Mailing List Archive

xen/arch/x86/mm.c | 6 ------
xen/arch/x86/mm/mem_sharing.c | 29 +++++++++++++++++++++++++++++
xen/arch/x86/x86_64/compat/mm.c | 6 ++++++
xen/arch/x86/x86_64/mm.c | 7 +++++++
xen/include/asm-x86/mem_sharing.h | 1 +
xen/include/public/memory.h | 1 +
6 files changed, 44 insertions(+), 6 deletions(-)


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>

diff -r 4a189125d71e -r dbfabd1bbfb1 xen/arch/x86/mm.c
--- 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
@@ -5093,11 +5092,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
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 -r 4a189125d71e -r dbfabd1bbfb1 xen/arch/x86/mm/mem_sharing.c
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -72,6 +72,7 @@ static inline int mem_sharing_audit(void

static shr_handle_t next_handle = 1;
static atomic_t nr_saved_mfns = ATOMIC_INIT(0);
+static atomic_t nr_shared_mfns = ATOMIC_INIT(0);

typedef struct gfn_info
{
@@ -150,9 +151,12 @@ static struct page_info* mem_sharing_loo
static int 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)
{
@@ -200,6 +204,10 @@ static int mem_sharing_audit(void)
continue;
}

+ /* Only increase our expected count for pages that are actually shared */
+ if ( !list_has_one_entry(&pg->shared_info->gfns) )
+ count_found++;
+
/* Check if all GFNs map to the MFN, and the p2m types */
list_for_each(le, &pg->shared_info->gfns)
{
@@ -245,6 +253,13 @@ static int mem_sharing_audit(void)
}
}

+ if ( count_found != count_expected )
+ {
+ MEM_SHARING_DEBUG("Expected %ld shared mfns, found %ld.",
+ count_expected, count_found);
+ errors++;
+ }
+
return errors;
}
#endif
@@ -294,6 +309,11 @@ unsigned int mem_sharing_get_nr_saved_mf
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;
@@ -577,6 +597,14 @@ int mem_sharing_share_pages(struct domai
ASSERT(list_empty(&cpage->shared_info->gfns));
if ( single_source_gfn )
atomic_inc(&sd->shr_pages);
+ /* We only increase the number of shared pages when
+ * sharing for the first time */
+ if ( single_source_gfn && single_client_gfn )
+ atomic_inc(&nr_shared_mfns);
+ /* And we decrease it when re-sharing already shared
+ * (because one of them becomes a "saved" page). */
+ if ( !single_source_gfn && !single_client_gfn )
+ atomic_dec(&nr_shared_mfns);

/* Clear the rest of the shared state */
audit_del_list(cpage);
@@ -659,6 +687,7 @@ gfn_found:
BUG_ON(!d);
atomic_dec(&d->shr_pages);
put_domain(d);
+ atomic_dec(&nr_shared_mfns);
}
} else {
/* Clean up shared state */
diff -r 4a189125d71e -r dbfabd1bbfb1 xen/arch/x86/x86_64/compat/mm.c
--- 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_GU
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 -r 4a189125d71e -r dbfabd1bbfb1 xen/arch/x86/x86_64/mm.c
--- 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. */
@@ -1090,6 +1091,12 @@ long subarch_memory_op(int op, XEN_GUEST

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 -r 4a189125d71e -r dbfabd1bbfb1 xen/include/asm-x86/mem_sharing.h
--- 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 -r 4a189125d71e -r dbfabd1bbfb1 xen/include/public/memory.h
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -294,6 +294,7 @@ typedef struct xen_pod_target xen_pod_ta
* The call never fails.
*/
#define XENMEM_get_sharing_freed_pages 18
+#define XENMEM_get_sharing_shared_pages 19

#endif /* __XEN_PUBLIC_MEMORY_H__ */


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