[Qemu-devel] Re: [PATCH 10/10] introduce qemu_ram_map

[Marcelo Tosatti <mtosatti@redhat.com>]

On Tue, Apr 27, 2010 at 08:32:27AM -0600, Cam Macdonell wrote:
> >
> > +ram_addr_t qemu_ram_map(ram_addr_t size, void *host)
> > +{
> > +    RAMBlock *new_block;
> > +
> > +    size = TARGET_PAGE_ALIGN(size);
> > +    new_block = qemu_malloc(sizeof(*new_block));
> > +
> > +    new_block->host = host;
> > +
> > +    new_block->offset = last_ram_offset;
> > +    new_block->length = size;
> > +
> > +    new_block->next = ram_blocks;
> > +    ram_blocks = new_block;
> > +
> > +    phys_ram_dirty = qemu_realloc(phys_ram_dirty,
> > +        (last_ram_offset + size) >> TARGET_PAGE_BITS);
> > +    memset(phys_ram_dirty + (last_ram_offset >> TARGET_PAGE_BITS),
> > +           0xff, size >> TARGET_PAGE_BITS);
> > +
> > +    last_ram_offset += size;
> > +
> > +    if (kvm_enabled())
> > +        kvm_setup_guest_memory(new_block->host, size);
> > +
> > +    return new_block->offset;
> > +}
> > +
> >  ram_addr_t qemu_ram_alloc(ram_addr_t size)
> >  {
> >     RAMBlock *new_block;
> > --
> > 1.6.6.1
> >
> 
> Sorry for being late to reply, is there a strong reason not to have
> the function handle the mmap itself?  As As Anthony points out, that
> way we don't have worry about realloc changing the pointer in the
> function.

The caller might want a different protection for the memory map.