| Message ID | 20180525110441.7185-4-tiwei.bie@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | Support host notifiers in vhost-user | expand |
On 2018年05月25日 19:04, Tiwei Bie wrote: > This patch introduces VHOST_USER_PROTOCOL_F_HOST_NOTIFIER. > With this feature negotiated, vhost-user backend can register > memory region based host notifiers. And it will allow the guest > driver in the VM to notify the hardware accelerator at the > vhost-user backend directly. > > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> > --- > docs/interop/vhost-user.txt | 33 +++++++++ > hw/virtio/vhost-user.c | 123 +++++++++++++++++++++++++++++++++ > include/hw/virtio/vhost-user.h | 8 +++ > 3 files changed, 164 insertions(+) > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt > index 534caab18a..9e57b36b20 100644 > --- a/docs/interop/vhost-user.txt > +++ b/docs/interop/vhost-user.txt > @@ -132,6 +132,16 @@ Depending on the request type, payload can be: > Payload: Size bytes array holding the contents of the virtio > device's configuration space > > + * Vring area description > + ----------------------- > + | u64 | size | offset | > + ----------------------- > + > + u64: a 64-bit integer contains vring index and flags > + Size: a 64-bit size of this area > + Offset: a 64-bit offset of this area from the start of the > + supplied file descriptor > + > In QEMU the vhost-user message is implemented with the following struct: > > typedef struct VhostUserMsg { > @@ -146,6 +156,7 @@ typedef struct VhostUserMsg { > VhostUserLog log; > struct vhost_iotlb_msg iotlb; > VhostUserConfig config; > + VhostUserVringArea area; > }; > } QEMU_PACKED VhostUserMsg; > > @@ -380,6 +391,7 @@ Protocol features > #define VHOST_USER_PROTOCOL_F_CRYPTO_SESSION 7 > #define VHOST_USER_PROTOCOL_F_PAGEFAULT 8 > #define VHOST_USER_PROTOCOL_F_CONFIG 9 > +#define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER 10 > > Master message types > -------------------- > @@ -777,6 +789,27 @@ Slave message types > the VHOST_USER_NEED_REPLY flag, master must respond with zero when > operation is successfully completed, or non-zero otherwise. > > + * VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG > + > + Id: 3 > + Equivalent ioctl: N/A > + Slave payload: vring area description > + Master payload: N/A > + > + Sets host notifier for a specified queue. The queue index is contained > + in the u64 field of the vring area description. The host notifier is > + described by the file descriptor (typically it's a VFIO device fd) which > + is passed as ancillary data and the size (which is mmap size and should > + be the same as host page size) and offset (which is mmap offset) carried > + in the vring area description. QEMU can mmap the file descriptor based > + on the size and offset to get a memory range. Registering a host notifier > + means mapping this memory range to the VM as the specified queue's notify > + MMIO region. Slave sends this request to tell QEMU to de-register the > + existing notifier if any and register the new notifier if the request is > + sent with a file descriptor. > + This request should be sent only when VHOST_USER_PROTOCOL_F_HOST_NOTIFIER > + protocol feature has been successfully negotiated. > + > VHOST_USER_PROTOCOL_F_REPLY_ACK: > ------------------------------- > The original vhost-user specification only demands replies for certain > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > index 5f72ed68da..259a841af9 100644 > --- a/hw/virtio/vhost-user.c > +++ b/hw/virtio/vhost-user.c > @@ -13,6 +13,7 @@ > #include "hw/virtio/vhost.h" > #include "hw/virtio/vhost-user.h" > #include "hw/virtio/vhost-backend.h" > +#include "hw/virtio/virtio.h" > #include "hw/virtio/virtio-net.h" > #include "chardev/char-fe.h" > #include "sysemu/kvm.h" > @@ -48,6 +49,7 @@ enum VhostUserProtocolFeature { > VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7, > VHOST_USER_PROTOCOL_F_PAGEFAULT = 8, > VHOST_USER_PROTOCOL_F_CONFIG = 9, > + VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 10, > VHOST_USER_PROTOCOL_F_MAX > }; > > @@ -92,6 +94,7 @@ typedef enum VhostUserSlaveRequest { > VHOST_USER_SLAVE_NONE = 0, > VHOST_USER_SLAVE_IOTLB_MSG = 1, > VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2, > + VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3, > VHOST_USER_SLAVE_MAX > } VhostUserSlaveRequest; > > @@ -136,6 +139,12 @@ static VhostUserConfig c __attribute__ ((unused)); > + sizeof(c.size) \ > + sizeof(c.flags)) > > +typedef struct VhostUserVringArea { > + uint64_t u64; > + uint64_t size; > + uint64_t offset; > +} VhostUserVringArea; > + > typedef struct { > VhostUserRequest request; > > @@ -157,6 +166,7 @@ typedef union { > struct vhost_iotlb_msg iotlb; > VhostUserConfig config; > VhostUserCryptoSession session; > + VhostUserVringArea area; > } VhostUserPayload; > > typedef struct VhostUserMsg { > @@ -638,9 +648,37 @@ static int vhost_user_set_vring_num(struct vhost_dev *dev, > return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring); > } > > +static void vhost_user_host_notifier_restore(struct vhost_dev *dev, > + int queue_idx) > +{ > + struct vhost_user *u = dev->opaque; > + VhostUserHostNotifier *n = &u->user->notifier[queue_idx]; > + VirtIODevice *vdev = dev->vdev; > + > + if (n->addr && !n->set) { > + virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true); > + n->set = true; > + } > +} > + > +static void vhost_user_host_notifier_remove(struct vhost_dev *dev, > + int queue_idx) > +{ > + struct vhost_user *u = dev->opaque; > + VhostUserHostNotifier *n = &u->user->notifier[queue_idx]; > + VirtIODevice *vdev = dev->vdev; > + > + if (n->addr && n->set) { > + virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false); > + n->set = false; > + } > +} > + > static int vhost_user_set_vring_base(struct vhost_dev *dev, > struct vhost_vring_state *ring) > { > + vhost_user_host_notifier_restore(dev, ring->index); > + > return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring); > } > > @@ -674,6 +712,8 @@ static int vhost_user_get_vring_base(struct vhost_dev *dev, > .hdr.size = sizeof(msg.payload.state), > }; > > + vhost_user_host_notifier_remove(dev, ring->index); > + > if (vhost_user_write(dev, &msg, NULL, 0) < 0) { > return -1; > } > @@ -847,6 +887,76 @@ static int vhost_user_slave_handle_config_change(struct vhost_dev *dev) > return ret; > } > > +static int vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev, > + VhostUserVringArea *area, > + int fd) > +{ > + int queue_idx = area->u64 & VHOST_USER_VRING_IDX_MASK; > + size_t page_size = qemu_real_host_page_size; > + struct vhost_user *u = dev->opaque; > + VhostUserState *user = u->user; > + VirtIODevice *vdev = dev->vdev; > + VhostUserHostNotifier *n; > + int ret = 0; > + void *addr; > + char *name; > + > + if (!virtio_has_feature(dev->protocol_features, > + VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) || > + vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) { > + ret = -1; > + goto out; > + } > + > + n = &user->notifier[queue_idx]; > + > + if (n->addr) { > + virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false); > + object_unparent(OBJECT(&n->mr)); > + munmap(n->addr, page_size); > + n->addr = NULL; > + } > + > + if (area->u64 & VHOST_USER_VRING_NOFD_MASK) { > + goto out; > + } > + > + /* Sanity check. */ > + if (area->size != page_size) { > + ret = -1; > + goto out; > + } > + > + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, It looks to me that PROT_WRITE is sufficient here? Thanks > + fd, area->offset); > + if (addr == MAP_FAILED) { > + ret = -1; > + goto out; > + } > + > + name = g_strdup_printf("vhost-user/host-notifier@%p mmaps[%d]", > + user, queue_idx); > + memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name, > + page_size, addr); > + g_free(name); > + > + if (virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true)) { > + munmap(addr, page_size); > + ret = -1; > + goto out; > + } > + > + n->addr = addr; > + n->set = true; > + > +out: > + /* Always close the fd. */ > + if (fd != -1) { > + close(fd); > + } > + return ret; > +} > + > static void slave_read(void *opaque) > { > struct vhost_dev *dev = opaque; > @@ -913,6 +1023,10 @@ static void slave_read(void *opaque) > case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG : > ret = vhost_user_slave_handle_config_change(dev); > break; > + case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG: > + ret = vhost_user_slave_handle_vring_host_notifier(dev, &payload.area, > + fd); > + break; > default: > error_report("Received unexpected msg type."); > if (fd != -1) { > @@ -1641,6 +1755,15 @@ VhostUserState *vhost_user_init(void) > > void vhost_user_cleanup(VhostUserState *user) > { > + int i; > + > + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { > + if (user->notifier[i].addr) { > + object_unparent(OBJECT(&user->notifier[i].mr)); > + munmap(user->notifier[i].addr, qemu_real_host_page_size); > + user->notifier[i].addr = NULL; > + } > + } > } > > const VhostOps user_ops = { > diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h > index eb8bc0d90d..fd660393a0 100644 > --- a/include/hw/virtio/vhost-user.h > +++ b/include/hw/virtio/vhost-user.h > @@ -9,9 +9,17 @@ > #define HW_VIRTIO_VHOST_USER_H > > #include "chardev/char-fe.h" > +#include "hw/virtio/virtio.h" > + > +typedef struct VhostUserHostNotifier { > + MemoryRegion mr; > + void *addr; > + bool set; > +} VhostUserHostNotifier; > > typedef struct VhostUserState { > CharBackend *chr; > + VhostUserHostNotifier notifier[VIRTIO_QUEUE_MAX]; > } VhostUserState; > > VhostUserState *vhost_user_init(void);
On Fri, May 25, 2018 at 07:26:05PM +0800, Jason Wang wrote: > On 2018年05月25日 19:04, Tiwei Bie wrote: [...] > > +static int vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev, > > + VhostUserVringArea *area, > > + int fd) > > +{ > > + int queue_idx = area->u64 & VHOST_USER_VRING_IDX_MASK; > > + size_t page_size = qemu_real_host_page_size; > > + struct vhost_user *u = dev->opaque; > > + VhostUserState *user = u->user; > > + VirtIODevice *vdev = dev->vdev; > > + VhostUserHostNotifier *n; > > + int ret = 0; > > + void *addr; > > + char *name; > > + > > + if (!virtio_has_feature(dev->protocol_features, > > + VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) || > > + vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) { > > + ret = -1; > > + goto out; > > + } > > + > > + n = &user->notifier[queue_idx]; > > + > > + if (n->addr) { > > + virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false); > > + object_unparent(OBJECT(&n->mr)); > > + munmap(n->addr, page_size); > > + n->addr = NULL; > > + } > > + > > + if (area->u64 & VHOST_USER_VRING_NOFD_MASK) { > > + goto out; > > + } > > + > > + /* Sanity check. */ > > + if (area->size != page_size) { > > + ret = -1; > > + goto out; > > + } > > + > > + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, > > It looks to me that PROT_WRITE is sufficient here? > > Thanks > I think it's safer to add PROT_READ. And there's no harm to do that. Best regards, Tiwei Bie
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt index 534caab18a..9e57b36b20 100644 --- a/docs/interop/vhost-user.txt +++ b/docs/interop/vhost-user.txt @@ -132,6 +132,16 @@ Depending on the request type, payload can be: Payload: Size bytes array holding the contents of the virtio device's configuration space + * Vring area description + ----------------------- + | u64 | size | offset | + ----------------------- + + u64: a 64-bit integer contains vring index and flags + Size: a 64-bit size of this area + Offset: a 64-bit offset of this area from the start of the + supplied file descriptor + In QEMU the vhost-user message is implemented with the following struct: typedef struct VhostUserMsg { @@ -146,6 +156,7 @@ typedef struct VhostUserMsg { VhostUserLog log; struct vhost_iotlb_msg iotlb; VhostUserConfig config; + VhostUserVringArea area; }; } QEMU_PACKED VhostUserMsg; @@ -380,6 +391,7 @@ Protocol features #define VHOST_USER_PROTOCOL_F_CRYPTO_SESSION 7 #define VHOST_USER_PROTOCOL_F_PAGEFAULT 8 #define VHOST_USER_PROTOCOL_F_CONFIG 9 +#define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER 10 Master message types -------------------- @@ -777,6 +789,27 @@ Slave message types the VHOST_USER_NEED_REPLY flag, master must respond with zero when operation is successfully completed, or non-zero otherwise. + * VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG + + Id: 3 + Equivalent ioctl: N/A + Slave payload: vring area description + Master payload: N/A + + Sets host notifier for a specified queue. The queue index is contained + in the u64 field of the vring area description. The host notifier is + described by the file descriptor (typically it's a VFIO device fd) which + is passed as ancillary data and the size (which is mmap size and should + be the same as host page size) and offset (which is mmap offset) carried + in the vring area description. QEMU can mmap the file descriptor based + on the size and offset to get a memory range. Registering a host notifier + means mapping this memory range to the VM as the specified queue's notify + MMIO region. Slave sends this request to tell QEMU to de-register the + existing notifier if any and register the new notifier if the request is + sent with a file descriptor. + This request should be sent only when VHOST_USER_PROTOCOL_F_HOST_NOTIFIER + protocol feature has been successfully negotiated. + VHOST_USER_PROTOCOL_F_REPLY_ACK: ------------------------------- The original vhost-user specification only demands replies for certain diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 5f72ed68da..259a841af9 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -13,6 +13,7 @@ #include "hw/virtio/vhost.h" #include "hw/virtio/vhost-user.h" #include "hw/virtio/vhost-backend.h" +#include "hw/virtio/virtio.h" #include "hw/virtio/virtio-net.h" #include "chardev/char-fe.h" #include "sysemu/kvm.h" @@ -48,6 +49,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7, VHOST_USER_PROTOCOL_F_PAGEFAULT = 8, VHOST_USER_PROTOCOL_F_CONFIG = 9, + VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 10, VHOST_USER_PROTOCOL_F_MAX }; @@ -92,6 +94,7 @@ typedef enum VhostUserSlaveRequest { VHOST_USER_SLAVE_NONE = 0, VHOST_USER_SLAVE_IOTLB_MSG = 1, VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2, + VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3, VHOST_USER_SLAVE_MAX } VhostUserSlaveRequest; @@ -136,6 +139,12 @@ static VhostUserConfig c __attribute__ ((unused)); + sizeof(c.size) \ + sizeof(c.flags)) +typedef struct VhostUserVringArea { + uint64_t u64; + uint64_t size; + uint64_t offset; +} VhostUserVringArea; + typedef struct { VhostUserRequest request; @@ -157,6 +166,7 @@ typedef union { struct vhost_iotlb_msg iotlb; VhostUserConfig config; VhostUserCryptoSession session; + VhostUserVringArea area; } VhostUserPayload; typedef struct VhostUserMsg { @@ -638,9 +648,37 @@ static int vhost_user_set_vring_num(struct vhost_dev *dev, return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring); } +static void vhost_user_host_notifier_restore(struct vhost_dev *dev, + int queue_idx) +{ + struct vhost_user *u = dev->opaque; + VhostUserHostNotifier *n = &u->user->notifier[queue_idx]; + VirtIODevice *vdev = dev->vdev; + + if (n->addr && !n->set) { + virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true); + n->set = true; + } +} + +static void vhost_user_host_notifier_remove(struct vhost_dev *dev, + int queue_idx) +{ + struct vhost_user *u = dev->opaque; + VhostUserHostNotifier *n = &u->user->notifier[queue_idx]; + VirtIODevice *vdev = dev->vdev; + + if (n->addr && n->set) { + virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false); + n->set = false; + } +} + static int vhost_user_set_vring_base(struct vhost_dev *dev, struct vhost_vring_state *ring) { + vhost_user_host_notifier_restore(dev, ring->index); + return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring); } @@ -674,6 +712,8 @@ static int vhost_user_get_vring_base(struct vhost_dev *dev, .hdr.size = sizeof(msg.payload.state), }; + vhost_user_host_notifier_remove(dev, ring->index); + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { return -1; } @@ -847,6 +887,76 @@ static int vhost_user_slave_handle_config_change(struct vhost_dev *dev) return ret; } +static int vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev, + VhostUserVringArea *area, + int fd) +{ + int queue_idx = area->u64 & VHOST_USER_VRING_IDX_MASK; + size_t page_size = qemu_real_host_page_size; + struct vhost_user *u = dev->opaque; + VhostUserState *user = u->user; + VirtIODevice *vdev = dev->vdev; + VhostUserHostNotifier *n; + int ret = 0; + void *addr; + char *name; + + if (!virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) || + vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) { + ret = -1; + goto out; + } + + n = &user->notifier[queue_idx]; + + if (n->addr) { + virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false); + object_unparent(OBJECT(&n->mr)); + munmap(n->addr, page_size); + n->addr = NULL; + } + + if (area->u64 & VHOST_USER_VRING_NOFD_MASK) { + goto out; + } + + /* Sanity check. */ + if (area->size != page_size) { + ret = -1; + goto out; + } + + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, + fd, area->offset); + if (addr == MAP_FAILED) { + ret = -1; + goto out; + } + + name = g_strdup_printf("vhost-user/host-notifier@%p mmaps[%d]", + user, queue_idx); + memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name, + page_size, addr); + g_free(name); + + if (virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true)) { + munmap(addr, page_size); + ret = -1; + goto out; + } + + n->addr = addr; + n->set = true; + +out: + /* Always close the fd. */ + if (fd != -1) { + close(fd); + } + return ret; +} + static void slave_read(void *opaque) { struct vhost_dev *dev = opaque; @@ -913,6 +1023,10 @@ static void slave_read(void *opaque) case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG : ret = vhost_user_slave_handle_config_change(dev); break; + case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG: + ret = vhost_user_slave_handle_vring_host_notifier(dev, &payload.area, + fd); + break; default: error_report("Received unexpected msg type."); if (fd != -1) { @@ -1641,6 +1755,15 @@ VhostUserState *vhost_user_init(void) void vhost_user_cleanup(VhostUserState *user) { + int i; + + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { + if (user->notifier[i].addr) { + object_unparent(OBJECT(&user->notifier[i].mr)); + munmap(user->notifier[i].addr, qemu_real_host_page_size); + user->notifier[i].addr = NULL; + } + } } const VhostOps user_ops = { diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h index eb8bc0d90d..fd660393a0 100644 --- a/include/hw/virtio/vhost-user.h +++ b/include/hw/virtio/vhost-user.h @@ -9,9 +9,17 @@ #define HW_VIRTIO_VHOST_USER_H #include "chardev/char-fe.h" +#include "hw/virtio/virtio.h" + +typedef struct VhostUserHostNotifier { + MemoryRegion mr; + void *addr; + bool set; +} VhostUserHostNotifier; typedef struct VhostUserState { CharBackend *chr; + VhostUserHostNotifier notifier[VIRTIO_QUEUE_MAX]; } VhostUserState; VhostUserState *vhost_user_init(void);
This patch introduces VHOST_USER_PROTOCOL_F_HOST_NOTIFIER. With this feature negotiated, vhost-user backend can register memory region based host notifiers. And it will allow the guest driver in the VM to notify the hardware accelerator at the vhost-user backend directly. Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> --- docs/interop/vhost-user.txt | 33 +++++++++ hw/virtio/vhost-user.c | 123 +++++++++++++++++++++++++++++++++ include/hw/virtio/vhost-user.h | 8 +++ 3 files changed, 164 insertions(+)