[Qemu-devel] [PULL v4 0/2] virtio: fixes

[Qemu-devel] [PULL v4 0/2] virtio: fixes

[Michael S. Tsirkin]

The following changes since commit d1eb8f2acba579830cf3798c3c15ce51be852c56:

  fpu: add mechanism to check for invalid long double formats (2016-09-15 12:43:18 +0100)

are available in the git repository at:

  git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream

for you to fetch changes up to 6bd7776cd0a9581cdb5e9dd40df8821a96e355d6:

  MAINTAINERS: add virtio-* tests (2016-09-16 21:54:03 +0300)

----------------------------------------------------------------
virtio: fixes

virtio feature negotiation rework

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

----------------------------------------------------------------
Greg Kurz (1):
      MAINTAINERS: add virtio-* tests

Maxime Coquelin (1):
      virtio-bus: Plug devices after features are negotiated

 hw/virtio/virtio-pci.h         |  5 +++++
 include/hw/virtio/virtio-bus.h | 10 +++++-----
 hw/s390x/virtio-ccw.c          | 30 +++++++++++++++---------------
 hw/virtio/virtio-bus.c         |  9 +++++----
 hw/virtio/virtio-pci.c         | 36 ++++++++++++++++++++++++++++++++----
 MAINTAINERS                    |  7 +++++++
 6 files changed, 69 insertions(+), 28 deletions(-)

[Qemu-devel] [PULL v4 1/2] virtio-bus: Plug devices after features are negotiated

[Michael S. Tsirkin]

From: Maxime Coquelin <maxime.coquelin@redhat.com>

Currently, devices are plugged before features are negotiated.
If the backend doesn't support VIRTIO_F_VERSION_1, the transport
needs to rewind some settings.

This is the case for CCW, for which a post_plugged callback had
been introduced, where max_rev field is just updated if
VIRTIO_F_VERSION_1 is not supported by the backend.
For PCI, implementing post_plugged would be much more
complicated, so it needs to know whether the backend supports
VIRTIO_F_VERSION_1 at plug time.

Currently, nothing is done for PCI. Modern capabilities get
exposed to the guest even if VIRTIO_F_VERSION_1 is not supported
by the backend, which confuses the guest.

This patch replaces existing post_plugged solution with an
approach that fits with both transports.
Features negotiation is performed before ->device_plugged() call.
A pre_plugged callback is introduced so that the transports can
set their supported features.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-stable@nongnu.org
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com> [ccw]
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 hw/virtio/virtio-pci.h         |  5 +++++
 include/hw/virtio/virtio-bus.h | 10 +++++-----
 hw/s390x/virtio-ccw.c          | 30 +++++++++++++++---------------
 hw/virtio/virtio-bus.c         |  9 +++++----
 hw/virtio/virtio-pci.c         | 36 ++++++++++++++++++++++++++++++++----
 5 files changed, 62 insertions(+), 28 deletions(-)

diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 0698157..541cbdb 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -181,6 +181,11 @@ static inline void virtio_pci_force_virtio_1(VirtIOPCIProxy *proxy)
     proxy->disable_legacy = ON_OFF_AUTO_ON;
 }
 
+static inline void virtio_pci_disable_modern(VirtIOPCIProxy *proxy)
+{
+    proxy->disable_modern = true;
+}
+
 /*
  * virtio-scsi-pci: This extends VirtioPCIProxy.
  */
diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h
index f3e5ef3..24caa0a 100644
--- a/include/hw/virtio/virtio-bus.h
+++ b/include/hw/virtio/virtio-bus.h
@@ -54,16 +54,16 @@ typedef struct VirtioBusClass {
     int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);
     void (*vmstate_change)(DeviceState *d, bool running);
     /*
+     * Expose the features the transport layer supports before
+     * the negotiation takes place.
+     */
+    void (*pre_plugged)(DeviceState *d, Error **errp);
+    /*
      * transport independent init function.
      * This is called by virtio-bus just after the device is plugged.
      */
     void (*device_plugged)(DeviceState *d, Error **errp);
     /*
-     * Re-evaluate setup after feature bits have been validated
-     * by the device backend.
-     */
-    void (*post_plugged)(DeviceState *d, Error **errp);
-    /*
      * transport independent exit function.
      * This is called by virtio-bus just before the device is unplugged.
      */
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 9678956..9f3f386 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1261,6 +1261,16 @@ static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
     return 0;
 }
 
+static void virtio_ccw_pre_plugged(DeviceState *d, Error **errp)
+{
+   VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
+   VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+
+    if (dev->max_rev >= 1) {
+        virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
+    }
+}
+
 /* This is called by virtio-bus just after the device is plugged. */
 static void virtio_ccw_device_plugged(DeviceState *d, Error **errp)
 {
@@ -1270,6 +1280,10 @@ static void virtio_ccw_device_plugged(DeviceState *d, Error **errp)
     SubchDev *sch = ccw_dev->sch;
     int n = virtio_get_num_queues(vdev);
 
+    if (!virtio_has_feature(vdev->host_features, VIRTIO_F_VERSION_1)) {
+        dev->max_rev = 0;
+    }
+
     if (virtio_get_num_queues(vdev) > VIRTIO_CCW_QUEUE_MAX) {
         error_setg(errp, "The number of virtqueues %d "
                    "exceeds ccw limit %d", n,
@@ -1283,25 +1297,11 @@ static void virtio_ccw_device_plugged(DeviceState *d, Error **errp)
 
     sch->id.cu_model = virtio_bus_get_vdev_id(&dev->bus);
 
-    if (dev->max_rev >= 1) {
-        virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
-    }
 
     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
                           d->hotplugged, 1);
 }
 
-static void virtio_ccw_post_plugged(DeviceState *d, Error **errp)
-{
-   VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
-   VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
-
-   if (!virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1)) {
-        /* A backend didn't support modern virtio. */
-       dev->max_rev = 0;
-   }
-}
-
 static void virtio_ccw_device_unplugged(DeviceState *d)
 {
     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
@@ -1593,8 +1593,8 @@ static void virtio_ccw_bus_class_init(ObjectClass *klass, void *data)
     k->load_queue = virtio_ccw_load_queue;
     k->save_config = virtio_ccw_save_config;
     k->load_config = virtio_ccw_load_config;
+    k->pre_plugged = virtio_ccw_pre_plugged;
     k->device_plugged = virtio_ccw_device_plugged;
-    k->post_plugged = virtio_ccw_post_plugged;
     k->device_unplugged = virtio_ccw_device_unplugged;
     k->ioeventfd_started = virtio_ccw_ioeventfd_started;
     k->ioeventfd_set_started = virtio_ccw_ioeventfd_set_started;
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index 1492793..11f65bd 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -49,16 +49,17 @@ void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp)
 
     DPRINTF("%s: plug device.\n", qbus->name);
 
-    if (klass->device_plugged != NULL) {
-        klass->device_plugged(qbus->parent, errp);
+    if (klass->pre_plugged != NULL) {
+        klass->pre_plugged(qbus->parent, errp);
     }
 
     /* Get the features of the plugged device. */
     assert(vdc->get_features != NULL);
     vdev->host_features = vdc->get_features(vdev, vdev->host_features,
                                             errp);
-    if (klass->post_plugged != NULL) {
-        klass->post_plugged(qbus->parent, errp);
+
+    if (klass->device_plugged != NULL) {
+        klass->device_plugged(qbus->parent, errp);
     }
 }
 
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index dde71a5..2d60a00 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1576,18 +1576,48 @@ static void virtio_pci_modern_io_region_unmap(VirtIOPCIProxy *proxy,
                                 &region->mr);
 }
 
+static void virtio_pci_pre_plugged(DeviceState *d, Error **errp)
+{
+    VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+    if (virtio_pci_modern(proxy)) {
+        virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
+    }
+
+    virtio_add_feature(&vdev->host_features, VIRTIO_F_BAD_FEATURE);
+}
+
 /* This is called by virtio-bus just after the device is plugged. */
 static void virtio_pci_device_plugged(DeviceState *d, Error **errp)
 {
     VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
     VirtioBusState *bus = &proxy->bus;
     bool legacy = virtio_pci_legacy(proxy);
-    bool modern = virtio_pci_modern(proxy);
+    bool modern;
     bool modern_pio = proxy->flags & VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY;
     uint8_t *config;
     uint32_t size;
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
+    /*
+     * Virtio capabilities present without
+     * VIRTIO_F_VERSION_1 confuses guests
+     */
+    if (!virtio_has_feature(vdev->host_features, VIRTIO_F_VERSION_1)) {
+        virtio_pci_disable_modern(proxy);
+
+        if (!legacy) {
+            error_setg(errp, "Device doesn't support modern mode, and legacy"
+                             " mode is disabled");
+            error_append_hint(errp, "Set disable-legacy to off\n");
+
+            return;
+        }
+    }
+
+    modern = virtio_pci_modern(proxy);
+
     config = proxy->pci_dev.config;
     if (proxy->class_code) {
         pci_config_set_class(config, proxy->class_code);
@@ -1629,7 +1659,6 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp)
 
         struct virtio_pci_cfg_cap *cfg_mask;
 
-        virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
         virtio_pci_modern_regions_init(proxy);
 
         virtio_pci_modern_mem_region_map(proxy, &proxy->common, &cap);
@@ -1694,8 +1723,6 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp)
     if (!kvm_has_many_ioeventfds()) {
         proxy->flags &= ~VIRTIO_PCI_FLAG_USE_IOEVENTFD;
     }
-
-    virtio_add_feature(&vdev->host_features, VIRTIO_F_BAD_FEATURE);
 }
 
 static void virtio_pci_device_unplugged(DeviceState *d)
@@ -2508,6 +2535,7 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
     k->query_guest_notifiers = virtio_pci_query_guest_notifiers;
     k->set_guest_notifiers = virtio_pci_set_guest_notifiers;
     k->vmstate_change = virtio_pci_vmstate_change;
+    k->pre_plugged = virtio_pci_pre_plugged;
     k->device_plugged = virtio_pci_device_plugged;
     k->device_unplugged = virtio_pci_device_unplugged;
     k->query_nvectors = virtio_pci_query_nvectors;
-- 
MST

[Qemu-devel] [PULL v4 2/2] MAINTAINERS: add virtio-* tests

[Michael S. Tsirkin]

From: Greg Kurz <groug@kaod.org>

Except virtio-9p, all virtio-* tests are orphan. This patch tries to fix
it, according to the following logic:

- when the related subsystem has its own section in MAINTAINERS, the test
  is added there
- otherwise it is added to the "parent" section (aka. SCSI, Network devices,
  virtio)

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 MAINTAINERS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 4db611f..0e0c326 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -830,6 +830,7 @@ Network devices
 M: Jason Wang <jasowang@redhat.com>
 S: Odd Fixes
 F: hw/net/
+F: tests/virtio-net-test.c
 T: git git://github.com/jasowang/qemu.git net
 
 SCSI
@@ -837,6 +838,7 @@ M: Paolo Bonzini <pbonzini@redhat.com>
 S: Supported
 F: include/hw/scsi/*
 F: hw/scsi/*
+F: tests/virtio-scsi-test.c
 T: git git://github.com/bonzini/qemu.git scsi-next
 
 LSI53C895A
@@ -889,6 +891,7 @@ S: Supported
 F: hw/*/virtio*
 F: net/vhost-user.c
 F: include/hw/virtio/
+F: tests/virtio-balloon-test.c
 
 virtio-9p
 M: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
@@ -907,6 +910,7 @@ S: Supported
 F: hw/block/virtio-blk.c
 F: hw/block/dataplane/*
 F: hw/virtio/dataplane/*
+F: tests/virtio-blk-test.c
 T: git git://github.com/stefanha/qemu.git block
 
 virtio-ccw
@@ -929,6 +933,8 @@ S: Supported
 F: hw/char/virtio-serial-bus.c
 F: hw/char/virtio-console.c
 F: include/hw/virtio/virtio-serial.h
+F: tests/virtio-console-test.c
+F: tests/virtio-serial-test.c
 
 virtio-rng
 M: Amit Shah <amit.shah@redhat.com>
@@ -937,6 +943,7 @@ F: hw/virtio/virtio-rng.c
 F: include/hw/virtio/virtio-rng.h
 F: include/sysemu/rng*.h
 F: backends/rng*.c
+F: tests/virtio-rng-test.c
 
 nvme
 M: Keith Busch <keith.busch@intel.com>
-- 
MST

Re: [Qemu-devel] [PULL v4 0/2] virtio: fixes

[Peter Maydell]

On 16 September 2016 at 19:55, Michael S. Tsirkin <mst@redhat.com> wrote:
> The following changes since commit d1eb8f2acba579830cf3798c3c15ce51be852c56:
>
>   fpu: add mechanism to check for invalid long double formats (2016-09-15 12:43:18 +0100)
>
> are available in the git repository at:
>
>   git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream
>
> for you to fetch changes up to 6bd7776cd0a9581cdb5e9dd40df8821a96e355d6:
>
>   MAINTAINERS: add virtio-* tests (2016-09-16 21:54:03 +0300)
>
> ----------------------------------------------------------------
> virtio: fixes
>
> virtio feature negotiation rework
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>
> ----------------------------------------------------------------
> Greg Kurz (1):
>       MAINTAINERS: add virtio-* tests
>
> Maxime Coquelin (1):
>       virtio-bus: Plug devices after features are negotiated

Applied, thanks.

-- PMM