Hi,
Background: The drivers in seabios work on both virtual and physical hardware (you can run seabios as coreboot payload on physical hardware). There are quite a few places where are delays and timeouts which are required to work properly on physical hardware. But typically virtual hardware is alot faster. There is -- for example -- no time needed to establish a sata link. Link detection in ahci is instant on qemu.
I'll investigate also other timeouts.
I'd focus on legacy lpc/isa hardware here. PCI-ish hardware which has such timeouts (sata, usb, ...) typically isn't present in the virtual machine if you care about performance. Or, in other words, the best way to handle the sata link detection delay is to use "qemu -M q35,sata=off".
cheers, Gerd