Expose the amount of resident and wired memory from the guest's vmspace.

This is different than the amount shown for the process e.g. by
/usr/bin/top - that is the mappings faulted in by the mmap'd region
of guest memory.

The values can be fetched with bhyvectl

 # bhyvectl --get-stats --vm=myvm
 ...
 Resident memory                         	413749248
 Wired memory                            	0
 ...

vmm_stat.[ch] -
 Modify the counter code in bhyve to allow direct setting of a counter
as opposed to incrementing, and providing a callback to fetch a
counter's value.

Reviewed by:	neel

3 files changed, 78 insertions, 5 deletions

diff --git a/sys/amd64/vmm/vmm.c b/sys/amd64/vmm/vmm.c
index 8edb3fb47917..c2a9fd1e117e 100644
--- a/sys/amd64/vmm/vmm.c
+++ b/sys/amd64/vmm/vmm.c
@@ -1992,3 +1992,34 @@ vm_segment_name(int seg)
 	    ("%s: invalid segment encoding %d", __func__, seg));
 	return (seg_names[seg]);
 }
+
+
+/*
+ * Return the amount of in-use and wired memory for the VM. Since
+ * these are global stats, only return the values with for vCPU 0
+ */
+VMM_STAT_DECLARE(VMM_MEM_RESIDENT);
+VMM_STAT_DECLARE(VMM_MEM_WIRED);
+
+static void
+vm_get_rescnt(struct vm *vm, int vcpu, struct vmm_stat_type *stat)
+{
+
+	if (vcpu == 0) {
+		vmm_stat_set(vm, vcpu, VMM_MEM_RESIDENT,
+	       	    PAGE_SIZE * vmspace_resident_count(vm->vmspace));
+	}	
+}
+
+static void
+vm_get_wiredcnt(struct vm *vm, int vcpu, struct vmm_stat_type *stat)
+{
+
+	if (vcpu == 0) {
+		vmm_stat_set(vm, vcpu, VMM_MEM_WIRED,
+	      	    PAGE_SIZE * pmap_wired_count(vmspace_pmap(vm->vmspace)));
+	}	
+}
+
+VMM_STAT_FUNC(VMM_MEM_RESIDENT, "Resident memory", vm_get_rescnt);
+VMM_STAT_FUNC(VMM_MEM_WIRED, "Wired memory", vm_get_wiredcnt);
diff --git a/sys/amd64/vmm/vmm_stat.c b/sys/amd64/vmm/vmm_stat.c
index ef9f41173fee..9ecf9afd8a81 100644
--- a/sys/amd64/vmm/vmm_stat.c
+++ b/sys/amd64/vmm/vmm_stat.c
@@ -83,12 +83,21 @@ vmm_stat_register(void *arg)
 int
 vmm_stat_copy(struct vm *vm, int vcpu, int *num_stats, uint64_t *buf)
 {
-	int i;
+	struct vmm_stat_type *vst;
 	uint64_t *stats;
+	int i;
 
 	if (vcpu < 0 || vcpu >= VM_MAXCPU)
 		return (EINVAL);
-		
+
+	/* Let stats functions update their counters */
+	for (i = 0; i < vst_num_types; i++) {
+		vst = vsttab[i];
+		if (vst->func != NULL)
+			(*vst->func)(vm, vcpu, vst);
+	}
+
+	/* Copy over the stats */
 	stats = vcpu_stats(vm, vcpu);
 	for (i = 0; i < vst_num_elems; i++)
 		buf[i] = stats[i];
diff --git a/sys/amd64/vmm/vmm_stat.h b/sys/amd64/vmm/vmm_stat.h
index 6e98965ac270..1640ba37e025 100644
--- a/sys/amd64/vmm/vmm_stat.h
+++ b/sys/amd64/vmm/vmm_stat.h
@@ -42,21 +42,29 @@ enum vmm_stat_scope {
 	VMM_STAT_SCOPE_AMD,		/* AMD SVM specific statistic */
 };
 
+struct vmm_stat_type;
+typedef void (*vmm_stat_func_t)(struct vm *vm, int vcpu,
+    struct vmm_stat_type *stat);
+
 struct vmm_stat_type {
 	int	index;			/* position in the stats buffer */
 	int	nelems;			/* standalone or array */
 	const char *desc;		/* description of statistic */
+	vmm_stat_func_t func;
 	enum vmm_stat_scope scope;
 };
 
 void	vmm_stat_register(void *arg);
 
-#define	VMM_STAT_DEFINE(type, nelems, desc, scope)			\
+#define	VMM_STAT_FDEFINE(type, nelems, desc, func, scope)		\
 	struct vmm_stat_type type[1] = {				\
-		{ -1, nelems, desc, scope }				\
+		{ -1, nelems, desc, func, scope }			\
 	};								\
 	SYSINIT(type##_stat, SI_SUB_KLD, SI_ORDER_ANY, vmm_stat_register, type)
 
+#define VMM_STAT_DEFINE(type, nelems, desc, scope) 			\
+	VMM_STAT_FDEFINE(type, nelems, desc, NULL, scope)
+
 #define	VMM_STAT_DECLARE(type)						\
 	extern struct vmm_stat_type type[1]
 
@@ -67,6 +75,9 @@ void	vmm_stat_register(void *arg);
 #define	VMM_STAT_AMD(type, desc)	\
 	VMM_STAT_DEFINE(type, 1, desc, VMM_STAT_SCOPE_AMD)
 
+#define	VMM_STAT_FUNC(type, desc, func)	\
+	VMM_STAT_FDEFINE(type, 1, desc, func, VMM_STAT_SCOPE_ANY)
+
 #define	VMM_STAT_ARRAY(type, nelems, desc)	\
 	VMM_STAT_DEFINE(type, nelems, desc, VMM_STAT_SCOPE_ANY)
 
@@ -93,9 +104,22 @@ vmm_stat_array_incr(struct vm *vm, int vcpu, struct vmm_stat_type *vst,
 		stats[vst->index + statidx] += x;
 #endif
 }
-		   
 
 static void __inline
+vmm_stat_array_set(struct vm *vm, int vcpu, struct vmm_stat_type *vst,
+		   int statidx, uint64_t val)
+{
+#ifdef VMM_KEEP_STATS
+	uint64_t *stats;
+	
+	stats = vcpu_stats(vm, vcpu);
+
+	if (vst->index >= 0 && statidx < vst->nelems)
+		stats[vst->index + statidx] = val;
+#endif
+}
+		   
+static void __inline
 vmm_stat_incr(struct vm *vm, int vcpu, struct vmm_stat_type *vst, uint64_t x)
 {
 
@@ -104,6 +128,15 @@ vmm_stat_incr(struct vm *vm, int vcpu, struct vmm_stat_type *vst, uint64_t x)
 #endif
 }
 
+static void __inline
+vmm_stat_set(struct vm *vm, int vcpu, struct vmm_stat_type *vst, uint64_t val)
+{
+
+#ifdef VMM_KEEP_STATS
+	vmm_stat_array_set(vm, vcpu, vst, 0, val);
+#endif
+}
+
 VMM_STAT_DECLARE(VCPU_MIGRATIONS);
 VMM_STAT_DECLARE(VMEXIT_COUNT);
 VMM_STAT_DECLARE(VMEXIT_EXTINT);