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

[Jonathan Cameron via <qemu-devel@nongnu.org>]

On Wed, 28 May 2025 13:31:06 +0100
Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote:

> On Fri, 16 May 2025 19:12:45 +0530
> Arpit Kumar <arpit1.kumar@samsung.com> wrote:
> 
> > 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.  
> 
> I wonder if we are better off just filling it in in cxl_init_cci()
> So change the type of the element in struct CXLCCI to
> CXLLogCapabiliites supported_log_cap[MAX_LOGS];
> 
> then assign the elements at runtime.
> 
> That should avoid any issues with whether it is const or not at the
> cost of a little more code.
e.g.
diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index 87a376c982..86fc6e03a1 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -189,7 +189,7 @@ typedef struct CXLCCI {
     size_t cel_size;

     /* get log capabilities */
-    const CXLLogCapabilities *supported_log_cap;
+    CXLLogCapabilities supported_log_cap[MAX_LOG_TYPE];

     /* background command handling (times in ms) */
     struct {
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index f35fc4f112..4ef81c058e 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -3552,15 +3552,14 @@ 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 },
-};
-
 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->supported_log_cap[0] = (CXLLogCapabilities) {
+        .param_flags = 0,
+        .uuid = cel_uuid,
+    };

     cci->bg.complete_pct = 0;
     cci->bg.starttime = 0;

Should I think do the job. 

I don't have a test to hand for this, so please let me know if I messed it up!

> 
> > 
> > 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.  
> 
> Isn't it just copying the content which should be fine?
> 
> > 
> > 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    
> > >>
> > >>    
> > >    
> >   
> 
>