Re: [Qemu-devel] [PATCH v4 1/4] Modify DIRTY_FLAG value and introduce DIRTY_IDX to use as indexes of bit-based phys_ram_dirty.

[Anthony Liguori <anthony@codemonkey.ws>]

Hi Yoshi,

Could you rebase this series and resubmit?  It conflicts with the latest 
HEAD.

Regards,

Anthony Liguori

On 04/19/2010 10:40 PM, Yoshiaki Tamura wrote:
> Replaces byte-based phys_ram_dirty bitmap with four (MASTER, VGA, CODE,
> MIGRATION) bit-based phys_ram_dirty bitmap.  On allocation, it sets all bits in
> the bitmap.  It uses ffs() to convert DIRTY_FLAG to DIRTY_IDX.
>
> Modifies wrapper functions for byte-based phys_ram_dirty bitmap to bit-based
> phys_ram_dirty bitmap.  MASTER works as a buffer, and upon get_diry() or
> get_dirty_flags(), it calls cpu_physical_memory_sync_master() to update VGA and
> MIGRATION.
>
> Signed-off-by: Yoshiaki Tamura<tamura.yoshiaki@lab.ntt.co.jp>
> ---
>   cpu-all.h     |  127 ++++++++++++++++++++++++++++++++++++++++++++++++---------
>   exec.c        |   15 +++++--
>   qemu-common.h |    3 +
>   3 files changed, 121 insertions(+), 24 deletions(-)
>
> diff --git a/cpu-all.h b/cpu-all.h
> index f8bfa66..b6a2d91 100644
> --- a/cpu-all.h
> +++ b/cpu-all.h
> @@ -37,6 +37,9 @@
>
>   #include "softfloat.h"
>
> +/* to use ffs in flag_to_idx() */
> +#include<strings.h>
> +
>   #if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)
>   #define BSWAP_NEEDED
>   #endif
> @@ -853,7 +856,6 @@ target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr);
>   /* memory API */
>
>   extern int phys_ram_fd;
> -extern uint8_t *phys_ram_dirty;
>   extern ram_addr_t ram_size;
>   extern ram_addr_t last_ram_offset;
>
> @@ -878,50 +880,137 @@ extern int mem_prealloc;
>   /* Set if TLB entry is an IO callback.  */
>   #define TLB_MMIO        (1<<  5)
>
> -#define VGA_DIRTY_FLAG       0x01
> -#define CODE_DIRTY_FLAG      0x02
> -#define MIGRATION_DIRTY_FLAG 0x08
> +/* Use DIRTY_IDX as indexes of bit-based phys_ram_dirty. */
> +#define MASTER_DIRTY_IDX    0
> +#define VGA_DIRTY_IDX       1
> +#define CODE_DIRTY_IDX      2
> +#define MIGRATION_DIRTY_IDX 3
> +#define NUM_DIRTY_IDX       4
> +
> +#define MASTER_DIRTY_FLAG    (1<<  MASTER_DIRTY_IDX)
> +#define VGA_DIRTY_FLAG       (1<<  VGA_DIRTY_IDX)
> +#define CODE_DIRTY_FLAG      (1<<  CODE_DIRTY_IDX)
> +#define MIGRATION_DIRTY_FLAG (1<<  MIGRATION_DIRTY_IDX)
> +
> +extern unsigned long *phys_ram_dirty[NUM_DIRTY_IDX];
> +
> +static inline int dirty_flag_to_idx(int flag)
> +{
> +    return ffs(flag) - 1;
> +}
> +
> +static inline int dirty_idx_to_flag(int idx)
> +{
> +    return 1<<  idx;
> +}
>
>   /* read dirty bit (return 0 or 1) */
>   static inline int cpu_physical_memory_is_dirty(ram_addr_t addr)
>   {
> -    return phys_ram_dirty[addr>>  TARGET_PAGE_BITS] == 0xff;
> +    unsigned long mask;
> +    ram_addr_t index = (addr>>  TARGET_PAGE_BITS) / HOST_LONG_BITS;
> +    int offset = (addr>>  TARGET_PAGE_BITS)&  (HOST_LONG_BITS - 1);
> +
> +    mask = 1UL<<  offset;
> +    return (phys_ram_dirty[MASTER_DIRTY_IDX][index]&  mask) == mask;
> +}
> +
> +static inline void cpu_physical_memory_sync_master(ram_addr_t index)
> +{
> +    if (phys_ram_dirty[MASTER_DIRTY_IDX][index]) {
> +        phys_ram_dirty[VGA_DIRTY_IDX][index]
> +            |=  phys_ram_dirty[MASTER_DIRTY_IDX][index];
> +        phys_ram_dirty[MIGRATION_DIRTY_IDX][index]
> +            |=  phys_ram_dirty[MASTER_DIRTY_IDX][index];
> +        phys_ram_dirty[MASTER_DIRTY_IDX][index] = 0UL;
> +    }
>   }
>
>   static inline int cpu_physical_memory_get_dirty_flags(ram_addr_t addr)
>   {
> -    return phys_ram_dirty[addr>>  TARGET_PAGE_BITS];
> +     unsigned long mask;
> +     ram_addr_t index = (addr>>  TARGET_PAGE_BITS) / HOST_LONG_BITS;
> +     int offset = (addr>>  TARGET_PAGE_BITS)&  (HOST_LONG_BITS - 1);
> +     int ret = 0, i;
> +
> +     mask = 1UL<<  offset;
> +     cpu_physical_memory_sync_master(index);
> +
> +     for (i = VGA_DIRTY_IDX; i<= MIGRATION_DIRTY_IDX; i++) {
> +         if (phys_ram_dirty[i][index]&  mask) {
> +             ret |= dirty_idx_to_flag(i);
> +         }
> +     }
> +
> +     return ret;
> +}
> +
> +static inline int cpu_physical_memory_get_dirty_idx(ram_addr_t addr,
> +                                                    int dirty_idx)
> +{
> +    unsigned long mask;
> +    ram_addr_t index = (addr>>  TARGET_PAGE_BITS) / HOST_LONG_BITS;
> +    int offset = (addr>>  TARGET_PAGE_BITS)&  (HOST_LONG_BITS - 1);
> +
> +    mask = 1UL<<  offset;
> +    cpu_physical_memory_sync_master(index);
> +    return (phys_ram_dirty[dirty_idx][index]&  mask) == mask;
>   }
>
>   static inline int cpu_physical_memory_get_dirty(ram_addr_t addr,
>                                                   int dirty_flags)
>   {
> -    return phys_ram_dirty[addr>>  TARGET_PAGE_BITS]&  dirty_flags;
> +    return cpu_physical_memory_get_dirty_idx(addr,
> +                                             dirty_flag_to_idx(dirty_flags));
>   }
>
>   static inline void cpu_physical_memory_set_dirty(ram_addr_t addr)
>   {
> -    phys_ram_dirty[addr>>  TARGET_PAGE_BITS] = 0xff;
> +    unsigned long mask;
> +    ram_addr_t index = (addr>>  TARGET_PAGE_BITS) / HOST_LONG_BITS;
> +    int offset = (addr>>  TARGET_PAGE_BITS)&  (HOST_LONG_BITS - 1);
> +
> +    mask = 1UL<<  offset;
> +    phys_ram_dirty[MASTER_DIRTY_IDX][index] |= mask;
> +}
> +
> +static inline void cpu_physical_memory_set_dirty_range(ram_addr_t addr,
> +                                                       unsigned long mask)
> +{
> +    ram_addr_t index = (addr>>  TARGET_PAGE_BITS) / HOST_LONG_BITS;
> +
> +    phys_ram_dirty[MASTER_DIRTY_IDX][index] |= mask;
>   }
>
> -static inline int cpu_physical_memory_set_dirty_flags(ram_addr_t addr,
> -                                                      int dirty_flags)
> +static inline void cpu_physical_memory_set_dirty_flags(ram_addr_t addr,
> +                                                       int dirty_flags)
>   {
> -    return phys_ram_dirty[addr>>  TARGET_PAGE_BITS] |= dirty_flags;
> +    unsigned long mask;
> +    ram_addr_t index = (addr>>  TARGET_PAGE_BITS) / HOST_LONG_BITS;
> +    int offset = (addr>>  TARGET_PAGE_BITS)&  (HOST_LONG_BITS - 1);
> +
> +    mask = 1UL<<  offset;
> +    phys_ram_dirty[MASTER_DIRTY_IDX][index] |= mask;
> +
> +    if (dirty_flags&  CODE_DIRTY_FLAG) {
> +        phys_ram_dirty[CODE_DIRTY_IDX][index] |= mask;
> +    }
>   }
>
>   static inline void cpu_physical_memory_mask_dirty_range(ram_addr_t start,
> -                                                        int length,
> +                                                        unsigned long length,
>                                                           int dirty_flags)
>   {
> -    int i, mask, len;
> -    uint8_t *p;
> +    ram_addr_t addr = start, index;
> +    unsigned long mask;
> +    int offset, i;
>
> -    len = length>>  TARGET_PAGE_BITS;
> -    mask = ~dirty_flags;
> -    p = phys_ram_dirty + (start>>  TARGET_PAGE_BITS);
> -    for (i = 0; i<  len; i++)
> -        p[i]&= mask;
> +    for (i = 0;  i<  length; i += TARGET_PAGE_SIZE) {
> +        index = ((addr + i)>>  TARGET_PAGE_BITS) / HOST_LONG_BITS;
> +        offset = ((addr + i)>>  TARGET_PAGE_BITS)&  (HOST_LONG_BITS - 1);
> +        mask = ~(1UL<<  offset);
> +        phys_ram_dirty[dirty_flag_to_idx(dirty_flags)][index]&= mask;
> +     }
>   }
>
>   void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end,
> diff --git a/exec.c b/exec.c
> index c74b0a4..82b7c32 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -110,7 +110,7 @@ uint8_t *code_gen_ptr;
>
>   #if !defined(CONFIG_USER_ONLY)
>   int phys_ram_fd;
> -uint8_t *phys_ram_dirty;
> +unsigned long *phys_ram_dirty[NUM_DIRTY_IDX];
>   static int in_migration;
>
>   typedef struct RAMBlock {
> @@ -2793,6 +2793,7 @@ static void *file_ram_alloc(ram_addr_t memory, const char *path)
>   ram_addr_t qemu_ram_alloc(ram_addr_t size)
>   {
>       RAMBlock *new_block;
> +    int i;
>
>       size = TARGET_PAGE_ALIGN(size);
>       new_block = qemu_malloc(sizeof(*new_block));
> @@ -2825,10 +2826,14 @@ ram_addr_t qemu_ram_alloc(ram_addr_t 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);
> +    for (i = MASTER_DIRTY_IDX; i<  NUM_DIRTY_IDX; i++) {
> +        phys_ram_dirty[i]
> +            = qemu_realloc(phys_ram_dirty[i],
> +                           BITMAP_SIZE(last_ram_offset + size));
> +        memset((uint8_t *)phys_ram_dirty[i] + BITMAP_SIZE(last_ram_offset),
> +               0xff, BITMAP_SIZE(last_ram_offset + size)
> +               - BITMAP_SIZE(last_ram_offset));
> +    }
>
>       last_ram_offset += size;
>
> diff --git a/qemu-common.h b/qemu-common.h
> index 4ba0cda..efe5b1f 100644
> --- a/qemu-common.h
> +++ b/qemu-common.h
> @@ -285,6 +285,9 @@ static inline uint8_t from_bcd(uint8_t val)
>       return ((val>>  4) * 10) + (val&  0x0f);
>   }
>
> +#define ALIGN(x, y)  (((x)+(y)-1)&  ~((y)-1))
> +#define BITMAP_SIZE(m) (ALIGN(((m)>>TARGET_PAGE_BITS), HOST_LONG_BITS) / 8)
> +
>   #include "module.h"
>
>   #endif /* dyngen-exec.h hack */
>