[Xen-devel] [V4 PATCH 5/7] pvh: change xsm_add_to_physmap

[Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>]

In preparation for the next patch, we update xsm_add_to_physmap to
allow for checking of foreign domain. Thus, the current domain must
have the right to update the mappings of target domain with pages from
foreign domain.

Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
---
 xen/arch/x86/mm.c       |   18 +++++++++++++++---
 xen/include/xsm/dummy.h |   10 ++++++++--
 xen/include/xsm/xsm.h   |    6 +++---
 xen/xsm/flask/hooks.c   |    9 +++++++--
 4 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 4ae4523..e3da479 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4730,7 +4730,7 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) 
arg)
         if ( d == NULL )
             return -ESRCH;
 
-        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
+        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d, NULL) )
         {
             rcu_unlock_domain(d);
             return -EPERM;
@@ -4756,7 +4756,7 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) 
arg)
     case XENMEM_add_to_physmap_range:
     {
         struct xen_add_to_physmap_range xatpr;
-        struct domain *d;
+        struct domain *d, *fd = NULL;
 
         if ( copy_from_guest(&xatpr, arg, 1) )
             return -EFAULT;
@@ -4769,10 +4769,22 @@ long arch_memory_op(int op, 
XEN_GUEST_HANDLE_PARAM(void) arg)
         if ( d == NULL )
             return -ESRCH;
 
-        if ( (rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d)) == 0 )
+        if ( xatpr.space == XENMAPSPACE_gmfn_foreign )
+        {
+            fd = get_pg_owner(xatpr.foreign_domid);
+            if ( fd == NULL )
+            {
+                rcu_unlock_domain(d);
+                return -ESRCH;
+            }
+        }
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d, fd);
+        if ( rc == 0 )
             rc = xenmem_add_to_physmap_range(d, &xatpr);
 
         rcu_unlock_domain(d);
+        if ( fd )
+            put_pg_owner(fd);
 
         if ( rc == -EAGAIN )
             rc = hypercall_create_continuation(
diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h
index eb9e1a1..1228e52 100644
--- a/xen/include/xsm/dummy.h
+++ b/xen/include/xsm/dummy.h
@@ -467,10 +467,16 @@ static XSM_INLINE int 
xsm_pci_config_permission(XSM_DEFAULT_ARG struct domain *d
     return xsm_default_action(action, current->domain, d);
 }
 
-static XSM_INLINE int xsm_add_to_physmap(XSM_DEFAULT_ARG struct domain *d1, 
struct domain *d2)
+static XSM_INLINE int xsm_add_to_physmap(XSM_DEFAULT_ARG struct domain *d, 
struct domain *t, struct domain *f)
 {
+    int rc;
+
     XSM_ASSERT_ACTION(XSM_TARGET);
-    return xsm_default_action(action, d1, d2);
+    rc = xsm_default_action(action, d, t);
+    if ( f && !rc )
+        rc = xsm_default_action(action, d, f);
+
+    return rc;
 }
 
 static XSM_INLINE int xsm_remove_from_physmap(XSM_DEFAULT_ARG struct domain 
*d1, struct domain *d2)
diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h
index 1939453..9ee9543 100644
--- a/xen/include/xsm/xsm.h
+++ b/xen/include/xsm/xsm.h
@@ -90,7 +90,7 @@ struct xsm_operations {
     int (*memory_adjust_reservation) (struct domain *d1, struct domain *d2);
     int (*memory_stat_reservation) (struct domain *d1, struct domain *d2);
     int (*memory_pin_page) (struct domain *d1, struct domain *d2, struct 
page_info *page);
-    int (*add_to_physmap) (struct domain *d1, struct domain *d2);
+    int (*add_to_physmap) (struct domain *d, struct domain *t, struct domain 
*f);
     int (*remove_from_physmap) (struct domain *d1, struct domain *d2);
     int (*claim_pages) (struct domain *d);
 
@@ -344,9 +344,9 @@ static inline int xsm_memory_pin_page(xsm_default_t def, 
struct domain *d1, stru
     return xsm_ops->memory_pin_page(d1, d2, page);
 }
 
-static inline int xsm_add_to_physmap(xsm_default_t def, struct domain *d1, 
struct domain *d2)
+static inline int xsm_add_to_physmap(xsm_default_t def, struct domain *d, 
struct domain *t, struct domain *f)
 {
-    return xsm_ops->add_to_physmap(d1, d2);
+    return xsm_ops->add_to_physmap(d, t, f);
 }
 
 static inline int xsm_remove_from_physmap(xsm_default_t def, struct domain 
*d1, struct domain *d2)
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index b1e2593..30807e9 100644
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -1068,9 +1068,14 @@ static inline int flask_tmem_control(void)
     return domain_has_xen(current->domain, XEN__TMEM_CONTROL);
 }
 
-static int flask_add_to_physmap(struct domain *d1, struct domain *d2)
+static int flask_add_to_physmap(struct domain *d, struct domain *t, struct 
domain *f)
 {
-    return domain_has_perm(d1, d2, SECCLASS_MMU, MMU__PHYSMAP);
+    int rc;
+
+    rc = domain_has_perm(d, t, SECCLASS_MMU, MMU__PHYSMAP);
+    if ( f && !rc )
+        rc = domain_has_perm(d, f, SECCLASS_MMU, MMU__MAP_READ|MMU__MAP_WRITE);
+    return rc;
 }
 
 static int flask_remove_from_physmap(struct domain *d1, struct domain *d2)
-- 
1.7.2.3


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