From: Haiyang Zhang <haiyangz@microsoft.com>

quoted

quoted

...
-	if (gen2vm) {
-		pot_start = 0;
-		pot_end = -1;
-	} else {
-		if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
-		    pci_resource_len(pdev, 0) < screen_fb_size) {
-			pr_err("Resource not available or (0x%lx < 0x%lx)\n",
-			       (unsigned long) pci_resource_len(pdev, 0),
-			       (unsigned long) screen_fb_size);
-			goto err1;

This restriction has been in place since day 1. Haiyang, you wrote this
driver. Can you comment on whether this change here is sensible?

When I initially implemented this driver 10 years ago, I believe there
was smaller limit for the fb... But I think this patch is good for the
newer MMIO alloc scheme. I hope to see reviews also from
 @Dexuan Cui @Michael Kelley (LINUX) who are more familiar with
the PCI/BAR/MMIO area.

Thanks,
- Haiyang

The patch looks good to me but I suggest we check with the Hyper-V
team to figure out how a Gen1 Windows VM supports a higher
resolution that needs a VRAM size of more than 64MB. Just in case we
miss something..

Thanks,
-- Dexuan