| /* |
| * Virtio Support |
| * |
| * Copyright IBM, Corp. 2007 |
| * |
| * Authors: |
| * Anthony Liguori <aliguori@us.ibm.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| * |
| */ |
| |
| #include <inttypes.h> |
| |
| #include "virtio.h" |
| #include "sysemu.h" |
| |
| /* The alignment to use between consumer and producer parts of vring. |
| * x86 pagesize again. */ |
| #define VIRTIO_PCI_VRING_ALIGN 4096 |
| |
| /* QEMU doesn't strictly need write barriers since everything runs in |
| * lock-step. We'll leave the calls to wmb() in though to make it obvious for |
| * KVM or if kqemu gets SMP support. |
| */ |
| #define wmb() do { } while (0) |
| |
| typedef struct VRingDesc |
| { |
| uint64_t addr; |
| uint32_t len; |
| uint16_t flags; |
| uint16_t next; |
| } VRingDesc; |
| |
| typedef struct VRingAvail |
| { |
| uint16_t flags; |
| uint16_t idx; |
| uint16_t ring[0]; |
| } VRingAvail; |
| |
| typedef struct VRingUsedElem |
| { |
| uint32_t id; |
| uint32_t len; |
| } VRingUsedElem; |
| |
| typedef struct VRingUsed |
| { |
| uint16_t flags; |
| uint16_t idx; |
| VRingUsedElem ring[0]; |
| } VRingUsed; |
| |
| typedef struct VRing |
| { |
| unsigned int num; |
| target_phys_addr_t desc; |
| target_phys_addr_t avail; |
| target_phys_addr_t used; |
| } VRing; |
| |
| struct VirtQueue |
| { |
| VRing vring; |
| target_phys_addr_t pa; |
| uint16_t last_avail_idx; |
| int inuse; |
| void (*handle_output)(VirtIODevice *vdev, VirtQueue *vq); |
| }; |
| |
| #define VIRTIO_PCI_QUEUE_MAX 16 |
| |
| /* virt queue functions */ |
| static void virtqueue_init(VirtQueue *vq) |
| { |
| target_phys_addr_t pa = vq->pa; |
| |
| vq->vring.desc = pa; |
| vq->vring.avail = pa + vq->vring.num * sizeof(VRingDesc); |
| vq->vring.used = vring_align(vq->vring.avail + |
| offsetof(VRingAvail, ring[vq->vring.num]), |
| VIRTIO_PCI_VRING_ALIGN); |
| } |
| |
| static inline uint64_t vring_desc_addr(VirtQueue *vq, int i) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.desc + sizeof(VRingDesc) * i + offsetof(VRingDesc, addr); |
| return ldq_phys(pa); |
| } |
| |
| static inline uint32_t vring_desc_len(VirtQueue *vq, int i) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.desc + sizeof(VRingDesc) * i + offsetof(VRingDesc, len); |
| return ldl_phys(pa); |
| } |
| |
| static inline uint16_t vring_desc_flags(VirtQueue *vq, int i) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.desc + sizeof(VRingDesc) * i + offsetof(VRingDesc, flags); |
| return lduw_phys(pa); |
| } |
| |
| static inline uint16_t vring_desc_next(VirtQueue *vq, int i) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.desc + sizeof(VRingDesc) * i + offsetof(VRingDesc, next); |
| return lduw_phys(pa); |
| } |
| |
| static inline uint16_t vring_avail_flags(VirtQueue *vq) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.avail + offsetof(VRingAvail, flags); |
| return lduw_phys(pa); |
| } |
| |
| static inline uint16_t vring_avail_idx(VirtQueue *vq) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.avail + offsetof(VRingAvail, idx); |
| return lduw_phys(pa); |
| } |
| |
| static inline uint16_t vring_avail_ring(VirtQueue *vq, int i) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.avail + offsetof(VRingAvail, ring[i]); |
| return lduw_phys(pa); |
| } |
| |
| static inline void vring_used_ring_id(VirtQueue *vq, int i, uint32_t val) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.used + offsetof(VRingUsed, ring[i].id); |
| stl_phys(pa, val); |
| } |
| |
| static inline void vring_used_ring_len(VirtQueue *vq, int i, uint32_t val) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.used + offsetof(VRingUsed, ring[i].len); |
| stl_phys(pa, val); |
| } |
| |
| static uint16_t vring_used_idx(VirtQueue *vq) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.used + offsetof(VRingUsed, idx); |
| return lduw_phys(pa); |
| } |
| |
| static inline void vring_used_idx_increment(VirtQueue *vq, uint16_t val) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.used + offsetof(VRingUsed, idx); |
| stw_phys(pa, vring_used_idx(vq) + val); |
| } |
| |
| static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.used + offsetof(VRingUsed, flags); |
| stw_phys(pa, lduw_phys(pa) | mask); |
| } |
| |
| static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask) |
| { |
| target_phys_addr_t pa; |
| pa = vq->vring.used + offsetof(VRingUsed, flags); |
| stw_phys(pa, lduw_phys(pa) & ~mask); |
| } |
| |
| void virtio_queue_set_notification(VirtQueue *vq, int enable) |
| { |
| if (enable) |
| vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); |
| else |
| vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); |
| } |
| |
| int virtio_queue_ready(VirtQueue *vq) |
| { |
| return vq->vring.avail != 0; |
| } |
| |
| int virtio_queue_empty(VirtQueue *vq) |
| { |
| return vring_avail_idx(vq) == vq->last_avail_idx; |
| } |
| |
| void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, |
| unsigned int len, unsigned int idx) |
| { |
| unsigned int offset; |
| int i; |
| |
| offset = 0; |
| for (i = 0; i < elem->in_num; i++) { |
| size_t size = MIN(len - offset, elem->in_sg[i].iov_len); |
| |
| cpu_physical_memory_unmap(elem->in_sg[i].iov_base, |
| elem->in_sg[i].iov_len, |
| 1, size); |
| |
| offset += elem->in_sg[i].iov_len; |
| } |
| |
| for (i = 0; i < elem->out_num; i++) |
| cpu_physical_memory_unmap(elem->out_sg[i].iov_base, |
| elem->out_sg[i].iov_len, |
| 0, elem->out_sg[i].iov_len); |
| |
| idx = (idx + vring_used_idx(vq)) % vq->vring.num; |
| |
| /* Get a pointer to the next entry in the used ring. */ |
| vring_used_ring_id(vq, idx, elem->index); |
| vring_used_ring_len(vq, idx, len); |
| } |
| |
| void virtqueue_flush(VirtQueue *vq, unsigned int count) |
| { |
| /* Make sure buffer is written before we update index. */ |
| wmb(); |
| vring_used_idx_increment(vq, count); |
| vq->inuse -= count; |
| } |
| |
| void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, |
| unsigned int len) |
| { |
| virtqueue_fill(vq, elem, len, 0); |
| virtqueue_flush(vq, 1); |
| } |
| |
| static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) |
| { |
| uint16_t num_heads = vring_avail_idx(vq) - idx; |
| |
| /* Check it isn't doing very strange things with descriptor numbers. */ |
| if (num_heads > vq->vring.num) { |
| fprintf(stderr, "Guest moved used index from %u to %u", |
| idx, vring_avail_idx(vq)); |
| exit(1); |
| } |
| |
| return num_heads; |
| } |
| |
| static unsigned int virtqueue_get_head(VirtQueue *vq, unsigned int idx) |
| { |
| unsigned int head; |
| |
| /* Grab the next descriptor number they're advertising, and increment |
| * the index we've seen. */ |
| head = vring_avail_ring(vq, idx % vq->vring.num); |
| |
| /* If their number is silly, that's a fatal mistake. */ |
| if (head >= vq->vring.num) { |
| fprintf(stderr, "Guest says index %u is available", head); |
| exit(1); |
| } |
| |
| return head; |
| } |
| |
| static unsigned virtqueue_next_desc(VirtQueue *vq, unsigned int i) |
| { |
| unsigned int next; |
| |
| /* If this descriptor says it doesn't chain, we're done. */ |
| if (!(vring_desc_flags(vq, i) & VRING_DESC_F_NEXT)) |
| return vq->vring.num; |
| |
| /* Check they're not leading us off end of descriptors. */ |
| next = vring_desc_next(vq, i); |
| /* Make sure compiler knows to grab that: we don't want it changing! */ |
| wmb(); |
| |
| if (next >= vq->vring.num) { |
| fprintf(stderr, "Desc next is %u", next); |
| exit(1); |
| } |
| |
| return next; |
| } |
| |
| int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes) |
| { |
| unsigned int idx; |
| int num_bufs, in_total, out_total; |
| |
| idx = vq->last_avail_idx; |
| |
| num_bufs = in_total = out_total = 0; |
| while (virtqueue_num_heads(vq, idx)) { |
| int i; |
| |
| i = virtqueue_get_head(vq, idx++); |
| do { |
| /* If we've got too many, that implies a descriptor loop. */ |
| if (++num_bufs > vq->vring.num) { |
| fprintf(stderr, "Looped descriptor"); |
| exit(1); |
| } |
| |
| if (vring_desc_flags(vq, i) & VRING_DESC_F_WRITE) { |
| if (in_bytes > 0 && |
| (in_total += vring_desc_len(vq, i)) >= in_bytes) |
| return 1; |
| } else { |
| if (out_bytes > 0 && |
| (out_total += vring_desc_len(vq, i)) >= out_bytes) |
| return 1; |
| } |
| } while ((i = virtqueue_next_desc(vq, i)) != vq->vring.num); |
| } |
| |
| return 0; |
| } |
| |
| int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) |
| { |
| unsigned int i, head; |
| target_phys_addr_t len; |
| |
| if (!virtqueue_num_heads(vq, vq->last_avail_idx)) |
| return 0; |
| |
| /* When we start there are none of either input nor output. */ |
| elem->out_num = elem->in_num = 0; |
| |
| i = head = virtqueue_get_head(vq, vq->last_avail_idx++); |
| do { |
| struct iovec *sg; |
| int is_write = 0; |
| |
| if (vring_desc_flags(vq, i) & VRING_DESC_F_WRITE) { |
| elem->in_addr[elem->in_num] = vring_desc_addr(vq, i); |
| sg = &elem->in_sg[elem->in_num++]; |
| is_write = 1; |
| } else |
| sg = &elem->out_sg[elem->out_num++]; |
| |
| /* Grab the first descriptor, and check it's OK. */ |
| sg->iov_len = vring_desc_len(vq, i); |
| len = sg->iov_len; |
| |
| sg->iov_base = cpu_physical_memory_map(vring_desc_addr(vq, i), &len, is_write); |
| |
| if (sg->iov_base == NULL || len != sg->iov_len) { |
| fprintf(stderr, "virtio: trying to map MMIO memory\n"); |
| exit(1); |
| } |
| |
| /* If we've got too many, that implies a descriptor loop. */ |
| if ((elem->in_num + elem->out_num) > vq->vring.num) { |
| fprintf(stderr, "Looped descriptor"); |
| exit(1); |
| } |
| } while ((i = virtqueue_next_desc(vq, i)) != vq->vring.num); |
| |
| elem->index = head; |
| |
| vq->inuse++; |
| |
| return elem->in_num + elem->out_num; |
| } |
| |
| /* virtio device */ |
| |
| void virtio_update_irq(VirtIODevice *vdev) |
| { |
| if (vdev->binding->update_irq) { |
| vdev->binding->update_irq(vdev->binding_opaque); |
| } |
| } |
| |
| void virtio_reset(void *opaque) |
| { |
| VirtIODevice *vdev = opaque; |
| int i; |
| |
| if (vdev->reset) |
| vdev->reset(vdev); |
| |
| vdev->features = 0; |
| vdev->queue_sel = 0; |
| vdev->status = 0; |
| vdev->isr = 0; |
| virtio_update_irq(vdev); |
| |
| for(i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
| vdev->vq[i].vring.desc = 0; |
| vdev->vq[i].vring.avail = 0; |
| vdev->vq[i].vring.used = 0; |
| vdev->vq[i].last_avail_idx = 0; |
| vdev->vq[i].pa = 0; |
| } |
| } |
| |
| uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) |
| { |
| uint8_t val; |
| |
| vdev->get_config(vdev, vdev->config); |
| |
| if (addr > (vdev->config_len - sizeof(val))) |
| return (uint32_t)-1; |
| |
| memcpy(&val, vdev->config + addr, sizeof(val)); |
| return val; |
| } |
| |
| uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) |
| { |
| uint16_t val; |
| |
| vdev->get_config(vdev, vdev->config); |
| |
| if (addr > (vdev->config_len - sizeof(val))) |
| return (uint32_t)-1; |
| |
| memcpy(&val, vdev->config + addr, sizeof(val)); |
| return val; |
| } |
| |
| uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) |
| { |
| uint32_t val; |
| |
| vdev->get_config(vdev, vdev->config); |
| |
| if (addr > (vdev->config_len - sizeof(val))) |
| return (uint32_t)-1; |
| |
| memcpy(&val, vdev->config + addr, sizeof(val)); |
| return val; |
| } |
| |
| void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) |
| { |
| uint8_t val = data; |
| |
| if (addr > (vdev->config_len - sizeof(val))) |
| return; |
| |
| memcpy(vdev->config + addr, &val, sizeof(val)); |
| |
| if (vdev->set_config) |
| vdev->set_config(vdev, vdev->config); |
| } |
| |
| void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) |
| { |
| uint16_t val = data; |
| |
| if (addr > (vdev->config_len - sizeof(val))) |
| return; |
| |
| memcpy(vdev->config + addr, &val, sizeof(val)); |
| |
| if (vdev->set_config) |
| vdev->set_config(vdev, vdev->config); |
| } |
| |
| void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) |
| { |
| uint32_t val = data; |
| |
| if (addr > (vdev->config_len - sizeof(val))) |
| return; |
| |
| memcpy(vdev->config + addr, &val, sizeof(val)); |
| |
| if (vdev->set_config) |
| vdev->set_config(vdev, vdev->config); |
| } |
| |
| void virtio_queue_set_addr(VirtIODevice *vdev, int n, target_phys_addr_t addr) |
| { |
| if (addr == 0) { |
| virtio_reset(vdev); |
| } else { |
| vdev->vq[n].pa = addr; |
| virtqueue_init(&vdev->vq[n]); |
| } |
| } |
| |
| target_phys_addr_t virtio_queue_get_addr(VirtIODevice *vdev, int n) |
| { |
| return vdev->vq[n].pa; |
| } |
| |
| int virtio_queue_get_num(VirtIODevice *vdev, int n) |
| { |
| return vdev->vq[n].vring.num; |
| } |
| |
| void virtio_queue_notify(VirtIODevice *vdev, int n) |
| { |
| if (n < VIRTIO_PCI_QUEUE_MAX && vdev->vq[n].vring.desc) { |
| vdev->vq[n].handle_output(vdev, &vdev->vq[n]); |
| } |
| } |
| |
| VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, |
| void (*handle_output)(VirtIODevice *, VirtQueue *)) |
| { |
| int i; |
| |
| for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
| if (vdev->vq[i].vring.num == 0) |
| break; |
| } |
| |
| if (i == VIRTIO_PCI_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) |
| abort(); |
| |
| vdev->vq[i].vring.num = queue_size; |
| vdev->vq[i].handle_output = handle_output; |
| |
| return &vdev->vq[i]; |
| } |
| |
| void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) |
| { |
| /* Always notify when queue is empty (when feature acknowledge) */ |
| if ((vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT) && |
| (!(vdev->features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) || |
| (vq->inuse || vring_avail_idx(vq) != vq->last_avail_idx))) |
| return; |
| |
| vdev->isr |= 0x01; |
| virtio_update_irq(vdev); |
| } |
| |
| void virtio_notify_config(VirtIODevice *vdev) |
| { |
| if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) |
| return; |
| |
| vdev->isr |= 0x03; |
| virtio_update_irq(vdev); |
| } |
| |
| void virtio_save(VirtIODevice *vdev, QEMUFile *f) |
| { |
| int i; |
| |
| /* FIXME: load/save binding. */ |
| //pci_device_save(&vdev->pci_dev, f); |
| |
| qemu_put_8s(f, &vdev->status); |
| qemu_put_8s(f, &vdev->isr); |
| qemu_put_be16s(f, &vdev->queue_sel); |
| qemu_put_be32s(f, &vdev->features); |
| qemu_put_be32(f, vdev->config_len); |
| qemu_put_buffer(f, vdev->config, vdev->config_len); |
| |
| for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
| if (vdev->vq[i].vring.num == 0) |
| break; |
| } |
| |
| qemu_put_be32(f, i); |
| |
| for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) { |
| if (vdev->vq[i].vring.num == 0) |
| break; |
| |
| qemu_put_be32(f, vdev->vq[i].vring.num); |
| qemu_put_be64(f, vdev->vq[i].pa); |
| qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); |
| } |
| } |
| |
| void virtio_load(VirtIODevice *vdev, QEMUFile *f) |
| { |
| int num, i; |
| |
| /* FIXME: load/save binding. */ |
| //pci_device_load(&vdev->pci_dev, f); |
| |
| qemu_get_8s(f, &vdev->status); |
| qemu_get_8s(f, &vdev->isr); |
| qemu_get_be16s(f, &vdev->queue_sel); |
| qemu_get_be32s(f, &vdev->features); |
| vdev->config_len = qemu_get_be32(f); |
| qemu_get_buffer(f, vdev->config, vdev->config_len); |
| |
| num = qemu_get_be32(f); |
| |
| for (i = 0; i < num; i++) { |
| vdev->vq[i].vring.num = qemu_get_be32(f); |
| vdev->vq[i].pa = qemu_get_be64(f); |
| qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); |
| |
| if (vdev->vq[i].pa) { |
| virtqueue_init(&vdev->vq[i]); |
| } |
| } |
| |
| virtio_update_irq(vdev); |
| } |
| |
| void virtio_cleanup(VirtIODevice *vdev) |
| { |
| if (vdev->config) |
| qemu_free(vdev->config); |
| qemu_free(vdev->vq); |
| } |
| |
| VirtIODevice *virtio_common_init(const char *name, uint16_t device_id, |
| size_t config_size, size_t struct_size) |
| { |
| VirtIODevice *vdev; |
| |
| vdev = qemu_mallocz(struct_size); |
| |
| vdev->device_id = device_id; |
| vdev->status = 0; |
| vdev->isr = 0; |
| vdev->queue_sel = 0; |
| vdev->vq = qemu_mallocz(sizeof(VirtQueue) * VIRTIO_PCI_QUEUE_MAX); |
| |
| vdev->name = name; |
| vdev->config_len = config_size; |
| if (vdev->config_len) |
| vdev->config = qemu_mallocz(config_size); |
| else |
| vdev->config = NULL; |
| |
| qemu_register_reset(virtio_reset, 0, vdev); |
| |
| return vdev; |
| } |
| |
| void virtio_bind_device(VirtIODevice *vdev, const VirtIOBindings *binding, |
| void *opaque) |
| { |
| vdev->binding = binding; |
| vdev->binding_opaque = opaque; |
| } |