qemu-e2k/hw/virtio.c

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/*
* 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 "trace.h"
#include "qemu-error.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.
* In any case, we must prevent the compiler from reordering the code.
* TODO: we likely need some rmb()/mb() as well.
*/
#define wmb() __asm__ __volatile__("": : :"memory")
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;
uint16_t vector;
void (*handle_output)(VirtIODevice *vdev, VirtQueue *vq);
VirtIODevice *vdev;
EventNotifier guest_notifier;
EventNotifier host_notifier;
};
/* 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(target_phys_addr_t desc_pa, int i)
{
target_phys_addr_t pa;
pa = desc_pa + sizeof(VRingDesc) * i + offsetof(VRingDesc, addr);
return ldq_phys(pa);
}
static inline uint32_t vring_desc_len(target_phys_addr_t desc_pa, int i)
{
target_phys_addr_t pa;
pa = desc_pa + sizeof(VRingDesc) * i + offsetof(VRingDesc, len);
return ldl_phys(pa);
}
static inline uint16_t vring_desc_flags(target_phys_addr_t desc_pa, int i)
{
target_phys_addr_t pa;
pa = desc_pa + sizeof(VRingDesc) * i + offsetof(VRingDesc, flags);
return lduw_phys(pa);
}
static inline uint16_t vring_desc_next(target_phys_addr_t desc_pa, int i)
{
target_phys_addr_t pa;
pa = desc_pa + 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;
trace_virtqueue_fill(vq, elem, len, idx);
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();
trace_virtqueue_flush(vq, count);
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) {
error_report("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) {
error_report("Guest says index %u is available", head);
exit(1);
}
return head;
}
static unsigned virtqueue_next_desc(target_phys_addr_t desc_pa,
unsigned int i, unsigned int max)
{
unsigned int next;
/* If this descriptor says it doesn't chain, we're done. */
if (!(vring_desc_flags(desc_pa, i) & VRING_DESC_F_NEXT))
return max;
/* Check they're not leading us off end of descriptors. */
next = vring_desc_next(desc_pa, i);
/* Make sure compiler knows to grab that: we don't want it changing! */
wmb();
if (next >= max) {
error_report("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 total_bufs, in_total, out_total;
idx = vq->last_avail_idx;
total_bufs = in_total = out_total = 0;
while (virtqueue_num_heads(vq, idx)) {
unsigned int max, num_bufs, indirect = 0;
target_phys_addr_t desc_pa;
int i;
max = vq->vring.num;
num_bufs = total_bufs;
i = virtqueue_get_head(vq, idx++);
desc_pa = vq->vring.desc;
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_INDIRECT) {
if (vring_desc_len(desc_pa, i) % sizeof(VRingDesc)) {
error_report("Invalid size for indirect buffer table");
exit(1);
}
/* If we've got too many, that implies a descriptor loop. */
if (num_bufs >= max) {
error_report("Looped descriptor");
exit(1);
}
/* loop over the indirect descriptor table */
indirect = 1;
max = vring_desc_len(desc_pa, i) / sizeof(VRingDesc);
num_bufs = i = 0;
desc_pa = vring_desc_addr(desc_pa, i);
}
do {
/* If we've got too many, that implies a descriptor loop. */
if (++num_bufs > max) {
error_report("Looped descriptor");
exit(1);
}
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) {
if (in_bytes > 0 &&
(in_total += vring_desc_len(desc_pa, i)) >= in_bytes)
return 1;
} else {
if (out_bytes > 0 &&
(out_total += vring_desc_len(desc_pa, i)) >= out_bytes)
return 1;
}
} while ((i = virtqueue_next_desc(desc_pa, i, max)) != max);
if (!indirect)
total_bufs = num_bufs;
else
total_bufs++;
}
return 0;
}
void virtqueue_map_sg(struct iovec *sg, target_phys_addr_t *addr,
size_t num_sg, int is_write)
{
unsigned int i;
target_phys_addr_t len;
for (i = 0; i < num_sg; i++) {
len = sg[i].iov_len;
sg[i].iov_base = cpu_physical_memory_map(addr[i], &len, is_write);
if (sg[i].iov_base == NULL || len != sg[i].iov_len) {
error_report("virtio: trying to map MMIO memory");
exit(1);
}
}
}
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem)
{
unsigned int i, head, max;
target_phys_addr_t desc_pa = vq->vring.desc;
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;
max = vq->vring.num;
i = head = virtqueue_get_head(vq, vq->last_avail_idx++);
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_INDIRECT) {
if (vring_desc_len(desc_pa, i) % sizeof(VRingDesc)) {
error_report("Invalid size for indirect buffer table");
exit(1);
}
/* loop over the indirect descriptor table */
max = vring_desc_len(desc_pa, i) / sizeof(VRingDesc);
desc_pa = vring_desc_addr(desc_pa, i);
i = 0;
}
/* Collect all the descriptors */
do {
struct iovec *sg;
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) {
elem->in_addr[elem->in_num] = vring_desc_addr(desc_pa, i);
sg = &elem->in_sg[elem->in_num++];
} else {
elem->out_addr[elem->out_num] = vring_desc_addr(desc_pa, i);
sg = &elem->out_sg[elem->out_num++];
}
sg->iov_len = vring_desc_len(desc_pa, i);
/* If we've got too many, that implies a descriptor loop. */
if ((elem->in_num + elem->out_num) > max) {
error_report("Looped descriptor");
exit(1);
}
} while ((i = virtqueue_next_desc(desc_pa, i, max)) != max);
/* Now map what we have collected */
virtqueue_map_sg(elem->in_sg, elem->in_addr, elem->in_num, 1);
virtqueue_map_sg(elem->out_sg, elem->out_addr, elem->out_num, 0);
elem->index = head;
vq->inuse++;
trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);
return elem->in_num + elem->out_num;
}
/* virtio device */
static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector)
{
if (vdev->binding->notify) {
vdev->binding->notify(vdev->binding_opaque, vector);
}
}
void virtio_update_irq(VirtIODevice *vdev)
{
virtio_notify_vector(vdev, VIRTIO_NO_VECTOR);
}
void virtio_reset(void *opaque)
{
VirtIODevice *vdev = opaque;
int i;
virtio_set_status(vdev, 0);
if (vdev->reset)
vdev->reset(vdev);
vdev->guest_features = 0;
vdev->queue_sel = 0;
vdev->status = 0;
vdev->isr = 0;
vdev->config_vector = VIRTIO_NO_VECTOR;
virtio_notify_vector(vdev, vdev->config_vector);
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;
vdev->vq[i].vector = VIRTIO_NO_VECTOR;
}
}
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)
{
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;
}
virtio-pci: Use ioeventfd for virtqueue notify Virtqueue notify is currently handled synchronously in userspace virtio. This prevents the vcpu from executing guest code while hardware emulation code handles the notify. On systems that support KVM, the ioeventfd mechanism can be used to make virtqueue notify a lightweight exit by deferring hardware emulation to the iothread and allowing the VM to continue execution. This model is similar to how vhost receives virtqueue notifies. The result of this change is improved performance for userspace virtio devices. Virtio-blk throughput increases especially for multithreaded scenarios and virtio-net transmit throughput increases substantially. Some virtio devices are known to have guest drivers which expect a notify to be processed synchronously and spin waiting for completion. For virtio-net, this also seems to interact with the guest stack in strange ways so that TCP throughput for small message sizes (~200bytes) is harmed. Only enable ioeventfd for virtio-blk for now. Care must be taken not to interfere with vhost-net, which uses host notifiers. If the set_host_notifier() API is used by a device virtio-pci will disable virtio-ioeventfd and let the device deal with host notifiers as it wishes. Finally, there used to be a limit of 6 KVM io bus devices inside the kernel. On such a kernel, don't use ioeventfd for virtqueue host notification since the limit is reached too easily. This ensures that existing vhost-net setups (which always use ioeventfd) have ioeventfds available so they can continue to work. After migration and on VM change state (running/paused) virtio-ioeventfd will enable/disable itself. * VIRTIO_CONFIG_S_DRIVER_OK -> enable virtio-ioeventfd * !VIRTIO_CONFIG_S_DRIVER_OK -> disable virtio-ioeventfd * virtio_pci_set_host_notifier() -> disable virtio-ioeventfd * vm_change_state(running=0) -> disable virtio-ioeventfd * vm_change_state(running=1) -> enable virtio-ioeventfd Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-12-17 13:01:50 +01:00
void virtio_queue_notify_vq(VirtQueue *vq)
{
if (vq->vring.desc) {
VirtIODevice *vdev = vq->vdev;
trace_virtio_queue_notify(vdev, vq - vdev->vq, vq);
vq->handle_output(vdev, vq);
}
}
void virtio_queue_notify(VirtIODevice *vdev, int n)
{
virtio-pci: Use ioeventfd for virtqueue notify Virtqueue notify is currently handled synchronously in userspace virtio. This prevents the vcpu from executing guest code while hardware emulation code handles the notify. On systems that support KVM, the ioeventfd mechanism can be used to make virtqueue notify a lightweight exit by deferring hardware emulation to the iothread and allowing the VM to continue execution. This model is similar to how vhost receives virtqueue notifies. The result of this change is improved performance for userspace virtio devices. Virtio-blk throughput increases especially for multithreaded scenarios and virtio-net transmit throughput increases substantially. Some virtio devices are known to have guest drivers which expect a notify to be processed synchronously and spin waiting for completion. For virtio-net, this also seems to interact with the guest stack in strange ways so that TCP throughput for small message sizes (~200bytes) is harmed. Only enable ioeventfd for virtio-blk for now. Care must be taken not to interfere with vhost-net, which uses host notifiers. If the set_host_notifier() API is used by a device virtio-pci will disable virtio-ioeventfd and let the device deal with host notifiers as it wishes. Finally, there used to be a limit of 6 KVM io bus devices inside the kernel. On such a kernel, don't use ioeventfd for virtqueue host notification since the limit is reached too easily. This ensures that existing vhost-net setups (which always use ioeventfd) have ioeventfds available so they can continue to work. After migration and on VM change state (running/paused) virtio-ioeventfd will enable/disable itself. * VIRTIO_CONFIG_S_DRIVER_OK -> enable virtio-ioeventfd * !VIRTIO_CONFIG_S_DRIVER_OK -> disable virtio-ioeventfd * virtio_pci_set_host_notifier() -> disable virtio-ioeventfd * vm_change_state(running=0) -> disable virtio-ioeventfd * vm_change_state(running=1) -> enable virtio-ioeventfd Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-12-17 13:01:50 +01:00
if (n < VIRTIO_PCI_QUEUE_MAX) {
virtio_queue_notify_vq(&vdev->vq[n]);
}
}
uint16_t virtio_queue_vector(VirtIODevice *vdev, int n)
{
return n < VIRTIO_PCI_QUEUE_MAX ? vdev->vq[n].vector :
VIRTIO_NO_VECTOR;
}
void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector)
{
if (n < VIRTIO_PCI_QUEUE_MAX)
vdev->vq[n].vector = vector;
}
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_irq(VirtQueue *vq)
{
trace_virtio_irq(vq);
vq->vdev->isr |= 0x01;
virtio_notify_vector(vq->vdev, vq->vector);
}
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->guest_features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) ||
(vq->inuse || vring_avail_idx(vq) != vq->last_avail_idx)))
return;
trace_virtio_notify(vdev, vq);
vdev->isr |= 0x01;
virtio_notify_vector(vdev, vq->vector);
}
void virtio_notify_config(VirtIODevice *vdev)
{
if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))
return;
vdev->isr |= 0x03;
virtio_notify_vector(vdev, vdev->config_vector);
}
void virtio_save(VirtIODevice *vdev, QEMUFile *f)
{
int i;
if (vdev->binding->save_config)
vdev->binding->save_config(vdev->binding_opaque, 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->guest_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);
if (vdev->binding->save_queue)
vdev->binding->save_queue(vdev->binding_opaque, i, f);
}
}
int virtio_load(VirtIODevice *vdev, QEMUFile *f)
{
int num, i, ret;
uint32_t features;
uint32_t supported_features =
vdev->binding->get_features(vdev->binding_opaque);
if (vdev->binding->load_config) {
ret = vdev->binding->load_config(vdev->binding_opaque, f);
if (ret)
return ret;
}
qemu_get_8s(f, &vdev->status);
qemu_get_8s(f, &vdev->isr);
qemu_get_be16s(f, &vdev->queue_sel);
qemu_get_be32s(f, &features);
if (features & ~supported_features) {
error_report("Features 0x%x unsupported. Allowed features: 0x%x",
features, supported_features);
return -1;
}
if (vdev->set_features)
vdev->set_features(vdev, features);
vdev->guest_features = 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) {
uint16_t nheads;
virtqueue_init(&vdev->vq[i]);
nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx;
/* Check it isn't doing very strange things with descriptor numbers. */
if (nheads > vdev->vq[i].vring.num) {
error_report("VQ %d size 0x%x Guest index 0x%x "
"inconsistent with Host index 0x%x: delta 0x%x\n",
i, vdev->vq[i].vring.num,
vring_avail_idx(&vdev->vq[i]),
vdev->vq[i].last_avail_idx, nheads);
return -1;
}
} else if (vdev->vq[i].last_avail_idx) {
error_report("VQ %d address 0x0 "
"inconsistent with Host index 0x%x\n",
i, vdev->vq[i].last_avail_idx);
return -1;
}
if (vdev->binding->load_queue) {
ret = vdev->binding->load_queue(vdev->binding_opaque, i, f);
if (ret)
return ret;
}
}
virtio_notify_vector(vdev, VIRTIO_NO_VECTOR);
return 0;
}
void virtio_cleanup(VirtIODevice *vdev)
{
qemu_del_vm_change_state_handler(vdev->vmstate);
if (vdev->config)
qemu_free(vdev->config);
qemu_free(vdev->vq);
}
static void virtio_vmstate_change(void *opaque, int running, int reason)
{
VirtIODevice *vdev = opaque;
bool backend_run = running && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK);
vdev->vm_running = running;
if (backend_run) {
virtio_set_status(vdev, vdev->status);
}
if (vdev->binding->vmstate_change) {
vdev->binding->vmstate_change(vdev->binding_opaque, backend_run);
}
if (!backend_run) {
virtio_set_status(vdev, vdev->status);
}
}
VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
size_t config_size, size_t struct_size)
{
VirtIODevice *vdev;
int i;
vdev = qemu_mallocz(struct_size);
vdev->device_id = device_id;
vdev->status = 0;
vdev->isr = 0;
vdev->queue_sel = 0;
vdev->config_vector = VIRTIO_NO_VECTOR;
vdev->vq = qemu_mallocz(sizeof(VirtQueue) * VIRTIO_PCI_QUEUE_MAX);
for(i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) {
vdev->vq[i].vector = VIRTIO_NO_VECTOR;
vdev->vq[i].vdev = vdev;
}
vdev->name = name;
vdev->config_len = config_size;
if (vdev->config_len)
vdev->config = qemu_mallocz(config_size);
else
vdev->config = NULL;
vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, vdev);
return vdev;
}
void virtio_bind_device(VirtIODevice *vdev, const VirtIOBindings *binding,
void *opaque)
{
vdev->binding = binding;
vdev->binding_opaque = opaque;
}
target_phys_addr_t virtio_queue_get_desc_addr(VirtIODevice *vdev, int n)
{
return vdev->vq[n].vring.desc;
}
target_phys_addr_t virtio_queue_get_avail_addr(VirtIODevice *vdev, int n)
{
return vdev->vq[n].vring.avail;
}
target_phys_addr_t virtio_queue_get_used_addr(VirtIODevice *vdev, int n)
{
return vdev->vq[n].vring.used;
}
target_phys_addr_t virtio_queue_get_ring_addr(VirtIODevice *vdev, int n)
{
return vdev->vq[n].vring.desc;
}
target_phys_addr_t virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
{
return sizeof(VRingDesc) * vdev->vq[n].vring.num;
}
target_phys_addr_t virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
{
return offsetof(VRingAvail, ring) +
sizeof(uint64_t) * vdev->vq[n].vring.num;
}
target_phys_addr_t virtio_queue_get_used_size(VirtIODevice *vdev, int n)
{
return offsetof(VRingUsed, ring) +
sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
}
target_phys_addr_t virtio_queue_get_ring_size(VirtIODevice *vdev, int n)
{
return vdev->vq[n].vring.used - vdev->vq[n].vring.desc +
virtio_queue_get_used_size(vdev, n);
}
uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
{
return vdev->vq[n].last_avail_idx;
}
void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx)
{
vdev->vq[n].last_avail_idx = idx;
}
VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n)
{
return vdev->vq + n;
}
EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq)
{
return &vq->guest_notifier;
}
EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)
{
return &vq->host_notifier;
}