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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 1/6] x86: detect and initialize Intel CAT feature
Detect Intel Cache Allocation Technology(CAT) feature and store the
cpuid information for later use. Currently only L3 cache allocation is
supported. The L3 CAT features may vary among sockets so per-socket
feature information is stored. The initialization can happen either at
boot time or when CPU(s) is hot plugged after booting.
Signed-off-by: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>
---
docs/misc/xen-command-line.markdown | 15 +++-
xen/arch/x86/psr.c | 151 +++++++++++++++++++++++++++++++++---
xen/include/asm-x86/cpufeature.h | 1 +
3 files changed, 155 insertions(+), 12 deletions(-)
diff --git a/docs/misc/xen-command-line.markdown
b/docs/misc/xen-command-line.markdown
index 63871cb..a4b36e6 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -1090,9 +1090,9 @@ This option can be specified more than once (up to 8
times at present).
> `= <integer>`
### psr (Intel)
-> `= List of ( cmt:<boolean> | rmid_max:<integer> )`
+> `= List of ( cmt:<boolean> | rmid_max:<integer> | socket_num:<interger> )`
-> Default: `psr=cmt:0,rmid_max:255`
+> Default: `psr=cmt:0,rmid_max:255,cat:0,socket_num:0 (Detect at boot time)`
Platform Shared Resource(PSR) Services. Intel Haswell and later server
platforms offer information about the sharing of resources.
@@ -1102,6 +1102,11 @@ Monitoring ID(RMID) is used to bind the domain to
corresponding shared
resource. RMID is a hardware-provided layer of abstraction between software
and logical processors.
+To use the PSR cache allocation service for a certain domain, a capacity
+bitmasks(CBM) is used to bind the domain to corresponding shared resource.
+CBM represents cache capacity and indicates the degree of overlap and isolation
+between domains.
+
The following resources are available:
* Cache Monitoring Technology (Haswell and later). Information regarding the
@@ -1112,6 +1117,12 @@ The following resources are available:
total/local memory bandwidth. Follow the same options with Cache Monitoring
Technology.
+* Cache Alllocation Technology (Broadwell and later). Information regarding
+ the cache allocation.
+ * `cat` instructs Xen to enable/disable Cache Allocation Technology.
+ * `socket_num` indicates socket number. Detecte automatically at boot time
+ if not specified(0). Useful for CPU hot-plug case.
+
### reboot
> `= t[riple] | k[bd] | a[cpi] | p[ci] | n[o] [, [w]arm | [c]old]`
diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 2ef83df..df557e8 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -19,6 +19,14 @@
#include <asm/psr.h>
#define PSR_CMT (1<<0)
+#define PSR_CAT (1<<1)
+
+struct psr_cat_socket_info {
+ bool_t initialized;
+ bool_t enabled;
+ unsigned int cbm_len;
+ unsigned int cos_max;
+};
struct psr_assoc {
uint64_t val;
@@ -26,8 +34,11 @@ struct psr_assoc {
};
struct psr_cmt *__read_mostly psr_cmt;
-static bool_t __initdata opt_psr;
+static struct psr_cat_socket_info *__read_mostly cat_socket_info;
+
+static unsigned int __initdata opt_psr;
static unsigned int __initdata opt_rmid_max = 255;
+static unsigned int __read_mostly opt_socket_num;
static uint64_t rmid_mask;
static DEFINE_PER_CPU(struct psr_assoc, psr_assoc);
@@ -58,15 +69,31 @@ static void __init parse_psr_param(char *s)
val_str);
}
}
+ else if ( !strcmp(s, "cat") )
+ {
+ if ( !val_str )
+ opt_psr |= PSR_CAT;
+ else
+ {
+ int val_int = parse_bool(val_str);
+ if ( val_int == 1 )
+ opt_psr |= PSR_CAT;
+ else if ( val_int != 0 )
+ printk("PSR: unknown cat value: %s - CAT disabled!\n",
+ val_str);
+ }
+ }
else if ( val_str && !strcmp(s, "rmid_max") )
opt_rmid_max = simple_strtoul(val_str, NULL, 0);
+ else if ( val_str && !strcmp(s, "socket_num") )
+ opt_socket_num = simple_strtoul(val_str, NULL, 0);
s = ss + 1;
} while ( ss );
}
custom_param("psr", parse_psr_param);
-static void __init init_psr_cmt(unsigned int rmid_max)
+static void __init psr_cmt_init(unsigned int rmid_max)
{
unsigned int eax, ebx, ecx, edx;
unsigned int rmid;
@@ -115,14 +142,6 @@ static void __init init_psr_cmt(unsigned int rmid_max)
printk(XENLOG_INFO "Cache Monitoring Technology enabled\n");
}
-static int __init init_psr(void)
-{
- if ( (opt_psr & PSR_CMT) && opt_rmid_max )
- init_psr_cmt(opt_rmid_max);
- return 0;
-}
-__initcall(init_psr);
-
/* Called with domain lock held, no psr specific lock needed */
int psr_alloc_rmid(struct domain *d)
{
@@ -189,6 +208,118 @@ void psr_assoc_rmid(unsigned int rmid)
}
}
+static void do_cat_cpu_init(void* data)
+{
+ unsigned int eax, ebx, ecx, edx;
+ struct psr_cat_socket_info *info;
+
+ cpuid_count(0x10, 0, &eax, &ebx, &ecx, &edx);
+ if ( ebx & PSR_RESOURCE_TYPE_L3 )
+ {
+ info = data;
+
+ cpuid_count(0x10, 1, &eax, &ebx, &ecx, &edx);
+ info->cbm_len = (eax & 0x1f) + 1;
+ info->cos_max = (edx & 0xffff);
+
+ info->enabled = 1;
+ printk(XENLOG_INFO "CAT: enabled on socket %d, cos_max:%d,
cbm_len:%d\n",
+ (int)(info - cat_socket_info), info->cos_max, info->cbm_len);
+ }
+}
+
+static void cat_cpu_init(unsigned int cpu)
+{
+ struct psr_cat_socket_info *info;
+ unsigned int socket;
+ const struct cpuinfo_x86 *c;
+
+ socket = cpu_to_socket(cpu);
+ if ( socket >= opt_socket_num )
+ {
+ printk(XENLOG_WARNING "CAT: disabled on socket %d because socket_num
is %d\n",
+ socket, opt_socket_num);
+ return;
+ }
+
+ info = cat_socket_info + socket;
+
+ /* Avoid initializing more than one times for the same socket. */
+ if ( test_and_set_bool(info->initialized) )
+ return;
+
+ c = cpu_data + cpu;
+ if ( !cpu_has(c, X86_FEATURE_CAT) )
+ return;
+
+ if ( cpu == smp_processor_id() )
+ do_cat_cpu_init(info);
+ else
+ on_selected_cpus(cpumask_of(cpu), do_cat_cpu_init, info, 0);
+}
+
+static int cpu_callback(
+ struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+
+ switch ( action )
+ {
+ case CPU_ONLINE:
+ (void)cat_cpu_init(cpu);
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block cpu_nfb = {
+ .notifier_call = cpu_callback
+};
+
+static unsigned int get_max_socket(void)
+{
+ unsigned int cpu, max_apicid = boot_cpu_physical_apicid;
+
+ for_each_present_cpu(cpu)
+ if (max_apicid < x86_cpu_to_apicid[cpu])
+ max_apicid = x86_cpu_to_apicid[cpu];
+
+ return apicid_to_socket(max_apicid);
+}
+
+static void __init psr_cat_init(void)
+{
+ if ( opt_socket_num == 0 )
+ opt_socket_num = get_max_socket() + 1;
+ else if ( opt_socket_num > NR_CPUS )
+ printk(XENLOG_WARNING "socket_num > NR_CPUS(%d), set to NR_CPUS.\n",
+ NR_CPUS);
+
+ BUG_ON(opt_socket_num == 0);
+
+ cat_socket_info = xzalloc_array(struct psr_cat_socket_info,
opt_socket_num);
+ if ( !cat_socket_info )
+ return;
+
+ cat_cpu_init(smp_processor_id());
+ register_cpu_notifier(&cpu_nfb);
+}
+
+static int __init psr_presmp_init(void)
+{
+ if ( (opt_psr & PSR_CMT) && opt_rmid_max )
+ psr_cmt_init(opt_rmid_max);
+
+ if ( opt_psr & PSR_CAT )
+ psr_cat_init();
+
+ return 0;
+}
+presmp_initcall(psr_presmp_init);
+
/*
* Local variables:
* mode: C
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index 7963a3a..8c0f0a6 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -149,6 +149,7 @@
#define X86_FEATURE_CMT (7*32+12) /* Cache Monitoring Technology */
#define X86_FEATURE_NO_FPU_SEL (7*32+13) /* FPU CS/DS stored as zero */
#define X86_FEATURE_MPX (7*32+14) /* Memory Protection
Extensions */
+#define X86_FEATURE_CAT (7*32+15) /* Cache Allocation Technology */
#define X86_FEATURE_RDSEED (7*32+18) /* RDSEED instruction */
#define X86_FEATURE_ADX (7*32+19) /* ADCX, ADOX instructions */
#define X86_FEATURE_SMAP (7*32+20) /* Supervisor Mode Access Prevention
*/
--
1.9.1
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