As QEMU gains PCI bridge and PCIe root port support, we won't always
find the VGA device on the root bus. We therefore need to add support
to find and enable a VGA device and the path to it through the VGA
Enable support in the PCI bridge control register.
Signed-off-by: Alex Williamson <alex.williamson(a)redhat.com>
---
src/optionroms.c | 2 +-
src/pciinit.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
src/util.h | 1 +
3 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/src/optionroms.c b/src/optionroms.c
index caa2151..ac92613 100644
--- a/src/optionroms.c
+++ b/src/optionroms.c
@@ -213,7 +213,7 @@ run_file_roms(const char *prefix, int isvga, u64 *sources)
****************************************************************/
// Verify device is a vga device with legacy address decoding enabled.
-static int
+int
is_pci_vga(struct pci_device *pci)
{
if (pci->class != PCI_CLASS_DISPLAY_VGA)
diff --git a/src/pciinit.c b/src/pciinit.c
index ce0a4cc..eb49a76 100644
--- a/src/pciinit.c
+++ b/src/pciinit.c
@@ -316,6 +316,49 @@ static void pci_bios_init_devices(void)
}
}
+static void pci_enable_default_vga(void)
+{
+ struct pci_device *pci;
+
+ foreachpci(pci) {
+ if (is_pci_vga(pci)) {
+ dprintf(1, "PCI: Using %02x:%02x.%x for primary VGA\n",
+ pci_bdf_to_bus(pci->bdf), pci_bdf_to_dev(pci->bdf),
+ pci_bdf_to_fn(pci->bdf));
+ return;
+ }
+ }
+
+ pci = pci_find_class(PCI_CLASS_DISPLAY_VGA);
+ if (!pci) {
+ dprintf(1, "PCI: No VGA devices found\n");
+ return;
+ }
+
+ dprintf(1, "PCI: Enabling %02x:%02x.%x for primary VGA\n",
+ pci_bdf_to_bus(pci->bdf), pci_bdf_to_dev(pci->bdf),
+ pci_bdf_to_fn(pci->bdf));
+
+ u16 cmd = pci_config_readw(pci->bdf, PCI_COMMAND);
+ cmd |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
+ pci_config_writew(pci->bdf, PCI_COMMAND, cmd);
+
+ while (pci->parent) {
+ pci = pci->parent;
+
+ dprintf(1, "PCI: Setting VGA enable on bridge %02x:%02x.%x\n",
+ pci_bdf_to_bus(pci->bdf), pci_bdf_to_dev(pci->bdf),
+ pci_bdf_to_fn(pci->bdf));
+
+ u8 ctrl = pci_config_readb(pci->bdf, PCI_BRIDGE_CONTROL);
+ ctrl |= PCI_BRIDGE_CTL_VGA;
+ pci_config_writeb(pci->bdf, PCI_BRIDGE_CONTROL, ctrl);
+
+ u16 cmd = pci_config_readw(pci->bdf, PCI_COMMAND);
+ cmd |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
+ pci_config_writew(pci->bdf, PCI_COMMAND, cmd);
+ }
+}
/****************************************************************
* Platform device initialization
@@ -804,4 +847,6 @@ pci_setup(void)
pci_bios_init_devices();
free(busses);
+
+ pci_enable_default_vga();
}
diff --git a/src/util.h b/src/util.h
index 306a8bf..e1df295 100644
--- a/src/util.h
+++ b/src/util.h
@@ -343,6 +343,7 @@ void vgahook_setup(struct pci_device *pci);
// optionroms.c
void call_bcv(u16 seg, u16 ip);
+int is_pci_vga(struct pci_device *pci);
void optionrom_setup(void);
void vgarom_setup(void);
void s3_resume_vga(void);