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.c | |
| 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.c')
| -rw-r--r-- | hw/pci/pci.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/hw/pci/pci.c b/hw/pci/pci.c index ed43111bce..a88160236e 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -674,6 +674,10 @@ static void pci_init_mask_bridge(PCIDevice *d) #define PCI_BRIDGE_CTL_SEC_DISCARD 0x200 /* Secondary discard timer */ #define PCI_BRIDGE_CTL_DISCARD_STATUS 0x400 /* Discard timer status */ #define PCI_BRIDGE_CTL_DISCARD_SERR 0x800 /* Discard timer SERR# enable */ +/* + * TODO: Bridges default to 10-bit VGA decoding but we currently only + * implement 16-bit decoding (no alias support). + */ pci_set_word(d->wmask + PCI_BRIDGE_CONTROL, PCI_BRIDGE_CTL_PARITY | PCI_BRIDGE_CTL_SERR | |