Re: [Qemu-devel] [PATCH v2 01/16] Remove uses of ram.last_offset (aka last_ram_offset)

[Anthony Liguori]

On 06/25/2010 12:08 PM, Alex Williamson wrote:
> We currently need this either to allocate the next ram_addr_t for a
> new block, or for total memory to be migrated.  Both of which we can
> calculate without need of this to keep us in a contiguous address space.
>
> Signed-off-by: Alex Williamson<address@hidden>
>    

Applied all.  Thanks.

Regards,

Anthony Liguori

> ---
>
>   arch_init.c |   23 ++++++++++++++++-------
>   cpu-all.h   |    1 -
>   exec.c      |   19 ++++++++++++++-----
>   3 files changed, 30 insertions(+), 13 deletions(-)
>
> diff --git a/arch_init.c b/arch_init.c
> index eb5b67c..109dcef 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -108,9 +108,10 @@ static int ram_save_block(QEMUFile *f)
>       static ram_addr_t current_addr = 0;
>       ram_addr_t saved_addr = current_addr;
>       ram_addr_t addr = 0;
> +    uint64_t total_ram = ram_bytes_total();
>       int bytes_sent = 0;
>
> -    while (addr<  ram_list.last_offset) {
> +    while (addr<  total_ram) {
>           if (cpu_physical_memory_get_dirty(current_addr, 
> MIGRATION_DIRTY_FLAG)) {
>               uint8_t *p;
>
> @@ -133,7 +134,7 @@ static int ram_save_block(QEMUFile *f)
>               break;
>           }
>           addr += TARGET_PAGE_SIZE;
> -        current_addr = (saved_addr + addr) % ram_list.last_offset;
> +        current_addr = (saved_addr + addr) % total_ram;
>       }
>
>       return bytes_sent;
> @@ -145,8 +146,9 @@ static ram_addr_t ram_save_remaining(void)
>   {
>       ram_addr_t addr;
>       ram_addr_t count = 0;
> +    uint64_t total_ram = ram_bytes_total();
>
> -    for (addr = 0; addr<  ram_list.last_offset; addr += TARGET_PAGE_SIZE) {
> +    for (addr = 0; addr<  total_ram; addr += TARGET_PAGE_SIZE) {
>           if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) {
>               count++;
>           }
> @@ -167,7 +169,13 @@ uint64_t ram_bytes_transferred(void)
>
>   uint64_t ram_bytes_total(void)
>   {
> -    return ram_list.last_offset;
> +    RAMBlock *block;
> +    uint64_t total = 0;
> +
> +    QLIST_FOREACH(block,&ram_list.blocks, next)
> +        total += block->length;
> +
> +    return total;
>   }
>
>   int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
> @@ -188,10 +196,11 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, 
> void *opaque)
>       }
>
>       if (stage == 1) {
> +        uint64_t total_ram = ram_bytes_total();
>           bytes_transferred = 0;
>
>           /* Make sure all dirty bits are set */
> -        for (addr = 0; addr<  ram_list.last_offset; addr += TARGET_PAGE_SIZE) {
> +        for (addr = 0; addr<  total_ram; addr += TARGET_PAGE_SIZE) {
>               if (!cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) {
>                   cpu_physical_memory_set_dirty(addr);
>               }
> @@ -200,7 +209,7 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, 
> void *opaque)
>           /* Enable dirty memory tracking */
>           cpu_physical_memory_set_dirty_tracking(1);
>
> -        qemu_put_be64(f, ram_list.last_offset | RAM_SAVE_FLAG_MEM_SIZE);
> +        qemu_put_be64(f, total_ram | RAM_SAVE_FLAG_MEM_SIZE);
>       }
>
>       bytes_transferred_last = bytes_transferred;
> @@ -259,7 +268,7 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
>           addr&= TARGET_PAGE_MASK;
>
>           if (flags&  RAM_SAVE_FLAG_MEM_SIZE) {
> -            if (addr != ram_list.last_offset) {
> +            if (addr != ram_bytes_total()) {
>                   return -EINVAL;
>               }
>           }
> diff --git a/cpu-all.h b/cpu-all.h
> index e31c2de..dbb2139 100644
> --- a/cpu-all.h
> +++ b/cpu-all.h
> @@ -870,7 +870,6 @@ typedef struct RAMBlock {
>
>   typedef struct RAMList {
>       uint8_t *phys_dirty;
> -    ram_addr_t last_offset;
>       QLIST_HEAD(ram, RAMBlock) blocks;
>   } RAMList;
>   extern RAMList ram_list;
> diff --git a/exec.c b/exec.c
> index 7f64384..058b709 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2765,6 +2765,17 @@ static void *file_ram_alloc(ram_addr_t memory, const 
> char *path)
>   }
>   #endif
>
> +static ram_addr_t find_ram_offset(ram_addr_t size)
> +{
> +    RAMBlock *block;
> +    ram_addr_t last = 0;
> +
> +    QLIST_FOREACH(block,&ram_list.blocks, next)
> +        last = MAX(last, block->offset + block->length);
> +
> +    return last;
> +}
> +
>   ram_addr_t qemu_ram_alloc(ram_addr_t size)
>   {
>       RAMBlock *new_block;
> @@ -2798,18 +2809,16 @@ ram_addr_t qemu_ram_alloc(ram_addr_t size)
>           madvise(new_block->host, size, MADV_MERGEABLE);
>   #endif
>       }
> -    new_block->offset = ram_list.last_offset;
> +    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,
> -        (ram_list.last_offset + size)>>  TARGET_PAGE_BITS);
> -    memset(ram_list.phys_dirty + (ram_list.last_offset>>  TARGET_PAGE_BITS),
> +        (new_block->offset + size)>>  TARGET_PAGE_BITS);
> +    memset(ram_list.phys_dirty + (new_block->offset>>  TARGET_PAGE_BITS),
>              0xff, size>>  TARGET_PAGE_BITS);
>
> -    ram_list.last_offset += size;
> -
>       if (kvm_enabled())
>           kvm_setup_guest_memory(new_block->host, size);
>
>
>
>
>