Re: [PATCH v3 5/6] i386/pc: warn if phys-bits is too low

[Joao Martins <joao.m.martins@oracle.com>]

On 2/23/22 18:44, Joao Martins wrote:
> @@ -896,6 +897,15 @@ void pc_memory_init(PCMachineState *pcms,
>  
>      x86_update_above_4g_mem_start(pcms, pci_hole64_size);
>  
> +    maxphysaddr = ((hwaddr)1 << X86_CPU(first_cpu)->phys_bits) - 1;
> +    maxusedaddr = x86_max_phys_addr(pcms, pci_hole64_size);
> +    if (maxphysaddr < maxusedaddr) {
> +        warn_report("Address space above 4G at %"PRIx64"-%"PRIx64
> +                    " phys-bits too low (%u)",
> +                    x86ms->above_4g_mem_start, maxusedaddr,
> +                    X86_CPU(first_cpu)->phys_bits);
> +    }
> +
And in addition to the change in patch 4, for 32-bit I will change this
to an error_report(...) and exit right after, and updating commit message
accordingly. The error message changes slightly too given that it was
too specific to the above 4G region. All qtests pass.

diffstat below:

@@ -904,6 +905,16 @@ void pc_memory_init(PCMachineState *pcms,

     x86_update_above_4g_mem_start(pcms, pci_hole64_size);

+    maxphysaddr = ((hwaddr)1 << X86_CPU(first_cpu)->phys_bits) - 1;
+    maxusedaddr = x86_max_phys_addr(pcms, pci_hole64_size);
+    if (maxphysaddr < maxusedaddr) {
+        error_report("Address space limit 0x%"PRIx64" < 0x%"PRIx64
+                     " phys-bits too low (%u)",
+                     maxphysaddr, maxusedaddr,
+                     X86_CPU(first_cpu)->phys_bits);
+        exit(EXIT_FAILURE);
+    }