Commit 76036a5f authored by Roman Kagan's avatar Roman Kagan Committed by Paolo Bonzini
Browse files

hyperv: process POST_MESSAGE hypercall 



Add handling of POST_MESSAGE hypercall.  For that, add an interface to
regsiter a handler for the messages arrived from the guest on a
particular connection id (IOW set up a message connection in Hyper-V
speak).

Signed-off-by: default avatarRoman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-10-rkagan@virtuozzo.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 8d3bc0b7

hw/hyperv/hyperv.c

+84 −0
Original line number Diff line number Diff line
@@ -455,6 +455,14 @@ int hyperv_sint_route_set_sint(HvSintRoute *sint_route) 
    return event_notifier_set(&sint_route->sint_set_notifier);

}



typedef struct MsgHandler {

    struct rcu_head rcu;

    QLIST_ENTRY(MsgHandler) link;

    uint32_t conn_id;

    HvMsgHandler handler;

    void *data;

} MsgHandler;



typedef struct EventFlagHandler {

    struct rcu_head rcu;

    QLIST_ENTRY(EventFlagHandler) link;
@@ -462,15 +470,91 @@ typedef struct EventFlagHandler { 
    EventNotifier *notifier;

} EventFlagHandler;



static QLIST_HEAD(, MsgHandler) msg_handlers;

static QLIST_HEAD(, EventFlagHandler) event_flag_handlers;

static QemuMutex handlers_mutex;



static void __attribute__((constructor)) hv_init(void)

{

    QLIST_INIT(&msg_handlers);

    QLIST_INIT(&event_flag_handlers);

    qemu_mutex_init(&handlers_mutex);

}



int hyperv_set_msg_handler(uint32_t conn_id, HvMsgHandler handler, void *data)

{

    int ret;

    MsgHandler *mh;



    qemu_mutex_lock(&handlers_mutex);

    QLIST_FOREACH(mh, &msg_handlers, link) {

        if (mh->conn_id == conn_id) {

            if (handler) {

                ret = -EEXIST;

            } else {

                QLIST_REMOVE_RCU(mh, link);

                g_free_rcu(mh, rcu);

                ret = 0;

            }

            goto unlock;

        }

    }



    if (handler) {

        mh = g_new(MsgHandler, 1);

        mh->conn_id = conn_id;

        mh->handler = handler;

        mh->data = data;

        QLIST_INSERT_HEAD_RCU(&msg_handlers, mh, link);

        ret = 0;

    } else {

        ret = -ENOENT;

    }

unlock:

    qemu_mutex_unlock(&handlers_mutex);

    return ret;

}



uint16_t hyperv_hcall_post_message(uint64_t param, bool fast)

{

    uint16_t ret;

    hwaddr len;

    struct hyperv_post_message_input *msg;

    MsgHandler *mh;



    if (fast) {

        return HV_STATUS_INVALID_HYPERCALL_CODE;

    }

    if (param & (__alignof__(*msg) - 1)) {

        return HV_STATUS_INVALID_ALIGNMENT;

    }



    len = sizeof(*msg);

    msg = cpu_physical_memory_map(param, &len, 0);

    if (len < sizeof(*msg)) {

        ret = HV_STATUS_INSUFFICIENT_MEMORY;

        goto unmap;

    }

    if (msg->payload_size > sizeof(msg->payload)) {

        ret = HV_STATUS_INVALID_HYPERCALL_INPUT;

        goto unmap;

    }



    ret = HV_STATUS_INVALID_CONNECTION_ID;

    rcu_read_lock();

    QLIST_FOREACH_RCU(mh, &msg_handlers, link) {

        if (mh->conn_id == (msg->connection_id & HV_CONNECTION_ID_MASK)) {

            ret = mh->handler(msg, mh->data);

            break;

        }

    }

    rcu_read_unlock();



unmap:

    cpu_physical_memory_unmap(msg, len, 0, 0);

    return ret;

}



static int set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)

{

    int ret;

include/hw/hyperv/hyperv.h

+18 −0
Original line number Diff line number Diff line
@@ -39,6 +39,18 @@ int hyperv_post_msg(HvSintRoute *sint_route, struct hyperv_message *msg); 
 */

int hyperv_set_event_flag(HvSintRoute *sint_route, unsigned eventno);



/*

 * Handler for messages arriving from the guest via HV_POST_MESSAGE hypercall.

 * Executed in vcpu context.

 */

typedef uint16_t (*HvMsgHandler)(const struct hyperv_post_message_input *msg,

                                 void *data);

/*

 * Associate @handler with the message connection @conn_id, such that @handler

 * is called with @data when the guest executes HV_POST_MESSAGE hypercall on

 * @conn_id.  If @handler is NULL clear the association.

 */

int hyperv_set_msg_handler(uint32_t conn_id, HvMsgHandler handler, void *data);

/*

 * Associate @notifier with the event connection @conn_id, such that @notifier

 * is signaled when the guest executes HV_SIGNAL_EVENT hypercall on @conn_id.
@@ -46,6 +58,12 @@ int hyperv_set_event_flag(HvSintRoute *sint_route, unsigned eventno); 
 */

int hyperv_set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier);



/*

 * Process HV_POST_MESSAGE hypercall: parse the data in the guest memory as

 * specified in @param, and call the HvMsgHandler associated with the

 * connection on the message contained therein.

 */

uint16_t hyperv_hcall_post_message(uint64_t param, bool fast);

/*

 * Process HV_SIGNAL_EVENT hypercall: signal the EventNotifier associated with

 * the connection as specified in @param.

target/i386/hyperv.c

+3 −0
Original line number Diff line number Diff line
@@ -84,6 +84,9 @@ int kvm_hv_handle_exit(X86CPU *cpu, struct kvm_hyperv_exit *exit) 
        uint64_t param = exit->u.hcall.params[0];



        switch (code) {

        case HV_POST_MESSAGE:

            exit->u.hcall.result = hyperv_hcall_post_message(param, fast);

            break;

        case HV_SIGNAL_EVENT:

            exit->u.hcall.result = hyperv_hcall_signal_event(param, fast);

            break;