x86: restrict HVMOP_pagetable_dying to current

This is not used (and probably was never meant to be) by the tool stack.
Limiting it to the current domain in particular allows to eliminate a
bogus use of vCPU 0 in pagetable_dying().

Remove the now unnecessary domain/vCPU parameters from the wrapper/hook
functions at the same time.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 56a8de803428de143044448159347a7c19aed7b5..225c62f8bae387d334a7eb4b2f3fdd0547f53113 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4920,10 +4920,12 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
             return -ESRCH;
 
         rc = -EINVAL;
-        if ( is_hvm_domain(d) && paging_mode_shadow(d) )
+        if ( unlikely(d != current->domain) )
+            rc = -EOPNOTSUPP;
+        else if ( is_hvm_domain(d) && paging_mode_shadow(d) )
             rc = xsm_hvm_param(XSM_TARGET, d, op);
         if ( !rc )
-            pagetable_dying(d, a.gpa);
+            pagetable_dying(a.gpa);
 
         rcu_unlock_domain(d);
         break;

diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c
index f32a60188a241b69b35f38ed047bb64fc2457760..d5836eb68853ca6ff0ea2a810c1abd8949c4bcda 100644 (file)
--- a/xen/arch/x86/mm/paging.c
+++ b/xen/arch/x86/mm/paging.c
@@ -851,15 +851,14 @@ int paging_enable(struct domain *d, u32 mode)
 
 /* Called from the guest to indicate that a process is being torn down
  * and therefore its pagetables will soon be discarded */
-void pagetable_dying(struct domain *d, paddr_t gpa)
+void pagetable_dying(paddr_t gpa)
 {
 #ifdef CONFIG_SHADOW_PAGING
-    struct vcpu *v;
+    struct vcpu *curr = current;
 
-    ASSERT(paging_mode_shadow(d));
+    ASSERT(paging_mode_shadow(curr->domain));
 
-    v = d->vcpu[0];
-    v->arch.paging.mode->shadow.pagetable_dying(v, gpa);
+    curr->arch.paging.mode->shadow.pagetable_dying(gpa);
 #else
     BUG();
 #endif

diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index 5cb216f0db9cfdc2399a3bc8140a6867f8962c94..669c3f2c5e5bc291b55b052e99be9f0758e4e3ab 100644 (file)
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -4525,8 +4525,9 @@ int sh_remove_l3_shadow(struct domain *d, mfn_t sl4mfn, mfn_t sl3mfn)
  * and in the meantime we unhook its top-level user-mode entries. */
 
 #if GUEST_PAGING_LEVELS == 3
-static void sh_pagetable_dying(struct vcpu *v, paddr_t gpa)
+static void sh_pagetable_dying(paddr_t gpa)
 {
+    struct vcpu *v = current;
     struct domain *d = v->domain;
     int i = 0;
     int flush = 0;
@@ -4604,8 +4605,9 @@ out_put_gfn:
     put_gfn(d, l3gfn);
 }
 #else
-static void sh_pagetable_dying(struct vcpu *v, paddr_t gpa)
+static void sh_pagetable_dying(paddr_t gpa)
 {
+    struct vcpu *v = current;
     struct domain *d = v->domain;
     mfn_t smfn, gmfn;
     p2m_type_t p2mt;

diff --git a/xen/include/asm-x86/paging.h b/xen/include/asm-x86/paging.h
index b51e1709d3090553eeeedab70105fd6539fd49d3..dd0d6b5159964e13df448a1a0fb3bdbb73b36fe9 100644 (file)
--- a/xen/include/asm-x86/paging.h
+++ b/xen/include/asm-x86/paging.h
@@ -95,7 +95,7 @@ struct shadow_paging_mode {
     void          (*destroy_monitor_table )(struct vcpu *v, mfn_t mmfn);
     int           (*guess_wrmap           )(struct vcpu *v, 
                                             unsigned long vaddr, mfn_t gmfn);
-    void          (*pagetable_dying       )(struct vcpu *v, paddr_t gpa);
+    void          (*pagetable_dying       )(paddr_t gpa);
     void          (*trace_emul_write_val  )(const void *ptr, unsigned long vaddr,
                                             const void *src, unsigned int bytes);
 #endif
@@ -343,9 +343,11 @@ void paging_write_p2m_entry(struct p2m_domain *p2m, unsigned long gfn,
                             l1_pgentry_t *p, l1_pgentry_t new,
                             unsigned int level);
 
-/* Called from the guest to indicate that the a process is being
- * torn down and its pagetables will soon be discarded */
-void pagetable_dying(struct domain *d, paddr_t gpa);
+/*
+ * Called from the guest to indicate that the a process is being
+ * torn down and its pagetables will soon be discarded.
+ */
+void pagetable_dying(paddr_t gpa);
 
 /* Print paging-assistance info to the console */
 void paging_dump_domain_info(struct domain *d);