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authorAndres Lagar-Cavilla <andres@lagarcavilla.org>2012-01-26 12:46:26 +0000
committerAndres Lagar-Cavilla <andres@lagarcavilla.org>2012-01-26 12:46:26 +0000
commit2bc918fd8a5e7d81b8065e3399c614e7dfcdb659 (patch)
tree7515c290c84ffa9a5b7c469d8cd0653775fb330a /xen
parent8ed0c272481880b75442e62aad75c30ecfa798ce (diff)
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x86/mm: Check how many mfns are shared, in addition to how many are saved
This patch also moves the existing sharing-related memory op to the correct location, and adds logic to the audit() method that uses the new information. This patch only provides the Xen implementation of the domctls. Signed-off-by: Andres Lagar-Cavilla <andres@scannell.ca> Signed-off-by: Adin Scannell <adin@scannell.ca> Acked-by: Tim Deegan <tim@xen.org> Committed-by: Tim Deegan <tim@xen.org>
Diffstat (limited to 'xen')
-rw-r--r--xen/arch/x86/mm.c6
-rw-r--r--xen/arch/x86/mm/mem_sharing.c25
-rw-r--r--xen/arch/x86/x86_64/compat/mm.c6
-rw-r--r--xen/arch/x86/x86_64/mm.c7
-rw-r--r--xen/include/asm-x86/mem_sharing.h1
-rw-r--r--xen/include/public/memory.h1
6 files changed, 40 insertions, 6 deletions
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index ef9b202773..4478aae3e9 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -119,7 +119,6 @@
#include <xen/trace.h>
#include <asm/setup.h>
#include <asm/fixmap.h>
-#include <asm/mem_sharing.h>
/*
* Mapping of first 2 or 4 megabytes of memory. This is mapped with 4kB
@@ -5023,11 +5022,6 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
return rc;
}
-#ifdef __x86_64__
- case XENMEM_get_sharing_freed_pages:
- return mem_sharing_get_nr_saved_mfns();
-#endif
-
default:
return subarch_memory_op(op, arg);
}
diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index 237b5509f8..a01e7ece3a 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -138,6 +138,7 @@ static inline shr_handle_t get_next_handle(void)
#define page_to_mfn(_pg) _mfn(__page_to_mfn(_pg))
static atomic_t nr_saved_mfns = ATOMIC_INIT(0);
+static atomic_t nr_shared_mfns = ATOMIC_INIT(0);
typedef struct gfn_info
{
@@ -208,9 +209,12 @@ static struct page_info* mem_sharing_lookup(unsigned long mfn)
static void mem_sharing_audit(void)
{
int errors = 0;
+ unsigned long count_expected;
+ unsigned long count_found = 0;
struct list_head *ae;
ASSERT(shr_locked_by_me());
+ count_expected = atomic_read(&nr_shared_mfns);
list_for_each(ae, &shr_audit_list)
{
@@ -258,6 +262,9 @@ static void mem_sharing_audit(void)
continue;
}
+ /* We've found a page that is shared */
+ count_found++;
+
/* Check if all GFNs map to the MFN, and the p2m types */
list_for_each(le, &pg->shared_info->gfns)
{
@@ -302,6 +309,14 @@ static void mem_sharing_audit(void)
errors++;
}
}
+
+ if ( count_found != count_expected )
+ {
+ MEM_SHARING_DEBUG("Expected %ld shared mfns, found %ld.",
+ count_expected, count_found);
+ errors++;
+ }
+
}
#endif
@@ -342,6 +357,11 @@ unsigned int mem_sharing_get_nr_saved_mfns(void)
return ((unsigned int)atomic_read(&nr_saved_mfns));
}
+unsigned int mem_sharing_get_nr_shared_mfns(void)
+{
+ return (unsigned int)atomic_read(&nr_shared_mfns);
+}
+
int mem_sharing_sharing_resume(struct domain *d)
{
mem_event_response_t rsp;
@@ -663,6 +683,9 @@ int mem_sharing_nominate_page(struct domain *d,
goto out;
}
+ /* Account for this page. */
+ atomic_inc(&nr_shared_mfns);
+
/* Update m2p entry to SHARED_M2P_ENTRY */
set_gpfn_from_mfn(mfn_x(mfn), SHARED_M2P_ENTRY);
@@ -786,6 +809,7 @@ int mem_sharing_share_pages(struct domain *sd, unsigned long sgfn, shr_handle_t
put_page(cpage);
/* We managed to free a domain page. */
+ atomic_dec(&nr_shared_mfns);
atomic_inc(&nr_saved_mfns);
ret = 0;
@@ -851,6 +875,7 @@ gfn_found:
audit_del_list(page);
xfree(page->shared_info);
page->shared_info = NULL;
+ atomic_dec(&nr_shared_mfns);
}
else
atomic_dec(&nr_saved_mfns);
diff --git a/xen/arch/x86/x86_64/compat/mm.c b/xen/arch/x86/x86_64/compat/mm.c
index bea94fe6a8..93325792f5 100644
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -205,6 +205,12 @@ int compat_arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
break;
}
+ case XENMEM_get_sharing_freed_pages:
+ return mem_sharing_get_nr_saved_mfns();
+
+ case XENMEM_get_sharing_shared_pages:
+ return mem_sharing_get_nr_shared_mfns();
+
default:
rc = -ENOSYS;
break;
diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c
index 2f056fd3df..25bbbd1c7a 100644
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -34,6 +34,7 @@
#include <asm/msr.h>
#include <asm/setup.h>
#include <asm/numa.h>
+#include <asm/mem_sharing.h>
#include <public/memory.h>
/* Parameters for PFN/MADDR compression. */
@@ -1093,6 +1094,12 @@ long subarch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
break;
+ case XENMEM_get_sharing_freed_pages:
+ return mem_sharing_get_nr_saved_mfns();
+
+ case XENMEM_get_sharing_shared_pages:
+ return mem_sharing_get_nr_shared_mfns();
+
default:
rc = -ENOSYS;
break;
diff --git a/xen/include/asm-x86/mem_sharing.h b/xen/include/asm-x86/mem_sharing.h
index 7925697645..f4f7407c89 100644
--- a/xen/include/asm-x86/mem_sharing.h
+++ b/xen/include/asm-x86/mem_sharing.h
@@ -45,6 +45,7 @@ struct page_sharing_info
(is_hvm_domain(_d) && paging_mode_hap(_d))
unsigned int mem_sharing_get_nr_saved_mfns(void);
+unsigned int mem_sharing_get_nr_shared_mfns(void);
int mem_sharing_nominate_page(struct domain *d,
unsigned long gfn,
int expected_refcnt,
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index c5b78a8487..3bc2f25cdc 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -294,6 +294,7 @@ typedef struct xen_pod_target xen_pod_target_t;
* The call never fails.
*/
#define XENMEM_get_sharing_freed_pages 18
+#define XENMEM_get_sharing_shared_pages 19
#endif /* __XEN_PUBLIC_MEMORY_H__ */