Add the ability to poll stats about shared memory via the console

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: Adin Scannell <adin@scannell.ca>
Acked-by: Tim Deegan <tim@xen.org>
Committed-by: Tim Deegan <tim@xen.org>

4 files changed, 27 insertions, 2 deletions

diff --git a/xen/arch/ia64/xen/mm.c b/xen/arch/ia64/xen/mm.c
index 84f6a61ef1..b50a14911e 100644
--- a/xen/arch/ia64/xen/mm.c
+++ b/xen/arch/ia64/xen/mm.c
@@ -3574,6 +3574,11 @@ p2m_pod_decrease_reservation(struct domain *d, xen_pfn_t gpfn,
     return 0;
 }
 
+/* Simple no-op */
+void arch_dump_shared_mem_info(void)
+{
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 4478aae3e9..2183bade33 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -113,6 +113,7 @@
 #include <asm/e820.h>
 #include <asm/hypercall.h>
 #include <asm/shared.h>
+#include <asm/mem_sharing.h>
 #include <public/memory.h>
 #include <public/sched.h>
 #include <xsm/xsm.h>
@@ -5831,6 +5832,19 @@ void memguard_unguard_stack(void *p)
     memguard_unguard_range(p, PAGE_SIZE);
 }
 
+#if defined(__x86_64__)
+void arch_dump_shared_mem_info(void)
+{
+    printk("Shared frames %u -- Saved frames %u\n",
+            mem_sharing_get_nr_shared_mfns(),
+            mem_sharing_get_nr_saved_mfns());
+}
+#else
+void arch_dump_shared_mem_info(void)
+{
+}
+#endif
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index 1051a867bd..16a9f5e311 100644
--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -15,6 +15,7 @@
 #include <xen/compat.h>
 #include <xen/ctype.h>
 #include <xen/perfc.h>
+#include <xen/mm.h>
 #include <xen/init.h>
 #include <asm/debugger.h>
 #include <asm/div64.h>
@@ -249,8 +250,8 @@ static void dump_domains(unsigned char key)
         printk("    refcnt=%d dying=%d pause_count=%d\n",
                atomic_read(&d->refcnt), d->is_dying,
                atomic_read(&d->pause_count));
-        printk("    nr_pages=%d xenheap_pages=%d dirty_cpus=%s max_pages=%u\n",
-               d->tot_pages, d->xenheap_pages, tmpstr, d->max_pages);
+        printk("    nr_pages=%d xenheap_pages=%d shared_pages=%u dirty_cpus=%s max_pages=%u\n",
+               d->tot_pages, d->xenheap_pages, atomic_read(&d->shr_pages), tmpstr, d->max_pages);
         printk("    handle=%02x%02x%02x%02x-%02x%02x-%02x%02x-"
                "%02x%02x-%02x%02x%02x%02x%02x%02x vm_assist=%08lx\n",
                d->handle[ 0], d->handle[ 1], d->handle[ 2], d->handle[ 3],
@@ -309,6 +310,8 @@ static void dump_domains(unsigned char key)
         }
     }
 
+    arch_dump_shared_mem_info();
+
     rcu_read_unlock(&domlist_read_lock);
 #undef tmpstr
 }
diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index 313a459be3..94e7d42a8e 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -72,6 +72,9 @@ int assign_pages(
     unsigned int order,
     unsigned int memflags);
 
+/* Dump info to serial console */
+void arch_dump_shared_mem_info(void);
+
 /* memflags: */
 #define _MEMF_no_refcount 0
 #define  MEMF_no_refcount (1U<<_MEMF_no_refcount)