Merge ../linux-2.6-watchdog-mm

[pandora-kernel.git] / drivers / kvm / paging_tmpl.h

diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 4e6670f..149fa45 100644 (file)
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -63,13 +63,15 @@ struct guest_walker {
        pt_element_t *ptep;
        pt_element_t inherited_ar;
        gfn_t gfn;
+       u32 error_code;
 };
 
 /*
  * Fetch a guest pte for a guest virtual address
  */
-static void FNAME(walk_addr)(struct guest_walker *walker,
-                            struct kvm_vcpu *vcpu, gva_t addr)
+static int FNAME(walk_addr)(struct guest_walker *walker,
+                           struct kvm_vcpu *vcpu, gva_t addr,
+                           int write_fault, int user_fault, int fetch_fault)
 {
        hpa_t hpa;
        struct kvm_memory_slot *slot;
@@ -86,7 +88,7 @@ static void FNAME(walk_addr)(struct guest_walker *walker,
                walker->ptep = &vcpu->pdptrs[(addr >> 30) & 3];
                root = *walker->ptep;
                if (!(root & PT_PRESENT_MASK))
-                       return;
+                       goto not_present;
                --walker->level;
        }
 #endif
@@ -111,11 +113,23 @@ static void FNAME(walk_addr)(struct guest_walker *walker,
                ASSERT(((unsigned long)walker->table & PAGE_MASK) ==
                       ((unsigned long)ptep & PAGE_MASK));
 
-               if (is_present_pte(*ptep) && !(*ptep &  PT_ACCESSED_MASK))
-                       *ptep |= PT_ACCESSED_MASK;
-
                if (!is_present_pte(*ptep))
-                       break;
+                       goto not_present;
+
+               if (write_fault && !is_writeble_pte(*ptep))
+                       if (user_fault || is_write_protection(vcpu))
+                               goto access_error;
+
+               if (user_fault && !(*ptep & PT_USER_MASK))
+                       goto access_error;
+
+#if PTTYPE == 64
+               if (fetch_fault && is_nx(vcpu) && (*ptep & PT64_NX_MASK))
+                       goto access_error;
+#endif
+
+               if (!(*ptep & PT_ACCESSED_MASK))
+                       *ptep |= PT_ACCESSED_MASK;      /* avoid rmw */
 
                if (walker->level == PT_PAGE_TABLE_LEVEL) {
                        walker->gfn = (*ptep & PT_BASE_ADDR_MASK)
@@ -146,6 +160,23 @@ static void FNAME(walk_addr)(struct guest_walker *walker,
        }
        walker->ptep = ptep;
        pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)*ptep);
+       return 1;
+
+not_present:
+       walker->error_code = 0;
+       goto err;
+
+access_error:
+       walker->error_code = PFERR_PRESENT_MASK;
+
+err:
+       if (write_fault)
+               walker->error_code |= PFERR_WRITE_MASK;
+       if (user_fault)
+               walker->error_code |= PFERR_USER_MASK;
+       if (fetch_fault)
+               walker->error_code |= PFERR_FETCH_MASK;
+       return 0;
 }
 
 static void FNAME(release_walker)(struct guest_walker *walker)
@@ -274,7 +305,7 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
        struct kvm_mmu_page *page;
 
        if (is_writeble_pte(*shadow_ent))
-               return 0;
+               return !user || (*shadow_ent & PT_USER_MASK);
 
        writable_shadow = *shadow_ent & PT_SHADOW_WRITABLE_MASK;
        if (user) {
@@ -317,6 +348,7 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
        } else if (kvm_mmu_lookup_page(vcpu, gfn)) {
                pgprintk("%s: found shadow page for %lx, marking ro\n",
                         __FUNCTION__, gfn);
+               *guest_ent |= PT_DIRTY_MASK;
                *write_pt = 1;
                return 0;
        }
@@ -339,39 +371,45 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
  *   - normal guest page fault due to the guest pte marked not present, not
  *     writable, or not executable
  *
- *  Returns: 1 if we need to emulate the instruction, 0 otherwise
+ *  Returns: 1 if we need to emulate the instruction, 0 otherwise, or
+ *           a negative value on error.
  */
 static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                               u32 error_code)
 {
        int write_fault = error_code & PFERR_WRITE_MASK;
-       int pte_present = error_code & PFERR_PRESENT_MASK;
        int user_fault = error_code & PFERR_USER_MASK;
+       int fetch_fault = error_code & PFERR_FETCH_MASK;
        struct guest_walker walker;
        u64 *shadow_pte;
        int fixed;
        int write_pt = 0;
+       int r;
 
        pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code);
+       kvm_mmu_audit(vcpu, "pre page fault");
 
-       mmu_topup_memory_caches(vcpu);
+       r = mmu_topup_memory_caches(vcpu);
+       if (r)
+               return r;
 
        /*
         * Look up the shadow pte for the faulting address.
         */
-       FNAME(walk_addr)(&walker, vcpu, addr);
-       shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
+       r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault,
+                            fetch_fault);
 
        /*
         * The page is not mapped by the guest.  Let the guest handle it.
         */
-       if (!shadow_pte) {
-               pgprintk("%s: not mapped\n", __FUNCTION__);
-               inject_page_fault(vcpu, addr, error_code);
+       if (!r) {
+               pgprintk("%s: guest page fault\n", __FUNCTION__);
+               inject_page_fault(vcpu, addr, walker.error_code);
                FNAME(release_walker)(&walker);
                return 0;
        }
 
+       shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
        pgprintk("%s: shadow pte %p %llx\n", __FUNCTION__,
                 shadow_pte, *shadow_pte);
 
@@ -393,23 +431,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
         * mmio: emulate if accessible, otherwise its a guest fault.
         */
        if (is_io_pte(*shadow_pte)) {
-               if (may_access(*shadow_pte, write_fault, user_fault))
-                       return 1;
-               pgprintk("%s: io work, no access\n", __FUNCTION__);
-               inject_page_fault(vcpu, addr,
-                                 error_code | PFERR_PRESENT_MASK);
-               return 0;
-       }
-
-       /*
-        * pte not present, guest page fault.
-        */
-       if (pte_present && !fixed && !write_pt) {
-               inject_page_fault(vcpu, addr, error_code);
-               return 0;
+               return 1;
        }
 
        ++kvm_stat.pf_fixed;
+       kvm_mmu_audit(vcpu, "post page fault (fixed)");
 
        return write_pt;
 }
@@ -420,7 +446,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
        pt_element_t guest_pte;
        gpa_t gpa;
 
-       FNAME(walk_addr)(&walker, vcpu, vaddr);
+       FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0);
        guest_pte = *walker.ptep;
        FNAME(release_walker)(&walker);