From bf38c0c9b897040dddc38456f731006c817e3c39 Mon Sep 17 00:00:00 2001

From: "plai@redhat.com" <plai@redhat.com>

Date: Thu, 21 Jun 2018 18:54:45 +0200

Subject: [PATCH 36/57] libvhost-user: support host notifier

RH-Author: plai@redhat.com

Message-id: <1529607285-9942-11-git-send-email-plai@redhat.com>

Patchwork-id: 80939

O-Subject: [RHEL7.6 PATCH BZ 1526645 10/10] libvhost-user: support host notifier

Bugzilla: 1526645

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

RH-Acked-by: Maxime Coquelin <maxime.coquelin@redhat.com>

RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

From: Tiwei Bie <tiwei.bie@intel.com>

This patch introduces the host notifier support in

libvhost-user. A new API is added to support setting

host notifier for each queue.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

(cherry picked from commit d84599f56c820d8c1ac9928a76500dcdfbbf194d)

Signed-off-by: Paul Lai <plai@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 contrib/libvhost-user/libvhost-user.c | 81 +++++++++++++++++++++++++++++++----

 contrib/libvhost-user/libvhost-user.h | 32 ++++++++++++++

 2 files changed, 105 insertions(+), 8 deletions(-)

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c

index beeed0c..fa06eee 100644

--- a/contrib/libvhost-user/libvhost-user.c

+++ b/contrib/libvhost-user/libvhost-user.c

@@ -314,11 +314,6 @@ vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)

         msg.msg_controllen = 0;

     }

-    /* Set the version in the flags when sending the reply */

-    vmsg->flags &= ~VHOST_USER_VERSION_MASK;

-    vmsg->flags |= VHOST_USER_VERSION;

-    vmsg->flags |= VHOST_USER_REPLY_MASK;

-

     do {

         rc = sendmsg(conn_fd, &msg, 0);

     } while (rc < 0 && (errno == EINTR || errno == EAGAIN));

@@ -339,6 +334,39 @@ vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)

     return true;

 }

+static bool

+vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)

+{

+    /* Set the version in the flags when sending the reply */

+    vmsg->flags &= ~VHOST_USER_VERSION_MASK;

+    vmsg->flags |= VHOST_USER_VERSION;

+    vmsg->flags |= VHOST_USER_REPLY_MASK;

+

+    return vu_message_write(dev, conn_fd, vmsg);

+}

+

+static bool

+vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)

+{

+    VhostUserMsg msg_reply;

+

+    if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) {

+        return true;

+    }

+

+    if (!vu_message_read(dev, dev->slave_fd, &msg_reply)) {

+        return false;

+    }

+

+    if (msg_reply.request != vmsg->request) {

+        DPRINT("Received unexpected msg type. Expected %d received %d",

+               vmsg->request, msg_reply.request);

+        return false;

+    }

+

+    return msg_reply.payload.u64 == 0;

+}

+

 /* Kick the log_call_fd if required. */

 static void

 vu_log_kick(VuDev *dev)

@@ -534,7 +562,7 @@ vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)

     /* Send the message back to qemu with the addresses filled in */

     vmsg->fd_num = 0;

-    if (!vu_message_write(dev, dev->sock, vmsg)) {

+    if (!vu_send_reply(dev, dev->sock, vmsg)) {

         vu_panic(dev, "failed to respond to set-mem-table for postcopy");

         return false;

     }

@@ -914,6 +942,41 @@ void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,

     }

 }

+bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,

+                                int size, int offset)

+{

+    int qidx = vq - dev->vq;

+    int fd_num = 0;

+    VhostUserMsg vmsg = {

+        .request = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,

+        .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,

+        .size = sizeof(vmsg.payload.area),

+        .payload.area = {

+            .u64 = qidx & VHOST_USER_VRING_IDX_MASK,

+            .size = size,

+            .offset = offset,

+        },

+    };

+

+    if (fd == -1) {

+        vmsg.payload.area.u64 |= VHOST_USER_VRING_NOFD_MASK;

+    } else {

+        vmsg.fds[fd_num++] = fd;

+    }

+

+    vmsg.fd_num = fd_num;

+

+    if ((dev->protocol_features & VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) == 0) {

+        return false;

+    }

+

+    if (!vu_message_write(dev, dev->slave_fd, &vmsg)) {

+        return false;

+    }

+

+    return vu_process_message_reply(dev, &vmsg);

+}

+

 static bool

 vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)

 {

@@ -966,7 +1029,9 @@ static bool

 vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)

 {

     uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |

-                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ;

+                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ |

+                        1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER |

+                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD;

     if (have_userfault()) {

         features |= 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT;

@@ -1250,7 +1315,7 @@ vu_dispatch(VuDev *dev)

         goto end;

     }

-    if (!vu_message_write(dev, dev->sock, &vmsg)) {

+    if (!vu_send_reply(dev, dev->sock, &vmsg)) {

         goto end;

     }

diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h

index b27075e..4aa55b4 100644

--- a/contrib/libvhost-user/libvhost-user.h

+++ b/contrib/libvhost-user/libvhost-user.h

@@ -51,6 +51,8 @@ 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_SLAVE_SEND_FD = 10,

+    VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,

     VHOST_USER_PROTOCOL_F_MAX

 };

@@ -92,6 +94,14 @@ typedef enum VhostUserRequest {

     VHOST_USER_MAX

 } VhostUserRequest;

+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;

+

 typedef struct VhostUserMemoryRegion {

     uint64_t guest_phys_addr;

     uint64_t memory_size;

@@ -122,6 +132,12 @@ static VhostUserConfig c __attribute__ ((unused));

                                    + sizeof(c.size) \

                                    + sizeof(c.flags))

+typedef struct VhostUserVringArea {

+    uint64_t u64;

+    uint64_t size;

+    uint64_t offset;

+} VhostUserVringArea;

+

 #if defined(_WIN32)

 # define VU_PACKED __attribute__((gcc_struct, packed))

 #else

@@ -133,6 +149,7 @@ typedef struct VhostUserMsg {

 #define VHOST_USER_VERSION_MASK     (0x3)

 #define VHOST_USER_REPLY_MASK       (0x1 << 2)

+#define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)

     uint32_t flags;

     uint32_t size; /* the following payload size */

@@ -145,6 +162,7 @@ typedef struct VhostUserMsg {

         VhostUserMemory memory;

         VhostUserLog log;

         VhostUserConfig config;

+        VhostUserVringArea area;

     } payload;

     int fds[VHOST_MEMORY_MAX_NREGIONS];

@@ -368,6 +386,20 @@ VuVirtq *vu_get_queue(VuDev *dev, int qidx);

 void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,

                           vu_queue_handler_cb handler);

+/**

+ * vu_set_queue_host_notifier:

+ * @dev: a VuDev context

+ * @vq: a VuVirtq queue

+ * @fd: a file descriptor

+ * @size: host page size

+ * @offset: notifier offset in @fd file

+ *

+ * Set queue's host notifier. This function may be called several

+ * times for the same queue. If called with -1 @fd, the notifier

+ * is removed.

+ */

+bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,

+                                int size, int offset);

 /**

  * vu_queue_set_notification:

-- 

1.8.3.1