Comment 51 for bug 1884232

I don't know what's in the 5.18.10-76051810-generic kernel (I assume that's v5.18 + some Ubuntu patches). The upstream fixes for this went into v5.19: https://git.kernel.org/linus/3cc30140dbe2
I think v5.18 + the following patches (which somebody added in the "Bug Description" at the very beginning of this report) should work:

a2b36ffbf5b6 x86/PCI: Revert "x86/PCI: Clip only host bridge windows for E820 regions"
d341838d776a x86/PCI: Disable E820 reserved region clipping via quirks
fa6dae5d8208 x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions
4c5e242d3e93 x86/PCI: Clip only host bridge windows for E820 regions
31bf0f433325 x86: Log resource clipping for E820 regions
93d256cd3c1e x86/PCI: Eliminate remove_e820_regions() common subexpressions