[Qemu-devel] Re: [PATCH] exec: remove code duplication in qemu_ram_alloc() and qemu_ram_alloc_from_ptr()

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 2010-08-18 at 15:41 +0900, Yoshiaki Tamura wrote:
> Since most of the code in qemu_ram_alloc() and
> qemu_ram_alloc_from_ptr() are duplicated, let
> qemu_ram_alloc_from_ptr() to switch by checking void *host, and change
> qemu_ram_alloc() to a wrapper.
> 
> Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>

Acked-by: Alex Williamson <alex.williamson@redhat.com>

> ---
>  exec.c |   84 +++++++++++++++++++--------------------------------------------
>  1 files changed, 26 insertions(+), 58 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index 4fc96cb..82bfffc 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2809,7 +2809,7 @@ static ram_addr_t last_ram_offset(void)
>  }
>  
>  ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name,
> -                        ram_addr_t size, void *host)
> +                                   ram_addr_t size, void *host)
>  {
>      RAMBlock *new_block, *block;
>  
> @@ -2833,74 +2833,37 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name,
>          }
>      }
>  
> -    new_block->host = host;
> -
> -    new_block->offset = find_ram_offset(size);
> -    new_block->length = size;
> -
> -    QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
> -
> -    ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty,
> -                                       last_ram_offset() >> TARGET_PAGE_BITS);
> -    memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
> -           0xff, size >> TARGET_PAGE_BITS);
> -
> -    if (kvm_enabled())
> -        kvm_setup_guest_memory(new_block->host, size);
> -
> -    return new_block->offset;
> -}
> -
> -ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size)
> -{
> -    RAMBlock *new_block, *block;
> -
> -    size = TARGET_PAGE_ALIGN(size);
> -    new_block = qemu_mallocz(sizeof(*new_block));
> -
> -    if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
> -        char *id = dev->parent_bus->info->get_dev_path(dev);
> -        if (id) {
> -            snprintf(new_block->idstr, sizeof(new_block->idstr), "%s/", id);
> -            qemu_free(id);
> -        }
> -    }
> -    pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
> -
> -    QLIST_FOREACH(block, &ram_list.blocks, next) {
> -        if (!strcmp(block->idstr, new_block->idstr)) {
> -            fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
> -                    new_block->idstr);
> -            abort();
> -        }
> -    }
> -
> -    if (mem_path) {
> +    if (host) {
> +        new_block->host = host;
> +    } else {
> +        if (mem_path) {
>  #if defined (__linux__) && !defined(TARGET_S390X)
> -        new_block->host = file_ram_alloc(new_block, size, mem_path);
> -        if (!new_block->host) {
> -            new_block->host = qemu_vmalloc(size);
> +            new_block->host = file_ram_alloc(new_block, size, mem_path);
> +            if (!new_block->host) {
> +                new_block->host = qemu_vmalloc(size);
>  #ifdef MADV_MERGEABLE
> -            madvise(new_block->host, size, MADV_MERGEABLE);
> +                madvise(new_block->host, size, MADV_MERGEABLE);
>  #endif
> -        }
> +            }
>  #else
> -        fprintf(stderr, "-mem-path option unsupported\n");
> -        exit(1);
> +            fprintf(stderr, "-mem-path option unsupported\n");
> +            exit(1);
>  #endif
> -    } else {
> +        } else {
>  #if defined(TARGET_S390X) && defined(CONFIG_KVM)
> -        /* XXX S390 KVM requires the topmost vma of the RAM to be < 256GB */
> -        new_block->host = mmap((void*)0x1000000, size,
> -                                PROT_EXEC|PROT_READ|PROT_WRITE,
> -                                MAP_SHARED | MAP_ANONYMOUS, -1, 0);
> +            /* XXX S390 KVM requires the topmost vma of the RAM to be < 256GB */
> +            new_block->host = mmap((void*)0x1000000, size,
> +                                   PROT_EXEC|PROT_READ|PROT_WRITE,
> +                                   MAP_SHARED | MAP_ANONYMOUS, -1, 0);
>  #else
> -        new_block->host = qemu_vmalloc(size);
> +            new_block->host = qemu_vmalloc(size);
>  #endif
>  #ifdef MADV_MERGEABLE
> -        madvise(new_block->host, size, MADV_MERGEABLE);
> +            madvise(new_block->host, size, MADV_MERGEABLE);
>  #endif
> +        }
>      }
> +
>      new_block->offset = find_ram_offset(size);
>      new_block->length = size;
>  
> @@ -2917,6 +2880,11 @@ ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size)
>      return new_block->offset;
>  }
>  
> +ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size)
> +{
> +    return qemu_ram_alloc_from_ptr(dev, name, size, NULL);
> +}
> +
>  void qemu_ram_free(ram_addr_t addr)
>  {
>      RAMBlock *block;