[Xen-devel] [PATCH v2 8/8] x86: enable CQM monitoring for each domain RMID

[dongxiao.xu@xxxxxxxxx]

From: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>

If the CQM service is attached to a domain, its related RMID will be set
to hardware for monitoring when the domain's vcpu is scheduled in. When
the domain's vcpu is scheduled out, RMID 0 (system reserved) will be set
for monitoring.

Signed-off-by: Jiongxi Li <jiongxi.li@xxxxxxxxx>
Signed-off-by: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
---
 xen/arch/x86/domain.c           |    5 +++++
 xen/arch/x86/pqos.c             |   21 ++++++++++++++++++++-
 xen/include/asm-x86/msr-index.h |    1 +
 xen/include/asm-x86/pqos.h      |    1 +
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 9725649..1eda0ab 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1372,6 +1372,8 @@ static void __context_switch(void)
     {
         memcpy(&p->arch.user_regs, stack_regs, CTXT_SWITCH_STACK_BYTES);
         vcpu_save_fpu(p);
+        if ( system_supports_cqm() )
+            cqm_assoc_rmid(0);
         p->arch.ctxt_switch_from(p);
     }
 
@@ -1396,6 +1398,9 @@ static void __context_switch(void)
         }
         vcpu_restore_fpu_eager(n);
         n->arch.ctxt_switch_to(n);
+
+        if ( system_supports_cqm() && n->domain->arch.pqos_cqm_rmid > 0 )
+            cqm_assoc_rmid(n->domain->arch.pqos_cqm_rmid);
     }
 
     gdt = !is_pv_32on64_vcpu(n) ? per_cpu(gdt_table, cpu) :
diff --git a/xen/arch/x86/pqos.c b/xen/arch/x86/pqos.c
index d95784c..0cec172 100644
--- a/xen/arch/x86/pqos.c
+++ b/xen/arch/x86/pqos.c
@@ -27,6 +27,7 @@
 #include <asm/pqos.h>
 
 static bool_t pqos_enabled = 1;
+static unsigned int rmid_bitwidth;
 boolean_param("pqos", pqos_enabled);
 
 static void read_qm_data(void *arg)
@@ -43,6 +44,14 @@ static void get_generic_qm_info(struct qm_element 
*qm_element)
     on_selected_cpus(cpumask_of(cpu), read_qm_data, qm_element, 1);
 }
 
+void cqm_assoc_rmid(uint16_t rmid)
+{
+    uint64_t val;
+    uint64_t rmid_mask = ~(~0ull << rmid_bitwidth);
+    rdmsrl(MSR_IA32_PQR_ASSOC, val);
+    wrmsrl(MSR_IA32_PQR_ASSOC, (val & ~(rmid_mask)) | (rmid & rmid_mask));
+}
+
 unsigned int cqm_res_count = 0;
 unsigned int cqm_upscaling_factor = 0;
 bool_t cqm_enabled = 0;
@@ -78,13 +87,23 @@ static void __init init_cqm(void)
 static void __init init_qos_monitor(void)
 {
     unsigned int qm_features;
-    unsigned int eax, ebx, ecx;
+    unsigned int eax, ebx, ecx, i = 0;
 
     if ( !(boot_cpu_has(X86_FEATURE_QOSM)) )
         return;
 
     cpuid_count(0xf, 0, &eax, &ebx, &ecx, &qm_features);
 
+    while (1)
+    {
+        if ( (1 << i) - 1 >= ebx )
+        {
+            rmid_bitwidth = i;
+            break;
+        }
+        i++;
+    }
+
     if ( qm_features & QOS_MONITOR_TYPE_L3 )
         init_cqm();
 }
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index 46ef165..45f4918 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -491,5 +491,6 @@
 /* Platform QoS register */
 #define MSR_IA32_QOSEVTSEL             0x00000c8d
 #define MSR_IA32_QMC                   0x00000c8e
+#define MSR_IA32_PQR_ASSOC             0x00000c8f
 
 #endif /* __ASM_MSR_INDEX_H */
diff --git a/xen/include/asm-x86/pqos.h b/xen/include/asm-x86/pqos.h
index 5c86c5d..2bb983b 100644
--- a/xen/include/asm-x86/pqos.h
+++ b/xen/include/asm-x86/pqos.h
@@ -51,5 +51,6 @@ unsigned int get_cqm_count(void);
 unsigned int get_cqm_avail(void);
 void get_cqm_info(uint32_t rmid, cpumask_t cpu_cqmdata_map,
                   struct xen_domctl_getdomcqminfo *info);
+void cqm_assoc_rmid(uint16_t rmid);
 
 #endif
-- 
1.7.9.5


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