Reply 520 of 530, by LSS10999
nakos1212 wrote on 2024-05-22, 15:01:Did you have the chance to test out my idea? Sorry for the ping, just that I want to buy a new PC and the outcome of this VM experiment heavily influence my parts of choice. My debug cards sadly didnt arrive yet, possibly good old customs...
Just attempted experimenting it with VirtualBox but it was not successful. Turned out the functionality was removed since around 6.1 (mine is 7.0) due to it being "incomplete".
I'm not sure what hypervisor did you use to pass through just your host LPC controller. Did you use QEMU?
Normally a VM would virtualize a chipset of its own. I still have the question whether it's possible to somehow "replace" the VM's ISA bridge with the host's LPC controller, as I doubt two active ISA bridges (the virtualized one as well as the real one passed into the VM) would both function as expected. I don't know very much about the lower-level aspects of QEMU anyway.
If you don't have the debug card you may try just talking with your SuperIO (usually at 2Eh/2Fh) according to its datasheet, if available, to see if you can somehow reach it from inside the VM after passing the host LPC controller through.
On the other hand, the adapter apparently expects very strict electrical connectivity. Casually made cables won't cut it, as they'll likely come loose and break the functionality after a prolonged while.
Although I did manage to make a working IDC cable, it only lasted for about a week and now it coming loose again. I'm looking for some right materials to make one that'll hopefully stay working for a bit longer.
PS: I'm not sure how VMusic extpack performs. You may consider using it alongside VBox's own SB16 emulation to see how those emulations perform in overall. Actually, in some cases VBox's SB16 emulation does not suffer from certain bugs that existed on real hardware.
A notable example would be, with Windows NT 3.51, on real Sound Blaster 16/AWE hardware, I was unable to play any audio file past a certain bit rate (determined by sampling rate and bit-width), whereas VBox's SB16 emulation does not suffer from those same issues (all files played fine). I've already reproduced the issues in question on very different setups, such as CT2950 behind a LPC-ISA bridge, as well as an AWE64 Gold on a 865G/ICH5 based board. Logon/logoff sounds from Win2000/Me's "media" folder were notable examples, though interestingly the same files played fine with non-Creative sound cards (e.g. ALS007).
PPS: There are still some things I'm not informed. Firstly I wonder when ACS did become a thing, as my X99 board does not appear to offer that option. The BIOS was kind of crippled in overall, that even with the hidden "Advanced" menu unlocked I still don't get the option to bifurcate my second PCIe slot.
Additionally, when you did pass through your board's LPC controller, can you still access sensors like temperature and fan speed from your host, and were your system fans still operating as usual, if connected to the board instead of directly to PSU?