[Xen-devel] [PATCH v8 3/6] x86: collect CQM information from all sockets

[Dongxiao Xu <dongxiao.xu@xxxxxxxxx>]

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@xxxxxxxxx>
Signed-off-by: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
---
 xen/arch/x86/pqos.c             |   43 +++++++++++++++++++++++++++++
 xen/arch/x86/sysctl.c           |   58 +++++++++++++++++++++++++++++++++++++++
 xen/include/asm-x86/msr-index.h |    4 +++
 xen/include/asm-x86/pqos.h      |    3 ++
 xen/include/public/sysctl.h     |   11 ++++++++
 5 files changed, 119 insertions(+)

diff --git a/xen/arch/x86/pqos.c b/xen/arch/x86/pqos.c
index eb469ac..2cde56e 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/mm.h>
 #include <xen/spinlock.h>
@@ -205,6 +206,48 @@ out:
     spin_unlock(&cqm->cqm_lock);
 }
 
+static void read_cqm_data(void *arg)
+{
+    uint64_t cqm_data;
+    unsigned int rmid;
+    int socket = cpu_to_socket(smp_processor_id());
+    unsigned long i;
+
+    ASSERT(system_supports_cqm());
+
+    if ( socket < 0 )
+        return;
+
+    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 = (unsigned long)(cqm->max_rmid + 1) * socket + rmid;
+        if ( !(cqm_data & IA32_QM_CTR_ERROR_MASK) )
+            cqm->buffer[i] = cqm_data * cqm->upscaling_factor;
+    }
+}
+
+void get_cqm_info(const cpumask_t *cpu_cqmdata_map)
+{
+    unsigned int nr_sockets = cpumask_weight(cpu_cqmdata_map) + 1;
+    unsigned int nr_rmids = cqm->max_rmid + 1;
+
+    /* Read CQM data in current CPU */
+    read_cqm_data(NULL);
+    /* Issue IPI to other CPUs to read CQM data */
+    on_selected_cpus(cpu_cqmdata_map, read_cqm_data, NULL, 1);
+
+    /* Copy the rmid_to_dom info to the buffer */
+    memcpy(cqm->buffer + nr_sockets * nr_rmids, cqm->rmid_to_dom,
+           sizeof(domid_t) * (cqm->max_rmid + 1));
+
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c
index 15d4b91..7b0acc9 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 +67,30 @@ 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;
+    int socket, socket_curr = cpu_to_socket(smp_processor_id());
+    DECLARE_BITMAP(sockets, NR_CPUS);
+
+    bitmap_zero(sockets, NR_CPUS);
+    if (socket_curr >= 0)
+        set_bit(socket_curr, sockets);
+
+    cpumask_clear(cpu_bitmap);
+    for ( i = 0; i < NR_CPUS; i++ )
+    {
+        socket = cpu_to_socket(i);
+        if ( socket < 0 || test_and_set_bit(socket, sockets) )
+            continue;
+        cpu = cpumask_any(per_cpu(cpu_core_mask, 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 +126,39 @@ long arch_do_sysctl(
     }
     break;
 
+    case XEN_SYSCTL_getcqminfo:
+    {
+        cpumask_var_t cpu_cqmdata_map;
+
+        if ( !system_supports_cqm() )
+        {
+            ret = -ENODEV;
+            break;
+        }
+
+        if ( !zalloc_cpumask_var(&cpu_cqmdata_map) )
+        {
+            ret = -ENOMEM;
+            break;
+        }
+
+        memset(cqm->buffer, 0, cqm->buffer_size);
+
+        select_socket_cpu(cpu_cqmdata_map);
+        get_cqm_info(cpu_cqmdata_map);
+
+        sysctl->u.getcqminfo.buffer_mfn = virt_to_mfn(cqm->buffer);
+        sysctl->u.getcqminfo.size = cqm->buffer_size;
+        sysctl->u.getcqminfo.nr_rmids = cqm->max_rmid + 1;
+        sysctl->u.getcqminfo.nr_sockets = cpumask_weight(cpu_cqmdata_map) + 1;
+
+        if ( __copy_to_guest(u_sysctl, sysctl, 1) )
+            ret = -EFAULT;
+
+        free_cpumask_var(cpu_cqmdata_map);
+    }
+    break;
+
     default:
         ret = -ENOSYS;
         break;
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index fc9fbc6..e3ff10c 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -489,4 +489,8 @@
 /* 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 f25037d..4372af6 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>
 #include <xen/spinlock.h>
@@ -51,5 +53,6 @@ void init_platform_qos(void);
 
 int alloc_cqm_rmid(struct domain *d);
 void free_cqm_rmid(struct domain *d);
+void get_cqm_info(const cpumask_t *cpu_cqmdata_map);
 
 #endif
diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index 8437d31..335b1d9 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -632,6 +632,15 @@ 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);
 
+struct xen_sysctl_getcqminfo {
+    uint64_aligned_t buffer_mfn;
+    uint32_t size;
+    uint32_t nr_rmids;
+    uint32_t nr_sockets;
+};
+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 +663,7 @@ 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 +685,7 @@ 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


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