[PATCH v5 4/7] x86: collect CQM information from all sockets

[Dongxiao Xu <dongxiao.xu@intel.com>]

Collect CQM information (L3 cache occupancy) from all sockets.
Upper layer application can parse the data structure to get the
information of guest's L3 cache occupancy on certain sockets.

Signed-off-by: Jiongxi Li <jiongxi.li@intel.com>
Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
---
 xen/arch/x86/pqos.c             |   49 +++++++++++++++++++++++++++++
 xen/arch/x86/sysctl.c           |   65 +++++++++++++++++++++++++++++++++++++++
 xen/include/asm-x86/msr-index.h |    4 +++
 xen/include/asm-x86/pqos.h      |    7 +++++
 xen/include/public/domctl.h     |    9 ++++++
 xen/include/public/sysctl.h     |   10 ++++++
 6 files changed, 144 insertions(+)

diff --git a/xen/arch/x86/pqos.c b/xen/arch/x86/pqos.c
index 67d733e..f585c10 100644
--- a/xen/arch/x86/pqos.c
+++ b/xen/arch/x86/pqos.c
@@ -15,6 +15,7 @@
  * more details.
  */
 #include <asm/processor.h>
+#include <asm/msr.h>
 #include <xen/init.h>
 #include <xen/spinlock.h>
 #include <asm/pqos.h>
@@ -126,6 +127,12 @@ bool_t system_supports_cqm(void)
     return !!cqm;
 }
 
+unsigned int get_cqm_count(void)
+{
+    ASSERT(system_supports_cqm());
+    return cqm->max_rmid + 1;
+}
+
 int alloc_cqm_rmid(struct domain *d)
 {
     int rc = 0;
@@ -170,6 +177,48 @@ void free_cqm_rmid(struct domain *d)
     d->arch.pqos_cqm_rmid = 0;
 }
 
+static void read_cqm_data(void *arg)
+{
+    uint64_t cqm_data;
+    unsigned int rmid;
+    int socket = cpu_to_socket(smp_processor_id());
+    struct xen_socket_cqmdata *data = arg;
+    unsigned long flags, i;
+
+    ASSERT(system_supports_cqm());
+
+    if ( socket < 0 )
+        return;
+
+    spin_lock_irqsave(&cqm_lock, flags);
+    for ( rmid = cqm->min_rmid; rmid <= cqm->max_rmid; rmid++ )
+    {
+        if ( cqm->rmid_to_dom[rmid] == DOMID_INVALID )
+            continue;
+
+        wrmsr(MSR_IA32_QOSEVTSEL, QOS_MONITOR_EVTID_L3, rmid);
+        rdmsrl(MSR_IA32_QMC, cqm_data);
+
+        i = socket * (cqm->max_rmid + 1) + rmid;
+        data[i].valid = !(cqm_data & IA32_QM_CTR_ERROR_MASK);
+        if ( data[i].valid )
+        {
+            data[i].l3c_occupancy = cqm_data * cqm->upscaling_factor;
+            data[i].socket = socket;
+            data[i].domid = cqm->rmid_to_dom[rmid];
+        }
+    }
+    spin_unlock_irqrestore(&cqm_lock, flags);
+}
+
+void get_cqm_info(cpumask_t *cpu_cqmdata_map, struct xen_socket_cqmdata *data)
+{
+    /* Read CQM data in current CPU */
+    read_cqm_data(data);
+    /* Issue IPI to other CPUs to read CQM data */
+    on_selected_cpus(cpu_cqmdata_map, read_cqm_data, data, 1);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c
index 15d4b91..4dcf221 100644
--- a/xen/arch/x86/sysctl.c
+++ b/xen/arch/x86/sysctl.c
@@ -28,6 +28,7 @@
 #include <xen/nodemask.h>
 #include <xen/cpu.h>
 #include <xsm/xsm.h>
+#include <asm/pqos.h>
 
 #define get_xen_guest_handle(val, hnd)  do { val = (hnd).p; } while (0)
 
@@ -66,6 +67,24 @@ void arch_do_physinfo(xen_sysctl_physinfo_t *pi)
         pi->capabilities |= XEN_SYSCTL_PHYSCAP_hvm_directio;
 }
 
+/* Select one random CPU for each socket. Current CPU's socket is excluded */
+static void select_socket_cpu(cpumask_t *cpu_bitmap)
+{
+    int i;
+    unsigned int cpu;
+    unsigned int socket_curr = cpu_to_socket(smp_processor_id());
+
+    cpumask_clear(cpu_bitmap);
+    for ( i = 0; i < MAX_NUM_SOCKETS; i++ )
+    {
+        if ( i == socket_curr )
+            continue;
+        cpu = cpumask_any(&socket_cpu_map[i]);
+        if ( cpu < nr_cpu_ids )
+            cpumask_set_cpu(cpu, cpu_bitmap);
+    }
+}
+
 long arch_do_sysctl(
     struct xen_sysctl *sysctl, XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) u_sysctl)
 {
@@ -101,6 +120,52 @@ long arch_do_sysctl(
     }
     break;
 
+    case XEN_SYSCTL_getcqminfo:
+    {
+        struct xen_socket_cqmdata *info;
+        uint32_t num_sockets;
+        uint32_t num_rmids;
+        cpumask_t cpu_cqmdata_map;
+
+        if ( !system_supports_cqm() )
+        {
+            ret = -ENODEV;
+            break;
+        }
+
+        select_socket_cpu(&cpu_cqmdata_map);
+
+        num_sockets = min((unsigned int)cpumask_weight(&cpu_cqmdata_map) + 1,
+                          sysctl->u.getcqminfo.num_sockets);
+        num_rmids = get_cqm_count();
+        info = xzalloc_array(struct xen_socket_cqmdata,
+                             num_rmids * num_sockets);
+        if ( !info )
+        {
+            ret = -ENOMEM;
+            break;
+        }
+
+        get_cqm_info(&cpu_cqmdata_map, info);
+
+        if ( copy_to_guest_offset(sysctl->u.getcqminfo.buffer,
+                                  0, info, num_rmids * num_sockets) )
+        {
+            ret = -EFAULT;
+            xfree(info);
+            break;
+        }
+
+        sysctl->u.getcqminfo.num_rmids = num_rmids;
+        sysctl->u.getcqminfo.num_sockets = num_sockets;
+
+        if ( copy_to_guest(u_sysctl, sysctl, 1) )
+            ret = -EFAULT;
+
+        xfree(info);
+    }
+    break;
+
     default:
         ret = -ENOSYS;
         break;
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index e597a28..46ef165 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -488,4 +488,8 @@
 /* Geode defined MSRs */
 #define MSR_GEODE_BUSCONT_CONF0		0x00001900
 
+/* Platform QoS register */
+#define MSR_IA32_QOSEVTSEL             0x00000c8d
+#define MSR_IA32_QMC                   0x00000c8e
+
 #endif /* __ASM_MSR_INDEX_H */
diff --git a/xen/include/asm-x86/pqos.h b/xen/include/asm-x86/pqos.h
index 16c4882..b1298b9 100644
--- a/xen/include/asm-x86/pqos.h
+++ b/xen/include/asm-x86/pqos.h
@@ -17,6 +17,8 @@
 #ifndef ASM_PQOS_H
 #define ASM_PQOS_H
 #include <xen/sched.h>
+#include <xen/cpumask.h>
+#include <public/domctl.h>
 
 #include <public/xen.h>
 
@@ -34,10 +36,15 @@ struct pqos_cqm {
 };
 extern struct pqos_cqm *cqm;
 
+/* IA32_QM_CTR */
+#define IA32_QM_CTR_ERROR_MASK         (0x3ul << 62)
+
 void init_platform_qos(void);
 
 bool_t system_supports_cqm(void);
 int alloc_cqm_rmid(struct domain *d);
 void free_cqm_rmid(struct domain *d);
+unsigned int get_cqm_count(void);
+void get_cqm_info(cpumask_t *cpu_cqmdata_map, struct xen_socket_cqmdata *data);
 
 #endif
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index d53e216..563aeaf 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -877,6 +877,15 @@ struct xen_domctl_qos_type {
 typedef struct xen_domctl_qos_type xen_domctl_qos_type_t;
 DEFINE_XEN_GUEST_HANDLE(xen_domctl_qos_type_t);
 
+struct xen_socket_cqmdata {
+    uint64_t l3c_occupancy;
+    uint32_t socket;
+    domid_t  domid;
+    uint8_t  valid;
+};
+typedef struct xen_socket_cqmdata xen_socket_cqmdata_t;
+DEFINE_XEN_GUEST_HANDLE(xen_socket_cqmdata_t);
+
 struct xen_domctl {
     uint32_t cmd;
 #define XEN_DOMCTL_createdomain                   1
diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index 8437d31..cf240a7 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -632,6 +632,14 @@ struct xen_sysctl_coverage_op {
 typedef struct xen_sysctl_coverage_op xen_sysctl_coverage_op_t;
 DEFINE_XEN_GUEST_HANDLE(xen_sysctl_coverage_op_t);
 
+/* XEN_SYSCTL_getcqminfo */
+struct xen_sysctl_getcqminfo {
+    XEN_GUEST_HANDLE_64(xen_socket_cqmdata_t) buffer; /* OUT */
+    uint32_t              num_sockets;    /* IN/OUT */
+    uint32_t              num_rmids;       /* OUT */
+};
+typedef struct xen_sysctl_getcqminfo xen_sysctl_getcqminfo_t;
+DEFINE_XEN_GUEST_HANDLE(xen_sysctl_getcqminfo_t);
 
 struct xen_sysctl {
     uint32_t cmd;
@@ -654,6 +662,7 @@ struct xen_sysctl {
 #define XEN_SYSCTL_cpupool_op                    18
 #define XEN_SYSCTL_scheduler_op                  19
 #define XEN_SYSCTL_coverage_op                   20
+#define XEN_SYSCTL_getcqminfo                    21
     uint32_t interface_version; /* XEN_SYSCTL_INTERFACE_VERSION */
     union {
         struct xen_sysctl_readconsole       readconsole;
@@ -675,6 +684,7 @@ struct xen_sysctl {
         struct xen_sysctl_cpupool_op        cpupool_op;
         struct xen_sysctl_scheduler_op      scheduler_op;
         struct xen_sysctl_coverage_op       coverage_op;
+        struct xen_sysctl_getcqminfo        getcqminfo;
         uint8_t                             pad[128];
     } u;
 };
-- 
1.7.9.5