Re: [PATCH 1/1] Added support for get/set alert configuration commands

[Sweta Kumari <s5.kumari@samsung.com>]

[-- Attachment #1: Type: text/plain, Size: 10545 bytes --]

On 04/02/25 11:15AM, Jonathan Cameron wrote:
>On Mon,  3 Feb 2025 17:14:45 +0530
>Sweta Kumari <s5.kumari@samsung.com> wrote:
>
>> Signed-off-by: Sweta Kumari <s5.kumari@samsung.com>
>> Reviewed-by: Alok Rathore <alok.rathore@samsung.com>
>> Reviewed-by: Krishna Kanth Reddy <krish.reddy@samsung.com>
>Hi Sweta,
>
>Thanks for the patch. Great to see someone working on these
>features.   As in previous thread, in general RB tags that are
>given before public posting aren't really very useful.  Reviews
>can mean very different things in different companies / groups within
>them.  Much prefer to see a final round of review done on the public
>mailing list if possible.
>
>Various comments inline.
>
>Jonathan
>
Hi Jonathan,

Thank you for the feedback. I'll fix this in V2 patch.
>> ---
>>  hw/cxl/cxl-mailbox-utils.c  | 91 +++++++++++++++++++++++++++++++++++++
>>  hw/mem/cxl_type3.c          | 20 ++++++++
>>  include/hw/cxl/cxl_device.h | 24 ++++++++++
>>  3 files changed, 135 insertions(+)
>>
>> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
>> index 9c7ea5bc35..7a054c059d 100644
>> --- a/hw/cxl/cxl-mailbox-utils.c
>> +++ b/hw/cxl/cxl-mailbox-utils.c
>> @@ -86,6 +86,9 @@ enum {
>>          #define GET_PARTITION_INFO     0x0
>>          #define GET_LSA       0x2
>>          #define SET_LSA       0x3
>> +    HEALTH_INFO_ALERTS = 0x42,
>> +        #define GET_ALERT_CONFIGURATION 0x1
>> +        #define SET_ALERT_CONFIGURATION 0x2
>>      SANITIZE    = 0x44,
>>          #define OVERWRITE     0x0
>>          #define SECURE_ERASE  0x1
>> @@ -1625,6 +1628,90 @@ static CXLRetCode cmd_ccls_set_lsa(const struct cxl_cmd *cmd,
>>      return CXL_MBOX_SUCCESS;
>>  }
>>
>> +/* CXL r3.1 Section 8.2.9.9.3.2 Get Alert Configuration (Opcode 4201h) */
>
>For new commands, preference is for spec references being to
>the latest spec as that's the one that is downloadable via a click through
>on the website.
>
Ok, Will fix it in V2 patch.
>> +static CXLRetCode cmd_get_alert_config(const struct cxl_cmd *cmd,
>> +                                   uint8_t *payload_in,
>
>Align immediate after ( unless we have very long lines.
>
>> +                                   size_t len_in,
>> +                                   uint8_t *payload_out,
>> +                                   size_t *len_out,
>> +                                   CXLCCI *cci)
>> +{
>> +    CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
>> +    CXLAlertConfig *out = (void *)payload_out;
>
>blank line here.
>
Ok.
>> +    memcpy(out, &ct3d->alert_config, sizeof(ct3d->alert_config));
>> +    *len_out = sizeof(ct3d->alert_config);
>
>blank line here.
>
Ok.
>> +    return CXL_MBOX_SUCCESS;
>> +
>> +}
>> +
>> +/* CXL r3.1 Section 8.2.9.9.3.3 Set Alert Configuration (Opcode 4202h) */
>> +static CXLRetCode cmd_set_alert_config(const struct cxl_cmd *cmd,
>> +                                   uint8_t *payload_in,
>> +                                   size_t len_in,
>> +                                   uint8_t *payload_out,
>> +                                   size_t *len_out,
>> +                                   CXLCCI *cci)
>> +{
>> +    CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
>> +    CXLAlertConfig *alert_config = &ct3d->alert_config;
>> +    struct {
>> +        CXLValidEnableAlerts valid_alert_actions;
>> +        CXLValidEnableAlerts enable_alert_actions;
>
>uint8_t for both of these + defines.
>
>> +        uint8_t lupwt;
>
>Longer names here as below.
>
Ok, I'll update both with defines and longer names as suggested.
>> +        uint8_t reserve;
>> +        uint16_t dotpwt;
>> +        uint16_t dutpwt;
>> +        uint16_t cvmepwt;
>> +        uint16_t cpmepwt;
>> +    } QEMU_PACKED *in = (void *)payload_in;
>> +
>> +    if (in->valid_alert_actions.lupwt) {
>> +        if ((in->lupwt > 100) || (in->lupwt >= alert_config->lucat)) {
>
>Add a spec reference for these constraints. Looks like they
>are in the get alert configuration output table.
>
Ok, as you mentioned, I'll remove the if (in->lupwt > 100) check and
retain only the if (in->lupwt >= alert_config->lucat) check.
As per CXL spec 3.2. The life used warning threshold shall be less than
the life used critical alert value.
>> +            return CXL_MBOX_INVALID_INPUT;
>> +        }
>> +
>> +        if (in->enable_alert_actions.lupwt) {
>> +            alert_config->lupwt = in->lupwt;
>
>That's interesting.  Do we only write it when enabled. I would have
>thought valid was enough.  Spec reference in a comment would help
>for this first case at least. No need to replicate in the
>others if it is a common thing.
>
>
Based on your feedback, I'll remove the checks for enable alert actions and
rely only on valid alert actions to determine if the field should be processed,
as it is sufficient for this operation
>> +        }
>> +        alert_config->enable_alerts.lupwt = in->enable_alert_actions.lupwt;
>> +    }
>> +
>> +    if (in->valid_alert_actions.dotpwt) {
>> +        if (in->dotpwt >= alert_config->dotcat) {
>> +            return CXL_MBOX_INVALID_INPUT;
>> +        }
>> +        if (in->enable_alert_actions.dotpwt) {
>> +            alert_config->dotpwt = in->dotpwt;
>> +        }
>> +        alert_config->enable_alerts.dotpwt = in->enable_alert_actions.dotpwt;
>> +    }
>> +
>> +    if (in->valid_alert_actions.dutpwt) {
>> +        if (in->dutpwt < alert_config->dutcat) {
>> +            return CXL_MBOX_INVALID_INPUT;
>> +        }
>> +        if (in->enable_alert_actions.dutpwt) {
>> +            alert_config->dutpwt = in->dutpwt;
>> +        }
>> +        alert_config->enable_alerts.dutpwt = in->enable_alert_actions.dutpwt;
>> +    }
>> +
>> +    if (in->valid_alert_actions.cvmepwt) {
>> +        if (in->enable_alert_actions.cvmepwt) {
>> +            alert_config->cvmepwt = in->cvmepwt;
>> +        }
>> +        alert_config->enable_alerts.cvmepwt = in->valid_alert_actions.cvmepwt;
>> +    }
>> +
>> +    if (in->valid_alert_actions.cpmepwt) {
>> +        if (in->enable_alert_actions.cpmepwt) {
>> +            alert_config->cpmepwt = in->cpmepwt;
>> +        }
>> +        alert_config->enable_alerts.cpmepwt = in->valid_alert_actions.cpmepwt;
>> +    }
>> +    return CXL_MBOX_SUCCESS;
>> +}
>> +
>>  /* Perform the actual device zeroing */
>>  static void __do_sanitization(CXLType3Dev *ct3d)
>>  {
>> @@ -2859,6 +2946,10 @@ static const struct cxl_cmd cxl_cmd_set[256][256] = {
>>      [CCLS][GET_LSA] = { "CCLS_GET_LSA", cmd_ccls_get_lsa, 8, 0 },
>>      [CCLS][SET_LSA] = { "CCLS_SET_LSA", cmd_ccls_set_lsa,
>>          ~0, CXL_MBOX_IMMEDIATE_CONFIG_CHANGE | CXL_MBOX_IMMEDIATE_DATA_CHANGE },
>> +    [HEALTH_INFO_ALERTS][GET_ALERT_CONFIGURATION] = {"GET_ALERT_CONFIGURATION",
>> +        cmd_get_alert_config, 0, 0 },
>> +    [HEALTH_INFO_ALERTS][SET_ALERT_CONFIGURATION] = {"SET_ALERT_CONFIGURATION",
>> +        cmd_set_alert_config, 12, CXL_MBOX_IMMEDIATE_POLICY_CHANGE },
>>      [SANITIZE][OVERWRITE] = { "SANITIZE_OVERWRITE", cmd_sanitize_overwrite, 0,
>>          (CXL_MBOX_IMMEDIATE_DATA_CHANGE |
>>           CXL_MBOX_SECURITY_STATE_CHANGE |
>> diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
>> index 5f365afb4d..ce5a4962da 100644
>> --- a/hw/mem/cxl_type3.c
>> +++ b/hw/mem/cxl_type3.c
>> @@ -956,6 +956,25 @@ static DOEProtocol doe_comp_prot[] = {
>>      { }
>>  };
>>
>> +/*
>> + * Initialize CXL device alerts with default threshold values.
>> + */
>> +static void init_alert_config(CXLType3Dev *ct3d)
>> +{
>> +    CXLAlertConfig *alert_config = &ct3d->alert_config;
>> +
>> +    memset(&alert_config->valid_alerts, 0, sizeof(CXLValidEnableAlerts));
>> +    memset(&alert_config->enable_alerts, 0, sizeof(CXLValidEnableAlerts));
>> +    alert_config->lucat = 75;
>> +    alert_config->lupwt = 0;
>> +    alert_config->dotcat = 35;
>> +    alert_config->dutcat = 10;
>> +    alert_config->dotpwt = 25;
>> +    alert_config->dutpwt = 20;
>> +    alert_config->cvmepwt = 0;
>> +    alert_config->cpmepwt = 0;
>Easier to read as
>      ct3d_alert_config = (CXLAlertConfig) {
>          .life_used_critical_thresh = 75,
>...
>
>You can skip anything where a default of 0 is an obvious default.
>Perhaps the valid_alerts and enable alerts for instance.
>
Ok, I'll address this in V2 patch.
>      };
>> +}
>> +
>>  void ct3_realize(PCIDevice *pci_dev, Error **errp)
>>  {
>>      ERRP_GUARD();
>> @@ -1030,6 +1049,7 @@ void ct3_realize(PCIDevice *pci_dev, Error **errp)
>>          goto err_free_special_ops;
>>      }
>>
>> +    init_alert_config(ct3d);
>>      pcie_cap_deverr_init(pci_dev);
>>      /* Leave a bit of room for expansion */
>>      rc = pcie_aer_init(pci_dev, PCI_ERR_VER, 0x200, PCI_ERR_SIZEOF, NULL);
>> diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
>> index a64739be25..6acae7d74d 100644
>> --- a/include/hw/cxl/cxl_device.h
>> +++ b/include/hw/cxl/cxl_device.h
>> @@ -581,6 +581,28 @@ typedef struct CXLSetFeatureInfo {
>>      size_t data_size;
>>  } CXLSetFeatureInfo;
>>
>> +typedef struct CXLValidEnableAlerts {
>> +    uint8_t lupwt:1;
>
>Give these longer names.
>life_used_warning_threshold etc
>etc as we don't want to go find the spec to figure
>out what they are.
>
>
Ok, I'll update this in V2 patch.
>> +    uint8_t dotpwt:1;
>> +    uint8_t dutpwt:1;
>> +    uint8_t cvmepwt:1;
>> +    uint8_t cpmepwt:1;
>> +    uint8_t reserved:3;
>
>Generally bit fields do not play well with potential endian
>variations or low level code in general.  There is too much
>flexibility in how they are stored.  So better to use a
>uint8_t and some defines for the bits that are set.
>
>
Ok.
>> +} CXLValidEnableAlerts;
>> +
>> +typedef struct CXLAlertConfig {
>> +    CXLValidEnableAlerts valid_alerts;
>> +    CXLValidEnableAlerts enable_alerts;
>> +    uint8_t lucat;
>Longer names.  These want to be at least vaguely comprehensible
>without the spec in front of us.
>lif_used_critical_thresh
>life_used_warning_thresh (I'm not sure why programmable matters!)
>etc
>
Ok, will fix this in V2 patch.
>> +    uint8_t lupwt;
>> +    uint16_t dotcat;
>> +    uint16_t dutcat;
>> +    uint16_t dotpwt;
>> +    uint16_t dutpwt;
>> +    uint16_t cvmepwt;
>> +    uint16_t cpmepwt;
>> +} QEMU_PACKED CXLAlertConfig;
>> +
>>  struct CXLType3Dev {
>>      /* Private */
>>      PCIDevice parent_obj;
>> @@ -605,6 +627,8 @@ struct CXLType3Dev {
>>      CXLCCI vdm_fm_owned_ld_mctp_cci;
>>      CXLCCI ld0_cci;
>>
>> +    CXLAlertConfig alert_config;
>> +
>>      /* PCIe link characteristics */
>>      PCIExpLinkSpeed speed;
>>      PCIExpLinkWidth width;
>

[-- Attachment #2: Type: text/plain, Size: 0 bytes --]