| Message ID | 20190103101819.7418-3-xieyongji@baidu.com |
|---|---|
| State | New |
| Headers | show |
| Series | vhost-user-blk: Add support for backend reconnecting | expand |
On Thu, Jan 03, 2019 at 06:18:14PM +0800, elohimes@gmail.com wrote: > From: Xie Yongji <xieyongji@baidu.com> > > This patch introduces two new messages VHOST_USER_GET_SHM_SIZE > and VHOST_USER_SET_SHM_FD to support providing shared > memory to backend. So this seems a bit vague. Since we are going to use it for tracking in-flight I/O I would prefer it that we actually call it that. > > Firstly, qemu uses VHOST_USER_GET_SHM_SIZE to get the > required size of shared memory from backend. Then, qemu > allocates memory and sends them s/them/it/ ? > back to backend through > VHOST_USER_SET_SHM_FD. > > Note that the shared memory should be used to record > inflight I/O by backend. Qemu will clear it when vm reset. > > Signed-off-by: Xie Yongji <xieyongji@baidu.com> > Signed-off-by: Chai Wen <chaiwen@baidu.com> > Signed-off-by: Zhang Yu <zhangyu31@baidu.com> > --- > docs/interop/vhost-user.txt | 41 +++++++++++ > hw/virtio/vhost-user.c | 86 ++++++++++++++++++++++ > hw/virtio/vhost.c | 117 ++++++++++++++++++++++++++++++ > include/hw/virtio/vhost-backend.h | 9 +++ > include/hw/virtio/vhost.h | 19 +++++ > 5 files changed, 272 insertions(+) > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt > index c2194711d9..5ee9c28ab0 100644 > --- a/docs/interop/vhost-user.txt > +++ b/docs/interop/vhost-user.txt > @@ -142,6 +142,19 @@ Depending on the request type, payload can be: > Offset: a 64-bit offset of this area from the start of the > supplied file descriptor > > + * Shm description > + ----------------------------------- > + | mmap_size | mmap_offset | dev_size | vq_size | align | version | > + ----------------------------------- > + > + Mmap_size: a 64-bit size of the shared memory > + Mmap_offset: a 64-bit offset of the shared memory from the start > + of the supplied file descriptor > + Dev_size: a 32-bit size of device region in shared memory > + Vq_size: a 32-bit size of each virtqueue region in shared memory > + Align: a 32-bit align of each region in shared memory > + Version: a 32-bit version of this shared memory > + This is an informal description so please avoid _ in field names, just put a space in there. See e.g. log description. > In QEMU the vhost-user message is implemented with the following struct: > > typedef struct VhostUserMsg { For things to work, in-flight format must not change when backend reconnects. To encourage consistency, how about including a recommended format for this buffer in this document? > @@ -157,6 +170,7 @@ typedef struct VhostUserMsg { > struct vhost_iotlb_msg iotlb; > VhostUserConfig config; > VhostUserVringArea area; > + VhostUserShm shm; > }; > } QEMU_PACKED VhostUserMsg; > > @@ -175,6 +189,7 @@ the ones that do: > * VHOST_USER_GET_PROTOCOL_FEATURES > * VHOST_USER_GET_VRING_BASE > * VHOST_USER_SET_LOG_BASE (if VHOST_USER_PROTOCOL_F_LOG_SHMFD) > + * VHOST_USER_GET_SHM_SIZE (if VHOST_USER_PROTOCOL_F_SLAVE_SHMFD) > > [ Also see the section on REPLY_ACK protocol extension. ] > > @@ -188,6 +203,7 @@ in the ancillary data: > * VHOST_USER_SET_VRING_CALL > * VHOST_USER_SET_VRING_ERR > * VHOST_USER_SET_SLAVE_REQ_FD > + * VHOST_USER_SET_SHM_FD (if VHOST_USER_PROTOCOL_F_SLAVE_SHMFD) > > If Master is unable to send the full message or receives a wrong reply it will > close the connection. An optional reconnection mechanism can be implemented. > @@ -397,6 +413,7 @@ Protocol features > #define VHOST_USER_PROTOCOL_F_CONFIG 9 > #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD 10 > #define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER 11 > +#define VHOST_USER_PROTOCOL_F_SLAVE_SHMFD 12 > > Master message types > -------------------- > @@ -761,6 +778,30 @@ Master message types > was previously sent. > The value returned is an error indication; 0 is success. > > + * VHOST_USER_GET_SHM_SIZE > + Id: 31 > + Equivalent ioctl: N/A > + Master payload: shm description > + > + When VHOST_USER_PROTOCOL_F_SLAVE_SHMFD protocol feature has been > + successfully negotiated, master need to provide a shared memory to > + slave. This message is used by master to get required size from slave. > + The shared memory contains one region for device and several regions > + for virtqueue. The size of those two kinds of regions is specified > + by dev_size field and vq_size filed. The align field specify the alignment > + of those regions. > + > + * VHOST_USER_SET_SHM_FD > + Id: 32 > + Equivalent ioctl: N/A > + Master payload: shm description > + > + When VHOST_USER_PROTOCOL_F_SLAVE_SHMFD protocol feature has been > + successfully negotiated, master uses this message to set shared memory > + for slave. The memory fd is passed in the ancillary data. The shared > + memory should be used to record inflight I/O by slave. And master will > + clear it when vm reset. > + > Slave message types > ------------------- > > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > index e09bed0e4a..8cdf3b5121 100644 > --- a/hw/virtio/vhost-user.c > +++ b/hw/virtio/vhost-user.c > @@ -52,6 +52,7 @@ enum VhostUserProtocolFeature { > VHOST_USER_PROTOCOL_F_CONFIG = 9, > VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10, > VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11, > + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD = 12, > VHOST_USER_PROTOCOL_F_MAX > }; > > @@ -89,6 +90,8 @@ typedef enum VhostUserRequest { > VHOST_USER_POSTCOPY_ADVISE = 28, > VHOST_USER_POSTCOPY_LISTEN = 29, > VHOST_USER_POSTCOPY_END = 30, > + VHOST_USER_GET_SHM_SIZE = 31, > + VHOST_USER_SET_SHM_FD = 32, > VHOST_USER_MAX > } VhostUserRequest; > > @@ -147,6 +150,15 @@ typedef struct VhostUserVringArea { > uint64_t offset; > } VhostUserVringArea; > > +typedef struct VhostUserShm { > + uint64_t mmap_size; > + uint64_t mmap_offset; > + uint32_t dev_size; > + uint32_t vq_size; > + uint32_t align; > + uint32_t version; > +} VhostUserShm; > + > typedef struct { > VhostUserRequest request; > > @@ -169,6 +181,7 @@ typedef union { > VhostUserConfig config; > VhostUserCryptoSession session; > VhostUserVringArea area; > + VhostUserShm shm; > } VhostUserPayload; > > typedef struct VhostUserMsg { > @@ -1739,6 +1752,77 @@ static bool vhost_user_mem_section_filter(struct vhost_dev *dev, > return result; > } > > +static int vhost_user_get_shm_size(struct vhost_dev *dev, > + struct vhost_shm *shm) > +{ > + VhostUserMsg msg = { > + .hdr.request = VHOST_USER_GET_SHM_SIZE, > + .hdr.flags = VHOST_USER_VERSION, > + .hdr.size = sizeof(msg.payload.shm), > + }; > + > + if (!virtio_has_feature(dev->protocol_features, > + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD)) { > + shm->dev_size = 0; > + shm->vq_size = 0; > + return 0; > + } > + > + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { > + return -1; > + } > + > + if (vhost_user_read(dev, &msg) < 0) { > + return -1; > + } > + > + if (msg.hdr.request != VHOST_USER_GET_SHM_SIZE) { > + error_report("Received unexpected msg type. " > + "Expected %d received %d", > + VHOST_USER_GET_SHM_SIZE, msg.hdr.request); > + return -1; > + } > + > + if (msg.hdr.size != sizeof(msg.payload.shm)) { > + error_report("Received bad msg size."); > + return -1; > + } > + > + shm->dev_size = msg.payload.shm.dev_size; > + shm->vq_size = msg.payload.shm.vq_size; > + shm->align = msg.payload.shm.align; > + shm->version = msg.payload.shm.version; > + > + return 0; > +} > + > +static int vhost_user_set_shm_fd(struct vhost_dev *dev, > + struct vhost_shm *shm) > +{ > + VhostUserMsg msg = { > + .hdr.request = VHOST_USER_SET_SHM_FD, > + .hdr.flags = VHOST_USER_VERSION, > + .payload.shm.mmap_size = shm->mmap_size, > + .payload.shm.mmap_offset = 0, > + .payload.shm.dev_size = shm->dev_size, > + .payload.shm.vq_size = shm->vq_size, > + .payload.shm.align = shm->align, > + .payload.shm.version = shm->version, > + .hdr.size = sizeof(msg.payload.shm), > + }; > + > + if (!virtio_has_feature(dev->protocol_features, > + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD)) { > + return 0; > + } > + > + if (vhost_user_write(dev, &msg, &shm->fd, 1) < 0) { > + return -1; > + } > + > + return 0; > +} > + > VhostUserState *vhost_user_init(void) > { > VhostUserState *user = g_new0(struct VhostUserState, 1); > @@ -1790,4 +1874,6 @@ const VhostOps user_ops = { > .vhost_crypto_create_session = vhost_user_crypto_create_session, > .vhost_crypto_close_session = vhost_user_crypto_close_session, > .vhost_backend_mem_section_filter = vhost_user_mem_section_filter, > + .vhost_get_shm_size = vhost_user_get_shm_size, > + .vhost_set_shm_fd = vhost_user_set_shm_fd, > }; > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index 569c4053ea..7a38fed50f 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -1481,6 +1481,123 @@ void vhost_dev_set_config_notifier(struct vhost_dev *hdev, > hdev->config_ops = ops; > } > > +void vhost_dev_reset_shm(struct vhost_shm *shm) > +{ > + if (shm->addr) { > + memset(shm->addr, 0, shm->mmap_size); > + } > +} > + > +void vhost_dev_free_shm(struct vhost_shm *shm) > +{ > + if (shm->addr) { > + qemu_memfd_free(shm->addr, shm->mmap_size, shm->fd); > + shm->addr = NULL; > + shm->fd = -1; > + } > +} > + > +int vhost_dev_alloc_shm(struct vhost_shm *shm) > +{ > + Error *err = NULL; > + int fd = -1; > + void *addr = qemu_memfd_alloc("vhost-shm", shm->mmap_size, > + F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, > + &fd, &err); > + if (err) { > + error_report_err(err); > + return -1; > + } > + > + shm->addr = addr; > + shm->fd = fd; > + > + return 0; > +} > + > +void vhost_dev_save_shm(struct vhost_shm *shm, QEMUFile *f) > +{ > + if (shm->addr) { > + qemu_put_be64(f, shm->mmap_size); > + qemu_put_be32(f, shm->dev_size); > + qemu_put_be32(f, shm->vq_size); > + qemu_put_be32(f, shm->align); > + qemu_put_be32(f, shm->version); > + qemu_put_buffer(f, shm->addr, shm->mmap_size); > + } else { > + qemu_put_be64(f, 0); > + } > +} > + > +int vhost_dev_load_shm(struct vhost_shm *shm, QEMUFile *f) > +{ > + uint64_t mmap_size; > + > + mmap_size = qemu_get_be64(f); > + if (!mmap_size) { > + return 0; > + } > + > + vhost_dev_free_shm(shm); > + > + shm->mmap_size = mmap_size; > + shm->dev_size = qemu_get_be32(f); > + shm->vq_size = qemu_get_be32(f); > + shm->align = qemu_get_be32(f); > + shm->version = qemu_get_be32(f); > + > + if (vhost_dev_alloc_shm(shm)) { > + return -ENOMEM; > + } > + > + qemu_get_buffer(f, shm->addr, mmap_size); > + > + return 0; > +} > + > +int vhost_dev_set_shm(struct vhost_dev *dev, struct vhost_shm *shm) > +{ > + int r; > + > + if (dev->vhost_ops->vhost_set_shm_fd && shm->addr) { > + r = dev->vhost_ops->vhost_set_shm_fd(dev, shm); > + if (r) { > + VHOST_OPS_DEBUG("vhost_set_vring_shm_fd failed"); > + return -errno; > + } > + } > + > + return 0; > +} > + > +int vhost_dev_init_shm(struct vhost_dev *dev, struct vhost_shm *shm) > +{ > + int r; > + > + if (dev->vhost_ops->vhost_get_shm_size) { > + r = dev->vhost_ops->vhost_get_shm_size(dev, shm); > + if (r) { > + VHOST_OPS_DEBUG("vhost_get_vring_shm_size failed"); > + return -errno; > + } > + > + if (!shm->dev_size && !shm->vq_size) { > + return 0; > + } > + > + shm->mmap_size = QEMU_ALIGN_UP(shm->dev_size, shm->align) + > + dev->nvqs * QEMU_ALIGN_UP(shm->vq_size, shm->align); > + > + if (vhost_dev_alloc_shm(shm)) { > + return -ENOMEM; > + } > + > + vhost_dev_reset_shm(shm); > + } > + > + return 0; > +} > + > /* Host notifiers must be enabled at this point. */ > int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) > { > diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h > index 81283ec50f..4e7f13c9e9 100644 > --- a/include/hw/virtio/vhost-backend.h > +++ b/include/hw/virtio/vhost-backend.h > @@ -25,6 +25,7 @@ typedef enum VhostSetConfigType { > VHOST_SET_CONFIG_TYPE_MIGRATION = 1, > } VhostSetConfigType; > > +struct vhost_shm; > struct vhost_dev; > struct vhost_log; > struct vhost_memory; > @@ -104,6 +105,12 @@ typedef int (*vhost_crypto_close_session_op)(struct vhost_dev *dev, > typedef bool (*vhost_backend_mem_section_filter_op)(struct vhost_dev *dev, > MemoryRegionSection *section); > > +typedef int (*vhost_get_shm_size_op)(struct vhost_dev *dev, > + struct vhost_shm *shm); > + > +typedef int (*vhost_set_shm_fd_op)(struct vhost_dev *dev, > + struct vhost_shm *shm); > + > typedef struct VhostOps { > VhostBackendType backend_type; > vhost_backend_init vhost_backend_init; > @@ -142,6 +149,8 @@ typedef struct VhostOps { > vhost_crypto_create_session_op vhost_crypto_create_session; > vhost_crypto_close_session_op vhost_crypto_close_session; > vhost_backend_mem_section_filter_op vhost_backend_mem_section_filter; > + vhost_get_shm_size_op vhost_get_shm_size; > + vhost_set_shm_fd_op vhost_set_shm_fd; > } VhostOps; > > extern const VhostOps user_ops; > diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h > index a7f449fa87..b6e3d6ab56 100644 > --- a/include/hw/virtio/vhost.h > +++ b/include/hw/virtio/vhost.h > @@ -7,6 +7,17 @@ > #include "exec/memory.h" > > /* Generic structures common for any vhost based device. */ > + > +struct vhost_shm { > + void *addr; > + uint64_t mmap_size; > + uint32_t dev_size; > + uint32_t vq_size; > + uint32_t align; > + uint32_t version; > + int fd; > +}; > + > struct vhost_virtqueue { > int kick; > int call; > @@ -120,4 +131,12 @@ int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data, > */ > void vhost_dev_set_config_notifier(struct vhost_dev *dev, > const VhostDevConfigOps *ops); > + > +void vhost_dev_reset_shm(struct vhost_shm *shm); > +void vhost_dev_free_shm(struct vhost_shm *shm); > +int vhost_dev_alloc_shm(struct vhost_shm *shm); > +void vhost_dev_save_shm(struct vhost_shm *shm, QEMUFile *f); > +int vhost_dev_load_shm(struct vhost_shm *shm, QEMUFile *f); > +int vhost_dev_set_shm(struct vhost_dev *dev, struct vhost_shm *shm); > +int vhost_dev_init_shm(struct vhost_dev *dev, struct vhost_shm *shm); > #endif > -- > 2.17.1
On Thu, Jan 03, 2019 at 06:18:14PM +0800, elohimes@gmail.com wrote: > From: Xie Yongji <xieyongji@baidu.com> > > This patch introduces two new messages VHOST_USER_GET_SHM_SIZE > and VHOST_USER_SET_SHM_FD to support providing shared > memory to backend. > > Firstly, qemu uses VHOST_USER_GET_SHM_SIZE to get the > required size of shared memory from backend. Then, qemu > allocates memory and sends them back to backend through > VHOST_USER_SET_SHM_FD. So this does create a security concern that remote can supply a very big area. How about returning a buffer from client to qemu? > Note that the shared memory should be used to record > inflight I/O by backend. Qemu will clear it when vm reset. > > Signed-off-by: Xie Yongji <xieyongji@baidu.com> > Signed-off-by: Chai Wen <chaiwen@baidu.com> > Signed-off-by: Zhang Yu <zhangyu31@baidu.com> > --- > docs/interop/vhost-user.txt | 41 +++++++++++ > hw/virtio/vhost-user.c | 86 ++++++++++++++++++++++ > hw/virtio/vhost.c | 117 ++++++++++++++++++++++++++++++ > include/hw/virtio/vhost-backend.h | 9 +++ > include/hw/virtio/vhost.h | 19 +++++ > 5 files changed, 272 insertions(+) > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt > index c2194711d9..5ee9c28ab0 100644 > --- a/docs/interop/vhost-user.txt > +++ b/docs/interop/vhost-user.txt > @@ -142,6 +142,19 @@ Depending on the request type, payload can be: > Offset: a 64-bit offset of this area from the start of the > supplied file descriptor > > + * Shm description > + ----------------------------------- > + | mmap_size | mmap_offset | dev_size | vq_size | align | version | > + ----------------------------------- > + > + Mmap_size: a 64-bit size of the shared memory > + Mmap_offset: a 64-bit offset of the shared memory from the start > + of the supplied file descriptor > + Dev_size: a 32-bit size of device region in shared memory > + Vq_size: a 32-bit size of each virtqueue region in shared memory > + Align: a 32-bit align of each region in shared memory > + Version: a 32-bit version of this shared memory > + > In QEMU the vhost-user message is implemented with the following struct: > > typedef struct VhostUserMsg { > @@ -157,6 +170,7 @@ typedef struct VhostUserMsg { > struct vhost_iotlb_msg iotlb; > VhostUserConfig config; > VhostUserVringArea area; > + VhostUserShm shm; > }; > } QEMU_PACKED VhostUserMsg; > > @@ -175,6 +189,7 @@ the ones that do: > * VHOST_USER_GET_PROTOCOL_FEATURES > * VHOST_USER_GET_VRING_BASE > * VHOST_USER_SET_LOG_BASE (if VHOST_USER_PROTOCOL_F_LOG_SHMFD) > + * VHOST_USER_GET_SHM_SIZE (if VHOST_USER_PROTOCOL_F_SLAVE_SHMFD) > > [ Also see the section on REPLY_ACK protocol extension. ] > > @@ -188,6 +203,7 @@ in the ancillary data: > * VHOST_USER_SET_VRING_CALL > * VHOST_USER_SET_VRING_ERR > * VHOST_USER_SET_SLAVE_REQ_FD > + * VHOST_USER_SET_SHM_FD (if VHOST_USER_PROTOCOL_F_SLAVE_SHMFD) > > If Master is unable to send the full message or receives a wrong reply it will > close the connection. An optional reconnection mechanism can be implemented. > @@ -397,6 +413,7 @@ Protocol features > #define VHOST_USER_PROTOCOL_F_CONFIG 9 > #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD 10 > #define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER 11 > +#define VHOST_USER_PROTOCOL_F_SLAVE_SHMFD 12 > > Master message types > -------------------- > @@ -761,6 +778,30 @@ Master message types > was previously sent. > The value returned is an error indication; 0 is success. > > + * VHOST_USER_GET_SHM_SIZE > + Id: 31 > + Equivalent ioctl: N/A > + Master payload: shm description > + > + When VHOST_USER_PROTOCOL_F_SLAVE_SHMFD protocol feature has been > + successfully negotiated, master need to provide a shared memory to > + slave. This message is used by master to get required size from slave. > + The shared memory contains one region for device and several regions > + for virtqueue. The size of those two kinds of regions is specified > + by dev_size field and vq_size filed. The align field specify the alignment > + of those regions. > + > + * VHOST_USER_SET_SHM_FD > + Id: 32 > + Equivalent ioctl: N/A > + Master payload: shm description > + > + When VHOST_USER_PROTOCOL_F_SLAVE_SHMFD protocol feature has been > + successfully negotiated, master uses this message to set shared memory > + for slave. The memory fd is passed in the ancillary data. The shared > + memory should be used to record inflight I/O by slave. And master will > + clear it when vm reset. > + > Slave message types > ------------------- > > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > index e09bed0e4a..8cdf3b5121 100644 > --- a/hw/virtio/vhost-user.c > +++ b/hw/virtio/vhost-user.c > @@ -52,6 +52,7 @@ enum VhostUserProtocolFeature { > VHOST_USER_PROTOCOL_F_CONFIG = 9, > VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10, > VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11, > + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD = 12, > VHOST_USER_PROTOCOL_F_MAX > }; > > @@ -89,6 +90,8 @@ typedef enum VhostUserRequest { > VHOST_USER_POSTCOPY_ADVISE = 28, > VHOST_USER_POSTCOPY_LISTEN = 29, > VHOST_USER_POSTCOPY_END = 30, > + VHOST_USER_GET_SHM_SIZE = 31, > + VHOST_USER_SET_SHM_FD = 32, > VHOST_USER_MAX > } VhostUserRequest; > > @@ -147,6 +150,15 @@ typedef struct VhostUserVringArea { > uint64_t offset; > } VhostUserVringArea; > > +typedef struct VhostUserShm { > + uint64_t mmap_size; > + uint64_t mmap_offset; > + uint32_t dev_size; > + uint32_t vq_size; > + uint32_t align; > + uint32_t version; > +} VhostUserShm; > + > typedef struct { > VhostUserRequest request; > > @@ -169,6 +181,7 @@ typedef union { > VhostUserConfig config; > VhostUserCryptoSession session; > VhostUserVringArea area; > + VhostUserShm shm; > } VhostUserPayload; > > typedef struct VhostUserMsg { > @@ -1739,6 +1752,77 @@ static bool vhost_user_mem_section_filter(struct vhost_dev *dev, > return result; > } > > +static int vhost_user_get_shm_size(struct vhost_dev *dev, > + struct vhost_shm *shm) > +{ > + VhostUserMsg msg = { > + .hdr.request = VHOST_USER_GET_SHM_SIZE, > + .hdr.flags = VHOST_USER_VERSION, > + .hdr.size = sizeof(msg.payload.shm), > + }; > + > + if (!virtio_has_feature(dev->protocol_features, > + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD)) { > + shm->dev_size = 0; > + shm->vq_size = 0; > + return 0; > + } > + > + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { > + return -1; > + } > + > + if (vhost_user_read(dev, &msg) < 0) { > + return -1; > + } > + > + if (msg.hdr.request != VHOST_USER_GET_SHM_SIZE) { > + error_report("Received unexpected msg type. " > + "Expected %d received %d", > + VHOST_USER_GET_SHM_SIZE, msg.hdr.request); > + return -1; > + } > + > + if (msg.hdr.size != sizeof(msg.payload.shm)) { > + error_report("Received bad msg size."); > + return -1; > + } > + > + shm->dev_size = msg.payload.shm.dev_size; > + shm->vq_size = msg.payload.shm.vq_size; > + shm->align = msg.payload.shm.align; > + shm->version = msg.payload.shm.version; > + > + return 0; > +} > + > +static int vhost_user_set_shm_fd(struct vhost_dev *dev, > + struct vhost_shm *shm) > +{ > + VhostUserMsg msg = { > + .hdr.request = VHOST_USER_SET_SHM_FD, > + .hdr.flags = VHOST_USER_VERSION, > + .payload.shm.mmap_size = shm->mmap_size, > + .payload.shm.mmap_offset = 0, > + .payload.shm.dev_size = shm->dev_size, > + .payload.shm.vq_size = shm->vq_size, > + .payload.shm.align = shm->align, > + .payload.shm.version = shm->version, > + .hdr.size = sizeof(msg.payload.shm), > + }; > + > + if (!virtio_has_feature(dev->protocol_features, > + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD)) { > + return 0; > + } > + > + if (vhost_user_write(dev, &msg, &shm->fd, 1) < 0) { > + return -1; > + } > + > + return 0; > +} > + > VhostUserState *vhost_user_init(void) > { > VhostUserState *user = g_new0(struct VhostUserState, 1); > @@ -1790,4 +1874,6 @@ const VhostOps user_ops = { > .vhost_crypto_create_session = vhost_user_crypto_create_session, > .vhost_crypto_close_session = vhost_user_crypto_close_session, > .vhost_backend_mem_section_filter = vhost_user_mem_section_filter, > + .vhost_get_shm_size = vhost_user_get_shm_size, > + .vhost_set_shm_fd = vhost_user_set_shm_fd, > }; > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index 569c4053ea..7a38fed50f 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -1481,6 +1481,123 @@ void vhost_dev_set_config_notifier(struct vhost_dev *hdev, > hdev->config_ops = ops; > } > > +void vhost_dev_reset_shm(struct vhost_shm *shm) > +{ > + if (shm->addr) { > + memset(shm->addr, 0, shm->mmap_size); > + } > +} > + > +void vhost_dev_free_shm(struct vhost_shm *shm) > +{ > + if (shm->addr) { > + qemu_memfd_free(shm->addr, shm->mmap_size, shm->fd); > + shm->addr = NULL; > + shm->fd = -1; > + } > +} > + > +int vhost_dev_alloc_shm(struct vhost_shm *shm) > +{ > + Error *err = NULL; > + int fd = -1; > + void *addr = qemu_memfd_alloc("vhost-shm", shm->mmap_size, > + F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, > + &fd, &err); > + if (err) { > + error_report_err(err); > + return -1; > + } > + > + shm->addr = addr; > + shm->fd = fd; > + > + return 0; > +} > + > +void vhost_dev_save_shm(struct vhost_shm *shm, QEMUFile *f) > +{ > + if (shm->addr) { > + qemu_put_be64(f, shm->mmap_size); > + qemu_put_be32(f, shm->dev_size); > + qemu_put_be32(f, shm->vq_size); > + qemu_put_be32(f, shm->align); > + qemu_put_be32(f, shm->version); > + qemu_put_buffer(f, shm->addr, shm->mmap_size); > + } else { > + qemu_put_be64(f, 0); > + } > +} > + > +int vhost_dev_load_shm(struct vhost_shm *shm, QEMUFile *f) > +{ > + uint64_t mmap_size; > + > + mmap_size = qemu_get_be64(f); > + if (!mmap_size) { > + return 0; > + } > + > + vhost_dev_free_shm(shm); > + > + shm->mmap_size = mmap_size; > + shm->dev_size = qemu_get_be32(f); > + shm->vq_size = qemu_get_be32(f); > + shm->align = qemu_get_be32(f); > + shm->version = qemu_get_be32(f); > + > + if (vhost_dev_alloc_shm(shm)) { > + return -ENOMEM; > + } > + > + qemu_get_buffer(f, shm->addr, mmap_size); > + > + return 0; > +} > + > +int vhost_dev_set_shm(struct vhost_dev *dev, struct vhost_shm *shm) > +{ > + int r; > + > + if (dev->vhost_ops->vhost_set_shm_fd && shm->addr) { > + r = dev->vhost_ops->vhost_set_shm_fd(dev, shm); > + if (r) { > + VHOST_OPS_DEBUG("vhost_set_vring_shm_fd failed"); > + return -errno; > + } > + } > + > + return 0; > +} > + > +int vhost_dev_init_shm(struct vhost_dev *dev, struct vhost_shm *shm) > +{ > + int r; > + > + if (dev->vhost_ops->vhost_get_shm_size) { > + r = dev->vhost_ops->vhost_get_shm_size(dev, shm); > + if (r) { > + VHOST_OPS_DEBUG("vhost_get_vring_shm_size failed"); > + return -errno; > + } > + > + if (!shm->dev_size && !shm->vq_size) { > + return 0; > + } > + > + shm->mmap_size = QEMU_ALIGN_UP(shm->dev_size, shm->align) + > + dev->nvqs * QEMU_ALIGN_UP(shm->vq_size, shm->align); > + > + if (vhost_dev_alloc_shm(shm)) { > + return -ENOMEM; > + } > + > + vhost_dev_reset_shm(shm); > + } > + > + return 0; > +} > + > /* Host notifiers must be enabled at this point. */ > int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) > { > diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h > index 81283ec50f..4e7f13c9e9 100644 > --- a/include/hw/virtio/vhost-backend.h > +++ b/include/hw/virtio/vhost-backend.h > @@ -25,6 +25,7 @@ typedef enum VhostSetConfigType { > VHOST_SET_CONFIG_TYPE_MIGRATION = 1, > } VhostSetConfigType; > > +struct vhost_shm; > struct vhost_dev; > struct vhost_log; > struct vhost_memory; > @@ -104,6 +105,12 @@ typedef int (*vhost_crypto_close_session_op)(struct vhost_dev *dev, > typedef bool (*vhost_backend_mem_section_filter_op)(struct vhost_dev *dev, > MemoryRegionSection *section); > > +typedef int (*vhost_get_shm_size_op)(struct vhost_dev *dev, > + struct vhost_shm *shm); > + > +typedef int (*vhost_set_shm_fd_op)(struct vhost_dev *dev, > + struct vhost_shm *shm); > + > typedef struct VhostOps { > VhostBackendType backend_type; > vhost_backend_init vhost_backend_init; > @@ -142,6 +149,8 @@ typedef struct VhostOps { > vhost_crypto_create_session_op vhost_crypto_create_session; > vhost_crypto_close_session_op vhost_crypto_close_session; > vhost_backend_mem_section_filter_op vhost_backend_mem_section_filter; > + vhost_get_shm_size_op vhost_get_shm_size; > + vhost_set_shm_fd_op vhost_set_shm_fd; > } VhostOps; > > extern const VhostOps user_ops; > diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h > index a7f449fa87..b6e3d6ab56 100644 > --- a/include/hw/virtio/vhost.h > +++ b/include/hw/virtio/vhost.h > @@ -7,6 +7,17 @@ > #include "exec/memory.h" > > /* Generic structures common for any vhost based device. */ > + > +struct vhost_shm { > + void *addr; > + uint64_t mmap_size; > + uint32_t dev_size; > + uint32_t vq_size; > + uint32_t align; > + uint32_t version; > + int fd; > +}; > + > struct vhost_virtqueue { > int kick; > int call; > @@ -120,4 +131,12 @@ int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data, > */ > void vhost_dev_set_config_notifier(struct vhost_dev *dev, > const VhostDevConfigOps *ops); > + > +void vhost_dev_reset_shm(struct vhost_shm *shm); > +void vhost_dev_free_shm(struct vhost_shm *shm); > +int vhost_dev_alloc_shm(struct vhost_shm *shm); > +void vhost_dev_save_shm(struct vhost_shm *shm, QEMUFile *f); > +int vhost_dev_load_shm(struct vhost_shm *shm, QEMUFile *f); > +int vhost_dev_set_shm(struct vhost_dev *dev, struct vhost_shm *shm); > +int vhost_dev_init_shm(struct vhost_dev *dev, struct vhost_shm *shm); > #endif > -- > 2.17.1
On Fri, 4 Jan 2019 at 01:02, Michael S. Tsirkin <mst@redhat.com> wrote: > > On Thu, Jan 03, 2019 at 06:18:14PM +0800, elohimes@gmail.com wrote: > > From: Xie Yongji <xieyongji@baidu.com> > > > > This patch introduces two new messages VHOST_USER_GET_SHM_SIZE > > and VHOST_USER_SET_SHM_FD to support providing shared > > memory to backend. > > So this seems a bit vague. Since we are going to use it > for tracking in-flight I/O I would prefer it that we > actually call it that. > > So how about VHOST_USER_GET_INFLIGHT_SIZE and VHOST_USER_SET_INFLIHGT_FD? > > > > Firstly, qemu uses VHOST_USER_GET_SHM_SIZE to get the > > required size of shared memory from backend. Then, qemu > > allocates memory and sends them > > s/them/it/ ? > Will fix it in v4. > > back to backend through > > VHOST_USER_SET_SHM_FD. > > > > Note that the shared memory should be used to record > > inflight I/O by backend. Qemu will clear it when vm reset. > > > > Signed-off-by: Xie Yongji <xieyongji@baidu.com> > > Signed-off-by: Chai Wen <chaiwen@baidu.com> > > Signed-off-by: Zhang Yu <zhangyu31@baidu.com> > > --- > > docs/interop/vhost-user.txt | 41 +++++++++++ > > hw/virtio/vhost-user.c | 86 ++++++++++++++++++++++ > > hw/virtio/vhost.c | 117 ++++++++++++++++++++++++++++++ > > include/hw/virtio/vhost-backend.h | 9 +++ > > include/hw/virtio/vhost.h | 19 +++++ > > 5 files changed, 272 insertions(+) > > > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt > > index c2194711d9..5ee9c28ab0 100644 > > --- a/docs/interop/vhost-user.txt > > +++ b/docs/interop/vhost-user.txt > > @@ -142,6 +142,19 @@ Depending on the request type, payload can be: > > Offset: a 64-bit offset of this area from the start of the > > supplied file descriptor > > > > + * Shm description > > + ----------------------------------- > > + | mmap_size | mmap_offset | dev_size | vq_size | align | version | > > + ----------------------------------- > > + > > + Mmap_size: a 64-bit size of the shared memory > > + Mmap_offset: a 64-bit offset of the shared memory from the start > > + of the supplied file descriptor > > + Dev_size: a 32-bit size of device region in shared memory > > + Vq_size: a 32-bit size of each virtqueue region in shared memory > > + Align: a 32-bit align of each region in shared memory > > + Version: a 32-bit version of this shared memory > > + > > This is an informal description so please avoid _ in field > names, just put a space in there. See e.g. log description. > > Got it! > > In QEMU the vhost-user message is implemented with the following struct: > > > > typedef struct VhostUserMsg { > > > For things to work, in-flight format must not change when > backend reconnects. > I'm not sure whether there will be some cases that we want to add some fields to the inflight area without stopping vm. > To encourage consistency, how about including a recommended format for > this buffer in this document? > > Sure. Will add it in v4. Thanks, Yongji
On Fri, Jan 04, 2019 at 10:31:34AM +0800, Yongji Xie wrote: > On Fri, 4 Jan 2019 at 01:02, Michael S. Tsirkin <mst@redhat.com> wrote: > > > > On Thu, Jan 03, 2019 at 06:18:14PM +0800, elohimes@gmail.com wrote: > > > From: Xie Yongji <xieyongji@baidu.com> > > > > > > This patch introduces two new messages VHOST_USER_GET_SHM_SIZE > > > and VHOST_USER_SET_SHM_FD to support providing shared > > > memory to backend. > > > > So this seems a bit vague. Since we are going to use it > > for tracking in-flight I/O I would prefer it that we > > actually call it that. > > > > > > So how about VHOST_USER_GET_INFLIGHT_SIZE and VHOST_USER_SET_INFLIHGT_FD? Sounds good. > > > > > > Firstly, qemu uses VHOST_USER_GET_SHM_SIZE to get the > > > required size of shared memory from backend. Then, qemu > > > allocates memory and sends them > > > > s/them/it/ ? > > > > Will fix it in v4. > > > > back to backend through > > > VHOST_USER_SET_SHM_FD. > > > > > > Note that the shared memory should be used to record > > > inflight I/O by backend. Qemu will clear it when vm reset. > > > > > > Signed-off-by: Xie Yongji <xieyongji@baidu.com> > > > Signed-off-by: Chai Wen <chaiwen@baidu.com> > > > Signed-off-by: Zhang Yu <zhangyu31@baidu.com> > > > --- > > > docs/interop/vhost-user.txt | 41 +++++++++++ > > > hw/virtio/vhost-user.c | 86 ++++++++++++++++++++++ > > > hw/virtio/vhost.c | 117 ++++++++++++++++++++++++++++++ > > > include/hw/virtio/vhost-backend.h | 9 +++ > > > include/hw/virtio/vhost.h | 19 +++++ > > > 5 files changed, 272 insertions(+) > > > > > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt > > > index c2194711d9..5ee9c28ab0 100644 > > > --- a/docs/interop/vhost-user.txt > > > +++ b/docs/interop/vhost-user.txt > > > @@ -142,6 +142,19 @@ Depending on the request type, payload can be: > > > Offset: a 64-bit offset of this area from the start of the > > > supplied file descriptor > > > > > > + * Shm description > > > + ----------------------------------- > > > + | mmap_size | mmap_offset | dev_size | vq_size | align | version | > > > + ----------------------------------- > > > + > > > + Mmap_size: a 64-bit size of the shared memory > > > + Mmap_offset: a 64-bit offset of the shared memory from the start > > > + of the supplied file descriptor > > > + Dev_size: a 32-bit size of device region in shared memory > > > + Vq_size: a 32-bit size of each virtqueue region in shared memory > > > + Align: a 32-bit align of each region in shared memory > > > + Version: a 32-bit version of this shared memory > > > + > > > > This is an informal description so please avoid _ in field > > names, just put a space in there. See e.g. log description. > > > > > Got it! > > > > In QEMU the vhost-user message is implemented with the following struct: > > > > > > typedef struct VhostUserMsg { > > > > > > For things to work, in-flight format must not change when > > backend reconnects. > > > > I'm not sure whether there will be some cases that we want to add some fields to > the inflight area without stopping vm. Sorry I'm not sure I understand this comment. All I am saying is that when one backend disconnects and another reconnects they must agree on the format, so it's a good idea to document it. > > To encourage consistency, how about including a recommended format for > > this buffer in this document? > > > > > > Sure. Will add it in v4. > > Thanks, > Yongji
On Fri, 4 Jan 2019 at 10:41, Michael S. Tsirkin <mst@redhat.com> wrote: > > On Fri, Jan 04, 2019 at 10:31:34AM +0800, Yongji Xie wrote: > > On Fri, 4 Jan 2019 at 01:02, Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > On Thu, Jan 03, 2019 at 06:18:14PM +0800, elohimes@gmail.com wrote: > > > > From: Xie Yongji <xieyongji@baidu.com> > > > > > > > > This patch introduces two new messages VHOST_USER_GET_SHM_SIZE > > > > and VHOST_USER_SET_SHM_FD to support providing shared > > > > memory to backend. > > > > > > So this seems a bit vague. Since we are going to use it > > > for tracking in-flight I/O I would prefer it that we > > > actually call it that. > > > > > > > > > > So how about VHOST_USER_GET_INFLIGHT_SIZE and VHOST_USER_SET_INFLIHGT_FD? > > Sounds good. > > > > > > > > > Firstly, qemu uses VHOST_USER_GET_SHM_SIZE to get the > > > > required size of shared memory from backend. Then, qemu > > > > allocates memory and sends them > > > > > > s/them/it/ ? > > > > > > > Will fix it in v4. > > > > > > back to backend through > > > > VHOST_USER_SET_SHM_FD. > > > > > > > > Note that the shared memory should be used to record > > > > inflight I/O by backend. Qemu will clear it when vm reset. > > > > > > > > Signed-off-by: Xie Yongji <xieyongji@baidu.com> > > > > Signed-off-by: Chai Wen <chaiwen@baidu.com> > > > > Signed-off-by: Zhang Yu <zhangyu31@baidu.com> > > > > --- > > > > docs/interop/vhost-user.txt | 41 +++++++++++ > > > > hw/virtio/vhost-user.c | 86 ++++++++++++++++++++++ > > > > hw/virtio/vhost.c | 117 ++++++++++++++++++++++++++++++ > > > > include/hw/virtio/vhost-backend.h | 9 +++ > > > > include/hw/virtio/vhost.h | 19 +++++ > > > > 5 files changed, 272 insertions(+) > > > > > > > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt > > > > index c2194711d9..5ee9c28ab0 100644 > > > > --- a/docs/interop/vhost-user.txt > > > > +++ b/docs/interop/vhost-user.txt > > > > @@ -142,6 +142,19 @@ Depending on the request type, payload can be: > > > > Offset: a 64-bit offset of this area from the start of the > > > > supplied file descriptor > > > > > > > > + * Shm description > > > > + ----------------------------------- > > > > + | mmap_size | mmap_offset | dev_size | vq_size | align | version | > > > > + ----------------------------------- > > > > + > > > > + Mmap_size: a 64-bit size of the shared memory > > > > + Mmap_offset: a 64-bit offset of the shared memory from the start > > > > + of the supplied file descriptor > > > > + Dev_size: a 32-bit size of device region in shared memory > > > > + Vq_size: a 32-bit size of each virtqueue region in shared memory > > > > + Align: a 32-bit align of each region in shared memory > > > > + Version: a 32-bit version of this shared memory > > > > + > > > > > > This is an informal description so please avoid _ in field > > > names, just put a space in there. See e.g. log description. > > > > > > > > Got it! > > > > > > In QEMU the vhost-user message is implemented with the following struct: > > > > > > > > typedef struct VhostUserMsg { > > > > > > > > > For things to work, in-flight format must not change when > > > backend reconnects. > > > > > > > I'm not sure whether there will be some cases that we want to add some fields to > > the inflight area without stopping vm. > > Sorry I'm not sure I understand this comment. All I am saying is that > when one backend disconnects and another reconnects they must agree on > the format, so it's a good idea to document it. > Oh, sorry. I may have misunderstood. I will document the format in v4. Thank you. Thanks, Yongji
On Fri, 4 Jan 2019 at 01:13, Michael S. Tsirkin <mst@redhat.com> wrote: > > On Thu, Jan 03, 2019 at 06:18:14PM +0800, elohimes@gmail.com wrote: > > From: Xie Yongji <xieyongji@baidu.com> > > > > This patch introduces two new messages VHOST_USER_GET_SHM_SIZE > > and VHOST_USER_SET_SHM_FD to support providing shared > > memory to backend. > > > > Firstly, qemu uses VHOST_USER_GET_SHM_SIZE to get the > > required size of shared memory from backend. Then, qemu > > allocates memory and sends them back to backend through > > VHOST_USER_SET_SHM_FD. > > So this does create a security concern that remote > can supply a very big area. > How about returning a buffer from client to qemu? > That's a good idea! Will do it v4. Thanks, Yongji
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt index c2194711d9..5ee9c28ab0 100644 --- a/docs/interop/vhost-user.txt +++ b/docs/interop/vhost-user.txt @@ -142,6 +142,19 @@ Depending on the request type, payload can be: Offset: a 64-bit offset of this area from the start of the supplied file descriptor + * Shm description + ----------------------------------- + | mmap_size | mmap_offset | dev_size | vq_size | align | version | + ----------------------------------- + + Mmap_size: a 64-bit size of the shared memory + Mmap_offset: a 64-bit offset of the shared memory from the start + of the supplied file descriptor + Dev_size: a 32-bit size of device region in shared memory + Vq_size: a 32-bit size of each virtqueue region in shared memory + Align: a 32-bit align of each region in shared memory + Version: a 32-bit version of this shared memory + In QEMU the vhost-user message is implemented with the following struct: typedef struct VhostUserMsg { @@ -157,6 +170,7 @@ typedef struct VhostUserMsg { struct vhost_iotlb_msg iotlb; VhostUserConfig config; VhostUserVringArea area; + VhostUserShm shm; }; } QEMU_PACKED VhostUserMsg; @@ -175,6 +189,7 @@ the ones that do: * VHOST_USER_GET_PROTOCOL_FEATURES * VHOST_USER_GET_VRING_BASE * VHOST_USER_SET_LOG_BASE (if VHOST_USER_PROTOCOL_F_LOG_SHMFD) + * VHOST_USER_GET_SHM_SIZE (if VHOST_USER_PROTOCOL_F_SLAVE_SHMFD) [ Also see the section on REPLY_ACK protocol extension. ] @@ -188,6 +203,7 @@ in the ancillary data: * VHOST_USER_SET_VRING_CALL * VHOST_USER_SET_VRING_ERR * VHOST_USER_SET_SLAVE_REQ_FD + * VHOST_USER_SET_SHM_FD (if VHOST_USER_PROTOCOL_F_SLAVE_SHMFD) If Master is unable to send the full message or receives a wrong reply it will close the connection. An optional reconnection mechanism can be implemented. @@ -397,6 +413,7 @@ Protocol features #define VHOST_USER_PROTOCOL_F_CONFIG 9 #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD 10 #define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER 11 +#define VHOST_USER_PROTOCOL_F_SLAVE_SHMFD 12 Master message types -------------------- @@ -761,6 +778,30 @@ Master message types was previously sent. The value returned is an error indication; 0 is success. + * VHOST_USER_GET_SHM_SIZE + Id: 31 + Equivalent ioctl: N/A + Master payload: shm description + + When VHOST_USER_PROTOCOL_F_SLAVE_SHMFD protocol feature has been + successfully negotiated, master need to provide a shared memory to + slave. This message is used by master to get required size from slave. + The shared memory contains one region for device and several regions + for virtqueue. The size of those two kinds of regions is specified + by dev_size field and vq_size filed. The align field specify the alignment + of those regions. + + * VHOST_USER_SET_SHM_FD + Id: 32 + Equivalent ioctl: N/A + Master payload: shm description + + When VHOST_USER_PROTOCOL_F_SLAVE_SHMFD protocol feature has been + successfully negotiated, master uses this message to set shared memory + for slave. The memory fd is passed in the ancillary data. The shared + memory should be used to record inflight I/O by slave. And master will + clear it when vm reset. + Slave message types ------------------- diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index e09bed0e4a..8cdf3b5121 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -52,6 +52,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_CONFIG = 9, VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10, VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11, + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD = 12, VHOST_USER_PROTOCOL_F_MAX }; @@ -89,6 +90,8 @@ typedef enum VhostUserRequest { VHOST_USER_POSTCOPY_ADVISE = 28, VHOST_USER_POSTCOPY_LISTEN = 29, VHOST_USER_POSTCOPY_END = 30, + VHOST_USER_GET_SHM_SIZE = 31, + VHOST_USER_SET_SHM_FD = 32, VHOST_USER_MAX } VhostUserRequest; @@ -147,6 +150,15 @@ typedef struct VhostUserVringArea { uint64_t offset; } VhostUserVringArea; +typedef struct VhostUserShm { + uint64_t mmap_size; + uint64_t mmap_offset; + uint32_t dev_size; + uint32_t vq_size; + uint32_t align; + uint32_t version; +} VhostUserShm; + typedef struct { VhostUserRequest request; @@ -169,6 +181,7 @@ typedef union { VhostUserConfig config; VhostUserCryptoSession session; VhostUserVringArea area; + VhostUserShm shm; } VhostUserPayload; typedef struct VhostUserMsg { @@ -1739,6 +1752,77 @@ static bool vhost_user_mem_section_filter(struct vhost_dev *dev, return result; } +static int vhost_user_get_shm_size(struct vhost_dev *dev, + struct vhost_shm *shm) +{ + VhostUserMsg msg = { + .hdr.request = VHOST_USER_GET_SHM_SIZE, + .hdr.flags = VHOST_USER_VERSION, + .hdr.size = sizeof(msg.payload.shm), + }; + + if (!virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD)) { + shm->dev_size = 0; + shm->vq_size = 0; + return 0; + } + + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { + return -1; + } + + if (vhost_user_read(dev, &msg) < 0) { + return -1; + } + + if (msg.hdr.request != VHOST_USER_GET_SHM_SIZE) { + error_report("Received unexpected msg type. " + "Expected %d received %d", + VHOST_USER_GET_SHM_SIZE, msg.hdr.request); + return -1; + } + + if (msg.hdr.size != sizeof(msg.payload.shm)) { + error_report("Received bad msg size."); + return -1; + } + + shm->dev_size = msg.payload.shm.dev_size; + shm->vq_size = msg.payload.shm.vq_size; + shm->align = msg.payload.shm.align; + shm->version = msg.payload.shm.version; + + return 0; +} + +static int vhost_user_set_shm_fd(struct vhost_dev *dev, + struct vhost_shm *shm) +{ + VhostUserMsg msg = { + .hdr.request = VHOST_USER_SET_SHM_FD, + .hdr.flags = VHOST_USER_VERSION, + .payload.shm.mmap_size = shm->mmap_size, + .payload.shm.mmap_offset = 0, + .payload.shm.dev_size = shm->dev_size, + .payload.shm.vq_size = shm->vq_size, + .payload.shm.align = shm->align, + .payload.shm.version = shm->version, + .hdr.size = sizeof(msg.payload.shm), + }; + + if (!virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_SLAVE_SHMFD)) { + return 0; + } + + if (vhost_user_write(dev, &msg, &shm->fd, 1) < 0) { + return -1; + } + + return 0; +} + VhostUserState *vhost_user_init(void) { VhostUserState *user = g_new0(struct VhostUserState, 1); @@ -1790,4 +1874,6 @@ const VhostOps user_ops = { .vhost_crypto_create_session = vhost_user_crypto_create_session, .vhost_crypto_close_session = vhost_user_crypto_close_session, .vhost_backend_mem_section_filter = vhost_user_mem_section_filter, + .vhost_get_shm_size = vhost_user_get_shm_size, + .vhost_set_shm_fd = vhost_user_set_shm_fd, }; diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 569c4053ea..7a38fed50f 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -1481,6 +1481,123 @@ void vhost_dev_set_config_notifier(struct vhost_dev *hdev, hdev->config_ops = ops; } +void vhost_dev_reset_shm(struct vhost_shm *shm) +{ + if (shm->addr) { + memset(shm->addr, 0, shm->mmap_size); + } +} + +void vhost_dev_free_shm(struct vhost_shm *shm) +{ + if (shm->addr) { + qemu_memfd_free(shm->addr, shm->mmap_size, shm->fd); + shm->addr = NULL; + shm->fd = -1; + } +} + +int vhost_dev_alloc_shm(struct vhost_shm *shm) +{ + Error *err = NULL; + int fd = -1; + void *addr = qemu_memfd_alloc("vhost-shm", shm->mmap_size, + F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, + &fd, &err); + if (err) { + error_report_err(err); + return -1; + } + + shm->addr = addr; + shm->fd = fd; + + return 0; +} + +void vhost_dev_save_shm(struct vhost_shm *shm, QEMUFile *f) +{ + if (shm->addr) { + qemu_put_be64(f, shm->mmap_size); + qemu_put_be32(f, shm->dev_size); + qemu_put_be32(f, shm->vq_size); + qemu_put_be32(f, shm->align); + qemu_put_be32(f, shm->version); + qemu_put_buffer(f, shm->addr, shm->mmap_size); + } else { + qemu_put_be64(f, 0); + } +} + +int vhost_dev_load_shm(struct vhost_shm *shm, QEMUFile *f) +{ + uint64_t mmap_size; + + mmap_size = qemu_get_be64(f); + if (!mmap_size) { + return 0; + } + + vhost_dev_free_shm(shm); + + shm->mmap_size = mmap_size; + shm->dev_size = qemu_get_be32(f); + shm->vq_size = qemu_get_be32(f); + shm->align = qemu_get_be32(f); + shm->version = qemu_get_be32(f); + + if (vhost_dev_alloc_shm(shm)) { + return -ENOMEM; + } + + qemu_get_buffer(f, shm->addr, mmap_size); + + return 0; +} + +int vhost_dev_set_shm(struct vhost_dev *dev, struct vhost_shm *shm) +{ + int r; + + if (dev->vhost_ops->vhost_set_shm_fd && shm->addr) { + r = dev->vhost_ops->vhost_set_shm_fd(dev, shm); + if (r) { + VHOST_OPS_DEBUG("vhost_set_vring_shm_fd failed"); + return -errno; + } + } + + return 0; +} + +int vhost_dev_init_shm(struct vhost_dev *dev, struct vhost_shm *shm) +{ + int r; + + if (dev->vhost_ops->vhost_get_shm_size) { + r = dev->vhost_ops->vhost_get_shm_size(dev, shm); + if (r) { + VHOST_OPS_DEBUG("vhost_get_vring_shm_size failed"); + return -errno; + } + + if (!shm->dev_size && !shm->vq_size) { + return 0; + } + + shm->mmap_size = QEMU_ALIGN_UP(shm->dev_size, shm->align) + + dev->nvqs * QEMU_ALIGN_UP(shm->vq_size, shm->align); + + if (vhost_dev_alloc_shm(shm)) { + return -ENOMEM; + } + + vhost_dev_reset_shm(shm); + } + + return 0; +} + /* Host notifiers must be enabled at this point. */ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) { diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h index 81283ec50f..4e7f13c9e9 100644 --- a/include/hw/virtio/vhost-backend.h +++ b/include/hw/virtio/vhost-backend.h @@ -25,6 +25,7 @@ typedef enum VhostSetConfigType { VHOST_SET_CONFIG_TYPE_MIGRATION = 1, } VhostSetConfigType; +struct vhost_shm; struct vhost_dev; struct vhost_log; struct vhost_memory; @@ -104,6 +105,12 @@ typedef int (*vhost_crypto_close_session_op)(struct vhost_dev *dev, typedef bool (*vhost_backend_mem_section_filter_op)(struct vhost_dev *dev, MemoryRegionSection *section); +typedef int (*vhost_get_shm_size_op)(struct vhost_dev *dev, + struct vhost_shm *shm); + +typedef int (*vhost_set_shm_fd_op)(struct vhost_dev *dev, + struct vhost_shm *shm); + typedef struct VhostOps { VhostBackendType backend_type; vhost_backend_init vhost_backend_init; @@ -142,6 +149,8 @@ typedef struct VhostOps { vhost_crypto_create_session_op vhost_crypto_create_session; vhost_crypto_close_session_op vhost_crypto_close_session; vhost_backend_mem_section_filter_op vhost_backend_mem_section_filter; + vhost_get_shm_size_op vhost_get_shm_size; + vhost_set_shm_fd_op vhost_set_shm_fd; } VhostOps; extern const VhostOps user_ops; diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index a7f449fa87..b6e3d6ab56 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -7,6 +7,17 @@ #include "exec/memory.h" /* Generic structures common for any vhost based device. */ + +struct vhost_shm { + void *addr; + uint64_t mmap_size; + uint32_t dev_size; + uint32_t vq_size; + uint32_t align; + uint32_t version; + int fd; +}; + struct vhost_virtqueue { int kick; int call; @@ -120,4 +131,12 @@ int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data, */ void vhost_dev_set_config_notifier(struct vhost_dev *dev, const VhostDevConfigOps *ops); + +void vhost_dev_reset_shm(struct vhost_shm *shm); +void vhost_dev_free_shm(struct vhost_shm *shm); +int vhost_dev_alloc_shm(struct vhost_shm *shm); +void vhost_dev_save_shm(struct vhost_shm *shm, QEMUFile *f); +int vhost_dev_load_shm(struct vhost_shm *shm, QEMUFile *f); +int vhost_dev_set_shm(struct vhost_dev *dev, struct vhost_shm *shm); +int vhost_dev_init_shm(struct vhost_dev *dev, struct vhost_shm *shm); #endif