Hi,
This series aims to fix an issue of booting a guest with many PVSCSI disk controllers (>=16). Currently, booting such a guest result in exhausting available memory in high-zone which leads to guest crash.
The 1st patch improve PVSCSI memory consumption by removing an unnecessary contraint of allocating a page-aligned memory.
The 2nd patch modifies SeaBIOS high-zone allocator to fallback to low-zone in case high-zone is exhausted. This is possible because high-zone is used only by 32-bit code which don't care if allocation is from high-zone or low-zone and just uses high-zone because it has more space. However, in case there is no more memory in high-zone, it makes sense to utilize remaining memory in low-zone to still be able to boot guest successfully.
Regards, -Liran