From 3a5f44900a64ea2bdf809f1a8df8a4a255dbe014 Mon Sep 17 00:00:00 2001 From: "plai@redhat.com" Date: Thu, 21 Jun 2018 18:54:44 +0200 Subject: [PATCH 35/57] vhost-user: support registering external host notifiers RH-Author: plai@redhat.com Message-id: <1529607285-9942-10-git-send-email-plai@redhat.com> Patchwork-id: 80940 O-Subject: [RHEL7.6 PATCH BZ 1526645 09/10] vhost-user: support registering external host notifiers Bugzilla: 1526645 RH-Acked-by: Michael S. Tsirkin RH-Acked-by: Maxime Coquelin RH-Acked-by: Laurent Vivier From: Tiwei Bie 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 Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 44866521bd6ea8e5152a87664dea1eee90c9438b) Signed-off-by: Paul Lai Signed-off-by: Miroslav Rezanina --- docs/interop/vhost-user.txt | 33 ++++++++++++ hw/virtio/vhost-user.c | 113 +++++++++++++++++++++++++++++++++++++++++ include/hw/virtio/vhost-user.h | 8 +++ 3 files changed, 154 insertions(+) diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt index 682a683..d51fd58 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; @@ -385,6 +396,7 @@ Protocol features #define VHOST_USER_PROTOCOL_F_PAGEFAULT 8 #define VHOST_USER_PROTOCOL_F_CONFIG 9 #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD 10 +#define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER 11 Master message types -------------------- @@ -782,6 +794,27 @@ 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 a715c5c..c30fc3d 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" @@ -50,6 +51,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_PAGEFAULT = 8, 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_MAX }; @@ -94,6 +96,7 @@ 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; @@ -138,6 +141,12 @@ 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; @@ -159,6 +168,7 @@ typedef union { struct vhost_iotlb_msg iotlb; VhostUserConfig config; VhostUserCryptoSession session; + VhostUserVringArea area; } VhostUserPayload; typedef struct VhostUserMsg { @@ -640,9 +650,37 @@ 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); } @@ -676,6 +714,8 @@ 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; } @@ -849,6 +889,66 @@ 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; + 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)) { + return -1; + } + + 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) { + return 0; + } + + /* Sanity check. */ + if (area->size != page_size) { + return -1; + } + + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, + fd, area->offset); + if (addr == MAP_FAILED) { + return -1; + } + + 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); + return -1; + } + + n->addr = addr; + n->set = true; + + return 0; +} + static void slave_read(void *opaque) { struct vhost_dev *dev = opaque; @@ -917,6 +1017,10 @@ 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[0]); + break; default: error_report("Received unexpected msg type."); ret = -EINVAL; @@ -1648,6 +1752,15 @@ 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 eb8bc0d..fd66039 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); -- 1.8.3.1