[PATCH v17 04/10] x86: detect and initialize Cache Monitoring Technology feature

[Chao Peng <chao.p.peng@linux.intel.com>]

Detect Cache Monitoring Technology(CMT) feature and enumerate the
resource types, one of which is to monitor the L3 cache occupancy.

Also introduce a Xen command line parameter to control the Platform
Shared Resource such as CMT.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
---
 docs/misc/xen-command-line.markdown |   21 +++++++
 xen/arch/x86/Makefile               |    1 +
 xen/arch/x86/psr.c                  |  114 +++++++++++++++++++++++++++++++++++
 xen/arch/x86/setup.c                |    1 +
 xen/include/asm-x86/cpufeature.h    |    1 +
 xen/include/asm-x86/psr.h           |   51 ++++++++++++++++
 6 files changed, 189 insertions(+)
 create mode 100644 xen/arch/x86/psr.c
 create mode 100644 xen/include/asm-x86/psr.h

diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
index af93e17..5514431 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -1005,6 +1005,27 @@ This option can be specified more than once (up to 8 times at present).
 ### ple\_window
 > `= <integer>`
 
+### psr (Intel)
+> `= List of ( cmt:<boolean> | rmid_max:<integer> )`
+
+> Default: `psr=cmt:0,rmid_max:255`
+
+Platform Shared Resource(PSR) Services.  Intel Haswell and later server
+platforms offer information about the sharing of resources.
+
+To use the PSR monitoring service for a certain domain, a Resource
+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.
+
+The following resources are available:
+* Cache Monitoring Technology (Haswell and later).  Information
+regarding the L3 cache occupancy.
+
+`cmt` instructs Xen to enable/disable Cache Monitoring Technology.
+
+`rmid_max` indicates the max value for rmid.
+
 ### reboot
 > `= t[riple] | k[bd] | a[cpi] | p[ci] | n[o] [, [w]arm | [c]old]`
 
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index c1e244d..86ca5f8 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -42,6 +42,7 @@ obj-y += numa.o
 obj-y += pci.o
 obj-y += percpu.o
 obj-y += physdev.o
+obj-y += psr.o
 obj-y += setup.o
 obj-y += shutdown.o
 obj-y += smp.o
diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
new file mode 100644
index 0000000..a4cbc0a
--- /dev/null
+++ b/xen/arch/x86/psr.c
@@ -0,0 +1,114 @@
+/*
+ * pqos.c: Platform Shared Resource related service for guest.
+ *
+ * Copyright (c) 2014, Intel Corporation
+ * Author: Dongxiao Xu <dongxiao.xu@intel.com>
+ *
+ * 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.
+ */
+#include <xen/init.h>
+#include <xen/cpu.h>
+#include <asm/psr.h>
+
+#define PSR_CMT        (1<<0)
+
+struct psr_cmt *__read_mostly psr_cmt;
+static bool_t __initdata opt_psr;
+static unsigned int __initdata opt_rmid_max = 255;
+
+static void __init parse_psr_param(char *s)
+{
+    char *ss, *val_str;
+
+    do {
+        ss = strchr(s, ',');
+        if ( ss )
+            *ss = '\0';
+
+        val_str = strchr(s, ':');
+        if ( val_str )
+            *val_str++ = '\0';
+
+        if ( !strcmp(s, "cmt") && ( !val_str || parse_bool(val_str) == 1 ) )
+            opt_psr |= PSR_CMT;
+        else if ( val_str && !strcmp(s, "rmid_max") )
+            opt_rmid_max = 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)
+{
+    unsigned int eax, ebx, ecx, edx;
+    unsigned int rmid;
+
+    if ( !boot_cpu_has(X86_FEATURE_CMT) )
+        return;
+
+    cpuid_count(0xf, 0, &eax, &ebx, &ecx, &edx);
+    if ( !edx )
+        return;
+
+    psr_cmt = xzalloc(struct psr_cmt);
+    if ( !psr_cmt )
+        return;
+
+    psr_cmt->features = edx;
+    psr_cmt->rmid_mask = ~(~0ull << get_count_order(ebx));
+    psr_cmt->rmid_max = min(rmid_max, ebx);
+
+    if ( psr_cmt->features & PSR_RESOURCE_TYPE_L3 )
+    {
+        cpuid_count(0xf, 1, &eax, &ebx, &ecx, &edx);
+        psr_cmt->l3.upscaling_factor = ebx;
+        psr_cmt->l3.rmid_max = ecx;
+        psr_cmt->l3.features = edx;
+    }
+
+    psr_cmt->rmid_max = min(rmid_max, psr_cmt->l3.rmid_max);
+    psr_cmt->rmid_to_dom = xmalloc_array(domid_t, psr_cmt->rmid_max + 1);
+    if ( !psr_cmt->rmid_to_dom )
+    {
+        xfree(psr_cmt);
+        psr_cmt = NULL;
+        return;
+    }
+
+    /*
+     * Once CMT is enabled each CPU will always require a RMID to associate
+     * with it. To reduce the waste of RMID, reserve RMID 0 for all CPUs that
+     * have no domain being monitored.
+     */
+    psr_cmt->rmid_to_dom[0] = DOMID_XEN;
+    for ( rmid = 1; rmid <= psr_cmt->rmid_max; rmid++ )
+        psr_cmt->rmid_to_dom[rmid] = DOMID_INVALID;
+
+    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);
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 8c8b91f..3856fcc 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -49,6 +49,7 @@
 #include <xen/cpu.h>
 #include <asm/nmi.h>
 #include <asm/alternative.h>
+#include <asm/psr.h>
 
 /* opt_nosmp: If true, secondary processors are ignored. */
 static bool_t __initdata opt_nosmp;
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index 8014241..137d75c 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -148,6 +148,7 @@
 #define X86_FEATURE_ERMS	(7*32+ 9) /* Enhanced REP MOVSB/STOSB */
 #define X86_FEATURE_INVPCID	(7*32+10) /* Invalidate Process Context ID */
 #define X86_FEATURE_RTM 	(7*32+11) /* Restricted Transactional Memory */
+#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_RDSEED	(7*32+18) /* RDSEED instruction */
diff --git a/xen/include/asm-x86/psr.h b/xen/include/asm-x86/psr.h
new file mode 100644
index 0000000..8a3803c
--- /dev/null
+++ b/xen/include/asm-x86/psr.h
@@ -0,0 +1,51 @@
+/*
+ * psr.h: Platform Shared Resource related service for guest.
+ *
+ * Copyright (c) 2014, Intel Corporation
+ * Author: Dongxiao Xu <dongxiao.xu@intel.com>
+ *
+ * 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_PSR_H__
+#define __ASM_PSR_H__
+
+/* Resource Type Enumeration */
+#define PSR_RESOURCE_TYPE_L3            0x2
+
+/* L3 Monitoring Features */
+#define PSR_CMT_L3_OCCUPANCY           0x1
+
+struct psr_cmt_l3 {
+    unsigned int features;
+    unsigned int upscaling_factor;
+    unsigned int rmid_max;
+};
+
+struct psr_cmt {
+    unsigned long rmid_mask;
+    unsigned int rmid_max;
+    unsigned int features;
+    domid_t *rmid_to_dom;
+    struct psr_cmt_l3 l3;
+};
+
+extern struct psr_cmt *psr_cmt;
+
+#endif /* __ASM_PSR_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
1.7.9.5