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[Xen-devel] [PATCH v9 1/6] x86: detect and initialize Cache QoS Monitoring feature



Detect platform QoS feature status and enumerate the resource types,
one of which is to monitor the L3 cache occupancy.

Also introduce a Xen grub command line parameter to control the
QoS feature status.

Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Signed-off-by: Jiongxi Li <jiongxi.li@xxxxxxxxx>
Signed-off-by: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
---
 docs/misc/xen-command-line.markdown |    7 ++
 xen/arch/x86/Makefile               |    1 +
 xen/arch/x86/pqos.c                 |  156 +++++++++++++++++++++++++++++++++++
 xen/arch/x86/setup.c                |    3 +
 xen/include/asm-x86/cpufeature.h    |    1 +
 xen/include/asm-x86/pqos.h          |   43 ++++++++++
 6 files changed, 211 insertions(+)
 create mode 100644 xen/arch/x86/pqos.c
 create mode 100644 xen/include/asm-x86/pqos.h

diff --git a/docs/misc/xen-command-line.markdown 
b/docs/misc/xen-command-line.markdown
index 15aa404..7751ffe 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -770,6 +770,13 @@ This option can be specified more than once (up to 8 times 
at present).
 ### ple\_window
 > `= <integer>`
 
+### pqos (Intel)
+> `= List of ( <boolean> | cqm:<boolean> | cqm_max_rmid:<integer> )`
+
+> Default: `pqos=1,cqm:1,cqm_max_rmid:255`
+
+Configure platform QoS services.
+
 ### reboot
 > `= t[riple] | k[bd] | n[o] [, [w]arm | [c]old]`
 
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index d502bdf..54962e0 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -58,6 +58,7 @@ obj-y += crash.o
 obj-y += tboot.o
 obj-y += hpet.o
 obj-y += xstate.o
+obj-y += pqos.o
 
 obj-$(crash_debug) += gdbstub.o
 
diff --git a/xen/arch/x86/pqos.c b/xen/arch/x86/pqos.c
new file mode 100644
index 0000000..ba0de37
--- /dev/null
+++ b/xen/arch/x86/pqos.c
@@ -0,0 +1,156 @@
+/*
+ * pqos.c: Platform QoS related service for guest.
+ *
+ * Copyright (c) 2014, Intel Corporation
+ * Author: Jiongxi Li  <jiongxi.li@xxxxxxxxx>
+ * 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.
+ */
+#include <asm/processor.h>
+#include <xen/init.h>
+#include <xen/mm.h>
+#include <asm/pqos.h>
+
+static bool_t __initdata opt_pqos = 1;
+static bool_t __initdata opt_cqm = 1;
+static unsigned int __initdata opt_cqm_max_rmid = 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, "cqm") &&
+                 (val = parse_bool(val_str)) >= 0 )
+                opt_cqm = val;
+            else if ( val_str && !strcmp(s, "cqm_max_rmid") )
+                opt_cqm_max_rmid = simple_strtoul(val_str, NULL, 0);
+        }
+
+        s = ss + 1;
+    } while ( ss );
+}
+
+custom_param("pqos", parse_pqos_param);
+
+struct pqos_cqm __read_mostly *cqm = NULL;
+
+static void __init init_cqm(void)
+{
+    unsigned int rmid;
+    unsigned int eax, edx;
+    unsigned int cqm_pages;
+    unsigned int i;
+
+    if ( !opt_cqm_max_rmid )
+        return;
+
+    cqm = xzalloc(struct pqos_cqm);
+    if ( !cqm )
+        return;
+
+    cpuid_count(0xf, 1, &eax, &cqm->upscaling_factor, &cqm->max_rmid, &edx);
+    if ( !(edx & QOS_MONITOR_EVTID_L3) )
+        goto out;
+
+    cqm->min_rmid = 1;
+    cqm->max_rmid = min(opt_cqm_max_rmid, cqm->max_rmid);
+
+    cqm->rmid_to_dom = xmalloc_array(domid_t, cqm->max_rmid + 1);
+    if ( !cqm->rmid_to_dom )
+        goto out;
+
+    /* Reserve RMID 0 for all domains not being monitored */
+    cqm->rmid_to_dom[0] = DOMID_XEN;
+    for ( rmid = cqm->min_rmid; rmid <= cqm->max_rmid; rmid++ )
+        cqm->rmid_to_dom[rmid] = DOMID_INVALID;
+
+    /* Allocate CQM buffer size in initialization stage */
+    cqm_pages = ((cqm->max_rmid + 1) * sizeof(domid_t) +
+                (cqm->max_rmid + 1) * sizeof(uint64_t) * NR_CPUS)/
+                PAGE_SIZE + 1;
+    cqm->buffer_size = cqm_pages * PAGE_SIZE;
+
+    cqm->buffer = alloc_xenheap_pages(get_order_from_pages(cqm_pages), 0);
+    if ( !cqm->buffer )
+    {
+        xfree(cqm->rmid_to_dom);
+        goto out;
+    }
+    memset(cqm->buffer, 0, cqm->buffer_size);
+
+    for ( i = 0; i < cqm_pages; i++ )
+        share_xen_page_with_privileged_guests(
+            virt_to_page((void *)((unsigned long)cqm->buffer + i * PAGE_SIZE)),
+            XENSHARE_readonly);
+
+    spin_lock_init(&cqm->cqm_lock);
+
+    cqm->used_rmid = 0;
+
+    printk(XENLOG_INFO "Cache QoS Monitoring Enabled.\n");
+
+    return;
+
+out:
+    xfree(cqm);
+    cqm = NULL;
+}
+
+static void __init init_qos_monitor(void)
+{
+    unsigned int qm_features;
+    unsigned int eax, ebx, ecx;
+
+    if ( !(boot_cpu_has(X86_FEATURE_QOSM)) )
+        return;
+
+    cpuid_count(0xf, 0, &eax, &ebx, &ecx, &qm_features);
+
+    if ( opt_cqm && (qm_features & QOS_MONITOR_TYPE_L3) )
+        init_cqm();
+}
+
+void __init init_platform_qos(void)
+{
+    if ( !opt_pqos )
+        return;
+
+    init_qos_monitor();
+}
+
+/*
+ * 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 b49256d..639528f 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -48,6 +48,7 @@
 #include <asm/setup.h>
 #include <xen/cpu.h>
 #include <asm/nmi.h>
+#include <asm/pqos.h>
 
 /* opt_nosmp: If true, secondary processors are ignored. */
 static bool_t __initdata opt_nosmp;
@@ -1419,6 +1420,8 @@ void __init __start_xen(unsigned long mbi_p)
 
     domain_unpause_by_systemcontroller(dom0);
 
+    init_platform_qos();
+
     reset_stack_and_jump(init_done);
 }
 
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index 1cfaf94..ca59668 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -147,6 +147,7 @@
 #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_QOSM       (7*32+12) /* Platform QoS monitoring capability 
*/
 #define X86_FEATURE_NO_FPU_SEL         (7*32+13) /* FPU CS/DS stored as zero */
 #define X86_FEATURE_SMAP       (7*32+20) /* Supervisor Mode Access Prevention 
*/
 
diff --git a/xen/include/asm-x86/pqos.h b/xen/include/asm-x86/pqos.h
new file mode 100644
index 0000000..0a8065c
--- /dev/null
+++ b/xen/include/asm-x86/pqos.h
@@ -0,0 +1,43 @@
+/*
+ * pqos.h: Platform QoS related service for guest.
+ *
+ * Copyright (c) 2014, Intel Corporation
+ * Author: Jiongxi Li  <jiongxi.li@xxxxxxxxx>
+ * 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>
+#include <xen/spinlock.h>
+
+/* QoS Resource Type Enumeration */
+#define QOS_MONITOR_TYPE_L3            0x2
+
+/* QoS Monitoring Event ID */
+#define QOS_MONITOR_EVTID_L3           0x1
+
+struct pqos_cqm {
+    spinlock_t cqm_lock;
+    uint64_t *buffer;
+    unsigned int min_rmid;
+    unsigned int max_rmid;
+    unsigned int used_rmid;
+    unsigned int upscaling_factor;
+    unsigned int buffer_size;
+    domid_t *rmid_to_dom;
+};
+extern struct pqos_cqm *cqm;
+
+void init_platform_qos(void);
+
+#endif
-- 
1.7.9.5


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