This adds vhost net support in qemu. Will be tied to tap device and
virtio by following patches. Raw backend is currently missing, will be
worked on/submitted separately.
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
Makefile.target | 1 +
hw/vhost.c | 603 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
hw/vhost.h | 44 ++++
hw/vhost_net.c | 147 ++++++++++++++
hw/vhost_net.h | 20 ++
5 files changed, 815 insertions(+), 0 deletions(-)
create mode 100644 hw/vhost.c
create mode 100644 hw/vhost.h
create mode 100644 hw/vhost_net.c
create mode 100644 hw/vhost_net.h
diff --git a/Makefile.target b/Makefile.target
index 7df9535..09ae105 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -184,6 +184,7 @@ obj-y = vl.o async.o monitor.o pci.o pci_host.o pcie_host.o machine.o gdbstub.o
# need to fix this properly
obj-y += virtio-blk.o virtio-balloon.o virtio-net.o virtio-pci.o virtio-serial-bus.o
obj-y += notifier.o
+obj-y += vhost_net.o vhost.o
obj-$(CONFIG_KVM) += kvm.o kvm-all.o
# MSI-X depends on kvm for interrupt injection,
# so moved it from Makefile.objs to Makefile.target for now
diff --git a/hw/vhost.c b/hw/vhost.c
new file mode 100644
index 0000000..e5c1ead
--- /dev/null
+++ b/hw/vhost.c
@@ -0,0 +1,603 @@
+#include "linux/vhost.h"
+#include <sys/ioctl.h>
+#include <sys/eventfd.h>
+#include "vhost.h"
+#include "hw/hw.h"
+/* For range_get_last */
+#include "pci.h"
+
+static void vhost_dev_sync_region(struct vhost_dev *dev,
+ uint64_t mfirst, uint64_t mlast,
+ uint64_t rfirst, uint64_t rlast)
+{
+ uint64_t start = MAX(mfirst, rfirst);
+ uint64_t end = MIN(mlast, rlast);
+ vhost_log_chunk_t *from = dev->log + start / VHOST_LOG_CHUNK;
+ vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1;
+ uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK;
+
+ assert(end / VHOST_LOG_CHUNK < dev->log_size);
+ assert(start / VHOST_LOG_CHUNK < dev->log_size);
+ if (end < start) {
+ return;
+ }
+ for (;from < to; ++from) {
+ vhost_log_chunk_t log;
+ int bit;
+ /* We first check with non-atomic: much cheaper,
+ * and we expect non-dirty to be the common case. */
+ if (!*from) {
+ continue;
+ }
+ /* Data must be read atomically. We don't really
+ * need the barrier semantics of __sync
+ * builtins, but it's easier to use them than
+ * roll our own. */
+ log = __sync_fetch_and_and(from, 0);
+ while ((bit = sizeof(log) > sizeof(int) ?
+ ffsll(log) : ffs(log))) {
+ bit -= 1;
+ cpu_physical_memory_set_dirty(addr + bit * VHOST_LOG_PAGE);
+ log &= ~(0x1ull << bit);
+ }
+ addr += VHOST_LOG_CHUNK;
+ }
+}
+
+static int vhost_client_sync_dirty_bitmap(struct CPUPhysMemoryClient *client,
+ target_phys_addr_t start_addr,
+ target_phys_addr_t end_addr)
+{
+ struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
+ int i;
+ if (!dev->log_enabled || !dev->started) {
+ return 0;
+ }
+ for (i = 0; i < dev->mem->nregions; ++i) {
+ struct vhost_memory_region *reg = dev->mem->regions + i;
+ vhost_dev_sync_region(dev, start_addr, end_addr,
+ reg->guest_phys_addr,
+ range_get_last(reg->guest_phys_addr,
+ reg->memory_size));
+ }
+ for (i = 0; i < dev->nvqs; ++i) {
+ struct vhost_virtqueue *vq = dev->vqs + i;
+ unsigned size = sizeof(struct vring_used_elem) * vq->num;
+ vhost_dev_sync_region(dev, start_addr, end_addr, vq->used_phys,
+ range_get_last(vq->used_phys, size));
+ }
+ return 0;
+}
+
+/* Assign/unassign. Keep an unsorted array of non-overlapping
+ * memory regions in dev->mem. */
+static void vhost_dev_unassign_memory(struct vhost_dev *dev,
+ uint64_t start_addr,
+ uint64_t size)
+{
+ int from, to, n = dev->mem->nregions;
+ /* Track overlapping/split regions for sanity checking. */
+ int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0;
+
+ for (from = 0, to = 0; from < n; ++from, ++to) {
+ struct vhost_memory_region *reg = dev->mem->regions + to;
+ uint64_t reglast;
+ uint64_t memlast;
+ uint64_t change;
+
+ /* clone old region */
+ if (to != from) {
+ memcpy(reg, dev->mem->regions + from, sizeof *reg);
+ }
+
+ /* No overlap is simple */
+ if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size,
+ start_addr, size)) {
+ continue;
+ }
+
+ /* Split only happens if supplied region
+ * is in the middle of an existing one. Thus it can not
+ * overlap with any other existing region. */
+ assert(!split);
+
+ reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
+ memlast = range_get_last(start_addr, size);
+
+ /* Remove whole region */
+ if (start_addr <= reg->guest_phys_addr && memlast >= reglast) {
+ --dev->mem->nregions;
+ --to;
+ assert(to >= 0);
+ ++overlap_middle;
+ continue;
+ }
+
+ /* Shrink region */
+ if (memlast >= reglast) {
+ reg->memory_size = start_addr - reg->guest_phys_addr;
+ assert(reg->memory_size);
+ assert(!overlap_end);
+ ++overlap_end;
+ continue;
+ }
+
+ /* Shift region */
+ if (start_addr <= reg->guest_phys_addr) {
+ change = memlast + 1 - reg->guest_phys_addr;
+ reg->memory_size -= change;
+ reg->guest_phys_addr += change;
+ reg->userspace_addr += change;
+ assert(reg->memory_size);
+ assert(!overlap_start);
+ ++overlap_start;
+ continue;
+ }
+
+ /* This only happens if supplied region
+ * is in the middle of an existing one. Thus it can not
+ * overlap with any other existing region. */
+ assert(!overlap_start);
+ assert(!overlap_end);
+ assert(!overlap_middle);
+ /* Split region: shrink first part, shift second part. */
+ memcpy(dev->mem->regions + n, reg, sizeof *reg);
+ reg->memory_size = start_addr - reg->guest_phys_addr;
+ assert(reg->memory_size);
+ change = memlast + 1 - reg->guest_phys_addr;
+ reg = dev->mem->regions + n;
+ reg->memory_size -= change;
+ assert(reg->memory_size);
+ reg->guest_phys_addr += change;
+ reg->userspace_addr += change;
+ /* Never add more than 1 region */
+ assert(dev->mem->nregions == n);
+ ++dev->mem->nregions;
+ ++split;
+ }
+}
+
+/* Called after unassign, so no regions overlap the given range. */
+static void vhost_dev_assign_memory(struct vhost_dev *dev,
+ uint64_t start_addr,
+ uint64_t size,
+ uint64_t uaddr)
+{
+ int from, to;
+ struct vhost_memory_region *merged = NULL;
+ for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) {
+ struct vhost_memory_region *reg = dev->mem->regions + to;
+ uint64_t prlast, urlast;
+ uint64_t pmlast, umlast;
+ uint64_t s, e, u;
+
+ /* clone old region */
+ if (to != from) {
+ memcpy(reg, dev->mem->regions + from, sizeof *reg);
+ }
+ prlast = range_get_last(reg->guest_phys_addr, reg->memory_size);
+ pmlast = range_get_last(start_addr, size);
+ urlast = range_get_last(reg->userspace_addr, reg->memory_size);
+ umlast = range_get_last(uaddr, size);
+
+ /* check for overlapping regions: should never happen. */
+ assert(prlast < start_addr || pmlast < reg->guest_phys_addr);
+ /* Not an adjacent or overlapping region - do not merge. */
+ if ((prlast + 1 != start_addr || urlast + 1 != uaddr) &&
+ (pmlast + 1 != reg->guest_phys_addr ||
+ umlast + 1 != reg->userspace_addr)) {
+ continue;
+ }
+
+ if (merged) {
+ --to;
+ assert(to >= 0);
+ } else {
+ merged = reg;
+ }
+ u = MIN(uaddr, reg->userspace_addr);
+ s = MIN(start_addr, reg->guest_phys_addr);
+ e = MAX(pmlast, prlast);
+ uaddr = merged->userspace_addr = u;
+ start_addr = merged->guest_phys_addr = s;
+ size = merged->memory_size = e - s + 1;
+ assert(merged->memory_size);
+ }
+
+ if (!merged) {
+ struct vhost_memory_region *reg = dev->mem->regions + to;
+ memset(reg, 0, sizeof *reg);
+ reg->memory_size = size;
+ assert(reg->memory_size);
+ reg->guest_phys_addr = start_addr;
+ reg->userspace_addr = uaddr;
+ ++to;
+ }
+ assert(to <= dev->mem->nregions + 1);
+ dev->mem->nregions = to;
+}
+
+static uint64_t vhost_get_log_size(struct vhost_dev *dev)
+{
+ uint64_t log_size = 0;
+ int i;
+ for (i = 0; i < dev->mem->nregions; ++i) {
+ struct vhost_memory_region *reg = dev->mem->regions + i;
+ uint64_t last = range_get_last(reg->guest_phys_addr,
+ reg->memory_size);
+ log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
+ }
+ for (i = 0; i < dev->nvqs; ++i) {
+ struct vhost_virtqueue *vq = dev->vqs + i;
+ uint64_t last = vq->used_phys +
+ sizeof(struct vring_used_elem) * vq->num - 1;
+ log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
+ }
+ return log_size;
+}
+
+static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
+{
+ vhost_log_chunk_t *log;
+ int r;
+ if (size) {
+ log = qemu_mallocz(size * sizeof *log);
+ } else {
+ log = NULL;
+ }
+ r = ioctl(dev->control, VHOST_SET_LOG_BASE,
+ (uint64_t)(unsigned long)log);
+ assert(r >= 0);
+ vhost_client_sync_dirty_bitmap(&dev->client, 0,
+ (target_phys_addr_t)~0x0ull);
+ if (dev->log) {
+ qemu_free(dev->log);
+ }
+ dev->log = log;
+ dev->log_size = size;
+}
+
+static void vhost_client_set_memory(CPUPhysMemoryClient *client,
+ target_phys_addr_t start_addr,
+ ram_addr_t size,
+ ram_addr_t phys_offset)
+{
+ struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
+ ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
+ int s = offsetof(struct vhost_memory, regions) +
+ (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
+ uint64_t log_size;
+ int r;
+ dev->mem = qemu_realloc(dev->mem, s);
+
+ assert(size);
+
+ vhost_dev_unassign_memory(dev, start_addr, size);
+ if (flags == IO_MEM_RAM) {
+ /* Add given mapping, merging adjacent regions if any */
+ vhost_dev_assign_memory(dev, start_addr, size,
+ (uintptr_t)qemu_get_ram_ptr(phys_offset));
+ } else {
+ /* Remove old mapping for this memory, if any. */
+ vhost_dev_unassign_memory(dev, start_addr, size);
+ }
+
+ if (!dev->started) {
+ return;
+ }
+ if (!dev->log_enabled) {
+ r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
+ assert(r >= 0);
+ return;
+ }
+ log_size = vhost_get_log_size(dev);
+ /* We allocate an extra 4K bytes to log,
+ * to reduce the * number of reallocations. */
+#define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log)
+ /* To log more, must increase log size before table update. */
+ if (dev->log_size < log_size) {
+ vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER);
+ }
+ r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
+ assert(r >= 0);
+ /* To log less, can only decrease log size after table update. */
+ if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
+ vhost_dev_log_resize(dev, log_size);
+ }
+}
+
+static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
+{
+ uint64_t features = dev->acked_features;
+ int r;
+ if (dev->log_enabled) {
+ features |= 0x1 << VHOST_F_LOG_ALL;
+ }
+ r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
+ return r < 0 ? -errno : 0;
+}
+
+static int vhost_client_migration_log(struct CPUPhysMemoryClient *client,
+ int enable)
+{
+ struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
+ int r;
+ if (!!enable == dev->log_enabled) {
+ return 0;
+ }
+ if (!dev->started) {
+ dev->log_enabled = enable;
+ return 0;
+ }
+ if (!enable) {
+ r = vhost_dev_set_log(dev, false);
+ if (r < 0) {
+ return r;
+ }
+ if (dev->log) {
+ qemu_free(dev->log);
+ }
+ dev->log = NULL;
+ dev->log_size = 0;
+ } else {
+ vhost_dev_log_resize(dev, vhost_get_log_size(dev));
+ r = vhost_dev_set_log(dev, false);
+ if (r < 0) {
+ return r;
+ }
+ }
+ dev->log_enabled = enable;
+ return 0;
+}
+
+static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq,
+ unsigned idx, bool enable_log)
+{
+ struct vhost_vring_addr addr = {
+ .index = idx,
+ .desc_user_addr = (u_int64_t)(unsigned long)vq->desc,
+ .avail_user_addr = (u_int64_t)(unsigned long)vq->avail,
+ .used_user_addr = (u_int64_t)(unsigned long)vq->used,
+ .log_guest_addr = vq->used_phys,
+ .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
+ };
+ int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
+ if (r < 0) {
+ return -errno;
+ }
+ return 0;
+}
+
+static int vhost_virtqueue_init(struct vhost_dev *dev,
+ struct VirtIODevice *vdev,
+ struct vhost_virtqueue *vq,
+ unsigned idx)
+{
+ target_phys_addr_t s, l, a;
+ int r;
+ struct vhost_vring_file file = {
+ .index = idx,
+ };
+ struct vhost_vring_state state = {
+ .index = idx,
+ };
+ struct VirtQueue *q = virtio_queue(vdev, idx);
+
+ vq->num = state.num = virtio_queue_get_num(vdev, idx);
+ r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
+ if (r) {
+ return -errno;
+ }
+
+ state.num = virtio_queue_last_avail_idx(vdev, idx);
+ r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
+ if (r) {
+ return -errno;
+ }
+
+ s = l = sizeof(struct vring_desc) * vq->num;
+ a = virtio_queue_get_desc(vdev, idx);
+ vq->desc = cpu_physical_memory_map(a, &l, 0);
+ if (!vq->desc || l != s) {
+ r = -ENOMEM;
+ goto fail_alloc;
+ }
+ s = l = offsetof(struct vring_avail, ring) +
+ sizeof(u_int64_t) * vq->num;
+ a = virtio_queue_get_avail(vdev, idx);
+ vq->avail = cpu_physical_memory_map(a, &l, 0);
+ if (!vq->avail || l != s) {
+ r = -ENOMEM;
+ goto fail_alloc;
+ }
+ s = l = offsetof(struct vring_used, ring) +
+ sizeof(struct vring_used_elem) * vq->num;
+ vq->used_phys = a = virtio_queue_get_used(vdev, idx);
+ vq->used = cpu_physical_memory_map(a, &l, 1);
+ if (!vq->used || l != s) {
+ r = -ENOMEM;
+ goto fail_alloc;
+ }
+
+ r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
+ if (r < 0) {
+ r = -errno;
+ goto fail_alloc;
+ }
+ if (!vdev->binding->guest_notifier || !vdev->binding->host_notifier) {
+ fprintf(stderr, "binding does not support irqfd/queuefd\n");
+ r = -ENOSYS;
+ goto fail_alloc;
+ }
+ r = vdev->binding->guest_notifier(vdev->binding_opaque, idx, true);
+ if (r < 0) {
+ fprintf(stderr, "Error binding guest notifier: %d\n", -r);
+ goto fail_guest_notifier;
+ }
+
+ r = vdev->binding->host_notifier(vdev->binding_opaque, idx, true);
+ if (r < 0) {
+ fprintf(stderr, "Error binding host notifier: %d\n", -r);
+ goto fail_host_notifier;
+ }
+
+ file.fd = event_notifier_get_fd(virtio_queue_host_notifier(q));
+ r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
+ if (r) {
+ goto fail_kick;
+ }
+
+ file.fd = event_notifier_get_fd(virtio_queue_guest_notifier(q));
+ r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
+ if (r) {
+ goto fail_call;
+ }
+
+ return 0;
+
+fail_call:
+fail_kick:
+ vdev->binding->host_notifier(vdev->binding_opaque, idx, false);
+fail_host_notifier:
+ vdev->binding->guest_notifier(vdev->binding_opaque, idx, false);
+fail_guest_notifier:
+fail_alloc:
+ return r;
+}
+
+static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
+ struct VirtIODevice *vdev,
+ struct vhost_virtqueue *vq,
+ unsigned idx)
+{
+ struct vhost_vring_state state = {
+ .index = idx,
+ };
+ int r;
+ r = vdev->binding->guest_notifier(vdev->binding_opaque, idx, false);
+ if (r < 0) {
+ fprintf(stderr, "vhost VQ %d guest cleanup failed: %d\n", idx, r);
+ fflush(stderr);
+ }
+ assert (r >= 0);
+
+ r = vdev->binding->host_notifier(vdev->binding_opaque, idx, false);
+ if (r < 0) {
+ fprintf(stderr, "vhost VQ %d host cleanup failed: %d\n", idx, r);
+ fflush(stderr);
+ }
+ assert (r >= 0);
+ r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
+ if (r < 0) {
+ fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
+ fflush(stderr);
+ }
+ virtio_queue_set_last_avail_idx(vdev, idx, state.num);
+ assert (r >= 0);
+}
+
+int vhost_dev_init(struct vhost_dev *hdev, int devfd)
+{
+ uint64_t features;
+ int r;
+ if (devfd >= 0) {
+ hdev->control = devfd;
+ } else {
+ hdev->control = open("/dev/vhost-net", O_RDWR);
+ if (hdev->control < 0)
+ return -errno;
+ }
+ r = ioctl(hdev->control, VHOST_SET_OWNER, NULL);
+ if (r < 0)
+ goto fail;
+
+ r = ioctl(hdev->control, VHOST_GET_FEATURES, &features);
+ if (r < 0)
+ goto fail;
+ hdev->features = features;
+
+ hdev->client.set_memory = vhost_client_set_memory;
+ hdev->client.sync_dirty_bitmap = vhost_client_sync_dirty_bitmap;
+ hdev->client.migration_log = vhost_client_migration_log;
+ hdev->mem = qemu_mallocz(offsetof(struct vhost_memory, regions));
+ hdev->log = NULL;
+ hdev->log_size = 0;
+ hdev->log_enabled = false;
+ hdev->started = false;
+ cpu_register_phys_memory_client(&hdev->client);
+ return 0;
+fail:
+ r = -errno;
+ close(hdev->control);
+ return r;
+}
+
+void vhost_dev_cleanup(struct vhost_dev *hdev)
+{
+ cpu_unregister_phys_memory_client(&hdev->client);
+ qemu_free(hdev->mem);
+ close(hdev->control);
+}
+
+int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
+{
+ int i, r;
+
+ r = vhost_dev_set_log(hdev, hdev->log_enabled);
+ if (r < 0)
+ goto fail;
+ r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem);
+ if (r < 0) {
+ r = -errno;
+ goto fail;
+ }
+ if (hdev->log_enabled) {
+ hdev->log_size = vhost_get_log_size(hdev);
+ hdev->log = hdev->log_size ?
+ qemu_mallocz(hdev->log_size * sizeof *hdev->log) : NULL;
+ r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
+ (uint64_t)(unsigned long)hdev->log);
+ if (r < 0) {
+ r = -errno;
+ goto fail;
+ }
+ }
+
+ for (i = 0; i < hdev->nvqs; ++i) {
+ r = vhost_virtqueue_init(hdev,
+ vdev,
+ hdev->vqs + i,
+ i);
+ if (r < 0)
+ goto fail_vq;
+ }
+ hdev->started = true;
+
+ return 0;
+fail_vq:
+ while (--i >= 0) {
+ vhost_virtqueue_cleanup(hdev,
+ vdev,
+ hdev->vqs + i,
+ i);
+ }
+fail:
+ return r;
+}
+
+void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
+{
+ int i;
+ for (i = 0; i < hdev->nvqs; ++i) {
+ vhost_virtqueue_cleanup(hdev,
+ vdev,
+ hdev->vqs + i,
+ i);
+ }
+ vhost_client_sync_dirty_bitmap(&hdev->client, 0,
+ (target_phys_addr_t)~0x0ull);
+ hdev->started = false;
+ qemu_free(hdev->log);
+ hdev->log_size = 0;
+}
diff --git a/hw/vhost.h b/hw/vhost.h
new file mode 100644
index 0000000..2ed3933
--- /dev/null
+++ b/hw/vhost.h
@@ -0,0 +1,44 @@
+#ifndef VHOST_H
+#define VHOST_H
+
+#include "hw/hw.h"
+#include "hw/virtio.h"
+
+/* Generic structures common for any vhost based device. */
+struct vhost_virtqueue {
+ int kick;
+ int call;
+ void *desc;
+ void *avail;
+ void *used;
+ int num;
+ unsigned long long used_phys;
+};
+
+typedef unsigned long vhost_log_chunk_t;
+#define VHOST_LOG_PAGE 0x1000
+#define VHOST_LOG_BITS (8 * sizeof(vhost_log_chunk_t))
+#define VHOST_LOG_CHUNK (VHOST_LOG_PAGE * VHOST_LOG_BITS)
+
+struct vhost_memory;
+struct vhost_dev {
+ CPUPhysMemoryClient client;
+ int control;
+ struct vhost_memory *mem;
+ struct vhost_virtqueue *vqs;
+ int nvqs;
+ unsigned long long features;
+ unsigned long long acked_features;
+ unsigned long long backend_features;
+ bool started;
+ bool log_enabled;
+ vhost_log_chunk_t *log;
+ unsigned long long log_size;
+};
+
+int vhost_dev_init(struct vhost_dev *hdev, int devfd);
+void vhost_dev_cleanup(struct vhost_dev *hdev);
+int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
+void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
+
+#endif
diff --git a/hw/vhost_net.c b/hw/vhost_net.c
new file mode 100644
index 0000000..c89ff40
--- /dev/null
+++ b/hw/vhost_net.c
@@ -0,0 +1,147 @@
+#include <sys/eventfd.h>
+#include <sys/socket.h>
+#include <linux/kvm.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/vhost.h>
+#include <linux/virtio_ring.h>
+#include <netpacket/packet.h>
+#include <net/ethernet.h>
+#include <net/if.h>
+#include <netinet/in.h>
+
+#include <stdio.h>
+
+#include "net.h"
+#include "net/tap.h"
+
+#include "virtio-net.h"
+#include "vhost.h"
+#include "vhost_net.h"
+
+struct vhost_net {
+ struct vhost_dev dev;
+ struct vhost_virtqueue vqs[2];
+ int backend;
+ VLANClientState *vc;
+};
+
+unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
+{
+ /* Clear features not supported by host kernel. */
+ if (!(net->dev.features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)))
+ features &= ~(1 << VIRTIO_F_NOTIFY_ON_EMPTY);
+ if (!(net->dev.features & (1 << VIRTIO_RING_F_INDIRECT_DESC)))
+ features &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC);
+ if (!(net->dev.features & (1 << VIRTIO_NET_F_MRG_RXBUF)))
+ features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
+ return features;
+}
+
+void vhost_net_ack_features(struct vhost_net *net, unsigned features)
+{
+ net->dev.acked_features = net->dev.backend_features;
+ if (features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY))
+ net->dev.acked_features |= (1 << VIRTIO_F_NOTIFY_ON_EMPTY);
+ if (features & (1 << VIRTIO_RING_F_INDIRECT_DESC))
+ net->dev.acked_features |= (1 << VIRTIO_RING_F_INDIRECT_DESC);
+}
+
+static int vhost_net_get_fd(VLANClientState *backend)
+{
+ switch (backend->info->type) {
+ case NET_CLIENT_TYPE_TAP:
+ return tap_get_fd(backend);
+ default:
+ fprintf(stderr, "vhost-net requires tap backend\n");
+ return -EBADFD;
+ }
+}
+
+struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd)
+{
+ int r;
+ struct vhost_net *net = qemu_malloc(sizeof *net);
+ if (!backend) {
+ fprintf(stderr, "vhost-net requires backend to be setup\n");
+ goto fail;
+ }
+ r = vhost_net_get_fd(backend);
+ if (r < 0)
+ goto fail;
+ net->vc = backend;
+ net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 :
+ (1 << VHOST_NET_F_VIRTIO_NET_HDR);
+ net->backend = r;
+
+ r = vhost_dev_init(&net->dev, devfd);
+ if (r < 0)
+ goto fail;
+ if (~net->dev.features & net->dev.backend_features) {
+ fprintf(stderr, "vhost lacks feature mask %llu for backend\n",
+ ~net->dev.features & net->dev.backend_features);
+ vhost_dev_cleanup(&net->dev);
+ goto fail;
+ }
+
+ /* Set sane init value. Override when guest acks. */
+ vhost_net_ack_features(net, 0);
+ return net;
+fail:
+ qemu_free(net);
+ return NULL;
+}
+
+int vhost_net_start(struct vhost_net *net,
+ VirtIODevice *dev)
+{
+ struct vhost_vring_file file = { };
+ int r;
+
+ net->dev.nvqs = 2;
+ net->dev.vqs = net->vqs;
+ r = vhost_dev_start(&net->dev, dev);
+ if (r < 0)
+ return r;
+
+ net->vc->info->poll(net->vc, false);
+ qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
+ file.fd = net->backend;
+ for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
+ r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
+ if (r < 0) {
+ r = -errno;
+ goto fail;
+ }
+ }
+ return 0;
+fail:
+ file.fd = -1;
+ while (--file.index >= 0) {
+ int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
+ assert(r >= 0);
+ }
+ net->vc->info->poll(net->vc, true);
+ vhost_dev_stop(&net->dev, dev);
+ return r;
+}
+
+void vhost_net_stop(struct vhost_net *net,
+ VirtIODevice *dev)
+{
+ struct vhost_vring_file file = { .fd = -1 };
+
+ for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
+ int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
+ assert(r >= 0);
+ }
+ net->vc->info->poll(net->vc, true);
+ vhost_dev_stop(&net->dev, dev);
+}
+
+void vhost_net_cleanup(struct vhost_net *net)
+{
+ vhost_dev_cleanup(&net->dev);
+ qemu_free(net);
+}
+/* TODO: log */
diff --git a/hw/vhost_net.h b/hw/vhost_net.h
new file mode 100644
index 0000000..21f0277
--- /dev/null
+++ b/hw/vhost_net.h
@@ -0,0 +1,20 @@
+#ifndef VHOST_NET_H
+#define VHOST_NET_H
+
+#include "net.h"
+
+struct vhost_net;
+
+struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd);
+
+int vhost_net_start(struct vhost_net *net,
+ VirtIODevice *dev);
+void vhost_net_stop(struct vhost_net *net,
+ VirtIODevice *dev);
+
+void vhost_net_cleanup(struct vhost_net *net);
+
+unsigned vhost_net_get_features(struct vhost_net *net, unsigned features);
+void vhost_net_ack_features(struct vhost_net *net, unsigned features);
+
+#endif
--
1.6.6.144.g5c3af
--
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