Re: [Qemu-devel] [PATCH v2 2/5] pflash: flush rom device memory region

[Philippe Mathieu-Daudé]

Hi Stefan,

On 1/23/19 10:22 PM, Stefan Hajnoczi wrote:
> pflash devices should mark the memory region dirty and invalidate TBs
> after directly writing to the RAM backing the ROM device.
> 
> Note that pflash_cfi01_get_memory() is used by several machine types to
> populate ROM contents directly.  Callers are untouched by this patch
> because they only modify memory before the guest is started.
> 
> Signed-off-by: Stefan Hajnoczi <address@hidden>
> ---
>  hw/block/pflash_cfi01.c | 5 +++++
>  hw/block/pflash_cfi02.c | 8 ++++++++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
> index bffb4c40e7..5301c11c18 100644
> --- a/hw/block/pflash_cfi01.c
> +++ b/hw/block/pflash_cfi01.c
> @@ -446,6 +446,7 @@ static inline void pflash_data_write(pflash_t *pfl, 
> hwaddr offset,
>          break;
>      }
>  
> +    memory_region_flush_rom_device(&pfl->mem, offset, width);
>  }
>  
>  static void pflash_write(pflash_t *pfl, hwaddr offset,
> @@ -482,6 +483,8 @@ static void pflash_write(pflash_t *pfl, hwaddr offset,
>              if (!pfl->ro) {
>                  memset(p + offset, 0xff, pfl->sector_len);
>                  pflash_update(pfl, offset, pfl->sector_len);
> +                memory_region_flush_rom_device(&pfl->mem, offset,
> +                                               pfl->sector_len);
>              } else {
>                  pfl->status |= 0x20; /* Block erase error */
>              }
> @@ -763,6 +766,8 @@ static void pflash_cfi01_realize(DeviceState *dev, Error 
> **errp)
>              error_setg(errp, "failed to read the initial flash content");
>              return;
>          }
> +
> +        memory_region_flush_rom_device(&pfl->mem, 0, total_len);

The device realize() is also executed before the guest is started, is
this call really necessary?

>      }
>  
>      /* Default to devices being used at their maximum device width. This was
> diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c
> index 0f8b7b8c7b..d04572eca4 100644
> --- a/hw/block/pflash_cfi02.c
> +++ b/hw/block/pflash_cfi02.c
> @@ -378,6 +378,8 @@ static void pflash_write (pflash_t *pfl, hwaddr offset,
>                      pflash_update(pfl, offset, 4);
>                      break;
>                  }
> +
> +                memory_region_flush_rom_device(&pfl->orig_mem, offset, 
> width);
>              }
>              pfl->status = 0x00 | ~(value & 0x80);
>              /* Let's pretend write is immediate */
> @@ -426,6 +428,8 @@ static void pflash_write (pflash_t *pfl, hwaddr offset,
>              if (!pfl->ro) {
>                  memset(pfl->storage, 0xFF, pfl->chip_len);
>                  pflash_update(pfl, 0, pfl->chip_len);
> +                memory_region_flush_rom_device(&pfl->orig_mem, 0,
> +                                               pfl->chip_len);
>              }
>              pfl->status = 0x00;
>              /* Let's wait 5 seconds before chip erase is done */
> @@ -441,6 +445,8 @@ static void pflash_write (pflash_t *pfl, hwaddr offset,
>              if (!pfl->ro) {
>                  memset(p + offset, 0xFF, pfl->sector_len);
>                  pflash_update(pfl, offset, pfl->sector_len);
> +                memory_region_flush_rom_device(&pfl->orig_mem, offset,
> +                                               pfl->sector_len);
>              }
>              pfl->status = 0x00;
>              /* Let's wait 1/2 second before sector erase is done */
> @@ -590,6 +596,8 @@ static void pflash_cfi02_realize(DeviceState *dev, Error 
> **errp)
>              error_setg(errp, "failed to read the initial flash content");
>              return;
>          }
> +
> +        memory_region_flush_rom_device(&pfl->orig_mem, 0, chip_len);

Ditto.

>      }
>  
>      pflash_setup_mappings(pfl);
>