[Qemu-devel] Re: [RFC 1/2] Add qemu_ram_remap

[Marcelo Tosatti <mtosatti@redhat.com>]

On Fri, Dec 31, 2010 at 01:22:34PM +0800, Huang Ying wrote:
> qemu_ram_remap() unmaps the specified RAM pages, then re-maps these
> pages again.  This is used by KVM HWPoison support to clear HWPoisoned
> page tables across guest rebooting, so that a new page may be
> allocated later to recover the memory error.
> 
> Signed-off-by: Huang Ying <ying.huang@intel.com>
> ---
>  cpu-all.h    |    4 +++
>  cpu-common.h |    1 
>  exec.c       |   61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  3 files changed, 65 insertions(+), 1 deletion(-)
> 
> --- a/cpu-all.h
> +++ b/cpu-all.h
> @@ -861,10 +861,14 @@ target_phys_addr_t cpu_get_phys_page_deb
>  extern int phys_ram_fd;
>  extern ram_addr_t ram_size;
>  
> +/* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */
> +#define RAM_PREALLOC_MASK	(1 << 0)
> +
>  typedef struct RAMBlock {
>      uint8_t *host;
>      ram_addr_t offset;
>      ram_addr_t length;
> +    uint32_t flags;
>      char idstr[256];
>      QLIST_ENTRY(RAMBlock) next;
>  #if defined(__linux__) && !defined(TARGET_S390X)
> --- a/exec.c
> +++ b/exec.c
> @@ -2845,6 +2845,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(Devic
>  
>      if (host) {
>          new_block->host = host;
> +        new_block->flags |= RAM_PREALLOC_MASK;
>      } else {
>          if (mem_path) {
>  #if defined (__linux__) && !defined(TARGET_S390X)
> @@ -2911,7 +2912,9 @@ void qemu_ram_free(ram_addr_t addr)
>      QLIST_FOREACH(block, &ram_list.blocks, next) {
>          if (addr == block->offset) {
>              QLIST_REMOVE(block, next);
> -            if (mem_path) {
> +            if (block->flags & RAM_PREALLOC_MASK)
> +                ;

Missing braces.

Otherwise looks fine to me.

Should be merged upstream QEMU... Anthony?