Re: [PATCH qemu 7/8] hw/cxl/cxl-mailbox-utils: Added support for Get Log Capabilities (Opcode 0402h)

[Arpit Kumar <arpit1.kumar@samsung.com>]

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On 12/05/25 05:40PM, Jonathan Cameron wrote:
>On Mon, 12 May 2025 09:37:07 -0400
>"Michael S. Tsirkin" <mst@redhat.com> wrote:
>
>> On Mon, May 12, 2025 at 04:42:41AM -0400, Michael S. Tsirkin wrote:
>> > On Wed, Mar 05, 2025 at 09:24:58AM +0000, Jonathan Cameron wrote:
>> > > From: Arpit Kumar <arpit1.kumar@samsung.com>
>> > >
>> > > CXL spec 3.2 section 8.2.10.5.3 describes Get Log Capabilities.
>> > > It provides log capabilities supported by specified log.
>> > >
>> > > Signed-off-by: Arpit Kumar <arpit1.kumar@samsung.com>
>> > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> > > ---
>> > >  include/hw/cxl/cxl_device.h  | 20 ++++++++++++++++
>> > >  include/hw/cxl/cxl_mailbox.h |  5 ++++
>> > >  hw/cxl/cxl-mailbox-utils.c   | 45 ++++++++++++++++++++++++++++++++++++
>> > >  3 files changed, 70 insertions(+)
>> > >
>> > > diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
>> > > index ed6cd50c67..87a376c982 100644
>> > > --- a/include/hw/cxl/cxl_device.h
>> > > +++ b/include/hw/cxl/cxl_device.h
>> > > @@ -133,6 +133,18 @@ typedef enum {
>> > >      CXL_MBOX_MAX = 0x20
>> > >  } CXLRetCode;
>> > >
>> > > +/* types of logs */
>> > > +typedef enum {
>> > > +    CXL_LOG_COMMAND_EFFECT,
>> > > +    CXL_LOG_VENDOR_DEBUG,
>> > > +    CXL_LOG_COMPONENT_STATE_DUMP,
>> > > +    CXL_LOG_ERROR_CHECK_SCRUB,
>> > > +    CXL_LOG_MEDIA_TEST_CAPABILITY,
>> > > +    CXL_LOG_MEDIA_TEST_RESULTS_SHORT,
>> > > +    CXL_LOG_MEDIA_TEST_RESULTS_LONG,
>> > > +    MAX_LOG_TYPE
>> > > +} CXLLogType;
>> > > +
>> > >  typedef struct CXLCCI CXLCCI;
>> > >  typedef struct cxl_device_state CXLDeviceState;
>> > >  struct cxl_cmd;
>> > > @@ -163,6 +175,11 @@ typedef struct CXLEventLog {
>> > >      QSIMPLEQ_HEAD(, CXLEvent) events;
>> > >  } CXLEventLog;
>> > >
>> > > +typedef struct CXLLogCapabilities {
>> > > +    uint32_t param_flags;
>> > > +    QemuUUID uuid;
>> > > +} CXLLogCapabilities;
>> > > +
>> > >  typedef struct CXLCCI {
>> > >      struct cxl_cmd cxl_cmd_set[256][256];
>> > >      struct cel_log {
>> > > @@ -171,6 +188,9 @@ typedef struct CXLCCI {
>> > >      } cel_log[1 << 16];
>> > >      size_t cel_size;
>> > >
>> > > +    /* get log capabilities */
>> > > +    const CXLLogCapabilities *supported_log_cap;
>> > > +
>> > >      /* background command handling (times in ms) */
>> > >      struct {
>> > >          uint16_t opcode;
>> > > diff --git a/include/hw/cxl/cxl_mailbox.h b/include/hw/cxl/cxl_mailbox.h
>> > > index 9008402d1c..8e1c7c5f15 100644
>> > > --- a/include/hw/cxl/cxl_mailbox.h
>> > > +++ b/include/hw/cxl/cxl_mailbox.h
>> > > @@ -16,4 +16,9 @@
>> > >  #define CXL_MBOX_BACKGROUND_OPERATION (1 << 6)
>> > >  #define CXL_MBOX_BACKGROUND_OPERATION_ABORT (1 << 7)
>> > >
>> > > +#define CXL_LOG_CAP_CLEAR_SUPPORTED (1 << 0)
>> > > +#define CXL_LOG_CAP_POPULATE_SUPPORTED (1 << 1)
>> > > +#define CXL_LOG_CAP_AUTO_POPULATE_SUPPORTED (1 << 2)
>> > > +#define CXL_LOG_CAP_PERSISTENT_COLD_RESET_SUPPORTED (1 << 3)
>> > > +
>> > >  #endif
>> > > diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
>> > > index 299f232f26..f35fc4f112 100644
>> > > --- a/hw/cxl/cxl-mailbox-utils.c
>> > > +++ b/hw/cxl/cxl-mailbox-utils.c
>> > > @@ -81,6 +81,7 @@ enum {
>> > >      LOGS        = 0x04,
>> > >          #define GET_SUPPORTED 0x0
>> > >          #define GET_LOG       0x1
>> > > +        #define GET_LOG_CAPABILITIES   0x2
>> > >      FEATURES    = 0x05,
>> > >          #define GET_SUPPORTED 0x0
>> > >          #define GET_FEATURE   0x1
>> > > @@ -1068,6 +1069,43 @@ static CXLRetCode cmd_logs_get_log(const struct cxl_cmd *cmd,
>> > >      return CXL_MBOX_SUCCESS;
>> > >  }
>> > >
>> > > +static const struct CXLLogCapabilities *find_log_index(QemuUUID *uuid, CXLCCI *cci)
>> > > +{
>> > > +    for (int i = CXL_LOG_COMMAND_EFFECT; i < MAX_LOG_TYPE; i++) {
>> > > +        if (qemu_uuid_is_equal(uuid,
>> > > +            &cci->supported_log_cap[i].uuid)) {
>> > > +                return &cci->supported_log_cap[i];
>> > > +        }
>> > > +    }
>> > > +    return NULL;
>> > > +}
>> > > +
>> > > +/* CXL r3.2 Section 8.2.10.5.3: Get Log Capabilities (Opcode 0402h) */
>> > > +static CXLRetCode cmd_logs_get_log_capabilities(const struct cxl_cmd *cmd,
>> > > +                                                uint8_t *payload_in,
>> > > +                                                size_t len_in,
>> > > +                                                uint8_t *payload_out,
>> > > +                                                size_t *len_out,
>> > > +                                                CXLCCI *cci)
>> > > +{
>> > > +    const CXLLogCapabilities *cap;
>> > > +    struct {
>> > > +        QemuUUID uuid;
>> > > +    } QEMU_PACKED QEMU_ALIGNED(8) *get_log_capabilities_in = (void *)payload_in;
>> > > +
>> > > +    uint32_t *get_log_capabilities_out = (uint32_t *)payload_out;
>> > > +
>> > > +    cap = find_log_index(&get_log_capabilities_in->uuid, cci);
>> > > +    if (!cap) {
>> > > +        return CXL_MBOX_INVALID_LOG;
>> > > +    }
>> > > +
>> > > +    memcpy(get_log_capabilities_out, &cap->param_flags,
>> > > +           sizeof(cap->param_flags));
>> > > +    *len_out = sizeof(*get_log_capabilities_out);
>> > > +    return CXL_MBOX_SUCCESS;
>> > > +}
>> > > +
>> > >  /* CXL r3.1 section 8.2.9.6: Features */
>> > >  /*
>> > >   * Get Supported Features output payload
>> > > @@ -3253,6 +3291,8 @@ static const struct cxl_cmd cxl_cmd_set[256][256] = {
>> > >      [LOGS][GET_SUPPORTED] = { "LOGS_GET_SUPPORTED", cmd_logs_get_supported,
>> > >                                0, 0 },
>> > >      [LOGS][GET_LOG] = { "LOGS_GET_LOG", cmd_logs_get_log, 0x18, 0 },
>> > > +    [LOGS][GET_LOG_CAPABILITIES] = { "LOGS_GET_LOG_CAPABILITIES",
>> > > +                                     cmd_logs_get_log_capabilities, 0x10, 0 },
>> > >      [FEATURES][GET_SUPPORTED] = { "FEATURES_GET_SUPPORTED",
>> > >                                    cmd_features_get_supported, 0x8, 0 },
>> > >      [FEATURES][GET_FEATURE] = { "FEATURES_GET_FEATURE",
>> > > @@ -3512,10 +3552,15 @@ static void cxl_rebuild_cel(CXLCCI *cci)
>> > >      }
>> > >  }
>> > >
>> > > +static const struct CXLLogCapabilities cxl_get_log_cap[MAX_LOG_TYPE] = {
>> > > +    [CXL_LOG_COMMAND_EFFECT] = { .param_flags = 0, .uuid = cel_uuid },
>> > > +};
>> > > +
>> >
>> >
>> > causes ci build failures:
>> >
>> > https://gitlab.com/mstredhat/qemu/-/jobs/9999980051
>> >
>> > ../hw/cxl/cxl-mailbox-utils.c:3556:60: error: initializer element is not constant
>> >      [CXL_LOG_COMMAND_EFFECT] = { .param_flags = 0, .uuid = cel_uuid },
>> >                                                             ^~~~~~~~
>> > ../hw/cxl/cxl-mailbox-utils.c:3556:60: note: (near initialization for ‘cxl_get_log_cap[0].uuid’)
>> >
>> >
>> > Fixed it up like this:
>> >
>> > diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
>> > index f35fc4f112..13d26e391b 100644
>> > --- a/hw/cxl/cxl-mailbox-utils.c
>> > +++ b/hw/cxl/cxl-mailbox-utils.c
>> > @@ -992,9 +992,10 @@ static CXLRetCode cmd_timestamp_set(const struct cxl_cmd *cmd,
>> >  }
>> >
>> >  /* CXL r3.1 Section 8.2.9.5.2.1: Command Effects Log (CEL) */
>> > -static const QemuUUID cel_uuid = {
>> > -    .data = UUID(0x0da9c0b5, 0xbf41, 0x4b78, 0x8f, 0x79,
>> > +#define CEL_UUID UUID(0x0da9c0b5, 0xbf41, 0x4b78, 0x8f, 0x79, \
>> >                   0x96, 0xb1, 0x62, 0x3b, 0x3f, 0x17)
>> > +static const QemuUUID cel_uuid = {
>> > +    .data = CEL_UUID
>> >  };
>> >
>> >  /* CXL r3.1 Section 8.2.9.5.1: Get Supported Logs (Opcode 0400h) */
>> > @@ -3553,7 +3554,7 @@ static void cxl_rebuild_cel(CXLCCI *cci)
>> >  }
>> >
>> >  static const struct CXLLogCapabilities cxl_get_log_cap[MAX_LOG_TYPE] = {
>> > -    [CXL_LOG_COMMAND_EFFECT] = { .param_flags = 0, .uuid = cel_uuid },
>> > +    [CXL_LOG_COMMAND_EFFECT] = { .param_flags = 0, .uuid = CEL_UUID },
>> >  };
>> >
>> >  void cxl_init_cci(CXLCCI *cci, size_t payload_max)
>> >
>>
>>
>> Actually no, does not help either. Dropped for now.
>> Next patch does not depend on this one, right?
>
>Indeed. Unrelated.
>
>Thanks,
>
>J

Thanks for pointing this out. The code builds successfully on my setup
with gcc version: 11.4.0. However, it fails to compile on gcc 7.5.0
"cc (SUSE Linux) 7.5.0" as used by Michael. This could be a compiler
issue as per the link:
https://stackoverflow.com/questions/54135942/why-initializer-
element-is-not-a-constant-is-not-working-anymore.

My setup doesn't allow me to regenerate the error using lower version
of compiler. A probable fix to it would be
type casting cel_uuid as: [CXL_LOG_COMMAND_EFFECT] =
{ .param_flags = 0,.uuid = (QemuUUID)cel_uuid }. It will be helpful
if you could test the same.

Also, In the existing code,
function: cmd_logs_get_supported(), cel_uuid(const) is assigned to a
non-const variable but I am unsure of why it is not throwing an error.

Thanks,
Arpit
>>
>> > >  void cxl_init_cci(CXLCCI *cci, size_t payload_max)
>> > >  {
>> > >      cci->payload_max = payload_max;
>> > >      cxl_rebuild_cel(cci);
>> > > +    cci->supported_log_cap = cxl_get_log_cap;
>> > >
>> > >      cci->bg.complete_pct = 0;
>> > >      cci->bg.starttime = 0;
>> > > --
>> > > 2.43.0
>>
>>
>

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