[PATCH v2 2/8] x86: handle CQM resource when creating/destroying guests

[dongxiao.xu@intel.com]

From: Dongxiao Xu <dongxiao.xu@intel.com>

Allocate an RMID for a guest when it is created. This per-guest
RMID will be used to monitor Cache QoS related data. The RMID will
be relinquished when guest is destroyed.

Signed-off-by: Jiongxi Li <jiongxi.li@intel.com>
Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
---
 xen/arch/x86/domain.c        |    9 +++++++
 xen/arch/x86/pqos.c          |   59 ++++++++++++++++++++++++++++++++++++++++++
 xen/common/domctl.c          |    5 +++-
 xen/include/asm-x86/domain.h |    2 ++
 xen/include/asm-x86/pqos.h   |    4 +++
 xen/include/public/domctl.h  |    3 +++
 xen/include/xen/sched.h      |    3 +++
 7 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index a3868f9..9725649 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -60,6 +60,7 @@
 #include <xen/numa.h>
 #include <xen/iommu.h>
 #include <compat/vcpu.h>
+#include <asm/pqos.h>
 
 DEFINE_PER_CPU(struct vcpu *, curr_vcpu);
 DEFINE_PER_CPU(unsigned long, cr4);
@@ -579,6 +580,11 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags)
     tsc_set_info(d, TSC_MODE_DEFAULT, 0UL, 0, 0);
     spin_lock_init(&d->arch.vtsc_lock);
 
+    /* Allocate CQM RMID for guest */
+    d->arch.pqos_cqm_rmid = 0;
+    if ( system_supports_cqm() && !!(domcr_flags & DOMCRF_pqos_cqm) )
+        alloc_cqm_rmid(d);
+
     return 0;
 
  fail:
@@ -612,6 +618,9 @@ void arch_domain_destroy(struct domain *d)
 
     free_xenheap_page(d->shared_info);
     cleanup_domain_irq_mapping(d);
+
+    if ( system_supports_cqm() )
+        free_cqm_rmid(d);
 }
 
 unsigned long pv_guest_cr4_fixup(const struct vcpu *v, unsigned long guest_cr4)
diff --git a/xen/arch/x86/pqos.c b/xen/arch/x86/pqos.c
index e6ab416..e294799 100644
--- a/xen/arch/x86/pqos.c
+++ b/xen/arch/x86/pqos.c
@@ -20,6 +20,8 @@
  */
 #include <asm/processor.h>
 #include <xen/init.h>
+#include <xen/spinlock.h>
+#include <xen/sched.h>
 #include <asm/pqos.h>
 
 static bool_t pqos_enabled = 1;
@@ -29,6 +31,7 @@ unsigned int cqm_res_count = 0;
 unsigned int cqm_upscaling_factor = 0;
 bool_t cqm_enabled = 0;
 struct cqm_res_struct *cqm_res_array = NULL;
+static DEFINE_SPINLOCK(cqm_lock);
 
 static void __init init_cqm(void)
 {
@@ -78,6 +81,62 @@ void __init init_platform_qos(void)
     init_qos_monitor();
 }
 
+bool_t system_supports_cqm(void)
+{
+    return cqm_enabled;
+}
+
+int alloc_cqm_rmid(struct domain *d)
+{
+    int rmid, rc = 0;
+    unsigned long flags;
+
+    ASSERT(system_supports_cqm());
+
+    spin_lock_irqsave(&cqm_lock, flags);
+    /* RMID=0 is reserved, enumerate from 1 */
+    for ( rmid = 1; rmid < cqm_res_count; rmid++ )
+    {
+        if ( cqm_res_array[rmid].inuse)
+            continue;
+
+        cqm_res_array[rmid].inuse = 1;
+        cqm_res_array[rmid].domain_id = d->domain_id;
+        break;
+    }
+    spin_unlock_irqrestore(&cqm_lock, flags);
+
+    /* No CQM RMID available, assign RMID=0 by default */
+    if ( rmid == cqm_res_count )
+    {
+        rmid = 0;
+        rc = -1;
+    }
+
+    d->arch.pqos_cqm_rmid = rmid;
+
+    return rc;
+}
+
+void free_cqm_rmid(struct domain *d)
+{
+    int rmid = d->arch.pqos_cqm_rmid;
+    unsigned long flags;
+
+    ASSERT(system_supports_cqm());
+
+    spin_lock_irqsave(&cqm_lock, flags);
+    /* We do not free system reserved "RMID=0" */
+    if ( rmid > 0 )
+    {
+        cqm_res_array[rmid].inuse = 0;
+        cqm_res_array[rmid].domain_id = 0;
+    }
+    spin_unlock_irqrestore(&cqm_lock, flags);
+
+    d->arch.pqos_cqm_rmid = 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 904d27b..1c2e320 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -425,7 +425,8 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
                | XEN_DOMCTL_CDF_pvh_guest
                | XEN_DOMCTL_CDF_hap
                | XEN_DOMCTL_CDF_s3_integrity
-               | XEN_DOMCTL_CDF_oos_off)) )
+               | XEN_DOMCTL_CDF_oos_off
+               | XEN_DOMCTL_CDF_pqos_cqm)) )
             break;
 
         dom = op->domain;
@@ -467,6 +468,8 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
             domcr_flags |= DOMCRF_s3_integrity;
         if ( op->u.createdomain.flags & XEN_DOMCTL_CDF_oos_off )
             domcr_flags |= DOMCRF_oos_off;
+        if ( op->u.createdomain.flags & XEN_DOMCTL_CDF_pqos_cqm )
+            domcr_flags |= DOMCRF_pqos_cqm;
 
         d = domain_create(dom, domcr_flags, op->u.createdomain.ssidref);
         if ( IS_ERR(d) )
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 9d39061..b0479aa 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -313,6 +313,8 @@ struct arch_domain
     spinlock_t e820_lock;
     struct e820entry *e820;
     unsigned int nr_e820;
+
+    int pqos_cqm_rmid;       /* CQM RMID assigned to the domain */
 } __cacheline_aligned;
 
 #define has_arch_pdevs(d)    (!list_empty(&(d)->arch.pdev_list))
diff --git a/xen/include/asm-x86/pqos.h b/xen/include/asm-x86/pqos.h
index 934d68a..88de139 100644
--- a/xen/include/asm-x86/pqos.h
+++ b/xen/include/asm-x86/pqos.h
@@ -34,4 +34,8 @@ struct cqm_res_struct {
 
 void init_platform_qos(void);
 
+bool_t system_supports_cqm(void);
+int alloc_cqm_rmid(struct domain *);
+void free_cqm_rmid(struct domain *);
+
 #endif
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 01a3652..47a850a 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -62,6 +62,9 @@ struct xen_domctl_createdomain {
  /* Is this a PVH guest (as opposed to an HVM or PV guest)? */
 #define _XEN_DOMCTL_CDF_pvh_guest     4
 #define XEN_DOMCTL_CDF_pvh_guest      (1U<<_XEN_DOMCTL_CDF_pvh_guest)
+ /* Enable pqos-cqm? */
+#define _XEN_DOMCTL_CDF_pqos_cqm      5
+#define XEN_DOMCTL_CDF_pqos_cqm       (1U<<_XEN_DOMCTL_CDF_pqos_cqm)
     uint32_t flags;
 };
 typedef struct xen_domctl_createdomain xen_domctl_createdomain_t;
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index cbdf377..3a42656 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -507,6 +507,9 @@ struct domain *domain_create(
  /* DOMCRF_pvh: Create PV domain in HVM container. */
 #define _DOMCRF_pvh             5
 #define DOMCRF_pvh              (1U<<_DOMCRF_pvh)
+ /* DOMCRF_pqos_cqm: Create a domain with CQM support */
+#define _DOMCRF_pqos_cqm        6
+#define DOMCRF_pqos_cqm         (1U<<_DOMCRF_pqos_cqm)
 
 /*
  * rcu_lock_domain_by_id() is more efficient than get_domain_by_id().
-- 
1.7.9.5