vmm: igvm: Generate memory map for SEV-SNP guests

For SEV-SNP guests we need to provide the extended memory. It follows a
very simple layout and very similar to other x86 guests.

First segment: [HIGH_RAM_START - MEM_32BIT_RESERVED_START]
PCI hole: [MEM_32BIT_RESERVED_START - RAM_64BIT_START]
Second segment: [RAM_64BIT_START - RAM_END]

Fixes #5993

Signed-off-by: Jinank Jain <jinankjain@microsoft.com>

vmm/src/vm.rs

@@ -998,8 +998,6 @@ impl Vm {
         memory_manager: Arc<Mutex<MemoryManager>>,
         cpu_manager: Arc<Mutex<cpu::CpuManager>>,
     ) -> Result<EntryPoint> {
-        //TODO: see issue https://github.com/cloud-hypervisor/cloud-hypervisor/issues/5993
-
         let res = igvm_loader::load_igvm(&igvm, memory_manager, cpu_manager, "")
             .map_err(Error::IgvmLoad)?;