 |
return val;
|
569 |
} |
570 |
|
571 |
uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) |
572 |
{ |
573 |
uint16_t val; |
574 |
|
575 |
vdev->get_config(vdev, vdev->config); |
576 |
|
577 |
if (addr > (vdev->config_len - sizeof(val))) |
578 |
return (uint32_t)-1; |
579 |
|
580 |
val = lduw_p(vdev->config + addr); |
581 |
return val;
|
582 |
} |
583 |
|
584 |
uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) |
585 |
{ |
586 |
uint32_t val; |
587 |
|
588 |
vdev->get_config(vdev, vdev->config); |
589 |
|
590 |
if (addr > (vdev->config_len - sizeof(val))) |
591 |
return (uint32_t)-1; |
592 |
|
593 |
val = ldl_p(vdev->config + addr); |
594 |
return val;
|
595 |
} |
596 |
|
597 |
void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data)
|
598 |
{ |
599 |
uint8_t val = data; |
600 |
|
601 |
if (addr > (vdev->config_len - sizeof(val))) |
602 |
return;
|
603 |
|
604 |
stb_p(vdev->config + addr, val); |
605 |
|
606 |
if (vdev->set_config)
|
607 |
vdev->set_config(vdev, vdev->config); |
608 |
} |
609 |
|
610 |
void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data)
|
611 |
{ |
612 |
uint16_t val = data; |
613 |
|
614 |
if (addr > (vdev->config_len - sizeof(val))) |
615 |
return;
|
616 |
|
617 |
stw_p(vdev->config + addr, val); |
618 |
|
619 |
if (vdev->set_config)
|
620 |
vdev->set_config(vdev, vdev->config); |
621 |
} |
622 |
|
623 |
void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data)
|
624 |
{ |
625 |
uint32_t val = data; |
626 |
|
627 |
if (addr > (vdev->config_len - sizeof(val))) |
628 |
return;
|
629 |
|
630 |
stl_p(vdev->config + addr, val); |
631 |
|
632 |
if (vdev->set_config)
|
633 |
vdev->set_config(vdev, vdev->config); |
634 |
} |
635 |
|
636 |
void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) |
637 |
{ |
638 |
vdev->vq[n].pa = addr; |
639 |
virtqueue_init(&vdev->vq[n]); |
640 |
} |
641 |
|
642 |
hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n)
|
643 |
{ |
644 |
return vdev->vq[n].pa;
|
645 |
} |
646 |
|
647 |
int virtio_queue_get_num(VirtIODevice *vdev, int n) |
648 |
{ |
649 |
return vdev->vq[n].vring.num;
|
650 |
} |
651 |
|
652 |
int virtio_queue_get_id(VirtQueue *vq)
|
653 |
{ |
654 |
VirtIODevice *vdev = vq->vdev; |
655 |
assert(vq >= &vdev->vq[0] && vq < &vdev->vq[VIRTIO_PCI_QUEUE_MAX]);
|
656 |
return vq - &vdev->vq[0]; |
657 |
} |
658 |
|
659 |
void virtio_queue_notify_vq(VirtQueue *vq)
|
660 |
{ |
661 |
if (vq->vring.desc) {
|
662 |
VirtIODevice *vdev = vq->vdev; |
663 |
trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); |
664 |
vq->handle_output(vdev, vq); |
665 |
} |
666 |
} |
667 |
|
668 |
void virtio_queue_notify(VirtIODevice *vdev, int n) |
669 |
{ |
670 |
virtio_queue_notify_vq(&vdev->vq[n]); |
671 |
} |
672 |
|
673 |
uint16_t virtio_queue_vector(VirtIODevice *vdev, int n)
|
674 |
{ |
675 |
return n < VIRTIO_PCI_QUEUE_MAX ? vdev->vq[n].vector :
|
676 |
VIRTIO_NO_VECTOR; |
677 |
} |
678 |
|
679 |
void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) |
680 |
{ |
681 |
if (n < VIRTIO_PCI_QUEUE_MAX)
|
682 |
vdev->vq[n].vector = vector; |
683 |
} |
684 |
|
685 |
VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
|
686 |
void (*handle_output)(VirtIODevice *, VirtQueue *))
|
687 |
{ |
688 |
int i;
|
689 |
|
690 |
for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
691 |
if (vdev->vq[i].vring.num == 0) |
692 |
break;
|
693 |
} |
694 |
|
695 |
if (i == VIRTIO_PCI_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE)
|
696 |
abort(); |
697 |
|
698 |
vdev->vq[i].vring.num = queue_size; |
699 |
vdev->vq[i].handle_output = handle_output; |
700 |
|
701 |
return &vdev->vq[i];
|
702 |
} |
703 |
|
704 |
void virtio_irq(VirtQueue *vq)
|
705 |
{ |
706 |
trace_virtio_irq(vq); |
707 |
vq->vdev->isr |= 0x01;
|
708 |
virtio_notify_vector(vq->vdev, vq->vector); |
709 |
} |
710 |
|
711 |
/* Assuming a given event_idx value from the other size, if
|
712 |
* we have just incremented index from old to new_idx,
|
713 |
* should we trigger an event? */
|
714 |
static inline int vring_need_event(uint16_t event, uint16_t new, uint16_t old) |
715 |
{ |
716 |
/* Note: Xen has similar logic for notification hold-off
|
717 |
* in include/xen/interface/io/ring.h with req_event and req_prod
|
718 |
* corresponding to event_idx + 1 and new respectively.
|
719 |
* Note also that req_event and req_prod in Xen start at 1,
|
720 |
* event indexes in virtio start at 0. */
|
721 |
return (uint16_t)(new - event - 1) < (uint16_t)(new - old); |
722 |
} |
723 |
|
724 |
static bool vring_notify(VirtIODevice *vdev, VirtQueue *vq) |
725 |
{ |
726 |
uint16_t old, new; |
727 |
bool v;
|
728 |
/* We need to expose used array entries before checking used event. */
|
729 |
smp_mb(); |
730 |
/* Always notify when queue is empty (when feature acknowledge) */
|
731 |
if (((vdev->guest_features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) && |
732 |
!vq->inuse && vring_avail_idx(vq) == vq->last_avail_idx)) { |
733 |
return true; |
734 |
} |
735 |
|
736 |
if (!(vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX))) { |
737 |
return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
|
738 |
} |
739 |
|
740 |
v = vq->signalled_used_valid; |
741 |
vq->signalled_used_valid = true;
|
742 |
old = vq->signalled_used; |
743 |
new = vq->signalled_used = vring_used_idx(vq); |
744 |
return !v || vring_need_event(vring_used_event(vq), new, old);
|
745 |
} |
746 |
|
747 |
void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)
|
748 |
{ |
749 |
if (!vring_notify(vdev, vq)) {
|
750 |
return;
|
751 |
} |
752 |
|
753 |
trace_virtio_notify(vdev, vq); |
754 |
vdev->isr |= 0x01;
|
755 |
virtio_notify_vector(vdev, vq->vector); |
756 |
} |
757 |
|
758 |
void virtio_notify_config(VirtIODevice *vdev)
|
759 |
{ |
760 |
if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))
|
761 |
return;
|
762 |
|
763 |
vdev->isr |= 0x03;
|
764 |
virtio_notify_vector(vdev, vdev->config_vector); |
765 |
} |
766 |
|
767 |
void virtio_save(VirtIODevice *vdev, QEMUFile *f)
|
768 |
{ |
769 |
int i;
|
770 |
|
771 |
if (vdev->binding->save_config)
|
772 |
vdev->binding->save_config(vdev->binding_opaque, f); |
773 |
|
774 |
qemu_put_8s(f, &vdev->status); |
775 |
qemu_put_8s(f, &vdev->isr); |
776 |
qemu_put_be16s(f, &vdev->queue_sel); |
777 |
qemu_put_be32s(f, &vdev->guest_features); |
778 |
qemu_put_be32(f, vdev->config_len); |
779 |
qemu_put_buffer(f, vdev->config, vdev->config_len); |
780 |
|
781 |
for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
782 |
if (vdev->vq[i].vring.num == 0) |
783 |
break;
|
784 |
} |
785 |
|
786 |
qemu_put_be32(f, i); |
787 |
|
788 |
for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
789 |
if (vdev->vq[i].vring.num == 0) |
790 |
break;
|
791 |
|
792 |
qemu_put_be32(f, vdev->vq[i].vring.num); |
793 |
qemu_put_be64(f, vdev->vq[i].pa); |
794 |
qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); |
795 |
if (vdev->binding->save_queue)
|
796 |
vdev->binding->save_queue(vdev->binding_opaque, i, f); |
797 |
} |
798 |
} |
799 |
|
800 |
int virtio_set_features(VirtIODevice *vdev, uint32_t val)
|
801 |
{ |
802 |
uint32_t supported_features = |
803 |
vdev->binding->get_features(vdev->binding_opaque); |
804 |
bool bad = (val & ~supported_features) != 0; |
805 |
|
806 |
val &= supported_features; |
807 |
if (vdev->set_features) {
|
808 |
vdev->set_features(vdev, val); |
809 |
} |
810 |
vdev->guest_features = val; |
811 |
return bad ? -1 : 0; |
812 |
} |
813 |
|
814 |
int virtio_load(VirtIODevice *vdev, QEMUFile *f)
|
815 |
{ |
816 |
int num, i, ret;
|
817 |
uint32_t features; |
818 |
uint32_t supported_features; |
819 |
|
820 |
if (vdev->binding->load_config) {
|
821 |
ret = vdev->binding->load_config(vdev->binding_opaque, f); |
822 |
if (ret)
|
823 |
return ret;
|
824 |
} |
825 |
|
826 |
qemu_get_8s(f, &vdev->status); |
827 |
qemu_get_8s(f, &vdev->isr); |
828 |
qemu_get_be16s(f, &vdev->queue_sel); |
829 |
qemu_get_be32s(f, &features); |
830 |
|
831 |
if (virtio_set_features(vdev, features) < 0) { |
832 |
supported_features = vdev->binding->get_features(vdev->binding_opaque); |
833 |
error_report("Features 0x%x unsupported. Allowed features: 0x%x",
|
834 |
features, supported_features); |
835 |
return -1; |
836 |
} |
837 |
vdev->config_len = qemu_get_be32(f); |
838 |
qemu_get_buffer(f, vdev->config, vdev->config_len); |
839 |
|
840 |
num = qemu_get_be32(f); |
841 |
|
842 |
for (i = 0; i < num; i++) { |
843 |
vdev->vq[i].vring.num = qemu_get_be32(f); |
844 |
vdev->vq[i].pa = qemu_get_be64(f); |
845 |
qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); |
846 |
vdev->vq[i].signalled_used_valid = false;
|
847 |
vdev->vq[i].notification = true;
|
848 |
|
849 |
if (vdev->vq[i].pa) {
|
850 |
uint16_t nheads; |
851 |
virtqueue_init(&vdev->vq[i]); |
852 |
nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; |
853 |
/* Check it isn't doing very strange things with descriptor numbers. */
|
854 |
if (nheads > vdev->vq[i].vring.num) {
|
855 |
error_report("VQ %d size 0x%x Guest index 0x%x "
|
856 |
"inconsistent with Host index 0x%x: delta 0x%x",
|
857 |
i, vdev->vq[i].vring.num, |
858 |
vring_avail_idx(&vdev->vq[i]), |
859 |
vdev->vq[i].last_avail_idx, nheads); |
860 |
return -1; |
861 |
} |
862 |
} else if (vdev->vq[i].last_avail_idx) { |
863 |
error_report("VQ %d address 0x0 "
|
864 |
"inconsistent with Host index 0x%x",
|
865 |
i, vdev->vq[i].last_avail_idx); |
866 |
return -1; |
867 |
} |
868 |
if (vdev->binding->load_queue) {
|
869 |
ret = vdev->binding->load_queue(vdev->binding_opaque, i, f); |
870 |
if (ret)
|
871 |
return ret;
|
872 |
} |
873 |
} |
874 |
|
875 |
virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); |
876 |
return 0; |
877 |
} |
878 |
|
879 |
void virtio_common_cleanup(VirtIODevice *vdev)
|
880 |
{ |
881 |
qemu_del_vm_change_state_handler(vdev->vmstate); |
882 |
g_free(vdev->config); |
883 |
g_free(vdev->vq); |
884 |
} |
885 |
|
886 |
void virtio_cleanup(VirtIODevice *vdev)
|
887 |
{ |
888 |
virtio_common_cleanup(vdev); |
889 |
g_free(vdev); |
890 |
} |
891 |
|
892 |
static void virtio_vmstate_change(void *opaque, int running, RunState state) |
893 |
{ |
894 |
VirtIODevice *vdev = opaque; |
895 |
bool backend_run = running && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK);
|
896 |
vdev->vm_running = running; |
897 |
|
898 |
if (backend_run) {
|
899 |
virtio_set_status(vdev, vdev->status); |
900 |
} |
901 |
|
902 |
if (vdev->binding->vmstate_change) {
|
903 |
vdev->binding->vmstate_change(vdev->binding_opaque, backend_run); |
904 |
} |
905 |
|
906 |
if (!backend_run) {
|
907 |
virtio_set_status(vdev, vdev->status); |
908 |
} |
909 |
} |
910 |
|
911 |
void virtio_init(VirtIODevice *vdev, const char *name, |
912 |
uint16_t device_id, size_t config_size) |
913 |
{ |
914 |
int i;
|
915 |
vdev->device_id = device_id; |
916 |
vdev->status = 0;
|
917 |
vdev->isr = 0;
|
918 |
vdev->queue_sel = 0;
|
919 |
vdev->config_vector = VIRTIO_NO_VECTOR; |
920 |
vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_PCI_QUEUE_MAX);
|
921 |
vdev->vm_running = runstate_is_running(); |
922 |
for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
923 |
vdev->vq[i].vector = VIRTIO_NO_VECTOR; |
924 |
vdev->vq[i].vdev = vdev; |
925 |
} |
926 |
|
927 |
vdev->name = name; |
928 |
vdev->config_len = config_size; |
929 |
if (vdev->config_len) {
|
930 |
vdev->config = g_malloc0(config_size); |
931 |
} else {
|
932 |
vdev->config = NULL;
|
933 |
} |
934 |
vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, |
935 |
vdev); |
936 |
} |
937 |
|
938 |
VirtIODevice *virtio_common_init(const char *name, uint16_t device_id, |
939 |
size_t config_size, size_t struct_size) |
940 |
{ |
941 |
VirtIODevice *vdev; |
942 |
vdev = g_malloc0(struct_size); |
943 |
virtio_init(vdev, name, device_id, config_size); |
944 |
return vdev;
|
945 |
} |
946 |
|
947 |
void virtio_bind_device(VirtIODevice *vdev, const VirtIOBindings *binding, |
948 |
DeviceState *opaque) |
949 |
{ |
950 |
vdev->binding = binding; |
951 |
vdev->binding_opaque = opaque; |
952 |
} |
953 |
|
954 |
hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n)
|
955 |
{ |
956 |
return vdev->vq[n].vring.desc;
|
957 |
} |
958 |
|
959 |
hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n)
|
960 |
{ |
961 |
return vdev->vq[n].vring.avail;
|
962 |
} |
963 |
|
964 |
hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n)
|
965 |
{ |
966 |
return vdev->vq[n].vring.used;
|
967 |
} |
968 |
|
969 |
hwaddr virtio_queue_get_ring_addr(VirtIODevice *vdev, int n)
|
970 |
{ |
971 |
return vdev->vq[n].vring.desc;
|
972 |
} |
973 |
|
974 |
hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
|
975 |
{ |
976 |
return sizeof(VRingDesc) * vdev->vq[n].vring.num; |
977 |
} |
978 |
|
979 |
hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
|
980 |
{ |
981 |
return offsetof(VRingAvail, ring) +
|
982 |
sizeof(uint64_t) * vdev->vq[n].vring.num;
|
983 |
} |
984 |
|
985 |
hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)
|
986 |
{ |
987 |
return offsetof(VRingUsed, ring) +
|
988 |
sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
|
989 |
} |
990 |
|
991 |
hwaddr virtio_queue_get_ring_size(VirtIODevice *vdev, int n)
|
992 |
{ |
993 |
return vdev->vq[n].vring.used - vdev->vq[n].vring.desc +
|
994 |
virtio_queue_get_used_size(vdev, n); |
995 |
} |
996 |
|
997 |
uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
|
998 |
{ |
999 |
return vdev->vq[n].last_avail_idx;
|
1000 |
} |
1001 |
|
1002 |
void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) |
1003 |
{ |
1004 |
vdev->vq[n].last_avail_idx = idx; |
1005 |
} |
1006 |
|
1007 |
VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n)
|
1008 |
{ |
1009 |
return vdev->vq + n;
|
1010 |
} |
1011 |
|
1012 |
static void virtio_queue_guest_notifier_read(EventNotifier *n) |
1013 |
{ |
1014 |
VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); |
1015 |
if (event_notifier_test_and_clear(n)) {
|
1016 |
virtio_irq(vq); |
1017 |
} |
1018 |
} |
1019 |
|
1020 |
void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, |
1021 |
bool with_irqfd)
|
1022 |
{ |
1023 |
if (assign && !with_irqfd) {
|
1024 |
event_notifier_set_handler(&vq->guest_notifier, |
1025 |
virtio_queue_guest_notifier_read); |
1026 |
} else {
|
1027 |
event_notifier_set_handler(&vq->guest_notifier, NULL);
|
1028 |
} |
1029 |
if (!assign) {
|
1030 |
/* Test and clear notifier before closing it,
|
1031 |
* in case poll callback didn't have time to run. */
|
1032 |
virtio_queue_guest_notifier_read(&vq->guest_notifier); |
1033 |
} |
1034 |
} |
1035 |
|
1036 |
EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) |
1037 |
{ |
1038 |
return &vq->guest_notifier;
|
1039 |
} |
1040 |
|
1041 |
static void virtio_queue_host_notifier_read(EventNotifier *n) |
1042 |
{ |
1043 |
VirtQueue *vq = container_of(n, VirtQueue, host_notifier); |
1044 |
if (event_notifier_test_and_clear(n)) {
|
1045 |
virtio_queue_notify_vq(vq); |
1046 |
} |
1047 |
} |
1048 |
|
1049 |
void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign, |
1050 |
bool set_handler)
|
1051 |
{ |
1052 |
if (assign && set_handler) {
|
1053 |
event_notifier_set_handler(&vq->host_notifier, |
1054 |
virtio_queue_host_notifier_read); |
1055 |
} else {
|
1056 |
event_notifier_set_handler(&vq->host_notifier, NULL);
|
1057 |
} |
1058 |
if (!assign) {
|
1059 |
/* Test and clear notifier before after disabling event,
|
1060 |
* in case poll callback didn't have time to run. */
|
1061 |
virtio_queue_host_notifier_read(&vq->host_notifier); |
1062 |
} |
1063 |
} |
1064 |
|
1065 |
EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) |
1066 |
{ |
1067 |
return &vq->host_notifier;
|
1068 |
} |
1069 |
|
1070 |
static int virtio_device_init(DeviceState *qdev) |
1071 |
{ |
1072 |
VirtIODevice *vdev = VIRTIO_DEVICE(qdev); |
1073 |
VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(qdev); |
1074 |
assert(k->init != NULL);
|
1075 |
if (k->init(vdev) < 0) { |
1076 |
return -1; |
1077 |
} |
1078 |
virtio_bus_plug_device(vdev); |
1079 |
return 0; |
1080 |
} |
1081 |
|
1082 |
static void virtio_device_class_init(ObjectClass *klass, void *data) |
1083 |
{ |
1084 |
/* Set the default value here. */
|
1085 |
DeviceClass *dc = DEVICE_CLASS(klass); |
1086 |
dc->init = virtio_device_init; |
1087 |
dc->bus_type = TYPE_VIRTIO_BUS; |
1088 |
} |
1089 |
|
1090 |
static const TypeInfo virtio_device_info = { |
1091 |
.name = TYPE_VIRTIO_DEVICE, |
1092 |
.parent = TYPE_DEVICE, |
1093 |
.instance_size = sizeof(VirtIODevice),
|
1094 |
.class_init = virtio_device_class_init, |
1095 |
.abstract = true,
|
1096 |
.class_size = sizeof(VirtioDeviceClass),
|
1097 |
}; |
1098 |
|
1099 |
static void virtio_register_types(void) |
1100 |
{ |
1101 |
type_register_static(&virtio_device_info); |
1102 |
} |
1103 |
|
1104 |
type_init(virtio_register_types) |