Re: [Qemu-devel] [PATCH 6/8] ipmi: provide support for FRUs

[Cédric Le Goater]

On 02/16/2016 04:38 AM, Corey Minyard wrote:
> On 02/15/2016 12:40 PM, Marcel Apfelbaum wrote:
>> On 02/15/2016 07:17 PM, Cédric Le Goater wrote:
>>> On 02/14/2016 10:25 AM, Marcel Apfelbaum wrote:
>>>> On 02/09/2016 02:13 PM, Cédric Le Goater wrote:
>>>>> This patch provides a simple FRU support for the BMC simulator. FRUs
>>>>> are loaded from a file which name is specified in the object
>>>>> properties, each entry having a fixed size, also specified in the
>>>>> properties. If the file is unknown or not accessible for some reason,
>>>>> a unique entry of 1024 bytes is created as a default. Just enough to
>>>>> start some simulation.
>>>>>
>>>>> Signed-off-by: Cédric Le Goater <address@hidden>
>>>>> ---
>>>>>    hw/ipmi/ipmi_bmc_sim.c | 140 
>>>>> +++++++++++++++++++++++++++++++++++++++++++++++++
>>>>>    1 file changed, 140 insertions(+)
>>>>>
>>>>> diff --git a/hw/ipmi/ipmi_bmc_sim.c b/hw/ipmi/ipmi_bmc_sim.c
>>>>> index 69318eb6b556..b0754893fc08 100644
>>>>> --- a/hw/ipmi/ipmi_bmc_sim.c
>>>>> +++ b/hw/ipmi/ipmi_bmc_sim.c
>>>>> @@ -80,6 +80,9 @@
>>>>>    #define IPMI_CMD_ENTER_SDR_REP_UPD_MODE   0x2A
>>>>>    #define IPMI_CMD_EXIT_SDR_REP_UPD_MODE    0x2B
>>>>>    #define IPMI_CMD_RUN_INIT_AGENT           0x2C
>>>>> +#define IPMI_CMD_GET_FRU_AREA_INFO        0x10
>>>>> +#define IPMI_CMD_READ_FRU_DATA            0x11
>>>>> +#define IPMI_CMD_WRITE_FRU_DATA           0x12
>>>>>    #define IPMI_CMD_GET_SEL_INFO             0x40
>>>>>    #define IPMI_CMD_GET_SEL_ALLOC_INFO       0x41
>>>>>    #define IPMI_CMD_RESERVE_SEL              0x42
>>>>> @@ -122,6 +125,13 @@ typedef struct IPMISdr {
>>>>>        uint8_t overflow;
>>>>>    } IPMISdr;
>>>>>
>>>>> +typedef struct IPMIFru {
>>>>> +    char *filename;
>>>>> +    unsigned int nentries;
>>>>> +    uint16_t size;
>>>>> +    uint8_t *data;
>>>>> +} IPMIFru;
>>>>> +
>>>>>    typedef struct IPMISensor {
>>>>>        uint8_t status;
>>>>>        uint8_t reading;
>>>>> @@ -208,6 +218,7 @@ struct IPMIBmcSim {
>>>>>
>>>>>        IPMISel sel;
>>>>>        IPMISdr sdr;
>>>>> +    IPMIFru fru;
>>>>>        IPMISensor sensors[MAX_SENSORS];
>>>>>        char *sdr_filename;
>>>>>
>>>>> @@ -1314,6 +1325,103 @@ static void get_sel_info(IPMIBmcSim *ibs,
>>>>>        IPMI_ADD_RSP_DATA((ibs->sel.overflow << 7) | 0x02);
>>>>>    }
>>>>>
>>>>> +static void get_fru_area_info(IPMIBmcSim *ibs,
>>>>> +                         uint8_t *cmd, unsigned int cmd_len,
>>>>> +                         uint8_t *rsp, unsigned int *rsp_len,
>>>>> +                         unsigned int max_rsp_len)
>>>>> +{
>>>>> +    uint8_t fruid;
>>>>> +    uint16_t fru_entry_size;
>>>>> +
>>>>> +    IPMI_CHECK_CMD_LEN(3);
>>>>
>>>> Hi,
>>>>
>>>> This is little awkward for me. The cmd_len and rsp
>>>> parameters of the macro are implied.
>>>
>>> hmm, I am not sure what you mean. Are you concerned by that fact
>>> we could overflow rsp and cmd ?
>>
>> Not really, no. Something more simple:
>>
>> IPMI_CHECK_CMD_LEN(3) should be actually IPMI_CHECK_CMD_LEN(3, cmd_len, rsp).
>> What bothers me is that both cmd_len and rsp are implied by the macro.
> 
> I would tend to agree.  The hidden stuff in these macros was really a bad 
> idea in
> hindsight.

IPMI_CHECK_CMD_LEN() could be replaced by an array of constants. 

I like the way IPMI_ADD_RSP_DATA() pushes bytes in the response 
buffer, it makes the code quite readable from the spec perspective. 
Maybe we could replace rsp and rsp_len with a simple stack-like 
struct and use one helper to push response bytes. 

It should not be too complex to cleanup. I will add a proposal in
the next round.

Thanks,

C.

> -corey
> 
>>
>> In other words, we don't know what parameters IPMI_CHECK_CMD_LEN really has.
>> "3" is for sure not enough, so we need to guess or look a the macro 
>> definition
>> to see what it uses.
>>
>> But again, maybe is only me.
>>
>> Thanks,
>> Marcel
>>
>>
>>>
>>> I guess we could probably move the IPMI_CHECK_CMD_LEN in the caller
>>> of these commands and use an array of expected argument lengths.
>>> For rsp, IPMI_ADD_RSP_DATA needs to be used to check that we are not
>>> exceeding max_rsp_len
>>>
>>>> Am I the only one this bothers?
>>>>
>>>>> +
>>>>> +    fruid = cmd[2];
>>>>> +
>>>>> +    if (fruid >= ibs->fru.nentries) {
>>>>> +        rsp[2] = IPMI_CC_INVALID_DATA_FIELD;
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    fru_entry_size = ibs->fru.size;
>>>>> +
>>>>> +    IPMI_ADD_RSP_DATA(fru_entry_size & 0xff);
>>>>> +    IPMI_ADD_RSP_DATA(fru_entry_size >> 8 & 0xff);
>>>>> +    IPMI_ADD_RSP_DATA(0x0);
>>>>
>>>> Same here. By the way, do you have some spec for the above or
>>>> is an ad-hoc encoding of the fields? If yes, you could
>>>> add a reference for the spec.(This is also for the other functions in this 
>>>> patch)
>>>
>>> Yes I will add the reference.
>>>
>>> Thanks,
>>>
>>> C.
>>>
>>>
>>>> Thanks,
>>>> Marcel
>>>>
>>>>> +}
>>>>> +
>>>>> +#define min(x, y) ((x) < (y) ? (x) : (y))
>>>>> +#define max(x, y) ((x) > (y) ? (x) : (y))
>>>>> +
>>>>> +static void read_fru_data(IPMIBmcSim *ibs,
>>>>> +                         uint8_t *cmd, unsigned int cmd_len,
>>>>> +                         uint8_t *rsp, unsigned int *rsp_len,
>>>>> +                         unsigned int max_rsp_len)
>>>>> +{
>>>>> +    uint8_t fruid;
>>>>> +    uint16_t offset;
>>>>> +    int i;
>>>>> +    uint8_t *fru_entry;
>>>>> +    unsigned int count;
>>>>> +
>>>>> +    IPMI_CHECK_CMD_LEN(5);
>>>>> +
>>>>> +    fruid = cmd[2];
>>>>> +    offset = (cmd[3] | cmd[4] << 8);
>>>>> +
>>>>> +    if (fruid >= ibs->fru.nentries) {
>>>>> +        rsp[2] = IPMI_CC_INVALID_DATA_FIELD;
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    if (offset >= ibs->fru.size - 1) {
>>>>> +        rsp[2] = IPMI_CC_INVALID_DATA_FIELD;
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    fru_entry = &ibs->fru.data[fruid * ibs->fru.size];
>>>>> +
>>>>> +    count = min(cmd[5], ibs->fru.size - offset);
>>>>> +
>>>>> +    IPMI_ADD_RSP_DATA(count & 0xff);
>>>>> +    for (i = 0; i < count; i++) {
>>>>> +        IPMI_ADD_RSP_DATA(fru_entry[offset + i]);
>>>>> +    }
>>>>> +}
>>>>> +
>>>>> +static void write_fru_data(IPMIBmcSim *ibs,
>>>>> +                         uint8_t *cmd, unsigned int cmd_len,
>>>>> +                         uint8_t *rsp, unsigned int *rsp_len,
>>>>> +                         unsigned int max_rsp_len)
>>>>> +{
>>>>> +    uint8_t fruid;
>>>>> +    uint16_t offset;
>>>>> +    uint8_t *fru_entry;
>>>>> +    unsigned int count;
>>>>> +
>>>>> +    IPMI_CHECK_CMD_LEN(5);
>>>>> +
>>>>> +    fruid = cmd[2];
>>>>> +    offset = (cmd[3] | cmd[4] << 8);
>>>>> +
>>>>> +    if (fruid >= ibs->fru.nentries) {
>>>>> +        rsp[2] = IPMI_CC_INVALID_DATA_FIELD;
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    if (offset >= ibs->fru.size - 1) {
>>>>> +        rsp[2] = IPMI_CC_INVALID_DATA_FIELD;
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    fru_entry = &ibs->fru.data[fruid * ibs->fru.size];
>>>>> +
>>>>> +    count = min(cmd_len - 5, ibs->fru.size - offset);
>>>>> +
>>>>> +    memcpy(fru_entry + offset, cmd + 5, count);
>>>>> +
>>>>> +    IPMI_ADD_RSP_DATA(count & 0xff);
>>>>> +}
>>>>> +
>>>>>    static void reserve_sel(IPMIBmcSim *ibs,
>>>>>                            uint8_t *cmd, unsigned int cmd_len,
>>>>>                            uint8_t *rsp, unsigned int *rsp_len,
>>>>> @@ -1667,6 +1775,9 @@ static const IPMINetfn app_netfn = {
>>>>>    };
>>>>>
>>>>>    static const IPMICmdHandler storage_cmds[] = {
>>>>> +    [IPMI_CMD_GET_FRU_AREA_INFO] = get_fru_area_info,
>>>>> +    [IPMI_CMD_READ_FRU_DATA] = read_fru_data,
>>>>> +    [IPMI_CMD_WRITE_FRU_DATA] = write_fru_data,
>>>>>        [IPMI_CMD_GET_SDR_REP_INFO] = get_sdr_rep_info,
>>>>>        [IPMI_CMD_RESERVE_SDR_REP] = reserve_sdr_rep,
>>>>>        [IPMI_CMD_GET_SDR] = get_sdr,
>>>>> @@ -1766,6 +1877,31 @@ static const VMStateDescription vmstate_ipmi_sim = 
>>>>> {
>>>>>        }
>>>>>    };
>>>>>
>>>>> +static void ipmi_fru_init(IPMIFru *fru)
>>>>> +{
>>>>> +    int fsize;
>>>>> +    int size = 0;
>>>>> +
>>>>> +    fsize = get_image_size(fru->filename);
>>>>> +    if (fsize > 0) {
>>>>> +        size = QEMU_ALIGN_UP(fsize, fru->size);
>>>>> +        fru->data = g_malloc0(size);
>>>>> +        if (load_image_size(fru->filename, fru->data, fsize) != fsize) {
>>>>> +            error_report("Could not load file '%s'", fru->filename);
>>>>> +            g_free(fru->data);
>>>>> +            fru->data = NULL;
>>>>> +        }
>>>>> +    }
>>>>> +
>>>>> +    if (!fru->data) {
>>>>> +        /* give one default FRU */
>>>>> +        size = fru->size;
>>>>> +        fru->data = g_malloc0(size);
>>>>> +    }
>>>>> +
>>>>> +    fru->nentries = size / fru->size;
>>>>> +}
>>>>> +
>>>>>    static void ipmi_sim_realize(DeviceState *dev, Error **errp)
>>>>
>>>>
>>>>>    {
>>>>>        IPMIBmc *b = IPMI_BMC(dev);
>>>>> @@ -1788,6 +1924,8 @@ static void ipmi_sim_realize(DeviceState *dev, 
>>>>> Error **errp)
>>>>>
>>>>>        ipmi_sdr_init(ibs);
>>>>>
>>>>> +    ipmi_fru_init(&ibs->fru);
>>>>> +
>>>>>        ibs->acpi_power_state[0] = 0;
>>>>>        ibs->acpi_power_state[1] = 0;
>>>>>
>>>>> @@ -1806,6 +1944,8 @@ static void ipmi_sim_realize(DeviceState *dev, 
>>>>> Error **errp)
>>>>>    }
>>>>>
>>>>>    static Property ipmi_sim_properties[] = {
>>>>> +    DEFINE_PROP_UINT16("frusize", IPMIBmcSim, fru.size, 1024),
>>>>> +    DEFINE_PROP_STRING("frufile", IPMIBmcSim, fru.filename),
>>>>>        DEFINE_PROP_STRING("sdr", IPMIBmcSim, sdr_filename),
>>>>>        DEFINE_PROP_END_OF_LIST(),
>>>>>    };
>>>>>
>>>>
>>>
>>
>