[Xen-devel] [PATCH v15 08/11] x86: enable QoS monitoring for each domain RMID

[Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>]

If the QoS monitoring 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: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
Signed-off-by: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/domain.c           |    5 +++++
 xen/arch/x86/pqos.c             |   27 +++++++++++++++++++++++++++
 xen/include/asm-x86/msr-index.h |    3 +++
 xen/include/asm-x86/pqos.h      |    1 +
 4 files changed, 36 insertions(+)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 99fce11..bb448ef 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1415,6 +1415,8 @@ static void __context_switch(void)
     {
         memcpy(&p->arch.user_regs, stack_regs, CTXT_SWITCH_STACK_BYTES);
         vcpu_save_fpu(p);
+        if ( pqos_monitor_enabled() )
+            pqos_monitor_assoc_rmid(0);
         p->arch.ctxt_switch_from(p);
     }
 
@@ -1439,6 +1441,9 @@ static void __context_switch(void)
         }
         vcpu_restore_fpu_eager(n);
         n->arch.ctxt_switch_to(n);
+
+        if ( pqos_monitor_enabled() && n->domain->arch.pqos_rmid > 0 )
+            pqos_monitor_assoc_rmid(n->domain->arch.pqos_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 885bd9b..8a8e0b2 100644
--- a/xen/arch/x86/pqos.c
+++ b/xen/arch/x86/pqos.c
@@ -20,9 +20,15 @@
 
 #define PQOS_MONITOR        (1<<0)
 
+struct pqr_assoc {
+    uint64_t val;
+    bool_t initialized;
+};
+
 struct pqos_monitor *__read_mostly pqosm = NULL;
 static bool_t __initdata opt_pqos = 0;
 static unsigned int __initdata opt_rmid_max = 255;
+static DEFINE_PER_CPU(struct pqr_assoc, pqr_assoc);
 
 static void __init parse_pqos_param(char *s)
 {
@@ -143,6 +149,27 @@ void pqos_monitor_free_rmid(struct domain *d)
     d->arch.pqos_rmid = 0;
 }
 
+void pqos_monitor_assoc_rmid(unsigned int rmid)
+{
+    uint64_t val;
+    uint64_t new_val;
+    struct pqr_assoc *pqr = &this_cpu(pqr_assoc);
+
+    if ( !pqr->initialized )
+    {
+        rdmsrl(MSR_IA32_PQR_ASSOC, pqr->val);
+        pqr->initialized = 1;
+    }
+    val = pqr->val;
+
+    new_val = (val & ~pqosm->rmid_mask) | (rmid & pqosm->rmid_mask);
+    if ( val != new_val )
+    {
+        wrmsrl(MSR_IA32_PQR_ASSOC, new_val);
+        pqr->val = new_val;
+    }
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index da732b7..0cf9548 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -328,6 +328,9 @@
 #define MSR_IA32_TSC_DEADLINE          0x000006E0
 #define MSR_IA32_ENERGY_PERF_BIAS      0x000001b0
 
+/* Platform QoS MSRs */
+#define MSR_IA32_PQR_ASSOC             0x00000c8f
+
 /* Intel Model 6 */
 #define MSR_P6_EVNTSEL0                        0x00000186
 #define MSR_P6_EVNTSEL1                        0x00000187
diff --git a/xen/include/asm-x86/pqos.h b/xen/include/asm-x86/pqos.h
index 5737b51..31b26b4 100644
--- a/xen/include/asm-x86/pqos.h
+++ b/xen/include/asm-x86/pqos.h
@@ -48,6 +48,7 @@ static inline bool_t pqos_monitor_enabled(void)
 void init_platform_qos(void);
 int pqos_monitor_alloc_rmid(struct domain *d);
 void pqos_monitor_free_rmid(struct domain *d);
+void pqos_monitor_assoc_rmid(unsigned int rmid);
 
 #endif /* __ASM_PQOS_H__ */
 
-- 
1.7.9.5


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