Re: [Xen-devel] [PATCH v12 4/9] x86: detect and initialize Platform QoS Monitoring feature

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 04.07.14 at 10:34, <dongxiao.xu@xxxxxxxxx> wrote:
> --- a/docs/misc/xen-command-line.markdown
> +++ b/docs/misc/xen-command-line.markdown
> @@ -863,6 +863,20 @@ This option can be specified more than once (up to 8 
> times at present).
>  ### ple\_window
>  > `= <integer>`
>  
> +### pqos (Intel)
> +> `= List of ( <boolean> | pqos_monitor:<boolean> | rmid_max:<integer> )`
> +
> +> Default: `pqos=1,pqos_monitor:1,rmid_max:255`

Please keep this in sync with the actual code.

> +struct pqos_monitor *__read_mostly pqosm = NULL;
> +static bool_t __initdata opt_pqos = 0;
> +static bool_t __initdata opt_pqos_monitor = 0;

So as said in response to the overview mail already - I think it's fine to
have the sub-option enabled by default, and just keeping the master
one off for now. In any event you don't need explicit 0 initializers for
static data.

> +static unsigned int __initdata opt_rmid_max = 255;
> +
> +static void __init parse_pqos_param(char *s)
> +{
> +    char *ss, *val_str;
> +    int val;
> +
> +    do {
> +        ss = strchr(s, ',');
> +        if ( ss )
> +            *ss = '\0';
> +
> +        val = parse_bool(s);
> +        if ( val >= 0 )
> +            opt_pqos = val;
> +        else
> +        {
> +            val = !!strncmp(s, "no-", 3);
> +            if ( !val )
> +                s += 3;
> +
> +            val_str = strchr(s, ':');
> +            if ( val_str )
> +                *val_str++ = '\0';
> +
> +            if ( val_str && !strcmp(s, "pqos_monitor") &&
> +                 (val = parse_bool(val_str)) >= 0 )
> +                opt_pqos_monitor = val;
> +            else if ( val_str && !strcmp(s, "rmid_max") )
> +                opt_rmid_max = simple_strtoul(val_str, NULL, 0);
> +        }
> +
> +        s = ss + 1;
> +    } while ( ss );
> +}
> +
> +custom_param("pqos", parse_pqos_param);
> +static void __init init_pqos_monitor(unsigned int rmid_max)

The blank line should be below custom_param() rather than above it.

> +{
> +    unsigned int eax, ebx, ecx, edx;
> +    unsigned int rmid;
> +
> +    if ( !boot_cpu_has(X86_FEATURE_QOSM) )
> +        return;
> +
> +    cpuid_count(0xf, 0, &eax, &ebx, &ecx, &edx);
> +    if ( !edx )
> +        return;
> +
> +    pqosm = xzalloc(struct pqos_monitor);
> +    if ( !pqosm )
> +        return;
> +
> +    pqosm->qm_features = edx;
> +    pqosm->rmid_mask = ~(~0ull << get_count_order(ebx));
> +    pqosm->rmid_inuse = 0;
> +    pqosm->rmid_min = 1;
> +    pqosm->rmid_max = min(rmid_max, ebx);
> +
> +    if ( pqosm->qm_features & QOS_MONITOR_TYPE_L3 ) {

Coding style (also further down).

> --- /dev/null
> +++ b/xen/include/asm-x86/pqos.h
> @@ -0,0 +1,56 @@
> +/*
> + * pqos.h: Platform QoS related service for guest.
> + *
> + * Copyright (c) 2014, Intel Corporation
> + * Author: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + */
> +#ifndef __ASM_PQOS_H__
> +#define __ASM_PQOS_H__
> +
> +#include <public/xen.h>
> +
> +/* QoS Resource Type Enumeration */
> +#define QOS_MONITOR_TYPE_L3            0x2
> +
> +/* L3 Monitoring Features */
> +#define L3_FEATURE_OCCUPANCY           0x1
> +
> +struct pqos_monitor_l3 {
> +    unsigned int l3_features;
> +    unsigned int upscaling_factor;
> +    unsigned int rmid_max;
> +};
> +
> +struct pqos_monitor {
> +    unsigned long rmid_mask;
> +    unsigned int rmid_min;
> +    unsigned int rmid_max;
> +    unsigned int rmid_inuse;
> +    unsigned int qm_features;
> +    domid_t *rmid_to_dom;
> +    struct pqos_monitor_l3 l3m;
> +};

Does any of the above get used outside of pqos.c? Anything used only
locally (until the end of the series of course) should be moved there.

> +extern struct pqos_monitor *pqosm;
> +
> +void __init init_platform_qos(void);

No __init annotaion on declarations please (these only belong on
definitions), even more so without including xen/init.h.

Jan

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