# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1261031276 0
# Node ID 68e964ec2c7bdb3b4f8997b3c027cedfaa2c7bb2
# Parent 8cf5bffd9663fc541be4d4a1b63630787739fd0d
Domctls defined for all relevant memory sharing operations.
Signed-off-by: Grzegorz Milos <Grzegorz.Milos@xxxxxxxxxx>
---
xen/arch/x86/domain.c | 1
xen/arch/x86/domctl.c | 16 ++
xen/arch/x86/mm.c | 3
xen/arch/x86/mm/mem_sharing.c | 223 ++++++++++++++++++++++++++++++++++----
xen/common/domctl.c | 1
xen/include/asm-x86/hvm/domain.h | 1
xen/include/asm-x86/mem_sharing.h | 3
xen/include/public/domctl.h | 49 ++++++++
xen/include/public/memory.h | 7 +
xen/include/xen/sched.h | 1
10 files changed, 283 insertions(+), 22 deletions(-)
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/arch/x86/domain.c Thu Dec 17 06:27:56 2009 +0000
@@ -404,6 +404,7 @@ int arch_domain_create(struct domain *d,
is_hvm_domain(d) &&
hvm_funcs.hap_supported &&
(domcr_flags & DOMCRF_hap);
+ d->arch.hvm_domain.mem_sharing_enabled = 0;
d->arch.s3_integrity = !!(domcr_flags & DOMCRF_s3_integrity);
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/arch/x86/domctl.c
--- a/xen/arch/x86/domctl.c Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/arch/x86/domctl.c Thu Dec 17 06:27:56 2009 +0000
@@ -32,6 +32,7 @@
#include <xen/iommu.h>
#include <asm/mem_event.h>
#include <public/mem_event.h>
+#include <asm/mem_sharing.h>
#ifdef XEN_GDBSX_CONFIG
#ifdef XEN_KDB_CONFIG
@@ -1317,6 +1318,21 @@ long arch_do_domctl(
}
break;
+ case XEN_DOMCTL_mem_sharing_op:
+ {
+ struct domain *d;
+
+ ret = -ESRCH;
+ d = rcu_lock_domain_by_id(domctl->domain);
+ if ( d != NULL )
+ {
+ ret = mem_sharing_domctl(d, &domctl->u.mem_sharing_op);
+ rcu_unlock_domain(d);
+ copy_to_guest(u_domctl, domctl, 1);
+ }
+ }
+ break;
+
default:
ret = -ENOSYS;
break;
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/arch/x86/mm.c Thu Dec 17 06:27:56 2009 +0000
@@ -4503,6 +4503,9 @@ long arch_memory_op(int op, XEN_GUEST_HA
return rc;
}
+ case XENMEM_get_sharing_freed_pages:
+ return mem_sharing_get_nr_saved_mfns();
+
default:
return subarch_memory_op(op, arg);
}
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/arch/x86/mm/mem_sharing.c
--- a/xen/arch/x86/mm/mem_sharing.c Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/arch/x86/mm/mem_sharing.c Thu Dec 17 06:27:56 2009 +0000
@@ -24,11 +24,18 @@
#include <asm/string.h>
#include <asm/p2m.h>
#include <asm/mem_event.h>
+#include <asm/atomic.h>
#include <xen/domain_page.h>
#include <xen/types.h>
#include <xen/spinlock.h>
#include <xen/mm.h>
#include <xen/sched.h>
+
+
+#define hap_enabled(d) \
+ (is_hvm_domain(d) && (d)->arch.hvm_domain.hap_enabled)
+#define mem_sharing_enabled(d) \
+ (is_hvm_domain(d) && (d)->arch.hvm_domain.mem_sharing_enabled)
#undef mfn_to_page
#define mfn_to_page(_m) __mfn_to_page(mfn_x(_m))
@@ -38,6 +45,7 @@
#define page_to_mfn(_pg) _mfn(__page_to_mfn(_pg))
static shr_handle_t next_handle = 1;
+static atomic_t nr_saved_mfns = ATOMIC_INIT(0);
typedef struct shr_hash_entry
{
@@ -64,6 +72,17 @@ typedef struct shr_lock
const char *locker_function; /* func that took it */
} shr_lock_t;
static shr_lock_t shr_lock;
+
+/* Returns true if list has only one entry. O(1) complexity. */
+static inline int list_has_one_entry(struct list_head *head)
+{
+ return (head->next != head) && (head->next->next == head);
+}
+
+static inline struct gfn_info* gfn_get_info(struct list_head *list)
+{
+ return list_entry(list->next, struct gfn_info, list);
+}
#define shr_lock_init(_i) \
do { \
@@ -97,8 +116,6 @@ static shr_lock_t shr_lock;
spin_unlock(&shr_lock.lock); \
} while (0)
-
-
static void mem_sharing_hash_init(void)
{
int i;
@@ -123,9 +140,21 @@ static gfn_info_t *mem_sharing_gfn_alloc
return xmalloc(gfn_info_t);
}
-static void mem_sharing_gfn_destroy(gfn_info_t *gfn_info)
-{
- xfree(gfn_info);
+static void mem_sharing_gfn_destroy(gfn_info_t *gfn, int was_shared)
+{
+ /* Decrement the number of pages, if the gfn was shared before */
+ if(was_shared)
+ {
+ struct domain *d = get_domain_by_id(gfn->domain);
+ /* Domain may have been destroyed by now, if we are called from
+ * p2m_teardown */
+ if(d)
+ {
+ atomic_dec(&d->shr_pages);
+ put_domain(d);
+ }
+ }
+ xfree(gfn);
}
static shr_hash_entry_t* mem_sharing_hash_lookup(shr_handle_t handle)
@@ -219,6 +248,11 @@ static struct page_info* mem_sharing_all
return page;
}
+unsigned int mem_sharing_get_nr_saved_mfns(void)
+{
+ return (unsigned int)atomic_read(&nr_saved_mfns);
+}
+
int mem_sharing_sharing_resume(struct domain *d)
{
mem_event_response_t rsp;
@@ -290,6 +324,61 @@ shared_entry_header(struct grant_table *
return &shared_entry_v2(t, ref).hdr;
}
+static int mem_sharing_gref_to_gfn(struct domain *d,
+ grant_ref_t ref,
+ unsigned long *gfn)
+{
+ if(d->grant_table->gt_version < 1)
+ return -1;
+
+ if (d->grant_table->gt_version == 1)
+ {
+ grant_entry_v1_t *sha1;
+ sha1 = &shared_entry_v1(d->grant_table, ref);
+ *gfn = sha1->frame;
+ return 0;
+ }
+ else
+ {
+ grant_entry_v2_t *sha2;
+ sha2 = &shared_entry_v2(d->grant_table, ref);
+ *gfn = sha2->full_page.frame;
+ return 0;
+ }
+
+ return -2;
+}
+
+/* Account for a GFN being shared/unshared.
+ * When sharing this function needs to be called _before_ gfn lists are merged
+ * together, but _after_ gfn is removed from the list when unsharing.
+ */
+static int mem_sharing_gfn_account(struct gfn_info *gfn, int sharing)
+{
+ struct domain *d;
+
+ /* A) When sharing:
+ * if the gfn being shared is in > 1 long list, its already been
+ * accounted for
+ * B) When unsharing:
+ * if the list is longer than > 1, we don't have to account yet.
+ */
+ if(list_has_one_entry(&gfn->list))
+ {
+ d = get_domain_by_id(gfn->domain);
+ BUG_ON(!d);
+ if(sharing)
+ atomic_inc(&d->shr_pages);
+ else
+ atomic_dec(&d->shr_pages);
+ put_domain(d);
+
+ return 1;
+ }
+
+ return 0;
+}
+
int mem_sharing_debug_gref(struct domain *d, grant_ref_t ref)
{
grant_entry_header_t *shah;
@@ -302,21 +391,12 @@ int mem_sharing_debug_gref(struct domain
d->domain_id, ref);
return -1;
}
+ mem_sharing_gref_to_gfn(d, ref, &gfn);
shah = shared_entry_header(d->grant_table, ref);
if (d->grant_table->gt_version == 1)
- {
- grant_entry_v1_t *sha1;
- sha1 = &shared_entry_v1(d->grant_table, ref);
status = shah->flags;
- gfn = sha1->frame;
- }
else
- {
- grant_entry_v2_t *sha2;
- sha2 = &shared_entry_v2(d->grant_table, ref);
status = status_entry(d->grant_table, ref);
- gfn = sha2->full_page.frame;
- }
printk("==> Grant [dom=%d,ref=%d], status=%x. ",
d->domain_id, ref, status);
@@ -381,7 +461,7 @@ int mem_sharing_nominate_page(struct dom
* since no-one knew that the mfn was temporarily sharable */
ASSERT(page_make_private(d, page) == 0);
mem_sharing_hash_destroy(hash_entry);
- mem_sharing_gfn_destroy(gfn_info);
+ mem_sharing_gfn_destroy(gfn_info, 0);
shr_unlock();
goto out;
}
@@ -415,14 +495,17 @@ int mem_sharing_share_pages(shr_handle_t
shr_lock();
- ret = -1;
+ ret = XEN_DOMCTL_MEM_SHARING_S_HANDLE_INVALID;
se = mem_sharing_hash_lookup(sh);
if(se == NULL) goto err_out;
- ret = -2;
+ ret = XEN_DOMCTL_MEM_SHARING_C_HANDLE_INVALID;
ce = mem_sharing_hash_lookup(ch);
if(ce == NULL) goto err_out;
spage = mfn_to_page(se->mfn);
cpage = mfn_to_page(ce->mfn);
+ /* gfn lists always have at least one entry => save to call list_entry */
+ mem_sharing_gfn_account(gfn_get_info(&ce->gfns), 1);
+ mem_sharing_gfn_account(gfn_get_info(&se->gfns), 1);
list_for_each_safe(le, te, &ce->gfns)
{
gfn = list_entry(le, struct gfn_info, list);
@@ -440,6 +523,7 @@ int mem_sharing_share_pages(shr_handle_t
}
ASSERT(list_empty(&ce->gfns));
mem_sharing_hash_delete(ch);
+ atomic_inc(&nr_saved_mfns);
/* Free the client page */
if(test_and_clear_bit(_PGC_allocated, &cpage->count_info))
put_page(cpage);
@@ -491,8 +575,13 @@ gfn_found:
* (possibly freeing the page), and exit early */
if(flags & MEM_SHARING_DESTROY_GFN)
{
- mem_sharing_gfn_destroy(gfn_info);
- if(last_gfn) mem_sharing_hash_delete(handle);
+ mem_sharing_gfn_destroy(gfn_info, !last_gfn);
+ if(last_gfn)
+ mem_sharing_hash_delete(handle);
+ else
+ /* Even though we don't allocate a private page, we have to account
+ * for the MFN that originally backed this PFN. */
+ atomic_dec(&nr_saved_mfns);
shr_unlock();
put_page_and_type(page);
if(last_gfn &&
@@ -528,8 +617,11 @@ gfn_found:
private_page_found:
/* We've got a private page, we can commit the gfn destruction */
- mem_sharing_gfn_destroy(gfn_info);
- if(last_gfn) mem_sharing_hash_delete(handle);
+ mem_sharing_gfn_destroy(gfn_info, !last_gfn);
+ if(last_gfn)
+ mem_sharing_hash_delete(handle);
+ else
+ atomic_dec(&nr_saved_mfns);
shr_unlock();
if(p2m_change_type(d, gfn, p2m_ram_shared, p2m_ram_rw) !=
@@ -544,6 +636,93 @@ private_page_found:
return 0;
}
+int mem_sharing_domctl(struct domain *d, xen_domctl_mem_sharing_op_t *mec)
+{
+ int rc;
+
+ switch(mec->op)
+ {
+ case XEN_DOMCTL_MEM_SHARING_OP_CONTROL:
+ {
+ rc = 0;
+ if(!hap_enabled(d))
+ return -EINVAL;
+ d->arch.hvm_domain.mem_sharing_enabled = mec->enable;
+ return 0;
+ }
+ break;
+
+ case XEN_DOMCTL_MEM_SHARING_OP_NOMINATE_GFN:
+ {
+ unsigned long gfn = mec->nominate.gfn;
+ shr_handle_t handle;
+ if(!mem_sharing_enabled(d))
+ return -EINVAL;
+ rc = mem_sharing_nominate_page(d, gfn, 0, &handle);
+ mec->nominate.handle = handle;
+ }
+ break;
+
+ case XEN_DOMCTL_MEM_SHARING_OP_NOMINATE_GREF:
+ {
+ grant_ref_t gref = mec->nominate.grant_ref;
+ unsigned long gfn;
+ shr_handle_t handle;
+
+ if(!mem_sharing_enabled(d))
+ return -EINVAL;
+ if(mem_sharing_gref_to_gfn(d, gref, &gfn) < 0)
+ return -EINVAL;
+ rc = mem_sharing_nominate_page(d, gfn, 3, &handle);
+ mec->nominate.handle = handle;
+ }
+ break;
+
+ case XEN_DOMCTL_MEM_SHARING_OP_SHARE:
+ {
+ shr_handle_t sh = mec->share.source_handle;
+ shr_handle_t ch = mec->share.client_handle;
+ rc = mem_sharing_share_pages(sh, ch);
+ }
+ break;
+
+ case XEN_DOMCTL_MEM_SHARING_OP_RESUME:
+ {
+ if(!mem_sharing_enabled(d))
+ return -EINVAL;
+ rc = mem_sharing_sharing_resume(d);
+ }
+ break;
+
+ case XEN_DOMCTL_MEM_SHARING_OP_DEBUG_GFN:
+ {
+ unsigned long gfn = mec->debug.gfn;
+ rc = mem_sharing_debug_gfn(d, gfn);
+ }
+ break;
+
+ case XEN_DOMCTL_MEM_SHARING_OP_DEBUG_MFN:
+ {
+ unsigned long mfn = mec->debug.mfn;
+ rc = mem_sharing_debug_mfn(mfn);
+ }
+ break;
+
+ case XEN_DOMCTL_MEM_SHARING_OP_DEBUG_GREF:
+ {
+ grant_ref_t gref = mec->debug.gref;
+ rc = mem_sharing_debug_gref(d, gref);
+ }
+ break;
+
+ default:
+ rc = -ENOSYS;
+ break;
+ }
+
+ return rc;
+}
+
void mem_sharing_init(void)
{
printk("Initing memory sharing.\n");
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/common/domctl.c
--- a/xen/common/domctl.c Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/common/domctl.c Thu Dec 17 06:27:56 2009 +0000
@@ -136,6 +136,7 @@ void getdomaininfo(struct domain *d, str
info->tot_pages = d->tot_pages;
info->max_pages = d->max_pages;
+ info->shr_pages = atomic_read(&d->shr_pages);
info->shared_info_frame = mfn_to_gmfn(d, __pa(d->shared_info)>>PAGE_SHIFT);
BUG_ON(SHARED_M2P(info->shared_info_frame));
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/include/asm-x86/hvm/domain.h
--- a/xen/include/asm-x86/hvm/domain.h Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/include/asm-x86/hvm/domain.h Thu Dec 17 06:27:56 2009 +0000
@@ -90,6 +90,7 @@ struct hvm_domain {
struct viridian_domain viridian;
bool_t hap_enabled;
+ bool_t mem_sharing_enabled;
bool_t qemu_mapcache_invalidate;
bool_t is_s3_suspended;
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/include/asm-x86/mem_sharing.h
--- a/xen/include/asm-x86/mem_sharing.h Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/include/asm-x86/mem_sharing.h Thu Dec 17 06:27:56 2009 +0000
@@ -27,6 +27,7 @@
typedef uint64_t shr_handle_t;
+unsigned int mem_sharing_get_nr_saved_mfns(void);
int mem_sharing_nominate_page(struct domain *d,
unsigned long gfn,
int expected_refcnt,
@@ -38,6 +39,8 @@ int mem_sharing_unshare_page(struct doma
uint16_t flags);
int mem_sharing_sharing_resume(struct domain *d);
int mem_sharing_cache_resize(struct domain *d, int new_size);
+int mem_sharing_domctl(struct domain *d,
+ xen_domctl_mem_sharing_op_t *mec);
void mem_sharing_init(void);
#endif /* __MEM_SHARING_H__ */
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/include/public/domctl.h
--- a/xen/include/public/domctl.h Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/include/public/domctl.h Thu Dec 17 06:27:56 2009 +0000
@@ -33,6 +33,7 @@
#endif
#include "xen.h"
+#include "grant_table.h"
#define XEN_DOMCTL_INTERFACE_VERSION 0x00000005
@@ -103,6 +104,7 @@ struct xen_domctl_getdomaininfo {
uint32_t flags; /* XEN_DOMINF_* */
uint64_aligned_t tot_pages;
uint64_aligned_t max_pages;
+ uint64_aligned_t shr_pages;
uint64_aligned_t shared_info_frame; /* GMFN of shared_info struct */
uint64_aligned_t cpu_time;
uint32_t nr_online_vcpus; /* Number of VCPUs currently online. */
@@ -726,6 +728,52 @@ struct xen_domctl_mem_event_op {
};
typedef struct xen_domctl_mem_event_op xen_domctl_mem_event_op_t;
DEFINE_XEN_GUEST_HANDLE(xen_domctl_mem_event_op_t);
+
+/*
+ * Memory sharing operations
+ */
+#define XEN_DOMCTL_mem_sharing_op 58
+
+#define XEN_DOMCTL_MEM_SHARING_OP_CONTROL 0
+#define XEN_DOMCTL_MEM_SHARING_OP_NOMINATE_GFN 1
+#define XEN_DOMCTL_MEM_SHARING_OP_NOMINATE_GREF 2
+#define XEN_DOMCTL_MEM_SHARING_OP_SHARE 3
+#define XEN_DOMCTL_MEM_SHARING_OP_RESUME 4
+#define XEN_DOMCTL_MEM_SHARING_OP_DEBUG_GFN 5
+#define XEN_DOMCTL_MEM_SHARING_OP_DEBUG_MFN 6
+#define XEN_DOMCTL_MEM_SHARING_OP_DEBUG_GREF 7
+
+#define XEN_DOMCTL_MEM_SHARING_S_HANDLE_INVALID (-10)
+#define XEN_DOMCTL_MEM_SHARING_C_HANDLE_INVALID (-9)
+
+struct xen_domctl_mem_sharing_op {
+ uint8_t op; /* XEN_DOMCTL_MEM_EVENT_OP_* */
+
+ union {
+ int enable; /* for OP_CONTROL */
+
+ struct mem_sharing_op_nominate { /* for OP_NOMINATE */
+ union {
+ unsigned long gfn; /* IN: gfn to nominate */
+ uint32_t grant_ref; /* IN: grant ref to nominate */
+ };
+ uint64_t handle; /* OUT: the handle */
+ } nominate;
+ struct mem_sharing_op_share {
+ uint64_t source_handle; /* IN: handle to the source page */
+ uint64_t client_handle; /* IN: handle to the client page */
+ } share;
+ struct mem_sharing_op_debug {
+ union {
+ unsigned long gfn; /* IN: gfn to debug */
+ unsigned long mfn; /* IN: mfn to debug */
+ grant_ref_t gref; /* IN: gref to debug */
+ };
+ } debug;
+ };
+};
+typedef struct xen_domctl_mem_sharing_op xen_domctl_mem_sharing_op_t;
+DEFINE_XEN_GUEST_HANDLE(xen_domctl_mem_sharing_op_t);
struct xen_domctl {
@@ -772,6 +820,7 @@ struct xen_domctl {
struct xen_domctl_subscribe subscribe;
struct xen_domctl_debug_op debug_op;
struct xen_domctl_mem_event_op mem_event_op;
+ struct xen_domctl_mem_sharing_op mem_sharing_op;
#if defined(__i386__) || defined(__x86_64__)
struct xen_domctl_cpuid cpuid;
#endif
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/include/public/memory.h
--- a/xen/include/public/memory.h Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/include/public/memory.h Thu Dec 17 06:27:56 2009 +0000
@@ -281,6 +281,13 @@ struct xen_pod_target {
domid_t domid;
};
typedef struct xen_pod_target xen_pod_target_t;
+
+/*
+ * Get the number of MFNs saved through memory sharing.
+ * The call never fails.
+ */
+#define XENMEM_get_sharing_freed_pages 18
+
#endif /* __XEN_PUBLIC_MEMORY_H__ */
/*
diff -r 8cf5bffd9663 -r 68e964ec2c7b xen/include/xen/sched.h
--- a/xen/include/xen/sched.h Thu Dec 17 06:27:56 2009 +0000
+++ b/xen/include/xen/sched.h Thu Dec 17 06:27:56 2009 +0000
@@ -201,6 +201,7 @@ struct domain
struct page_list_head xenpage_list; /* linked list (size xenheap_pages) */
unsigned int tot_pages; /* number of pages currently possesed */
unsigned int max_pages; /* maximum value for tot_pages */
+ atomic_t shr_pages; /* number of shared pages */
unsigned int xenheap_pages; /* # pages allocated from Xen heap */
unsigned int max_vcpus;
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