From c8498903f19357ce72eeb976b3054c56896a6c44 Mon Sep 17 00:00:00 2001

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

Date: Thu, 21 Jun 2018 18:54:37 +0200

Subject: [PATCH 28/57] virtio: support setting memory region based host

 notifier

RH-Author: plai@redhat.com

Message-id: <1529607285-9942-3-git-send-email-plai@redhat.com>

Patchwork-id: 80937

O-Subject: [RHEL7.6 PATCH BZ 1526645 02/10] virtio: support setting memory region based 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 support for setting memory region

based host notifiers for virtio device. This is helpful when

using a hardware accelerator for a virtio device, because

hardware heavily depends on the notification, this will allow

the guest driver in the VM to notify the hardware directly.

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 6f80e6170ede13605817e5c0ca73db0de7bdf261)

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

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

---

 hw/virtio/virtio-pci.c         | 22 ++++++++++++++++++++++

 hw/virtio/virtio.c             | 13 +++++++++++++

 include/hw/virtio/virtio-bus.h |  2 ++

 include/hw/virtio/virtio.h     |  2 ++

 4 files changed, 39 insertions(+)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c

index 18f7c2c..b887fc4 100644

--- a/hw/virtio/virtio-pci.c

+++ b/hw/virtio/virtio-pci.c

@@ -1037,6 +1037,27 @@ assign_error:

     return r;

 }

+static int virtio_pci_set_host_notifier_mr(DeviceState *d, int n,

+                                           MemoryRegion *mr, bool assign)

+{

+    VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);

+    int offset;

+

+    if (n >= VIRTIO_QUEUE_MAX || !virtio_pci_modern(proxy) ||

+        virtio_pci_queue_mem_mult(proxy) != memory_region_size(mr)) {

+        return -1;

+    }

+

+    if (assign) {

+        offset = virtio_pci_queue_mem_mult(proxy) * n;

+        memory_region_add_subregion_overlap(&proxy->notify.mr, offset, mr, 1);

+    } else {

+        memory_region_del_subregion(&proxy->notify.mr, mr);

+    }

+

+    return 0;

+}

+

 static void virtio_pci_vmstate_change(DeviceState *d, bool running)

 {

     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);

@@ -2652,6 +2673,7 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)

     k->has_extra_state = virtio_pci_has_extra_state;

     k->query_guest_notifiers = virtio_pci_query_guest_notifiers;

     k->set_guest_notifiers = virtio_pci_set_guest_notifiers;

+    k->set_host_notifier_mr = virtio_pci_set_host_notifier_mr;

     k->vmstate_change = virtio_pci_vmstate_change;

     k->pre_plugged = virtio_pci_pre_plugged;

     k->device_plugged = virtio_pci_device_plugged;

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c

index 4bcb4f4..5549bb4 100644

--- a/hw/virtio/virtio.c

+++ b/hw/virtio/virtio.c

@@ -2472,6 +2472,19 @@ EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)

     return &vq->host_notifier;

 }

+int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,

+                                      MemoryRegion *mr, bool assign)

+{

+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));

+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);

+

+    if (k->set_host_notifier_mr) {

+        return k->set_host_notifier_mr(qbus->parent, n, mr, assign);

+    }

+

+    return -1;

+}

+

 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name)

 {

     g_free(vdev->bus_name);

diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h

index ced3d2d..7fec9dc 100644

--- a/include/hw/virtio/virtio-bus.h

+++ b/include/hw/virtio/virtio-bus.h

@@ -52,6 +52,8 @@ typedef struct VirtioBusClass {

     bool (*has_extra_state)(DeviceState *d);

     bool (*query_guest_notifiers)(DeviceState *d);

     int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);

+    int (*set_host_notifier_mr)(DeviceState *d, int n,

+                                MemoryRegion *mr, bool assign);

     void (*vmstate_change)(DeviceState *d, bool running);

     /*

      * Expose the features the transport layer supports before

diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h

index 41e13d2..96313e8 100644

--- a/include/hw/virtio/virtio.h

+++ b/include/hw/virtio/virtio.h

@@ -240,6 +240,8 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);

 void virtio_queue_notify(VirtIODevice *vdev, int n);

 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);

 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);

+int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,

+                                      MemoryRegion *mr, bool assign);

 int virtio_set_status(VirtIODevice *vdev, uint8_t val);

 void virtio_reset(void *opaque);

 void virtio_update_irq(VirtIODevice *vdev);

-- 

1.8.3.1