On Thu, Dec 31, 2020 at 07:08:23PM -0800, Bin Gao wrote:
On real hardware especially server platforms, there might be multiple root buses, thus pci bus number could run up to 255. This patch fixed pci_probe_devices() by allowing to scan all 256 pci bus numbers(0-255).
Signed-off-by: Bin Gao gaobin@amazon.com
src/hw/pcidevice.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/src/hw/pcidevice.c b/src/hw/pcidevice.c index 8853cf7..8d9c401 100644 --- a/src/hw/pcidevice.c +++ b/src/hw/pcidevice.c @@ -26,6 +26,14 @@ pci_probe_devices(void) struct hlist_node **pprev = &PCIDevices.first; int extraroots = romfile_loadint("etc/extra-pci-roots", 0); int bus = -1, lastbus = 0, rootbuses = 0, count=0;
- // There might be multiple PCI root buses on physical hardware especially
- // server platforms, thus bus number could run up to the top value,
- // i.e. 0xff. Setting extraroots to 0xff to ensure we can enumerate all
- // PCI bus numbers.
- if (CONFIG_CSM)
extraroots = 0xff;
This doesn't look correct to me. It would take a noticeable amount of time to scan every possible PCI root bus. It would introduce a regression for any current users of CONFIG_CSM.
The "etc/extra-pci-roots" config is intended to allow users to make these choices at runtime. If more configurability is desired on CONFIG_CSM, then it will be needed to figure out a way to pass options to SeaBIOS when in that mode.
-Kevin