display/stdvga: add edid support.

This patch adds edid support to the qemu stdvga.  It is turned off by
default and can be enabled with the new edid property.  The patch also
adds xres and yres properties to specify the video mode you want the
guest use.  Works only with edid enabled and updated guest driver.

The mmio bar of the stdvga has some unused address space at the start.
It was reserved just in case it'll be needed for virtio, but it turned
out to not be needed for that.  So let's use that region to place the
EDID data block there.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20180925075646.25114-6-kraxel@redhat.com

docs/specs/standard-vga.txt

@@ -61,7 +61,7 @@ MMIO area spec
 
 Likewise applies to the pci variant only for obvious reasons.
 
-0000 - 03ff : reserved, for possible virtio extension.
+0000 - 03ff : edid data blob.
 0400 - 041f : vga ioports (0x3c0 -> 0x3df), remapped 1:1.
               word access is supported, bytes are written
               in little endia order (aka index port first),

hw/display/vga-pci.c

@@ -30,18 +30,22 @@
 #include "ui/pixel_ops.h"
 #include "qemu/timer.h"
 #include "hw/loader.h"
+#include "hw/display/edid.h"
 
 enum vga_pci_flags {
     PCI_VGA_FLAG_ENABLE_MMIO = 1,
     PCI_VGA_FLAG_ENABLE_QEXT = 2,
+    PCI_VGA_FLAG_ENABLE_EDID = 3,
 };
 
 typedef struct PCIVGAState {
     PCIDevice dev;
     VGACommonState vga;
     uint32_t flags;
+    qemu_edid_info edid_info;
     MemoryRegion mmio;
-    MemoryRegion mrs[3];
+    MemoryRegion mrs[4];
+    uint8_t edid[256];
 } PCIVGAState;
 
 #define TYPE_PCI_VGA "pci-vga"
@@ -195,8 +199,10 @@ void pci_std_vga_mmio_region_init(VGACommonState *s,
                                   Object *owner,
                                   MemoryRegion *parent,
                                   MemoryRegion *subs,
-                                  bool qext)
+                                  bool qext, bool edid)
 {
+    PCIVGAState *d = container_of(s, PCIVGAState, vga);
+
     memory_region_init_io(&subs[0], owner, &pci_vga_ioport_ops, s,
                           "vga ioports remapped", PCI_VGA_IOPORT_SIZE);
     memory_region_add_subregion(parent, PCI_VGA_IOPORT_OFFSET,
@@ -213,6 +219,12 @@ void pci_std_vga_mmio_region_init(VGACommonState *s,
         memory_region_add_subregion(parent, PCI_VGA_QEXT_OFFSET,
                                     &subs[2]);
     }
+
+    if (edid) {
+        qemu_edid_generate(d->edid, sizeof(d->edid), &d->edid_info);
+        qemu_edid_region_io(&subs[3], owner, d->edid, sizeof(d->edid));
+        memory_region_add_subregion(parent, 0, &subs[3]);
+    }
 }
 
 static void pci_std_vga_realize(PCIDevice *dev, Error **errp)
@@ -220,6 +232,7 @@ static void pci_std_vga_realize(PCIDevice *dev, Error **errp)
     PCIVGAState *d = PCI_VGA(dev);
     VGACommonState *s = &d->vga;
     bool qext = false;
+    bool edid = false;
 
     /* vga + console init */
     vga_common_init(s, OBJECT(dev));
@@ -240,7 +253,11 @@ static void pci_std_vga_realize(PCIDevice *dev, Error **errp)
             qext = true;
             pci_set_byte(&d->dev.config[PCI_REVISION_ID], 2);
         }
-        pci_std_vga_mmio_region_init(s, OBJECT(dev), &d->mmio, d->mrs, qext);
+        if (d->flags & (1 << PCI_VGA_FLAG_ENABLE_EDID)) {
+            edid = true;
+        }
+        pci_std_vga_mmio_region_init(s, OBJECT(dev), &d->mmio, d->mrs,
+                                     qext, edid);
 
         pci_register_bar(&d->dev, 2, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mmio);
     }
@@ -263,6 +280,7 @@ static void pci_secondary_vga_realize(PCIDevice *dev, Error **errp)
     PCIVGAState *d = PCI_VGA(dev);
     VGACommonState *s = &d->vga;
     bool qext = false;
+    bool edid = false;
 
     /* vga + console init */
     vga_common_init(s, OBJECT(dev));
@@ -276,7 +294,10 @@ static void pci_secondary_vga_realize(PCIDevice *dev, Error **errp)
         qext = true;
         pci_set_byte(&d->dev.config[PCI_REVISION_ID], 2);
     }
-    pci_std_vga_mmio_region_init(s, OBJECT(dev), &d->mmio, d->mrs, qext);
+    if (d->flags & (1 << PCI_VGA_FLAG_ENABLE_EDID)) {
+        edid = true;
+    }
+    pci_std_vga_mmio_region_init(s, OBJECT(dev), &d->mmio, d->mrs, qext, edid);
 
     pci_register_bar(&d->dev, 0, PCI_BASE_ADDRESS_MEM_PREFETCH, &s->vram);
     pci_register_bar(&d->dev, 2, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mmio);
@@ -308,6 +329,9 @@ static Property vga_pci_properties[] = {
     DEFINE_PROP_BIT("mmio", PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_MMIO, true),
     DEFINE_PROP_BIT("qemu-extended-regs",
                     PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_QEXT, true),
+    DEFINE_PROP_BIT("edid",
+                    PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_EDID, false),
+    DEFINE_EDID_PROPERTIES(PCIVGAState, edid_info),
     DEFINE_PROP_BOOL("global-vmstate", PCIVGAState, vga.global_vmstate, false),
     DEFINE_PROP_END_OF_LIST(),
 };
@@ -316,6 +340,9 @@ static Property secondary_pci_properties[] = {
     DEFINE_PROP_UINT32("vgamem_mb", PCIVGAState, vga.vram_size_mb, 16),
     DEFINE_PROP_BIT("qemu-extended-regs",
                     PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_QEXT, true),
+    DEFINE_PROP_BIT("edid",
+                    PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_EDID, false),
+    DEFINE_EDID_PROPERTIES(PCIVGAState, edid_info),
     DEFINE_PROP_END_OF_LIST(),
 };
 

hw/display/vga_int.h

@@ -197,6 +197,6 @@ void pci_std_vga_mmio_region_init(VGACommonState *s,
                                   Object *owner,
                                   MemoryRegion *parent,
                                   MemoryRegion *subs,
-                                  bool qext);
+                                  bool qext, bool edid);
 
 #endif

hw/display/virtio-vga.c

@@ -153,7 +153,7 @@ static void virtio_vga_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
 
     /* add stdvga mmio regions */
     pci_std_vga_mmio_region_init(vga, OBJECT(vvga), &vpci_dev->modern_bar,
-                                 vvga->vga_mrs, true);
+                                 vvga->vga_mrs, true, false);
 
     vga->con = g->scanout[0].con;
     graphic_console_set_hwops(vga->con, &virtio_vga_ops, vvga);