I received my Arc Pro B50 this week and finally had some time to play with it. I’ve got it in an X570 system running Ubuntu 24.04 and mainline kernel 6.17. I created a VF and a spun up a new Windows 11 (25H2) VM in virt-manager with it attached. Once Windows was booted I installed the Q3.25 driver (32.0.101.6979) and… it works? Here’s the Geekbench GPU score, which seems about right. Unfortunately it doesn’t look like video encode/decode is working; I see high CPU utilization and the GPU perf view in Task Manager shows 0% video decode and processing. We’ll see what kernel 6.18-rc and the Q4.25 driver bring, but this is a heck of an encouraging start!
Other notes: I cannot get the host stable when booted into Windows. The display goes dark and as far as I can tell it’s kernel-panicking. I was able to capture “Stop code: VIDEO_TDR_FAILURE (0x116) What failed: igdkmdnd64.sys” using another GPU for display out. Speaking of which, I also seem to hit a major snag when I bifurcate the PEG IOU. It will still boot to Linux with it set to x8x4x4 or x8x8 but I completely lose display out. Disabling SR-IOV doesn’t help but I didn’t troubleshoot any further than that. I suspect Intel support won’t be too keen to work with me to fix this on AM4. 
lspci -v showing PF and VF:
0e:00.0 VGA compatible controller: Intel Corporation Device e212 (prog-if 00 [VGA controller])
Subsystem: Intel Corporation Device 1114
Flags: bus master, fast devsel, latency 0, IRQ 255, IOMMU group 31
Memory at 7e0c000000 (64-bit, prefetchable) [size=16M]
Memory at 7400000000 (64-bit, prefetchable) [size=16G]
Expansion ROM at fc000000 [disabled] [size=2M]
Capabilities: [40] Vendor Specific Information: Len=0c <?>
Capabilities: [70] Express Endpoint, MSI 00
Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable+ 64bit+
Capabilities: [d0] Power Management version 3
Capabilities: [100] Alternative Routing-ID Interpretation (ARI)
Capabilities: [110] Null
Capabilities: [200] Address Translation Service (ATS)
Capabilities: [420] Physical Resizable BAR
Capabilities: [220] Virtual Resizable BAR
Capabilities: [320] Single Root I/O Virtualization (SR-IOV)
Capabilities: [400] Latency Tolerance Reporting
Kernel driver in use: xe
Kernel modules: xe
0e:00.1 VGA compatible controller: Intel Corporation Device e212 (prog-if 00 [VGA controller])
Subsystem: Intel Corporation Device 1114
Flags: bus master, fast devsel, latency 0, IRQ 301, IOMMU group 51
Memory at 7e00000000 (64-bit, prefetchable) [disabled] [size=16M]
Memory at 7800000000 (64-bit, prefetchable) [virtual] [size=8G]
Capabilities: [70] Express Endpoint, MSI 00
Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable+ 64bit+
Capabilities: [100] Alternative Routing-ID Interpretation (ARI)
Capabilities: [200] Address Translation Service (ATS)
Kernel driver in use: vfio-pci
Kernel modules: xe
No, it uses the newer xe driver with SR-IOV support built-in and enabled by default (as of 6.17, I think).