[Xen-devel] [PATCH v11 5/9] x86: dynamically attach/detach QoS monitoring service for a guest

[Dongxiao Xu <dongxiao.xu@xxxxxxxxx>]

Add hypervisor side support for dynamically attach and detach QoS
monitoring services for a certain guest.

When attach Qos monitoring service for a guest, system will allocate an
RMID for it. When detach or guest is shutdown, the RMID will be recycled
for future use.

Signed-off-by: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
---
 xen/arch/x86/domain.c        |  3 +++
 xen/arch/x86/domctl.c        | 29 ++++++++++++++++++++++
 xen/arch/x86/pqos.c          | 59 ++++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-x86/domain.h |  2 ++
 xen/include/asm-x86/pqos.h   |  9 +++++++
 xen/include/public/domctl.h  | 12 +++++++++
 6 files changed, 114 insertions(+)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index e896210..f8e0e33 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);
@@ -636,6 +637,8 @@ void arch_domain_destroy(struct domain *d)
 
     free_xenheap_page(d->shared_info);
     cleanup_domain_irq_mapping(d);
+
+    pqos_monitor_free_rmid(d);
 }
 
 unsigned long pv_guest_cr4_fixup(const struct vcpu *v, unsigned long guest_cr4)
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index f8b0a79..9047dc6 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -35,6 +35,7 @@
 #include <asm/mem_sharing.h>
 #include <asm/xstate.h>
 #include <asm/debugger.h>
+#include <asm/pqos.h>
 
 static int gdbsx_guest_mem_io(
     domid_t domid, struct xen_domctl_gdbsx_memio *iop)
@@ -1342,6 +1343,34 @@ long arch_do_domctl(
     }
     break;
 
+    case XEN_DOMCTL_pqos_monitor_op:
+        if ( !pqos_monitor_enabled() )
+        {
+            ret = -ENODEV;
+            break;
+        }
+
+        switch ( domctl->u.pqos_monitor_op.cmd )
+        {
+        case XEN_DOMCTL_PQOS_MONITOR_OP_ATTACH:
+            ret = pqos_monitor_alloc_rmid(d);
+            break;
+        case XEN_DOMCTL_PQOS_MONITOR_OP_DETACH:
+            if ( d->arch.pqos_rmid > 0 )
+                pqos_monitor_free_rmid(d);
+            else
+                ret = -ENOENT;
+            break;
+        case XEN_DOMCTL_PQOS_MONITOR_OP_QUERY_RMID:
+            domctl->u.pqos_monitor_op.data = d->arch.pqos_rmid;
+            copyback = 1;
+            break;
+        default:
+            ret = -ENOSYS;
+            break;
+        };
+        break;
+
     default:
         ret = iommu_do_domctl(domctl, d, u_domctl);
         break;
diff --git a/xen/arch/x86/pqos.c b/xen/arch/x86/pqos.c
index 1c431c7..c08cb99 100644
--- a/xen/arch/x86/pqos.c
+++ b/xen/arch/x86/pqos.c
@@ -111,6 +111,65 @@ void __init init_platform_qos(void)
         init_pqos_monitor(opt_rmid_max);
 }
 
+int pqos_monitor_alloc_rmid(struct domain *d)
+{
+    int rc = 0;
+    unsigned int rmid;
+
+    ASSERT(pqos_monitor_enabled());
+
+    spin_lock(&pqosm->pqosm_lock);
+
+    if ( d->arch.pqos_rmid > 0 )
+    {
+        rc = -EEXIST;
+        goto out;
+    }
+
+    for ( rmid = pqosm->rmid_min; rmid <= pqosm->rmid_max; rmid++ )
+    {
+        if ( pqosm->rmid_to_dom[rmid] != DOMID_INVALID)
+            continue;
+
+        pqosm->rmid_to_dom[rmid] = d->domain_id;
+        break;
+    }
+
+    /* No RMID available, assign RMID=0 by default */
+    if ( rmid > pqosm->rmid_max )
+    {
+        rmid = 0;
+        rc = -EUSERS;
+    }
+    else
+        pqosm->rmid_inuse++;
+
+    d->arch.pqos_rmid = rmid;
+
+out:
+    spin_unlock(&pqosm->pqosm_lock);
+
+    return rc;
+}
+
+void pqos_monitor_free_rmid(struct domain *d)
+{
+    unsigned int rmid;
+
+    spin_lock(&pqosm->pqosm_lock);
+    rmid = d->arch.pqos_rmid;
+    /* We do not free system reserved "RMID=0" */
+    if ( rmid == 0 )
+        goto out;
+
+    pqosm->rmid_to_dom[rmid] = DOMID_INVALID;
+    d->arch.pqos_rmid = 0;
+    pqosm->rmid_inuse--;
+
+out:
+    spin_unlock(&pqosm->pqosm_lock);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index abf55fb..cd53108 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -313,6 +313,8 @@ struct arch_domain
     /* Shared page for notifying that explicit PIRQ EOI is required. */
     unsigned long *pirq_eoi_map;
     unsigned long pirq_eoi_map_mfn;
+
+    unsigned int pqos_rmid; /* QoS monitoring 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 410fa3d..3a3f063 100644
--- a/xen/include/asm-x86/pqos.h
+++ b/xen/include/asm-x86/pqos.h
@@ -15,6 +15,7 @@
  */
 #ifndef ASM_PQOS_H
 #define ASM_PQOS_H
+#include <xen/sched.h>
 
 #include <public/xen.h>
 #include <xen/spinlock.h>
@@ -43,6 +44,14 @@ struct pqos_monitor {
 };
 extern struct pqos_monitor *pqosm;
 
+static inline bool_t pqos_monitor_enabled(void)
+{
+    return !!pqosm;
+}
+
 void __init init_platform_qos(void);
 
+int pqos_monitor_alloc_rmid(struct domain *d);
+void pqos_monitor_free_rmid(struct domain *d);
+
 #endif
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 565fa4c..32c0cb2 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -895,6 +895,16 @@ struct xen_domctl_cacheflush {
 typedef struct xen_domctl_cacheflush xen_domctl_cacheflush_t;
 DEFINE_XEN_GUEST_HANDLE(xen_domctl_cacheflush_t);
 
+struct xen_domctl_pqos_monitor_op {
+#define XEN_DOMCTL_PQOS_MONITOR_OP_DETACH         0
+#define XEN_DOMCTL_PQOS_MONITOR_OP_ATTACH         1
+#define XEN_DOMCTL_PQOS_MONITOR_OP_QUERY_RMID     2
+    uint32_t cmd;
+    uint32_t data;
+};
+typedef struct xen_domctl_pqos_op xen_domctl_pqos_op_t;
+DEFINE_XEN_GUEST_HANDLE(xen_domctl_pqos_op_t);
+
 struct xen_domctl {
     uint32_t cmd;
 #define XEN_DOMCTL_createdomain                   1
@@ -965,6 +975,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_getnodeaffinity               69
 #define XEN_DOMCTL_set_max_evtchn                70
 #define XEN_DOMCTL_cacheflush                    71
+#define XEN_DOMCTL_pqos_monitor_op               72
 #define XEN_DOMCTL_gdbsx_guestmemio            1000
 #define XEN_DOMCTL_gdbsx_pausevcpu             1001
 #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
@@ -1024,6 +1035,7 @@ struct xen_domctl {
         struct xen_domctl_cacheflush        cacheflush;
         struct xen_domctl_gdbsx_pauseunp_vcpu gdbsx_pauseunp_vcpu;
         struct xen_domctl_gdbsx_domstatus   gdbsx_domstatus;
+        struct xen_domctl_pqos_monitor_op   pqos_monitor_op;
         uint8_t                             pad[128];
     } u;
 };
-- 
1.8.1.5


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