[PATCH v2 2/8] virtio-gpu: hostmem [wip]

[Antonio Caggiano <antonio.caggiano@collabora.com>]

From: Gerd Hoffmann <kraxel@redhat.com>

---
 hw/display/virtio-gpu-base.c                |  4 +++
 hw/display/virtio-gpu-pci.c                 | 14 +++++++++
 hw/display/virtio-gpu.c                     |  1 +
 hw/display/virtio-vga.c                     | 32 +++++++++++++++------
 include/hw/virtio/virtio-gpu.h              |  5 ++++
 include/standard-headers/linux/virtio_gpu.h |  5 ++++
 6 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c
index 619185a9d2..31b430664f 100644
--- a/hw/display/virtio-gpu-base.c
+++ b/hw/display/virtio-gpu-base.c
@@ -214,6 +214,10 @@ virtio_gpu_base_get_features(VirtIODevice *vdev, uint64_t features,
 
     features |= (1 << VIRTIO_GPU_F_CONTEXT_INIT);
 
+    if (virtio_gpu_hostmem_enabled(g->conf)) {
+        features |= (1 << VIRTIO_GPU_F_HOSTMEM);
+    }
+
     return features;
 }
 
diff --git a/hw/display/virtio-gpu-pci.c b/hw/display/virtio-gpu-pci.c
index e36eee0c40..9808663d05 100644
--- a/hw/display/virtio-gpu-pci.c
+++ b/hw/display/virtio-gpu-pci.c
@@ -33,6 +33,20 @@ static void virtio_gpu_pci_base_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
     DeviceState *vdev = DEVICE(g);
     int i;
 
+    if (virtio_gpu_hostmem_enabled(g->conf)) {
+        vpci_dev->msix_bar_idx = 1;
+        vpci_dev->modern_mem_bar_idx = 2;
+        memory_region_init(&g->hostmem, OBJECT(g), "virtio-gpu-hostmem",
+                           g->conf.hostmem);
+        pci_register_bar(&vpci_dev->pci_dev, 4,
+                         PCI_BASE_ADDRESS_SPACE_MEMORY |
+                         PCI_BASE_ADDRESS_MEM_PREFETCH |
+                         PCI_BASE_ADDRESS_MEM_TYPE_64,
+                         &g->hostmem);
+        virtio_pci_add_shm_cap(vpci_dev, 4, 0, g->conf.hostmem, 0);
+    }
+
+    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus), errp);
     virtio_pci_force_virtio_1(vpci_dev);
     if (!qdev_realize(vdev, BUS(&vpci_dev->bus), errp)) {
         return;
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 990e71fd40..9686f17d79 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -1392,6 +1392,7 @@ static Property virtio_gpu_properties[] = {
                      256 * MiB),
     DEFINE_PROP_BIT("blob", VirtIOGPU, parent_obj.conf.flags,
                     VIRTIO_GPU_FLAG_BLOB_ENABLED, false),
+    DEFINE_PROP_SIZE("hostmem", VirtIOGPU, parent_obj.conf.hostmem, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/display/virtio-vga.c b/hw/display/virtio-vga.c
index 9e57f61e9e..61993dd3f2 100644
--- a/hw/display/virtio-vga.c
+++ b/hw/display/virtio-vga.c
@@ -125,16 +125,30 @@ static void virtio_vga_base_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
     pci_register_bar(&vpci_dev->pci_dev, 0,
                      PCI_BASE_ADDRESS_MEM_PREFETCH, &vga->vram);
 
-    /*
-     * Configure virtio bar and regions
-     *
-     * We use bar #2 for the mmio regions, to be compatible with stdvga.
-     * virtio regions are moved to the end of bar #2, to make room for
-     * the stdvga mmio registers at the start of bar #2.
-     */
-    vpci_dev->modern_mem_bar_idx = 2;
-    vpci_dev->msix_bar_idx = 4;
     vpci_dev->modern_io_bar_idx = 5;
+  
+    if (!virtio_gpu_hostmem_enabled(g->conf)) {
+        /*
+        * Configure virtio bar and regions
+        *
+        * We use bar #2 for the mmio regions, to be compatible with stdvga.
+        * virtio regions are moved to the end of bar #2, to make room for
+        * the stdvga mmio registers at the start of bar #2.
+        */
+        vpci_dev->modern_mem_bar_idx = 2;
+        vpci_dev->msix_bar_idx = 4;
+    } else {
+        vpci_dev->msix_bar_idx = 1;
+        vpci_dev->modern_mem_bar_idx = 2;
+        memory_region_init(&g->hostmem, OBJECT(g), "virtio-gpu-hostmem",
+                           g->conf.hostmem);
+        pci_register_bar(&vpci_dev->pci_dev, 4,
+                         PCI_BASE_ADDRESS_SPACE_MEMORY |
+                         PCI_BASE_ADDRESS_MEM_PREFETCH |
+                         PCI_BASE_ADDRESS_MEM_TYPE_64,
+                         &g->hostmem);
+        virtio_pci_add_shm_cap(vpci_dev, 4, 0, g->conf.hostmem, 0);
+    }
 
     if (!(vpci_dev->flags & VIRTIO_PCI_FLAG_PAGE_PER_VQ)) {
         /*
diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
index 24c6628944..835ebcb1a0 100644
--- a/include/hw/virtio/virtio-gpu.h
+++ b/include/hw/virtio/virtio-gpu.h
@@ -102,12 +102,15 @@ enum virtio_gpu_base_conf_flags {
     (_cfg.flags & (1 << VIRTIO_GPU_FLAG_DMABUF_ENABLED))
 #define virtio_gpu_blob_enabled(_cfg) \
     (_cfg.flags & (1 << VIRTIO_GPU_FLAG_BLOB_ENABLED))
+#define virtio_gpu_hostmem_enabled(_cfg) \
+    (_cfg.hostmem > 0)
 
 struct virtio_gpu_base_conf {
     uint32_t max_outputs;
     uint32_t flags;
     uint32_t xres;
     uint32_t yres;
+    uint64_t hostmem;
 };
 
 struct virtio_gpu_ctrl_command {
@@ -131,6 +134,8 @@ struct VirtIOGPUBase {
     int renderer_blocked;
     int enable;
 
+    MemoryRegion hostmem;
+
     struct virtio_gpu_scanout scanout[VIRTIO_GPU_MAX_SCANOUTS];
 
     int enabled_output_bitmask;
diff --git a/include/standard-headers/linux/virtio_gpu.h b/include/standard-headers/linux/virtio_gpu.h
index c9f9c24d6a..85898d41a7 100644
--- a/include/standard-headers/linux/virtio_gpu.h
+++ b/include/standard-headers/linux/virtio_gpu.h
@@ -65,6 +65,11 @@
  */
 #define VIRTIO_GPU_F_CONTEXT_INIT        4
 
+/*
+ * shared memory
+ */
+#define VIRTIO_GPU_F_HOSTMEM             5
+
 enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_UNDEFINED = 0,
 
-- 
2.30.2