Re: [Qemu-devel] [PATCH v5 2/8] fw_cfg: add write callback

[Michael S. Tsirkin]

On Mon, Aug 07, 2017 at 08:16:12PM +0200, Marc-André Lureau wrote:
> Reintroduce the write callback that was removed when write support was
> removed in commit 023e3148567ac898c7258138f8e86c3c2bb40d07.
> 
> The write_cb callback is called when a write reaches the end of file,
> that is when the write pointer/offset reaches the size of the file.
> 
> Signed-off-by: Marc-André Lureau 
> ---
>  include/hw/nvram/fw_cfg.h |  2 ++
>  hw/acpi/vmgenid.c |  2 +-
>  hw/core/loader.c  |  2 +-
>  hw/i386/acpi-build.c  |  2 +-
>  hw/isa/lpc_ich9.c |  4 ++--
>  hw/nvram/fw_cfg.c | 18 ++
>  6 files changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
> index f50d068563..3527cd51d8 100644
> --- a/include/hw/nvram/fw_cfg.h
> +++ b/include/hw/nvram/fw_cfg.h
> @@ -183,6 +183,7 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, 
> void *data,
>   * @s: fw_cfg device being modified
>   * @filename: name of new fw_cfg file item
>   * @select_cb: callback function when selecting
> + * @write_cb: callback function when write reached EOF
>   * @callback_opaque: argument to be passed into callback function
>   * @data: pointer to start of item data
>   * @len: size of item data
> @@ -202,6 +203,7 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, 
> void *data,
>   */
>  void fw_cfg_add_file_callback(FWCfgState *s, const char *filename,
>FWCfgCallback select_cb,
> +  FWCfgCallback write_cb,
>void *callback_opaque,
>void *data, size_t len, bool read_only);
>  
> diff --git a/hw/acpi/vmgenid.c b/hw/acpi/vmgenid.c
> index a32b847fe0..c1e935da9f 100644
> --- a/hw/acpi/vmgenid.c
> +++ b/hw/acpi/vmgenid.c
> @@ -124,7 +124,7 @@ void vmgenid_add_fw_cfg(VmGenIdState *vms, FWCfgState *s, 
> GArray *guid)
>  fw_cfg_add_file(s, VMGENID_GUID_FW_CFG_FILE, guid->data,
>  VMGENID_FW_CFG_SIZE);
>  /* Create a read-write fw_cfg file for Address */
> -fw_cfg_add_file_callback(s, VMGENID_ADDR_FW_CFG_FILE, NULL, NULL,
> +fw_cfg_add_file_callback(s, VMGENID_ADDR_FW_CFG_FILE, NULL, NULL, NULL,
>   vms->vmgenid_addr_le,
>   ARRAY_SIZE(vms->vmgenid_addr_le), false);
>  }
> diff --git a/hw/core/loader.c b/hw/core/loader.c
> index 4593061445..91669d65aa 100644
> --- a/hw/core/loader.c
> +++ b/hw/core/loader.c
> @@ -1023,7 +1023,7 @@ MemoryRegion *rom_add_blob(const char *name, const void 
> *blob, size_t len,
>  }
>  
>  fw_cfg_add_file_callback(fw_cfg, fw_file_name,
> - fw_callback, callback_opaque,
> + fw_callback, NULL, callback_opaque,
>   data, rom->datasize, read_only);
>  }
>  return mr;
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index b9c245c9bb..be2992b708 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2922,7 +2922,7 @@ void acpi_setup(void)
>  
>  build_state->rsdp = g_memdup(tables.rsdp->data, rsdp_size);
>  fw_cfg_add_file_callback(pcms->fw_cfg, ACPI_BUILD_RSDP_FILE,
> - acpi_build_update, build_state,
> + acpi_build_update, NULL, build_state,
>   build_state->rsdp, rsdp_size, true);
>  build_state->rsdp_mr = NULL;
>  } else {
> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
> index ac8416d42b..de8fbb7260 100644
> --- a/hw/isa/lpc_ich9.c
> +++ b/hw/isa/lpc_ich9.c
> @@ -402,12 +402,12 @@ void ich9_lpc_pm_init(PCIDevice *lpc_pci, bool 
> smm_enabled)
>   * just link them into fw_cfg here.
>   */
>  fw_cfg_add_file_callback(fw_cfg, "etc/smi/requested-features",
> - NULL, NULL,
> + NULL, NULL, NULL,
>   lpc->smi_guest_features_le,
>   sizeof lpc->smi_guest_features_le,
>   false);
>  fw_cfg_add_file_callback(fw_cfg, "etc/smi/features-ok",
> - smi_features_ok_callback, lpc,
> + smi_features_ok_callback, NULL, lpc,
>   >smi_features_ok,
>   sizeof lpc->smi_features_ok,
>   true);
> diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
> index e3bd626b8c..28780088b9 100644
> --- a/hw/nvram/fw_cfg.c
> +++ b/hw/nvram/fw_cfg.c
> @@ -56,6 +56,7 @@ struct FWCfgEntry {
>  uint8_t *data;
>  void *callback_opaque;
>  FWCfgCallback select_cb;
> +FWCfgCallback write_cb;
>  };
>  
>  #define JPG_FILE 0
> @@ -384,6 +385,12 @@ static void 

[Qemu-devel] [PATCH v5 2/8] fw_cfg: add write callback

[Marc-André Lureau]

Reintroduce the write callback that was removed when write support was
removed in commit 023e3148567ac898c7258138f8e86c3c2bb40d07.

The write_cb callback is called when a write reaches the end of file,
that is when the write pointer/offset reaches the size of the file.

Signed-off-by: Marc-André Lureau 
---
 include/hw/nvram/fw_cfg.h |  2 ++
 hw/acpi/vmgenid.c |  2 +-
 hw/core/loader.c  |  2 +-
 hw/i386/acpi-build.c  |  2 +-
 hw/isa/lpc_ich9.c |  4 ++--
 hw/nvram/fw_cfg.c | 18 ++
 6 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
index f50d068563..3527cd51d8 100644
--- a/include/hw/nvram/fw_cfg.h
+++ b/include/hw/nvram/fw_cfg.h
@@ -183,6 +183,7 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, 
void *data,
  * @s: fw_cfg device being modified
  * @filename: name of new fw_cfg file item
  * @select_cb: callback function when selecting
+ * @write_cb: callback function when write reached EOF
  * @callback_opaque: argument to be passed into callback function
  * @data: pointer to start of item data
  * @len: size of item data
@@ -202,6 +203,7 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, 
void *data,
  */
 void fw_cfg_add_file_callback(FWCfgState *s, const char *filename,
   FWCfgCallback select_cb,
+  FWCfgCallback write_cb,
   void *callback_opaque,
   void *data, size_t len, bool read_only);
 
diff --git a/hw/acpi/vmgenid.c b/hw/acpi/vmgenid.c
index a32b847fe0..c1e935da9f 100644
--- a/hw/acpi/vmgenid.c
+++ b/hw/acpi/vmgenid.c
@@ -124,7 +124,7 @@ void vmgenid_add_fw_cfg(VmGenIdState *vms, FWCfgState *s, 
GArray *guid)
 fw_cfg_add_file(s, VMGENID_GUID_FW_CFG_FILE, guid->data,
 VMGENID_FW_CFG_SIZE);
 /* Create a read-write fw_cfg file for Address */
-fw_cfg_add_file_callback(s, VMGENID_ADDR_FW_CFG_FILE, NULL, NULL,
+fw_cfg_add_file_callback(s, VMGENID_ADDR_FW_CFG_FILE, NULL, NULL, NULL,
  vms->vmgenid_addr_le,
  ARRAY_SIZE(vms->vmgenid_addr_le), false);
 }
diff --git a/hw/core/loader.c b/hw/core/loader.c
index 4593061445..91669d65aa 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -1023,7 +1023,7 @@ MemoryRegion *rom_add_blob(const char *name, const void 
*blob, size_t len,
 }
 
 fw_cfg_add_file_callback(fw_cfg, fw_file_name,
- fw_callback, callback_opaque,
+ fw_callback, NULL, callback_opaque,
  data, rom->datasize, read_only);
 }
 return mr;
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index b9c245c9bb..be2992b708 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -2922,7 +2922,7 @@ void acpi_setup(void)
 
 build_state->rsdp = g_memdup(tables.rsdp->data, rsdp_size);
 fw_cfg_add_file_callback(pcms->fw_cfg, ACPI_BUILD_RSDP_FILE,
- acpi_build_update, build_state,
+ acpi_build_update, NULL, build_state,
  build_state->rsdp, rsdp_size, true);
 build_state->rsdp_mr = NULL;
 } else {
diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
index ac8416d42b..de8fbb7260 100644
--- a/hw/isa/lpc_ich9.c
+++ b/hw/isa/lpc_ich9.c
@@ -402,12 +402,12 @@ void ich9_lpc_pm_init(PCIDevice *lpc_pci, bool 
smm_enabled)
  * just link them into fw_cfg here.
  */
 fw_cfg_add_file_callback(fw_cfg, "etc/smi/requested-features",
- NULL, NULL,
+ NULL, NULL, NULL,
  lpc->smi_guest_features_le,
  sizeof lpc->smi_guest_features_le,
  false);
 fw_cfg_add_file_callback(fw_cfg, "etc/smi/features-ok",
- smi_features_ok_callback, lpc,
+ smi_features_ok_callback, NULL, lpc,
  >smi_features_ok,
  sizeof lpc->smi_features_ok,
  true);
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index e3bd626b8c..28780088b9 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -56,6 +56,7 @@ struct FWCfgEntry {
 uint8_t *data;
 void *callback_opaque;
 FWCfgCallback select_cb;
+FWCfgCallback write_cb;
 };
 
 #define JPG_FILE 0
@@ -384,6 +385,12 @@ static void fw_cfg_dma_transfer(FWCfgState *s)
 stl_be_dma(s->dma_as, dma_addr + offsetof(FWCfgDmaAccess, control),
 dma.control);
 
+if (write &&
+!(dma.control & FW_CFG_DMA_CTL_ERROR) &&
+s->cur_offset == e->len) {
+e->write_cb(e->callback_opaque);
+}
+