Re: [Qemu-devel] [PATCH 3/3] support readonly memory feature in qemu

[Avi Kivity]

On 09/07/2012 11:26 AM, Liu Sheng wrote:
> as readonly memory is support in kvm, this patch supports this feature
> in qemu, mainly pluging the memory region with KVM_MEM_READONLY flag
> to kvm.
> 
> @@ -1607,10 +1623,19 @@ int kvm_cpu_exec(CPUArchState *env)
>              break;
>          case KVM_EXIT_MMIO:
>              DPRINTF("handle_mmio\n");
> -            cpu_physical_memory_rw(run->mmio.phys_addr,
> -                                   run->mmio.data,
> -                                   run->mmio.len,
> -                                   run->mmio.is_write);
> +            if (run->mmio.write_readonly_mem) {
> +                fprintf(stderr, "Guest is writing readonly memory, "
> +                    "phys_addr: %llx, len:%x, data[0]:%c, skip it.\n",
> +                    run->mmio.phys_addr,
> +                    run->mmio.len,
> +                    run->mmio.data[0]);
> +            } else {
> +                cpu_physical_memory_rw(run->mmio.phys_addr,
> +                                       run->mmio.data,
> +                                       run->mmio.len,
> +                                       run->mmio.is_write);
> +            }
> +
>              ret = 0;

I don't think this is needed.  A cpu_physical_memory_rw() to a ROM ought
to be ignored (and btw, it may not be a ROM - it could be a ROM/Device,
in which case it ought not to be ignored).


-- 
error compiling committee.c: too many arguments to function