[Qemu-devel] [PULL 10/11] hw/virtio: Add PCIe capability to virtio devices

["Michael S. Tsirkin" <mst@redhat.com>]

From: Marcel Apfelbaum <marcel@redhat.com>

The virtio devices are converted to PCI-Express
if they are plugged into a PCI-Express bus and
the 'modern' protocol is enabled.

Devices plugged directly into the Root Complex as
Integrated Endpoints remain PCI.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/virtio-pci.h |  2 ++
 include/hw/compat.h    |  4 ++++
 hw/virtio/virtio-pci.c | 22 ++++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 460c3c9..ffb74bb 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -72,8 +72,10 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
 /* virtio version flags */
 #define VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT 2
 #define VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT 3
+#define VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT 4
 #define VIRTIO_PCI_FLAG_DISABLE_LEGACY (1 << VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT)
 #define VIRTIO_PCI_FLAG_DISABLE_MODERN (1 << VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT)
+#define VIRTIO_PCI_FLAG_DISABLE_PCIE (1 << VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT)
 
 /* migrate extra state */
 #define VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT 4
diff --git a/include/hw/compat.h b/include/hw/compat.h
index 65799c1..845aace 100644
--- a/include/hw/compat.h
+++ b/include/hw/compat.h
@@ -8,6 +8,10 @@
             .value    = "true",\
         },{\
             .driver   = "virtio-pci",\
+            .property = "x-disable-pcie",\
+            .value    = "on",\
+        },{\
+            .driver   = "virtio-pci",\
             .property = "migrate-extra",\
             .value    = "off",\
         },
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 52a9e33..dd48562 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1814,6 +1814,26 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
 
     address_space_init(&proxy->modern_as, &proxy->modern_cfg, "virtio-pci-cfg-as");
 
+    if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE)
+        && !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN)
+        && pci_bus_is_express(pci_dev->bus)
+        && !pci_bus_is_root(pci_dev->bus)) {
+        int pos;
+
+        pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;
+        pos = pcie_endpoint_cap_init(pci_dev, 0);
+        assert(pos > 0);
+
+        pos = pci_add_capability(pci_dev, PCI_CAP_ID_PM, 0, PCI_PM_SIZEOF);
+        assert(pos > 0);
+
+        /*
+         * Indicates that this function complies with revision 1.2 of the
+         * PCI Power Management Interface Specification.
+         */
+        pci_set_word(pci_dev->config + pos + PCI_PM_PMC, 0x3);
+    }
+
     virtio_pci_bus_new(&proxy->bus, sizeof(proxy->bus), proxy);
     if (k->realize) {
         k->realize(proxy, errp);
@@ -1854,6 +1874,8 @@ static Property virtio_pci_properties[] = {
                     VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT, true),
     DEFINE_PROP_BIT("modern-pio-notify", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT, false),
+    DEFINE_PROP_BIT("x-disable-pcie", VirtIOPCIProxy, flags,
+                    VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
-- 
MST