[Qemu-devel] [PATCH 0/4] qga: add vsock-listen

[Qemu-devel] [PATCH 0/4] qga: add vsock-listen

[Stefan Hajnoczi]

This patch series adds virtio-vsock support to the QEMU guest agent.

  $ qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ...
  (guest)# qemu-ga -m vsock-listen -p 3:1234

You can interact with the qga monitor using the nc-vsock utility:
https://raw.githubusercontent.com/stefanha/linux/dd0d6a2aa62c0fd6cdc9dbd4b3dc4bfd0828c329/nc-vsock.c

  $ nc-vsock 3 1234
  {'execute': 'guest-info'}
  ...

For more information about virtio-vsock, see
http://qemu-project.org/Features/VirtioVsock.

Stefan Hajnoczi (4):
  qga: drop unused sockaddr in accept(2) call
  qga: drop unnecessary GA_CHANNEL_UNIX_LISTEN checks
  sockets: add AF_VSOCK support
  qga: add vsock-listen method

 qapi-schema.json    |  23 +++++-
 qga/channel-posix.c |  36 +++++++--
 qga/channel.h       |   1 +
 qga/main.c          |   6 +-
 util/qemu-sockets.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 277 insertions(+), 11 deletions(-)

-- 
2.7.4

[Qemu-devel] [PATCH 1/4] qga: drop unused sockaddr in accept(2) call

[Stefan Hajnoczi]

ga_channel_listen_accept() is currently hard-coded to support only
AF_UNIX because the struct sockaddr_un type is used.  This function
should work with any address family.

Drop the sockaddr since the client address is unused and is an optional
argument to accept(2).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qga/channel-posix.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/qga/channel-posix.c b/qga/channel-posix.c
index bb65d8b..bf32158 100644
--- a/qga/channel-posix.c
+++ b/qga/channel-posix.c
@@ -26,13 +26,10 @@ static gboolean ga_channel_listen_accept(GIOChannel *channel,
     GAChannel *c = data;
     int ret, client_fd;
     bool accepted = false;
-    struct sockaddr_un addr;
-    socklen_t addrlen = sizeof(addr);
 
     g_assert(channel != NULL);
 
-    client_fd = qemu_accept(g_io_channel_unix_get_fd(channel),
-                            (struct sockaddr *)&addr, &addrlen);
+    client_fd = qemu_accept(g_io_channel_unix_get_fd(channel), NULL, NULL);
     if (client_fd == -1) {
         g_warning("error converting fd to gsocket: %s", strerror(errno));
         goto out;
-- 
2.7.4

[Qemu-devel] [PATCH 2/4] qga: drop unnecessary GA_CHANNEL_UNIX_LISTEN checks

[Stefan Hajnoczi]

Throughout the code there are c->listen_channel checks which manage the
listen socket file descriptor (waiting for accept(2), closing the file
descriptor, etc).  These checks are currently preceded by explicit
c->method == GA_CHANNEL_UNIX_LISTEN checks.

Explicit GA_CHANNEL_UNIX_LISTEN checks are not necessary since serial
channel types do not create the listen channel (c->listen_channel).

As more listen channel types are added, explicitly checking all of them
becomes messy.  Rely on c->listen_channel to determine whether or not a
listen socket file descriptor is used.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qga/channel-posix.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/qga/channel-posix.c b/qga/channel-posix.c
index bf32158..579891d 100644
--- a/qga/channel-posix.c
+++ b/qga/channel-posix.c
@@ -61,7 +61,6 @@ static void ga_channel_listen_add(GAChannel *c, int listen_fd, bool create)
 
 static void ga_channel_listen_close(GAChannel *c)
 {
-    g_assert(c->method == GA_CHANNEL_UNIX_LISTEN);
     g_assert(c->listen_channel);
     g_io_channel_shutdown(c->listen_channel, true, NULL);
     g_io_channel_unref(c->listen_channel);
@@ -77,7 +76,7 @@ static void ga_channel_client_close(GAChannel *c)
     g_io_channel_shutdown(c->client_channel, true, NULL);
     g_io_channel_unref(c->client_channel);
     c->client_channel = NULL;
-    if (c->method == GA_CHANNEL_UNIX_LISTEN && c->listen_channel) {
+    if (c->listen_channel) {
         ga_channel_listen_add(c, 0, false);
     }
 }
@@ -255,8 +254,7 @@ GAChannel *ga_channel_new(GAChannelMethod method, const gchar *path,
 
 void ga_channel_free(GAChannel *c)
 {
-    if (c->method == GA_CHANNEL_UNIX_LISTEN
-        && c->listen_channel) {
+    if (c->listen_channel) {
         ga_channel_listen_close(c);
     }
     if (c->client_channel) {
-- 
2.7.4

[Qemu-devel] [PATCH 3/4] sockets: add AF_VSOCK support

[Stefan Hajnoczi]

Add the AF_VSOCK address family so that qemu-ga will be able to use
virtio-vsock.

The AF_VSOCK address family uses <cid, port> address tuples.  The cid is
the unique identifier comparable to an IP address.  AF_VSOCK does not
use name resolution so it's seasy to convert between struct sockaddr_vm
and strings.

This patch defines a VsockSocketAddress instead of trying to piggy-back
on InetSocketAddress.  This is cleaner in the long run since it avoids
lots of IPv4 vs IPv6 vs vsock special casing.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qapi-schema.json    |  23 +++++-
 util/qemu-sockets.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 244 insertions(+), 1 deletion(-)

diff --git a/qapi-schema.json b/qapi-schema.json
index c3dcf11..8864a96 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -987,12 +987,14 @@
 #
 # @unix: unix socket
 #
+# @vsock: vsock family (since 2.8)
+#
 # @unknown: otherwise
 #
 # Since: 2.1
 ##
 { 'enum': 'NetworkAddressFamily',
-  'data': [ 'ipv4', 'ipv6', 'unix', 'unknown' ] }
+  'data': [ 'ipv4', 'ipv6', 'unix', 'vsock', 'unknown' ] }
 
 ##
 # @VncBasicInfo
@@ -3017,6 +3019,24 @@
     'path': 'str' } }
 
 ##
+# @VsockSocketAddress
+#
+# Captures a socket address in the vsock namespace.
+#
+# @cid: unique host identifier
+# @port: port
+#
+# Note that string types are used to allow for possible future hostname or
+# service resolution support.
+#
+# Since 2.8
+##
+{ 'struct': 'VsockSocketAddress',
+  'data': {
+    'cid': 'str',
+    'port': 'str' } }
+
+##
 # @SocketAddress
 #
 # Captures the address of a socket, which could also be a named file descriptor
@@ -3027,6 +3047,7 @@
   'data': {
     'inet': 'InetSocketAddress',
     'unix': 'UnixSocketAddress',
+    'vsock': 'VsockSocketAddress',
     'fd': 'String' } }
 
 ##
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index 6db48b3..46cd1ba 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -17,6 +17,10 @@
  */
 #include "qemu/osdep.h"
 
+#ifdef AF_VSOCK
+#include <linux/vm_sockets.h>
+#endif /* AF_VSOCK */
+
 #include "monitor/monitor.h"
 #include "qapi/error.h"
 #include "qemu/sockets.h"
@@ -75,6 +79,9 @@ NetworkAddressFamily inet_netfamily(int family)
     case PF_INET6: return NETWORK_ADDRESS_FAMILY_IPV6;
     case PF_INET:  return NETWORK_ADDRESS_FAMILY_IPV4;
     case PF_UNIX:  return NETWORK_ADDRESS_FAMILY_UNIX;
+#ifdef AF_VSOCK
+    case PF_VSOCK: return NETWORK_ADDRESS_FAMILY_VSOCK;
+#endif /* AF_VSOCK */
     }
     return NETWORK_ADDRESS_FAMILY_UNKNOWN;
 }
@@ -650,6 +657,176 @@ int inet_connect(const char *str, Error **errp)
     return sock;
 }
 
+#ifdef AF_VSOCK
+static bool vsock_parse_vaddr_to_sockaddr(const VsockSocketAddress *vaddr,
+                                          struct sockaddr_vm *svm,
+                                          Error **errp)
+{
+    unsigned long long val;
+
+    memset(svm, 0, sizeof(*svm));
+    svm->svm_family = AF_VSOCK;
+
+    if (parse_uint_full(vaddr->cid, &val, 10) < 0 ||
+        val > UINT32_MAX) {
+        error_setg(errp, "Failed to parse cid '%s'", vaddr->cid);
+        return false;
+    }
+    svm->svm_cid = val;
+
+    if (parse_uint_full(vaddr->port, &val, 10) < 0 ||
+        val > UINT32_MAX) {
+        error_setg(errp, "Failed to parse port '%s'", vaddr->port);
+        return false;
+    }
+    svm->svm_port = val;
+
+    return true;
+}
+
+static int vsock_connect_addr(const struct sockaddr_vm *svm, bool *in_progress,
+                              ConnectState *connect_state, Error **errp)
+{
+    int sock, rc;
+
+    *in_progress = false;
+
+    sock = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
+    if (sock < 0) {
+        error_setg_errno(errp, errno, "Failed to create socket");
+        return -1;
+    }
+    if (connect_state != NULL) {
+        qemu_set_nonblock(sock);
+    }
+    /* connect to peer */
+    do {
+        rc = 0;
+        if (connect(sock, (const struct sockaddr *)svm, sizeof(*svm)) < 0) {
+            rc = -errno;
+        }
+    } while (rc == -EINTR);
+
+    if (connect_state != NULL && QEMU_SOCKET_RC_INPROGRESS(rc)) {
+        connect_state->fd = sock;
+        qemu_set_fd_handler(sock, NULL, wait_for_connect, connect_state);
+        *in_progress = true;
+    } else if (rc < 0) {
+        error_setg_errno(errp, errno, "Failed to connect socket");
+        closesocket(sock);
+        return -1;
+    }
+    return sock;
+}
+
+static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp,
+                               NonBlockingConnectHandler *callback,
+                               void *opaque)
+{
+    struct sockaddr_vm svm;
+    int sock = -1;
+    bool in_progress;
+    ConnectState *connect_state = NULL;
+
+    if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
+        return -1;
+    }
+
+    if (callback != NULL) {
+        connect_state = g_malloc0(sizeof(*connect_state));
+        connect_state->callback = callback;
+        connect_state->opaque = opaque;
+    }
+
+    sock = vsock_connect_addr(&svm, &in_progress, connect_state, errp);
+    if (sock < 0) {
+        /* do nothing */
+    } else if (in_progress) {
+        /* wait_for_connect() will do the rest */
+        return sock;
+    } else {
+        if (callback) {
+            callback(sock, NULL, opaque);
+        }
+    }
+    g_free(connect_state);
+    return sock;
+}
+
+static int vsock_listen_saddr(VsockSocketAddress *vaddr,
+                              Error **errp)
+{
+    struct sockaddr_vm svm;
+    int slisten;
+
+    if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
+        return -1;
+    }
+
+    slisten = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
+    if (slisten < 0) {
+        error_setg_errno(errp, errno, "Failed to create socket");
+        return -1;
+    }
+
+    if (bind(slisten, (const struct sockaddr *)&svm, sizeof(svm)) != 0) {
+        error_setg_errno(errp, errno, "Failed to bind socket");
+        closesocket(slisten);
+        return -1;
+    }
+
+    if (listen(slisten, 1) != 0) {
+        error_setg_errno(errp, errno, "Failed to listen on socket");
+        closesocket(slisten);
+        return -1;
+    }
+    return slisten;
+}
+
+static VsockSocketAddress *vsock_parse(const char *str, Error **errp)
+{
+    VsockSocketAddress *addr = NULL;
+    char cid[33];
+    char port[33];
+
+    if (sscanf(str, "%32[^:]:%32[^,]", cid, port) != 2) {
+        error_setg(errp, "error parsing address '%s'", str);
+        return NULL;
+    }
+
+    addr = g_new0(VsockSocketAddress, 1);
+    addr->cid = g_strdup(cid);
+    addr->port = g_strdup(port);
+    return addr;
+}
+#else
+static void vsock_unsupported(Error **errp)
+{
+    error_setg(errp, "socket family AF_VSOCK unsupported");
+}
+
+static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp,
+                               NonBlockingConnectHandler *callback,
+                               void *opaque)
+{
+    vsock_unsupported(errp);
+    return -1;
+}
+
+static int vsock_listen_saddr(VsockSocketAddress *vaddr,
+                              Error **errp)
+{
+    vsock_unsupported(errp);
+    return -1;
+}
+
+static VsockSocketAddress *vsock_parse(const char *str, Error **errp)
+{
+    vsock_unsupported(errp);
+    return NULL;
+}
+#endif /* AF_VSOCK */
+
 #ifndef _WIN32
 
 static int unix_listen_saddr(UnixSocketAddress *saddr,
@@ -864,6 +1041,12 @@ SocketAddress *socket_parse(const char *str, Error **errp)
             addr->u.fd.data = g_new(String, 1);
             addr->u.fd.data->str = g_strdup(str + 3);
         }
+    } else if (strstart(str, "vsock:", NULL)) {
+        addr->type = SOCKET_ADDRESS_KIND_VSOCK;
+        addr->u.vsock.data = vsock_parse(str + strlen("vsock:"), errp);
+        if (addr->u.vsock.data == NULL) {
+            goto fail;
+        }
     } else {
         addr->type = SOCKET_ADDRESS_KIND_INET;
         addr->u.inet.data = inet_parse(str, errp);
@@ -900,6 +1083,10 @@ int socket_connect(SocketAddress *addr, Error **errp,
         }
         break;
 
+    case SOCKET_ADDRESS_KIND_VSOCK:
+        fd = vsock_connect_saddr(addr->u.vsock.data, errp, callback, opaque);
+        break;
+
     default:
         abort();
     }
@@ -923,6 +1110,10 @@ int socket_listen(SocketAddress *addr, Error **errp)
         fd = monitor_get_fd(cur_mon, addr->u.fd.data->str, errp);
         break;
 
+    case SOCKET_ADDRESS_KIND_VSOCK:
+        fd = vsock_listen_saddr(addr->u.vsock.data, errp);
+        break;
+
     default:
         abort();
     }
@@ -1022,6 +1213,26 @@ socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
 }
 #endif /* WIN32 */
 
+#ifdef AF_VSOCK
+static SocketAddress *
+socket_sockaddr_to_address_vsock(struct sockaddr_storage *sa,
+                                 socklen_t salen,
+                                 Error **errp)
+{
+    SocketAddress *addr;
+    VsockSocketAddress *vaddr;
+    struct sockaddr_vm *svm = (struct sockaddr_vm *)sa;
+
+    addr = g_new0(SocketAddress, 1);
+    addr->type = SOCKET_ADDRESS_KIND_VSOCK;
+    addr->u.vsock.data = vaddr = g_new0(VsockSocketAddress, 1);
+    vaddr->cid = g_strdup_printf("%u", svm->svm_cid);
+    vaddr->port = g_strdup_printf("%u", svm->svm_port);
+
+    return addr;
+}
+#endif /* AF_VSOCK */
+
 SocketAddress *
 socket_sockaddr_to_address(struct sockaddr_storage *sa,
                            socklen_t salen,
@@ -1037,6 +1248,11 @@ socket_sockaddr_to_address(struct sockaddr_storage *sa,
         return socket_sockaddr_to_address_unix(sa, salen, errp);
 #endif /* WIN32 */
 
+#ifdef AF_VSOCK
+    case AF_VSOCK:
+        return socket_sockaddr_to_address_vsock(sa, salen, errp);
+#endif
+
     default:
         error_setg(errp, "socket family %d unsupported",
                    sa->ss_family);
@@ -1103,6 +1319,12 @@ char *socket_address_to_string(struct SocketAddress *addr, Error **errp)
         buf = g_strdup(addr->u.fd.data->str);
         break;
 
+    case SOCKET_ADDRESS_KIND_VSOCK:
+        buf = g_strdup_printf("%s:%s",
+                              addr->u.vsock.data->cid,
+                              addr->u.vsock.data->port);
+        break;
+
     default:
         error_setg(errp, "socket family %d unsupported",
                    addr->type);
-- 
2.7.4

[Qemu-devel] [PATCH 4/4] qga: add vsock-listen method

[Stefan Hajnoczi]

Add AF_VSOCK (virtio-vsock) support as an alternative to virtio-serial.

  $ qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ...
  (guest)# qemu-ga -m vsock-listen -p 3:1234

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qga/channel-posix.c | 25 +++++++++++++++++++++++++
 qga/channel.h       |  1 +
 qga/main.c          |  6 ++++--
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/qga/channel-posix.c b/qga/channel-posix.c
index 579891d..71582e0 100644
--- a/qga/channel-posix.c
+++ b/qga/channel-posix.c
@@ -193,6 +193,31 @@ static gboolean ga_channel_open(GAChannel *c, const gchar *path, GAChannelMethod
         ga_channel_listen_add(c, fd, true);
         break;
     }
+    case GA_CHANNEL_VSOCK_LISTEN: {
+        Error *local_err = NULL;
+        SocketAddress *addr;
+        char *addr_str;
+        int fd;
+
+        addr_str = g_strdup_printf("vsock:%s", path);
+        addr = socket_parse(addr_str, &local_err);
+        g_free(addr_str);
+        if (local_err != NULL) {
+            g_critical("%s", error_get_pretty(local_err));
+            error_free(local_err);
+            return false;
+        }
+
+        fd = socket_listen(addr, &local_err);
+        qapi_free_SocketAddress(addr);
+        if (local_err != NULL) {
+            g_critical("%s", error_get_pretty(local_err));
+            error_free(local_err);
+            return false;
+        }
+        ga_channel_listen_add(c, fd, true);
+        break;
+    }
     default:
         g_critical("error binding/listening to specified socket");
         return false;
diff --git a/qga/channel.h b/qga/channel.h
index ae8cf0f..8fd0c8f 100644
--- a/qga/channel.h
+++ b/qga/channel.h
@@ -19,6 +19,7 @@ typedef enum {
     GA_CHANNEL_VIRTIO_SERIAL,
     GA_CHANNEL_ISA_SERIAL,
     GA_CHANNEL_UNIX_LISTEN,
+    GA_CHANNEL_VSOCK_LISTEN,
 } GAChannelMethod;
 
 typedef gboolean (*GAChannelCallback)(GIOCondition condition, gpointer opaque);
diff --git a/qga/main.c b/qga/main.c
index 0b9d04e..6caf215 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -190,8 +190,8 @@ static void usage(const char *cmd)
 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 "QEMU Guest Agent %s\n"
 "\n"
-"  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
-"                    isa-serial (virtio-serial is the default)\n"
+"  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
+"                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 "                    %s,\n"
 "                    the default for isa-serial is:\n"
@@ -659,6 +659,8 @@ static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
         channel_method = GA_CHANNEL_ISA_SERIAL;
     } else if (strcmp(method, "unix-listen") == 0) {
         channel_method = GA_CHANNEL_UNIX_LISTEN;
+    } else if (strcmp(method, "vsock-listen") == 0) {
+        channel_method = GA_CHANNEL_VSOCK_LISTEN;
     } else {
         g_critical("unsupported channel method/type: %s", method);
         return false;
-- 
2.7.4

Re: [Qemu-devel] [PATCH 3/4] sockets: add AF_VSOCK support

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 2564 bytes --]

On 10/06/2016 11:40 AM, Stefan Hajnoczi wrote:
> Add the AF_VSOCK address family so that qemu-ga will be able to use
> virtio-vsock.
> 
> The AF_VSOCK address family uses <cid, port> address tuples.  The cid is
> the unique identifier comparable to an IP address.  AF_VSOCK does not
> use name resolution so it's seasy to convert between struct sockaddr_vm

s/seasy/easy/

> and strings.
> 
> This patch defines a VsockSocketAddress instead of trying to piggy-back
> on InetSocketAddress.  This is cleaner in the long run since it avoids
> lots of IPv4 vs IPv6 vs vsock special casing.

At any rate, it seems like SocketAddress would be a better fit for a
tri-state union between InetSocketAddress, UnixSocketAddress, and
VnetSocketAddress.

> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  qapi-schema.json    |  23 +++++-
>  util/qemu-sockets.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 244 insertions(+), 1 deletion(-)
> 

> +##
>  # @SocketAddress
>  #
>  # Captures the address of a socket, which could also be a named file descriptor
> @@ -3027,6 +3047,7 @@
>    'data': {
>      'inet': 'InetSocketAddress',
>      'unix': 'UnixSocketAddress',
> +    'vsock': 'VsockSocketAddress',
>      'fd': 'String' } }

Which is in fact what you did.


> +static int vsock_connect_addr(const struct sockaddr_vm *svm, bool *in_progress,
> +                              ConnectState *connect_state, Error **errp)
> +{
> +    int sock, rc;
> +
> +    *in_progress = false;
> +
> +    sock = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
> +    if (sock < 0) {
> +        error_setg_errno(errp, errno, "Failed to create socket");
> +        return -1;
> +    }
> +    if (connect_state != NULL) {
> +        qemu_set_nonblock(sock);

Isn't the presence of vsock support sufficient to prove that we have
SOCK_NONBLOCK support as part of our socket() call?  In which case,
wouldn't it be better to pass that option up front to atomically get a
non-blocking socket, rather than having to change its state after the fact?


> +static VsockSocketAddress *vsock_parse(const char *str, Error **errp)
> +{
> +    VsockSocketAddress *addr = NULL;
> +    char cid[33];
> +    char port[33];
> +
> +    if (sscanf(str, "%32[^:]:%32[^,]", cid, port) != 2) {

Would it be a wise idea to also use %n to ensure that you aren't
ignoring trailing garbage?

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
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Re: [Qemu-devel] [PATCH 3/4] sockets: add AF_VSOCK support

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 1488 bytes --]

On Thu, Oct 06, 2016 at 01:14:08PM -0500, Eric Blake wrote:
> On 10/06/2016 11:40 AM, Stefan Hajnoczi wrote:
> > +static int vsock_connect_addr(const struct sockaddr_vm *svm, bool *in_progress,
> > +                              ConnectState *connect_state, Error **errp)
> > +{
> > +    int sock, rc;
> > +
> > +    *in_progress = false;
> > +
> > +    sock = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
> > +    if (sock < 0) {
> > +        error_setg_errno(errp, errno, "Failed to create socket");
> > +        return -1;
> > +    }
> > +    if (connect_state != NULL) {
> > +        qemu_set_nonblock(sock);
> 
> Isn't the presence of vsock support sufficient to prove that we have
> SOCK_NONBLOCK support as part of our socket() call?  In which case,
> wouldn't it be better to pass that option up front to atomically get a
> non-blocking socket, rather than having to change its state after the fact?

I'm sending a separate patch series to introduce a QemuSockFlags
argument for qemu_socket() and qemu_accept().  It will convert existing
qemu_set_nonblock() callers too.

> > +static VsockSocketAddress *vsock_parse(const char *str, Error **errp)
> > +{
> > +    VsockSocketAddress *addr = NULL;
> > +    char cid[33];
> > +    char port[33];
> > +
> > +    if (sscanf(str, "%32[^:]:%32[^,]", cid, port) != 2) {
> 
> Would it be a wise idea to also use %n to ensure that you aren't
> ignoring trailing garbage?

Okay, will fix in the next version.

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Re: [Qemu-devel] [PATCH 1/4] qga: drop unused sockaddr in accept(2) call

[Michael Roth]

Quoting Stefan Hajnoczi (2016-10-06 11:40:15)
> ga_channel_listen_accept() is currently hard-coded to support only
> AF_UNIX because the struct sockaddr_un type is used.  This function
> should work with any address family.
> 
> Drop the sockaddr since the client address is unused and is an optional
> argument to accept(2).
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>

> ---
>  qga/channel-posix.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/qga/channel-posix.c b/qga/channel-posix.c
> index bb65d8b..bf32158 100644
> --- a/qga/channel-posix.c
> +++ b/qga/channel-posix.c
> @@ -26,13 +26,10 @@ static gboolean ga_channel_listen_accept(GIOChannel *channel,
>      GAChannel *c = data;
>      int ret, client_fd;
>      bool accepted = false;
> -    struct sockaddr_un addr;
> -    socklen_t addrlen = sizeof(addr);
> 
>      g_assert(channel != NULL);
> 
> -    client_fd = qemu_accept(g_io_channel_unix_get_fd(channel),
> -                            (struct sockaddr *)&addr, &addrlen);
> +    client_fd = qemu_accept(g_io_channel_unix_get_fd(channel), NULL, NULL);
>      if (client_fd == -1) {
>          g_warning("error converting fd to gsocket: %s", strerror(errno));
>          goto out;
> -- 
> 2.7.4
> 

Re: [Qemu-devel] [PATCH 2/4] qga: drop unnecessary GA_CHANNEL_UNIX_LISTEN checks

[Michael Roth]

Quoting Stefan Hajnoczi (2016-10-06 11:40:16)
> Throughout the code there are c->listen_channel checks which manage the
> listen socket file descriptor (waiting for accept(2), closing the file
> descriptor, etc).  These checks are currently preceded by explicit
> c->method == GA_CHANNEL_UNIX_LISTEN checks.
> 
> Explicit GA_CHANNEL_UNIX_LISTEN checks are not necessary since serial
> channel types do not create the listen channel (c->listen_channel).
> 
> As more listen channel types are added, explicitly checking all of them
> becomes messy.  Rely on c->listen_channel to determine whether or not a
> listen socket file descriptor is used.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>

> ---
>  qga/channel-posix.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/qga/channel-posix.c b/qga/channel-posix.c
> index bf32158..579891d 100644
> --- a/qga/channel-posix.c
> +++ b/qga/channel-posix.c
> @@ -61,7 +61,6 @@ static void ga_channel_listen_add(GAChannel *c, int listen_fd, bool create)
> 
>  static void ga_channel_listen_close(GAChannel *c)
>  {
> -    g_assert(c->method == GA_CHANNEL_UNIX_LISTEN);
>      g_assert(c->listen_channel);
>      g_io_channel_shutdown(c->listen_channel, true, NULL);
>      g_io_channel_unref(c->listen_channel);
> @@ -77,7 +76,7 @@ static void ga_channel_client_close(GAChannel *c)
>      g_io_channel_shutdown(c->client_channel, true, NULL);
>      g_io_channel_unref(c->client_channel);
>      c->client_channel = NULL;
> -    if (c->method == GA_CHANNEL_UNIX_LISTEN && c->listen_channel) {
> +    if (c->listen_channel) {
>          ga_channel_listen_add(c, 0, false);
>      }
>  }
> @@ -255,8 +254,7 @@ GAChannel *ga_channel_new(GAChannelMethod method, const gchar *path,
> 
>  void ga_channel_free(GAChannel *c)
>  {
> -    if (c->method == GA_CHANNEL_UNIX_LISTEN
> -        && c->listen_channel) {
> +    if (c->listen_channel) {
>          ga_channel_listen_close(c);
>      }
>      if (c->client_channel) {
> -- 
> 2.7.4
> 

Re: [Qemu-devel] [PATCH 3/4] sockets: add AF_VSOCK support

[Michael Roth]

Quoting Stefan Hajnoczi (2016-10-06 11:40:17)
> Add the AF_VSOCK address family so that qemu-ga will be able to use
> virtio-vsock.
> 
> The AF_VSOCK address family uses <cid, port> address tuples.  The cid is
> the unique identifier comparable to an IP address.  AF_VSOCK does not
> use name resolution so it's seasy to convert between struct sockaddr_vm
> and strings.
> 
> This patch defines a VsockSocketAddress instead of trying to piggy-back
> on InetSocketAddress.  This is cleaner in the long run since it avoids
> lots of IPv4 vs IPv6 vs vsock special casing.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  qapi-schema.json    |  23 +++++-
>  util/qemu-sockets.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 244 insertions(+), 1 deletion(-)
> 
> diff --git a/qapi-schema.json b/qapi-schema.json
> index c3dcf11..8864a96 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -987,12 +987,14 @@
>  #
>  # @unix: unix socket
>  #
> +# @vsock: vsock family (since 2.8)
> +#
>  # @unknown: otherwise
>  #
>  # Since: 2.1
>  ##
>  { 'enum': 'NetworkAddressFamily',
> -  'data': [ 'ipv4', 'ipv6', 'unix', 'unknown' ] }
> +  'data': [ 'ipv4', 'ipv6', 'unix', 'vsock', 'unknown' ] }
> 
>  ##
>  # @VncBasicInfo
> @@ -3017,6 +3019,24 @@
>      'path': 'str' } }
> 
>  ##
> +# @VsockSocketAddress
> +#
> +# Captures a socket address in the vsock namespace.
> +#
> +# @cid: unique host identifier
> +# @port: port
> +#
> +# Note that string types are used to allow for possible future hostname or
> +# service resolution support.
> +#
> +# Since 2.8
> +##
> +{ 'struct': 'VsockSocketAddress',
> +  'data': {
> +    'cid': 'str',
> +    'port': 'str' } }

Is there any reason to not define these as uint32_t? Not sure if there
are other reasons for this, but if it's just for consistency with how
Inet is handled, the code seems to do straight atoi()<->printf("%d") to
covert between numerical and string representation so it doesn't seem
like we need to account for any differences between command-line and
internal representation in sockaddr_vm.

Re: [Qemu-devel] [PATCH 4/4] qga: add vsock-listen method

[Michael Roth]

Quoting Stefan Hajnoczi (2016-10-06 11:40:18)
> Add AF_VSOCK (virtio-vsock) support as an alternative to virtio-serial.
> 
>   $ qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ...
>   (guest)# qemu-ga -m vsock-listen -p 3:1234
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>

I still need to get a vsock environment set up to test with, but looks
good other than minor comments in patch 3.

> ---
>  qga/channel-posix.c | 25 +++++++++++++++++++++++++
>  qga/channel.h       |  1 +
>  qga/main.c          |  6 ++++--
>  3 files changed, 30 insertions(+), 2 deletions(-)
> 
> diff --git a/qga/channel-posix.c b/qga/channel-posix.c
> index 579891d..71582e0 100644
> --- a/qga/channel-posix.c
> +++ b/qga/channel-posix.c
> @@ -193,6 +193,31 @@ static gboolean ga_channel_open(GAChannel *c, const gchar *path, GAChannelMethod
>          ga_channel_listen_add(c, fd, true);
>          break;
>      }
> +    case GA_CHANNEL_VSOCK_LISTEN: {
> +        Error *local_err = NULL;
> +        SocketAddress *addr;
> +        char *addr_str;
> +        int fd;
> +
> +        addr_str = g_strdup_printf("vsock:%s", path);
> +        addr = socket_parse(addr_str, &local_err);
> +        g_free(addr_str);
> +        if (local_err != NULL) {
> +            g_critical("%s", error_get_pretty(local_err));
> +            error_free(local_err);
> +            return false;
> +        }
> +
> +        fd = socket_listen(addr, &local_err);
> +        qapi_free_SocketAddress(addr);
> +        if (local_err != NULL) {
> +            g_critical("%s", error_get_pretty(local_err));
> +            error_free(local_err);
> +            return false;
> +        }
> +        ga_channel_listen_add(c, fd, true);
> +        break;
> +    }
>      default:
>          g_critical("error binding/listening to specified socket");
>          return false;
> diff --git a/qga/channel.h b/qga/channel.h
> index ae8cf0f..8fd0c8f 100644
> --- a/qga/channel.h
> +++ b/qga/channel.h
> @@ -19,6 +19,7 @@ typedef enum {
>      GA_CHANNEL_VIRTIO_SERIAL,
>      GA_CHANNEL_ISA_SERIAL,
>      GA_CHANNEL_UNIX_LISTEN,
> +    GA_CHANNEL_VSOCK_LISTEN,
>  } GAChannelMethod;
> 
>  typedef gboolean (*GAChannelCallback)(GIOCondition condition, gpointer opaque);
> diff --git a/qga/main.c b/qga/main.c
> index 0b9d04e..6caf215 100644
> --- a/qga/main.c
> +++ b/qga/main.c
> @@ -190,8 +190,8 @@ static void usage(const char *cmd)
>  "Usage: %s [-m <method> -p <path>] [<options>]\n"
>  "QEMU Guest Agent %s\n"
>  "\n"
> -"  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
> -"                    isa-serial (virtio-serial is the default)\n"
> +"  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
> +"                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
>  "  -p, --path        device/socket path (the default for virtio-serial is:\n"
>  "                    %s,\n"
>  "                    the default for isa-serial is:\n"
> @@ -659,6 +659,8 @@ static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
>          channel_method = GA_CHANNEL_ISA_SERIAL;
>      } else if (strcmp(method, "unix-listen") == 0) {
>          channel_method = GA_CHANNEL_UNIX_LISTEN;
> +    } else if (strcmp(method, "vsock-listen") == 0) {
> +        channel_method = GA_CHANNEL_VSOCK_LISTEN;
>      } else {
>          g_critical("unsupported channel method/type: %s", method);
>          return false;
> -- 
> 2.7.4
> 

Re: [Qemu-devel] [PATCH 3/4] sockets: add AF_VSOCK support

[Stefan Hajnoczi]

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On Fri, Oct 07, 2016 at 11:42:35AM -0500, Michael Roth wrote:
> Quoting Stefan Hajnoczi (2016-10-06 11:40:17)
> > Add the AF_VSOCK address family so that qemu-ga will be able to use
> > virtio-vsock.
> > 
> > The AF_VSOCK address family uses <cid, port> address tuples.  The cid is
> > the unique identifier comparable to an IP address.  AF_VSOCK does not
> > use name resolution so it's seasy to convert between struct sockaddr_vm
> > and strings.
> > 
> > This patch defines a VsockSocketAddress instead of trying to piggy-back
> > on InetSocketAddress.  This is cleaner in the long run since it avoids
> > lots of IPv4 vs IPv6 vs vsock special casing.
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >  qapi-schema.json    |  23 +++++-
> >  util/qemu-sockets.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 244 insertions(+), 1 deletion(-)
> > 
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index c3dcf11..8864a96 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -987,12 +987,14 @@
> >  #
> >  # @unix: unix socket
> >  #
> > +# @vsock: vsock family (since 2.8)
> > +#
> >  # @unknown: otherwise
> >  #
> >  # Since: 2.1
> >  ##
> >  { 'enum': 'NetworkAddressFamily',
> > -  'data': [ 'ipv4', 'ipv6', 'unix', 'unknown' ] }
> > +  'data': [ 'ipv4', 'ipv6', 'unix', 'vsock', 'unknown' ] }
> > 
> >  ##
> >  # @VncBasicInfo
> > @@ -3017,6 +3019,24 @@
> >      'path': 'str' } }
> > 
> >  ##
> > +# @VsockSocketAddress
> > +#
> > +# Captures a socket address in the vsock namespace.
> > +#
> > +# @cid: unique host identifier
> > +# @port: port
> > +#
> > +# Note that string types are used to allow for possible future hostname or
> > +# service resolution support.
> > +#
> > +# Since 2.8
> > +##
> > +{ 'struct': 'VsockSocketAddress',
> > +  'data': {
> > +    'cid': 'str',
> > +    'port': 'str' } }
> 
> Is there any reason to not define these as uint32_t? Not sure if there
> are other reasons for this, but if it's just for consistency with how
> Inet is handled, the code seems to do straight atoi()<->printf("%d") to
> covert between numerical and string representation so it doesn't seem
> like we need to account for any differences between command-line and
> internal representation in sockaddr_vm.

Just in case AF_VSOCK ever supports name and service resolution like
TCP/IP.  In that case cid could be a host name and port could be a
service name.

(I mentioned this in the doc comment.)

Stefan

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Re: [Qemu-devel] [PATCH 4/4] qga: add vsock-listen method

[Stefan Hajnoczi]

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On Fri, Oct 07, 2016 at 12:07:41PM -0500, Michael Roth wrote:
> Quoting Stefan Hajnoczi (2016-10-06 11:40:18)
> > Add AF_VSOCK (virtio-vsock) support as an alternative to virtio-serial.
> > 
> >   $ qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ...
> >   (guest)# qemu-ga -m vsock-listen -p 3:1234
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> 
> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> 
> I still need to get a vsock environment set up to test with, but looks
> good other than minor comments in patch 3.

Linux 4.8 has the guest and vhost drivers:

CONFIG_VSOCKETS=m
CONFIG_VIRTIO_VSOCKETS=m
CONFIG_VIRTIO_VSOCKETS_COMMON=m
CONFIG_VHOST_VSOCK=m

Stefan

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Re: [Qemu-devel] [PATCH 3/4] sockets: add AF_VSOCK support

[Michael Roth]

Quoting Stefan Hajnoczi (2016-10-12 10:06:10)
> On Fri, Oct 07, 2016 at 11:42:35AM -0500, Michael Roth wrote:
> > Quoting Stefan Hajnoczi (2016-10-06 11:40:17)
> > > Add the AF_VSOCK address family so that qemu-ga will be able to use
> > > virtio-vsock.
> > > 
> > > The AF_VSOCK address family uses <cid, port> address tuples.  The cid is
> > > the unique identifier comparable to an IP address.  AF_VSOCK does not
> > > use name resolution so it's seasy to convert between struct sockaddr_vm
> > > and strings.
> > > 
> > > This patch defines a VsockSocketAddress instead of trying to piggy-back
> > > on InetSocketAddress.  This is cleaner in the long run since it avoids
> > > lots of IPv4 vs IPv6 vs vsock special casing.
> > > 
> > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > > ---
> > >  qapi-schema.json    |  23 +++++-
> > >  util/qemu-sockets.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > >  2 files changed, 244 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/qapi-schema.json b/qapi-schema.json
> > > index c3dcf11..8864a96 100644
> > > --- a/qapi-schema.json
> > > +++ b/qapi-schema.json
> > > @@ -987,12 +987,14 @@
> > >  #
> > >  # @unix: unix socket
> > >  #
> > > +# @vsock: vsock family (since 2.8)
> > > +#
> > >  # @unknown: otherwise
> > >  #
> > >  # Since: 2.1
> > >  ##
> > >  { 'enum': 'NetworkAddressFamily',
> > > -  'data': [ 'ipv4', 'ipv6', 'unix', 'unknown' ] }
> > > +  'data': [ 'ipv4', 'ipv6', 'unix', 'vsock', 'unknown' ] }
> > > 
> > >  ##
> > >  # @VncBasicInfo
> > > @@ -3017,6 +3019,24 @@
> > >      'path': 'str' } }
> > > 
> > >  ##
> > > +# @VsockSocketAddress
> > > +#
> > > +# Captures a socket address in the vsock namespace.
> > > +#
> > > +# @cid: unique host identifier
> > > +# @port: port
> > > +#
> > > +# Note that string types are used to allow for possible future hostname or
> > > +# service resolution support.
> > > +#
> > > +# Since 2.8
> > > +##
> > > +{ 'struct': 'VsockSocketAddress',
> > > +  'data': {
> > > +    'cid': 'str',
> > > +    'port': 'str' } }
> > 
> > Is there any reason to not define these as uint32_t? Not sure if there
> > are other reasons for this, but if it's just for consistency with how
> > Inet is handled, the code seems to do straight atoi()<->printf("%d") to
> > covert between numerical and string representation so it doesn't seem
> > like we need to account for any differences between command-line and
> > internal representation in sockaddr_vm.
> 
> Just in case AF_VSOCK ever supports name and service resolution like
> TCP/IP.  In that case cid could be a host name and port could be a
> service name.
> 
> (I mentioned this in the doc comment.)

Ahh, sorry I missed that completely. Makes perfect sense then.

> 
> Stefan

Re: [Qemu-devel] [PATCH 4/4] qga: add vsock-listen method

[Michael Roth]

Quoting Stefan Hajnoczi (2016-10-12 10:07:33)
> On Fri, Oct 07, 2016 at 12:07:41PM -0500, Michael Roth wrote:
> > Quoting Stefan Hajnoczi (2016-10-06 11:40:18)
> > > Add AF_VSOCK (virtio-vsock) support as an alternative to virtio-serial.
> > > 
> > >   $ qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ...
> > >   (guest)# qemu-ga -m vsock-listen -p 3:1234
> > > 
> > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > 
> > Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> > 
> > I still need to get a vsock environment set up to test with, but looks
> > good other than minor comments in patch 3.
> 
> Linux 4.8 has the guest and vhost drivers:
> 
> CONFIG_VSOCKETS=m
> CONFIG_VIRTIO_VSOCKETS=m
> CONFIG_VIRTIO_VSOCKETS_COMMON=m
> CONFIG_VHOST_VSOCK=m

I still need to do some work to get this fully integrated into my
test set up, but I ran these patches through some basic testing
with a 4.8.0 host and 4.9 guest and everything seems to be in
working order. I think Eric had some comments related to parameter
parsing in patch 3, but otherwise looks good.

> 
> Stefan