diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index e632b1e..b4e57d8 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -2027,9 +2027,6 @@ int xc_altp2m_destroy_view(xc_interface *handle, domid_t domid,
 /* Switch all vCPUs of the domain to the specified altp2m view */
 int xc_altp2m_switch_to_view(xc_interface *handle, domid_t domid,
                              uint16_t view_id);
-int xc_altp2m_set_mem_access(xc_interface *handle, domid_t domid,
-                             uint16_t view_id, xen_pfn_t gfn,
-                             xenmem_access_t access);
 int xc_altp2m_change_gfn(xc_interface *handle, domid_t domid,
                          uint16_t view_id, xen_pfn_t old_gfn,
                          xen_pfn_t new_gfn);
@@ -2062,7 +2059,7 @@ int xc_mem_paging_load(xc_interface *xch, domid_t domain_id,
  */
 int xc_set_mem_access(xc_interface *xch, domid_t domain_id,
                       xenmem_access_t access, uint64_t first_pfn,
-                      uint32_t nr);
+                      uint32_t nr, uint16_t altp2m_idx);
 
 /*
  * Gets the mem access for the given page (returned in access on success)
diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c
index 0639632..4f44a7b 100644
--- a/tools/libxc/xc_altp2m.c
+++ b/tools/libxc/xc_altp2m.c
@@ -163,31 +163,6 @@ int xc_altp2m_switch_to_view(xc_interface *handle, domid_t domid,
     return rc;
 }
 
-int xc_altp2m_set_mem_access(xc_interface *handle, domid_t domid,
-                             uint16_t view_id, xen_pfn_t gfn,
-                             xenmem_access_t access)
-{
-    int rc;
-    DECLARE_HYPERCALL_BUFFER(xen_hvm_altp2m_op_t, arg);
-
-    arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg));
-    if ( arg == NULL )
-        return -1;
-
-    arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
-    arg->cmd = HVMOP_altp2m_set_mem_access;
-    arg->domain = domid;
-    arg->u.set_mem_access.view = view_id;
-    arg->u.set_mem_access.hvmmem_access = access;
-    arg->u.set_mem_access.gfn = gfn;
-
-    rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
-		  HYPERCALL_BUFFER_AS_ARG(arg));
-
-    xc_hypercall_buffer_free(handle, arg);
-    return rc;
-}
-
 int xc_altp2m_change_gfn(xc_interface *handle, domid_t domid,
                          uint16_t view_id, xen_pfn_t old_gfn,
                          xen_pfn_t new_gfn)
diff --git a/tools/libxc/xc_mem_access.c b/tools/libxc/xc_mem_access.c
index 3634c39..d6fb409 100644
--- a/tools/libxc/xc_mem_access.c
+++ b/tools/libxc/xc_mem_access.c
@@ -27,15 +27,17 @@ int xc_set_mem_access(xc_interface *xch,
                       domid_t domain_id,
                       xenmem_access_t access,
                       uint64_t first_pfn,
-                      uint32_t nr)
+                      uint32_t nr,
+                      uint16_t altp2m_idx)
 {
     xen_mem_access_op_t mao =
     {
-        .op     = XENMEM_access_op_set_access,
-        .domid  = domain_id,
-        .access = access,
-        .pfn    = first_pfn,
-        .nr     = nr
+        .op         = XENMEM_access_op_set_access,
+        .domid      = domain_id,
+        .access     = access,
+        .pfn        = first_pfn,
+        .nr         = nr,
+        .altp2m_idx = altp2m_idx
     };
 
     return do_memory_op(xch, XENMEM_access_op, &mao, sizeof(mao));
diff --git a/tools/tests/xen-access/xen-access.c b/tools/tests/xen-access/xen-access.c
index 7993947..2300e9a 100644
--- a/tools/tests/xen-access/xen-access.c
+++ b/tools/tests/xen-access/xen-access.c
@@ -448,9 +448,6 @@ int main(int argc, char *argv[])
     /* With altp2m we just create a new, restricted view of the memory */
     if ( altp2m )
     {
-        xen_pfn_t gfn = 0;
-        unsigned long perm_set = 0;
-
         rc = xc_altp2m_set_domain_state( xch, domain_id, 1 );
         if ( rc < 0 )
         {
@@ -466,17 +463,6 @@ int main(int argc, char *argv[])
         }
 
         DPRINTF("altp2m view created with id %u\n", altp2m_view_id);
-        DPRINTF("Setting altp2m mem_access permissions.. ");
-
-        for(; gfn < xenaccess->max_gpfn; ++gfn)
-        {
-            rc = xc_altp2m_set_mem_access( xch, domain_id, altp2m_view_id, gfn,
-                                           default_access);
-            if ( !rc )
-                perm_set++;
-        }
-
-        DPRINTF("done! Permissions set on %lu pages.\n", perm_set);
 
         rc = xc_altp2m_switch_to_view( xch, domain_id, altp2m_view_id );
         if ( rc < 0 )
@@ -493,25 +479,22 @@ int main(int argc, char *argv[])
         }
     }
 
-    if ( !altp2m )
+    /* Set the default access type and convert all pages to it */
+    rc = xc_set_mem_access(xch, domain_id, default_access, ~0ull, 0, 0);
+    if ( rc < 0 )
     {
-        /* Set the default access type and convert all pages to it */
-        rc = xc_set_mem_access(xch, domain_id, default_access, ~0ull, 0);
-        if ( rc < 0 )
-        {
-            ERROR("Error %d setting default mem access type\n", rc);
-            goto exit;
-        }
+        ERROR("Error %d setting default mem access type\n", rc);
+        goto exit;
+    }
 
-        rc = xc_set_mem_access(xch, domain_id, default_access, START_PFN,
-                               (xenaccess->max_gpfn - START_PFN) );
+    rc = xc_set_mem_access(xch, domain_id, default_access, START_PFN,
+                           (xenaccess->max_gpfn - START_PFN), altp2m_view_id );
 
-        if ( rc < 0 )
-        {
-            ERROR("Error %d setting all memory to access type %d\n", rc,
-                  default_access);
-            goto exit;
-        }
+    if ( rc < 0 )
+    {
+        ERROR("Error %d setting all memory to access type %d\n", rc,
+              default_access);
+        goto exit;
     }
 
     if ( breakpoint )
@@ -547,12 +530,12 @@ int main(int argc, char *argv[])
                 for ( vcpu_id = 0; vcpu_id<XEN_LEGACY_MAX_VCPUS; vcpu_id++)
                     rc = control_singlestep(xch, domain_id, vcpu_id, 0);
 
-            } else {
-                rc = xc_set_mem_access(xch, domain_id, XENMEM_access_rwx, ~0ull, 0);
-                rc = xc_set_mem_access(xch, domain_id, XENMEM_access_rwx, START_PFN,
-                                       (xenaccess->max_gpfn - START_PFN) );
             }
 
+            rc = xc_set_mem_access(xch, domain_id, XENMEM_access_rwx, ~0ull, 0, 0);
+            rc = xc_set_mem_access(xch, domain_id, XENMEM_access_rwx, START_PFN,
+                                   (xenaccess->max_gpfn - START_PFN), 0 );
+
             shutting_down = 1;
         }
 
@@ -623,7 +606,7 @@ int main(int argc, char *argv[])
                 else if ( default_access != after_first_access )
                 {
                     rc = xc_set_mem_access(xch, domain_id, after_first_access,
-                                           req.u.mem_access.gfn, 1);
+                                           req.u.mem_access.gfn, 1, 0);
                     if (rc < 0)
                     {
                         ERROR("Error %d setting gfn to access_type %d\n", rc,
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 2190908..8568087 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1709,13 +1709,13 @@ bool_t p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec)
     if ( npfec.write_access && xma == XENMEM_access_rx2rw )
     {
         rc = p2m_set_mem_access(v->domain, _gfn(paddr_to_pfn(gpa)), 1,
-                                0, ~0, XENMEM_access_rw);
+                                0, ~0, XENMEM_access_rw, 0);
         return false;
     }
     else if ( xma == XENMEM_access_n2rwx )
     {
         rc = p2m_set_mem_access(v->domain, _gfn(paddr_to_pfn(gpa)), 1,
-                                0, ~0, XENMEM_access_rwx);
+                                0, ~0, XENMEM_access_rwx, 0);
     }
 
     /* Otherwise, check if there is a vm_event monitor subscriber */
@@ -1737,7 +1737,7 @@ bool_t p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec)
                 /* A listener is not required, so clear the access
                  * restrictions. */
                 rc = p2m_set_mem_access(v->domain, _gfn(paddr_to_pfn(gpa)), 1,
-                                        0, ~0, XENMEM_access_rwx);
+                                        0, ~0, XENMEM_access_rwx, 0);
             }
         }
 
@@ -1788,7 +1788,8 @@ bool_t p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec)
  * If gfn == INVALID_GFN, sets the default access type.
  */
 long p2m_set_mem_access(struct domain *d, gfn_t gfn, uint32_t nr,
-                        uint32_t start, uint32_t mask, xenmem_access_t access)
+                        uint32_t start, uint32_t mask, xenmem_access_t access,
+                        unsigned int altp2m_idx)
 {
     struct p2m_domain *p2m = p2m_get_hostp2m(d);
     p2m_access_t a;
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 674feea..37305fb 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -6398,9 +6398,9 @@ static int do_altp2m_op(
         if ( a.u.set_mem_access.pad )
             rc = -EINVAL;
         else
-            rc = p2m_set_altp2m_mem_access(d, a.u.set_mem_access.view,
-                    _gfn(a.u.set_mem_access.gfn),
-                    a.u.set_mem_access.hvmmem_access);
+            rc = p2m_set_mem_access(d, _gfn(a.u.set_mem_access.gfn), 1, 0, 0,
+                                    a.u.set_mem_access.hvmmem_access,
+                                    a.u.set_mem_access.view);
         break;
 
     case HVMOP_altp2m_change_gfn:
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index a45ee35..a3181f3 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1777,14 +1777,57 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long gla,
     return (p2ma == p2m_access_n2rwx);
 }
 
+static int p2m_set_altp2m_mem_access(struct domain *d, struct p2m_domain *hp2m,
+                                     struct p2m_domain *ap2m, p2m_access_t a,
+                                     unsigned long gfn)
+{
+    mfn_t mfn;
+    p2m_type_t t;
+    p2m_access_t old_a;
+    unsigned int page_order;
+    int rc;
+
+    mfn = ap2m->get_entry(ap2m, gfn, &t, &old_a, 0, NULL, NULL);
+
+    /* Check host p2m if no valid entry in alternate */
+    if ( !mfn_valid(mfn) )
+    {
+        mfn = hp2m->get_entry(hp2m, gfn, &t, &old_a,
+                              P2M_ALLOC | P2M_UNSHARE, &page_order, NULL);
+
+        rc = -ESRCH;
+        if ( !mfn_valid(mfn) || t != p2m_ram_rw )
+            goto out;
+
+        /* If this is a superpage, copy that first */
+        if ( page_order != PAGE_ORDER_4K )
+        {
+            unsigned long mask = ~((1UL << page_order) - 1);
+            gfn_t gfn2 = _gfn(gfn & mask);
+            mfn_t mfn2 = _mfn(mfn_x(mfn) & mask);
+
+            rc = ap2m->set_entry(ap2m, gfn_x(gfn2), mfn2, page_order, t, old_a, 1);
+            if ( rc )
+                goto out;
+        }
+    }
+
+    rc = ap2m->set_entry(ap2m, gfn, mfn, PAGE_ORDER_4K, t, a,
+                         (current->domain != d));
+
+ out:
+    return rc;
+}
+
 /*
  * Set access type for a region of gfns.
  * If gfn == INVALID_GFN, sets the default access type.
  */
 long p2m_set_mem_access(struct domain *d, gfn_t gfn, uint32_t nr,
-                        uint32_t start, uint32_t mask, xenmem_access_t access)
+                        uint32_t start, uint32_t mask, xenmem_access_t access,
+                        unsigned int altp2m_idx)
 {
-    struct p2m_domain *p2m = p2m_get_hostp2m(d);
+    struct p2m_domain *p2m = p2m_get_hostp2m(d), *ap2m = NULL;
     p2m_access_t a, _a;
     p2m_type_t t;
     mfn_t mfn;
@@ -1806,6 +1849,16 @@ long p2m_set_mem_access(struct domain *d, gfn_t gfn, uint32_t nr,
 #undef ACCESS
     };
 
+    /* altp2m view 0 is treated as the hostp2m */
+    if ( altp2m_idx )
+    {
+        if ( altp2m_idx >= MAX_ALTP2M ||
+             d->arch.altp2m_eptp[altp2m_idx] == INVALID_MFN )
+            return -EINVAL;
+
+        ap2m = d->arch.altp2m_p2m[altp2m_idx];
+    }
+
     switch ( access )
     {
     case 0 ... ARRAY_SIZE(memaccess) - 1:
@@ -1826,12 +1879,25 @@ long p2m_set_mem_access(struct domain *d, gfn_t gfn, uint32_t nr,
     }
 
     p2m_lock(p2m);
+    if ( ap2m )
+        p2m_lock(ap2m);
+
     for ( gfn_l = gfn_x(gfn) + start; nr > start; ++gfn_l )
     {
-        mfn = p2m->get_entry(p2m, gfn_l, &t, &_a, 0, NULL, NULL);
-        rc = p2m->set_entry(p2m, gfn_l, mfn, PAGE_ORDER_4K, t, a, -1);
-        if ( rc )
-            break;
+        if ( ap2m )
+        {
+            rc = p2m_set_altp2m_mem_access(d, p2m, ap2m, a, gfn_l);
+            /* If the corresponding mfn is invalid we will just skip it */
+            if ( rc && rc != -ESRCH )
+                break;
+        }
+        else
+        {
+            mfn = p2m->get_entry(p2m, gfn_l, &t, &_a, 0, NULL, NULL);
+            rc = p2m->set_entry(p2m, gfn_l, mfn, PAGE_ORDER_4K, t, a, -1);
+            if ( rc )
+                break;
+        }
 
         /* Check for continuation if it's not the last iteration. */
         if ( nr > ++start && !(start & mask) && hypercall_preempt_check() )
@@ -1840,7 +1906,11 @@ long p2m_set_mem_access(struct domain *d, gfn_t gfn, uint32_t nr,
             break;
         }
     }
+
+    if ( ap2m )
+        p2m_unlock(ap2m);
     p2m_unlock(p2m);
+
     return rc;
 }
 
@@ -2395,93 +2465,6 @@ int p2m_switch_domain_altp2m_by_id(struct domain *d, unsigned int idx)
     return rc;
 }
 
-int p2m_set_altp2m_mem_access(struct domain *d, unsigned int idx,
-                              gfn_t gfn, xenmem_access_t access)
-{
-    struct p2m_domain *hp2m, *ap2m;
-    p2m_access_t req_a, old_a;
-    p2m_type_t t;
-    mfn_t mfn;
-    unsigned int page_order;
-    int rc = -EINVAL;
-
-    static const p2m_access_t memaccess[] = {
-#define ACCESS(ac) [XENMEM_access_##ac] = p2m_access_##ac
-        ACCESS(n),
-        ACCESS(r),
-        ACCESS(w),
-        ACCESS(rw),
-        ACCESS(x),
-        ACCESS(rx),
-        ACCESS(wx),
-        ACCESS(rwx),
-#undef ACCESS
-    };
-
-    if ( idx >= MAX_ALTP2M || d->arch.altp2m_eptp[idx] == INVALID_MFN )
-        return rc;
-
-    ap2m = d->arch.altp2m_p2m[idx];
-
-    switch ( access )
-    {
-    case 0 ... ARRAY_SIZE(memaccess) - 1:
-        req_a = memaccess[access];
-        break;
-    case XENMEM_access_default:
-        req_a = ap2m->default_access;
-        break;
-    default:
-        return rc;
-    }
-
-    /* If request to set default access */
-    if ( gfn_x(gfn) == INVALID_GFN )
-    {
-        ap2m->default_access = req_a;
-        return 0;
-    }
-
-    hp2m = p2m_get_hostp2m(d);
-
-    p2m_lock(ap2m);
-
-    mfn = ap2m->get_entry(ap2m, gfn_x(gfn), &t, &old_a, 0, NULL, NULL);
-
-    /* Check host p2m if no valid entry in alternate */
-    if ( !mfn_valid(mfn) )
-    {
-        mfn = hp2m->get_entry(hp2m, gfn_x(gfn), &t, &old_a,
-                              P2M_ALLOC | P2M_UNSHARE, &page_order, NULL);
-
-        if ( !mfn_valid(mfn) || t != p2m_ram_rw )
-            goto out;
-
-        /* If this is a superpage, copy that first */
-        if ( page_order != PAGE_ORDER_4K )
-        {
-            gfn_t gfn2;
-            unsigned long mask;
-            mfn_t mfn2;
-
-            mask = ~((1UL << page_order) - 1);
-            gfn2 = _gfn(gfn_x(gfn) & mask);
-            mfn2 = _mfn(mfn_x(mfn) & mask);
-
-            if ( ap2m->set_entry(ap2m, gfn_x(gfn2), mfn2, page_order, t, old_a, 1) )
-                goto out;
-        }
-    }
-
-    if ( !ap2m->set_entry(ap2m, gfn_x(gfn), mfn, PAGE_ORDER_4K, t, req_a,
-                          (current->domain != d)) )
-        rc = 0;
-
- out:
-    p2m_unlock(ap2m);
-    return rc;
-}
-
 int p2m_change_altp2m_gfn(struct domain *d, unsigned int idx,
                           gfn_t old_gfn, gfn_t new_gfn)
 {
diff --git a/xen/common/mem_access.c b/xen/common/mem_access.c
index 159c036..0411443 100644
--- a/xen/common/mem_access.c
+++ b/xen/common/mem_access.c
@@ -67,7 +67,7 @@ int mem_access_memop(unsigned long cmd,
             break;
 
         rc = p2m_set_mem_access(d, _gfn(mao.pfn), mao.nr, start_iter,
-                                MEMOP_CMD_MASK, mao.access);
+                                MEMOP_CMD_MASK, mao.access, mao.altp2m_idx);
         if ( rc > 0 )
         {
             ASSERT(!(rc & MEMOP_CMD_MASK));
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index fa46dd9..c0df1ea 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -808,10 +808,6 @@ int p2m_destroy_altp2m_by_id(struct domain *d, unsigned int idx);
 /* Switch alternate p2m for entire domain */
 int p2m_switch_domain_altp2m_by_id(struct domain *d, unsigned int idx);
 
-/* Set access type for a gfn */
-int p2m_set_altp2m_mem_access(struct domain *d, unsigned int idx,
-                              gfn_t gfn, xenmem_access_t access);
-
 /* Change a gfn->mfn mapping */
 int p2m_change_altp2m_gfn(struct domain *d, unsigned int idx,
                           gfn_t old_gfn, gfn_t new_gfn);
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 4df38d6..30ccb41 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -423,11 +423,14 @@ struct xen_mem_access_op {
     /* xenmem_access_t */
     uint8_t access;
     domid_t domid;
+    uint16_t altp2m_idx;
+    uint16_t _pad;
     /*
      * Number of pages for set op
      * Ignored on setting default access and other ops
      */
     uint32_t nr;
+    uint32_t _pad2;
     /*
      * First pfn for set op
      * pfn for get op
diff --git a/xen/include/xen/p2m-common.h b/xen/include/xen/p2m-common.h
index 47c40c7..8b70459 100644
--- a/xen/include/xen/p2m-common.h
+++ b/xen/include/xen/p2m-common.h
@@ -49,7 +49,8 @@ int unmap_mmio_regions(struct domain *d,
  * If gfn == INVALID_GFN, sets the default access type.
  */
 long p2m_set_mem_access(struct domain *d, gfn_t gfn, uint32_t nr,
-                        uint32_t start, uint32_t mask, xenmem_access_t access);
+                        uint32_t start, uint32_t mask, xenmem_access_t access,
+                        unsigned int altp2m_idx);
 
 /*
  * Get access type for a gfn.
