diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2013-03-03 10:21:32 -0700 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2013-03-26 21:02:17 +0200 |
| commit | ba7d8515c1e929baccea9f53d06d131fd2b007a1 (patch) | |
| tree | 9a1115a50f7eb6c5a87ece47075eb79ca9c78a2f /hw/pci/pci_bus.h | |
| parent | e01fd687185444944b0b5b0f8c739ae4b33eb029 (diff) | |
pci: Teach PCI Bridges about VGA routing
Each PCI Bridge has a set of implied VGA regions that are enabled when
the VGA bit is set in the bridge control register. This allows VGA
devices behind bridges. Unfortunately with VGA Enable, which we
formerly allowed but didn't back, comes along some required VGA
baggage. VGA Palette Snooping is required, along with VGA 16-bit
decoding. We don't yet have support for palette snooping.
We also don't have support for 10-bit VGA aliases, the default mode, but
we enable the register, even on root ports, to avoid confusing guests.
Fortunately there's likely nothing from this century that requires these
features, so the missing bits are noted with TODOs.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/pci/pci_bus.h')
| -rw-r--r-- | hw/pci/pci_bus.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/hw/pci/pci_bus.h b/hw/pci/pci_bus.h index f905b9e11e..aef559ae1f 100644 --- a/hw/pci/pci_bus.h +++ b/hw/pci/pci_bus.h @@ -47,6 +47,13 @@ struct PCIBridgeWindows { MemoryRegion alias_pref_mem; MemoryRegion alias_mem; MemoryRegion alias_io; + /* + * When bridge control VGA forwarding is enabled, bridges will + * provide positive decode on the PCI VGA defined I/O port and + * MMIO ranges. When enabled forwarding is only qualified on the + * I/O and memory enable bits in the bridge command register. + */ + MemoryRegion alias_vga[QEMU_PCI_VGA_NUM_REGIONS]; }; struct PCIBridge { |