[Qemu-devel] [PATCH 1/3] virtio-pci: add flags to enable/disable legacy/modern

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <address@hidden>
---
 hw/virtio/virtio-pci.c | 46 +++++++++++++++++++++++++++++++++-------------
 hw/virtio/virtio-pci.h |  6 ++++++
 2 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index a6ce3fe..407063c 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1234,6 +1234,8 @@ static void virtio_pci_device_plugged(DeviceState *d)
 {
     VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
     VirtioBusState *bus = &proxy->bus;
+    bool legacy = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_LEGACY);
+    bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN);
     uint8_t *config;
     uint32_t size;
 
@@ -1241,13 +1243,24 @@ static void virtio_pci_device_plugged(DeviceState *d)
     if (proxy->class_code) {
         pci_config_set_class(config, proxy->class_code);
     }
-    pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID,
-                 pci_get_word(config + PCI_VENDOR_ID));
-    pci_set_word(config + PCI_SUBSYSTEM_ID, virtio_bus_get_vdev_id(bus));
+
+    if (legacy) {
+        /* legacy and transitional */
+        pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID,
+                     pci_get_word(config + PCI_VENDOR_ID));
+        pci_set_word(config + PCI_SUBSYSTEM_ID, virtio_bus_get_vdev_id(bus));
+    } else {
+        /* pure virtio-1.0 */
+        pci_set_word(config + PCI_VENDOR_ID,
+                     PCI_VENDOR_ID_REDHAT_QUMRANET);
+        pci_set_word(config + PCI_DEVICE_ID,
+                     0x1040 + virtio_bus_get_vdev_id(bus));
+        pci_config_set_revision(config, 1);
+    }
     config[PCI_INTERRUPT_PIN] = 1;
 
 
-    if (1) { /* TODO: Make this optional, dependent on virtio 1.0 */
+    if (modern) {
         struct virtio_pci_cap common = {
             .cfg_type = VIRTIO_PCI_CAP_COMMON_CFG,
             .cap_len = sizeof common,
@@ -1360,17 +1373,20 @@ static void virtio_pci_device_plugged(DeviceState *d)
 
     proxy->pci_dev.config_write = virtio_write_config;
 
-    size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev)
-         + virtio_bus_get_vdev_config_len(bus);
-    if (size & (size - 1)) {
-        size = 1 << qemu_fls(size);
-    }
+    if (legacy) {
+        size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev)
+            + virtio_bus_get_vdev_config_len(bus);
+        if (size & (size - 1)) {
+            size = 1 << qemu_fls(size);
+        }
 
-    memory_region_init_io(&proxy->bar, OBJECT(proxy), &virtio_pci_config_ops,
-                          proxy, "virtio-pci", size);
+        memory_region_init_io(&proxy->bar, OBJECT(proxy),
+                              &virtio_pci_config_ops,
+                              proxy, "virtio-pci", size);
 
-    pci_register_bar(&proxy->pci_dev, 0, PCI_BASE_ADDRESS_SPACE_IO,
-                     &proxy->bar);
+        pci_register_bar(&proxy->pci_dev, 0, PCI_BASE_ADDRESS_SPACE_IO,
+                         &proxy->bar);
+    }
 
     if (!kvm_has_many_ioeventfds()) {
         proxy->flags &= ~VIRTIO_PCI_FLAG_USE_IOEVENTFD;
@@ -1417,6 +1433,10 @@ static void virtio_pci_reset(DeviceState *qdev)
 static Property virtio_pci_properties[] = {
     DEFINE_PROP_BIT("virtio-pci-bus-master-bug-migration", VirtIOPCIProxy, 
flags,
                     VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT, false),
+    DEFINE_PROP_BIT("disable-legacy", VirtIOPCIProxy, flags,
+                    VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT, false),
+    DEFINE_PROP_BIT("disable-modern", VirtIOPCIProxy, flags,
+                    VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT, false),
     DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 271a73a..938eeff 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -68,6 +68,12 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
 #define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1
 #define VIRTIO_PCI_FLAG_USE_IOEVENTFD   (1 << 
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT)
 
+/* virtio version flags */
+#define VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT 2
+#define VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT 3
+#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)
+
 typedef struct {
     MSIMessage msg;
     int virq;
-- 
1.8.3.1