Re: [PATCH v2] qapi: Cleanup SGX related comments and restore @section-size

["Daniel P. Berrangé" <berrange@redhat.com>]

On Wed, Jan 19, 2022 at 06:57:20PM -0500, Yang Zhong wrote:
> The SGX NUMA patches were merged into Qemu 7.0 release, we need
> clarify detailed version history information and also change
> some related comments, which make SGX related comments clearer.
> 
> The QMP command schema promises backwards compatibility as standard.
> We temporarily restore "@section-size", which can avoid incompatible
> API breakage. The "@section-size" will be deprecated in 7.2 version.
> 
> Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
> Signed-off-by: Yang Zhong <yang.zhong@intel.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  qapi/machine.json     |  4 ++--
>  qapi/misc-target.json | 17 ++++++++++++-----
>  hw/i386/sgx.c         | 11 +++++++++--
>  3 files changed, 23 insertions(+), 9 deletions(-)
> 
> diff --git a/qapi/machine.json b/qapi/machine.json
> index b6a37e17c4..cf47cb63a9 100644
> --- a/qapi/machine.json
> +++ b/qapi/machine.json
> @@ -1207,7 +1207,7 @@
>  #
>  # @memdev: memory backend linked with device
>  #
> -# @node: the numa node
> +# @node: the numa node (Since: 7.0)
>  #
>  # Since: 6.2
>  ##
> @@ -1288,7 +1288,7 @@
>  #
>  # @memdev: memory backend linked with device
>  #
> -# @node: the numa node
> +# @node: the numa node (Since: 7.0)
>  #
>  # Since: 6.2
>  ##
> diff --git a/qapi/misc-target.json b/qapi/misc-target.json
> index 1022aa0184..a87358ea44 100644
> --- a/qapi/misc-target.json
> +++ b/qapi/misc-target.json
> @@ -344,9 +344,9 @@
>  #
>  # @node: the numa node
>  #
> -# @size: the size of epc section
> +# @size: the size of EPC section
>  #
> -# Since: 6.2
> +# Since: 7.0
>  ##
>  { 'struct': 'SGXEPCSection',
>    'data': { 'node': 'int',
> @@ -365,7 +365,9 @@
>  #
>  # @flc: true if FLC is supported
>  #
> -# @sections: The EPC sections info for guest
> +# @section-size: The EPC section size for guest (Will be deprecated in 7.2)

I expected deprecation would start now (7.0, and it would be removed
in 7.2.

Also needs to be documented in docs/about/deprecated.rst



> +#
> +# @sections: The EPC sections info for guest (Since: 7.0)
>  #
>  # Since: 6.2
>  ##
> @@ -374,6 +376,7 @@
>              'sgx1': 'bool',
>              'sgx2': 'bool',
>              'flc': 'bool',
> +            'section-size': 'uint64',
>              'sections': ['SGXEPCSection']},
>     'if': 'TARGET_I386' }
>  
> @@ -390,7 +393,9 @@
>  #
>  # -> { "execute": "query-sgx" }
>  # <- { "return": { "sgx": true, "sgx1" : true, "sgx2" : true,
> -#                  "flc": true, "section-size" : 0 } }
> +#                  "flc": true,  "section-size" : 96468992,
> +#                  "sections": [{"node": 0, "size": 67108864},
> +#                  {"node": 1, "size": 29360128}]} }
>  #
>  ##
>  { 'command': 'query-sgx', 'returns': 'SGXInfo', 'if': 'TARGET_I386' }
> @@ -408,7 +413,9 @@
>  #
>  # -> { "execute": "query-sgx-capabilities" }
>  # <- { "return": { "sgx": true, "sgx1" : true, "sgx2" : true,
> -#                  "flc": true, "section-size" : 0 } }
> +#                  "flc": true, "section-size" : 96468992,
> +#                  "section" : [{"node": 0, "size": 67108864},
> +#                  {"node": 1, "size": 29360128}]} }
>  #
>  ##
>  { 'command': 'query-sgx-capabilities', 'returns': 'SGXInfo', 'if': 'TARGET_I386' }
> diff --git a/hw/i386/sgx.c b/hw/i386/sgx.c
> index 5de5dd0893..a2b318dd93 100644
> --- a/hw/i386/sgx.c
> +++ b/hw/i386/sgx.c
> @@ -83,7 +83,7 @@ static uint64_t sgx_calc_section_metric(uint64_t low, uint64_t high)
>             ((high & MAKE_64BIT_MASK(0, 20)) << 32);
>  }
>  
> -static SGXEPCSectionList *sgx_calc_host_epc_sections(void)
> +static SGXEPCSectionList *sgx_calc_host_epc_sections(uint64_t *size)
>  {
>      SGXEPCSectionList *head = NULL, **tail = &head;
>      SGXEPCSection *section;
> @@ -106,6 +106,7 @@ static SGXEPCSectionList *sgx_calc_host_epc_sections(void)
>          section = g_new0(SGXEPCSection, 1);
>          section->node = j++;
>          section->size = sgx_calc_section_metric(ecx, edx);
> +        *size += section->size;
>          QAPI_LIST_APPEND(tail, section);
>      }
>  
> @@ -156,6 +157,7 @@ SGXInfo *qmp_query_sgx_capabilities(Error **errp)
>  {
>      SGXInfo *info = NULL;
>      uint32_t eax, ebx, ecx, edx;
> +    uint64_t size = 0;
>  
>      int fd = qemu_open_old("/dev/sgx_vepc", O_RDWR);
>      if (fd < 0) {
> @@ -173,7 +175,8 @@ SGXInfo *qmp_query_sgx_capabilities(Error **errp)
>      info->sgx1 = eax & (1U << 0) ? true : false;
>      info->sgx2 = eax & (1U << 1) ? true : false;
>  
> -    info->sections = sgx_calc_host_epc_sections();
> +    info->sections = sgx_calc_host_epc_sections(&size);
> +    info->section_size = size;
>  
>      close(fd);
>  
> @@ -220,12 +223,14 @@ SGXInfo *qmp_query_sgx(Error **errp)
>          return NULL;
>      }
>  
> +    SGXEPCState *sgx_epc = &pcms->sgx_epc;
>      info = g_new0(SGXInfo, 1);
>  
>      info->sgx = true;
>      info->sgx1 = true;
>      info->sgx2 = true;
>      info->flc = true;
> +    info->section_size = sgx_epc->size;
>      info->sections = sgx_get_epc_sections_list();
>  
>      return info;
> @@ -249,6 +254,8 @@ void hmp_info_sgx(Monitor *mon, const QDict *qdict)
>                     info->sgx2 ? "enabled" : "disabled");
>      monitor_printf(mon, "FLC support: %s\n",
>                     info->flc ? "enabled" : "disabled");
> +    monitor_printf(mon, "size: %" PRIu64 "\n",
> +                   info->section_size);
>  
>      section_list = info->sections;
>      for (section = section_list; section; section = section->next) {
> 

Regards,
Daniel
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