[PATCH v7 07/10] xen/common: move the memory_mapping DOMCTL hypercall to common code

[Arianna Avanzini <avanzini.arianna@gmail.com>]

This commit moves to common code the implementation of the memory_mapping
DOMCTL, currently available only for the x86 architecture. This commit
also adds to ARM-related code an unmap_mmio_regions() function to match
the corresponding one available for x86.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Cc: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Paolo Valente <paolo.valente@unimore.it>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Julien Grall <julien.grall@citrix.com>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Eric Trudeau <etrudeau@broadcom.com>
Cc: Viktor Kleinik <viktor.kleinik@globallogic.com>

---

    v7:
        - Change the name of tmp_rc to rc. Also, do not uselessly initialize it.
        - ifdef out the invocation of memory_type_changed() to be called only
          if the architecture is x86 instead of adding an useless empty stub
          for ARM.

    v6:
        - Pass p2m_invalid as last parameter to unmap_mmio_regions() for ARM
          as it is not (and currently must not be) used.
        - Add an empty definition of the memory_type_changed() function for ARM.

    v5:
        - Rename new header to p2m-common.h.

    v4:
        - Use a define for paddr_bits instead of a new variable.
        - Define prototypes for common functions map_mmio_regions() and
          unmap_mmio_regions() only once in a common header.

    v3:
        - Add a paddr_bits variable for ARM.

    v2:
        - Move code to xen/arm/domctl.c.

---
 xen/arch/arm/p2m.c           | 12 ++++++++
 xen/arch/x86/domctl.c        | 69 ------------------------------------------
 xen/common/domctl.c          | 71 ++++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/p2m.h    | 13 ++++----
 xen/include/asm-x86/p2m.h    | 13 +-------
 xen/include/xen/p2m-common.h | 16 ++++++++++
 6 files changed, 106 insertions(+), 88 deletions(-)
 create mode 100644 xen/include/xen/p2m-common.h

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 2c7f542..d2568ad 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -521,6 +521,18 @@ int map_mmio_regions(struct domain *d,
                              MATTR_DEV, p2m_mmio_direct);
 }
 
+int unmap_mmio_regions(struct domain *d,
+                       unsigned long start_gfn,
+                       unsigned long nr_mfns,
+                       unsigned long mfn)
+{
+    return apply_p2m_changes(d, REMOVE,
+                             pfn_to_paddr(start_gfn),
+                             pfn_to_paddr(start_gfn + nr_mfns + 1),
+                             pfn_to_paddr(mfn),
+                             MATTR_DEV, p2m_invalid);
+}
+
 int guest_physmap_add_entry(struct domain *d,
                             unsigned long gpfn,
                             unsigned long mfn,
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index daaa371..55f0605 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -641,75 +641,6 @@ long arch_do_domctl(
     }
     break;
 
-    case XEN_DOMCTL_memory_mapping:
-    {
-        unsigned long gfn = domctl->u.memory_mapping.first_gfn;
-        unsigned long mfn = domctl->u.memory_mapping.first_mfn;
-        unsigned long nr_mfns = domctl->u.memory_mapping.nr_mfns;
-        unsigned long mfn_end = mfn + nr_mfns - 1;
-        unsigned long gfn_end = gfn + nr_mfns - 1;
-        int add = domctl->u.memory_mapping.add_mapping;
-
-        ret = -EINVAL;
-        if ( mfn_end < mfn || /* wrap? */
-             ((mfn | mfn_end) >> (paddr_bits - PAGE_SHIFT)) ||
-             gfn_end < gfn ) /* wrap? */
-            break;
-
-        ret = -EPERM;
-        if ( !iomem_access_permitted(current->domain, mfn, mfn_end) )
-            break;
-
-        ret = xsm_iomem_mapping(XSM_HOOK, d, mfn, mfn_end, add);
-        if ( ret )
-            break;
-
-        if ( add )
-        {
-            printk(XENLOG_G_INFO
-                   "memory_map:add: dom%d gfn=%lx mfn=%lx nr=%lx\n",
-                   d->domain_id, gfn, mfn, nr_mfns);
-
-            ret = iomem_permit_access(d, mfn, mfn_end);
-            if ( !ret )
-            {
-                ret = map_mmio_regions(d, gfn, nr_mfns, _mfn(mfn));
-                if ( ret )
-                {
-                    printk(XENLOG_G_WARNING
-                           "memory_map:fail: dom%d gfn=%lx mfn=%lx ret:%ld\n",
-                           d->domain_id, gfn, mfn, ret);
-                    if ( iomem_deny_access(d, mfn, mfn_end) &&
-                         is_hardware_domain(current->domain) )
-                        printk(XENLOG_ERR
-                               "memory_map: failed to deny dom%d access to [%lx,%lx]\n",
-                               d->domain_id, mfn, mfn_end);
-                }
-            }
-        }
-        else
-        {
-            int rc;
-
-            printk(XENLOG_G_INFO
-                   "memory_map:remove: dom%d gfn=%lx mfn=%lx nr=%lx\n",
-                   d->domain_id, gfn, mfn, nr_mfns);
-
-            rc = unmap_mmio_regions(d, gfn, nr_mfns, _mfn(mfn));
-            ret = iomem_deny_access(d, mfn, mfn_end);
-            if ( !ret )
-                ret = rc;
-            if ( ret && is_hardware_domain(current->domain) )
-                printk(XENLOG_ERR
-                       "memory_map: error %ld %s dom%d access to [%lx,%lx]\n",
-                       ret, rc ? "removing" : "denying", d->domain_id,
-                       mfn, mfn_end);
-        }
-        /* Do this unconditionally to cover errors on above failure paths. */
-        memory_type_changed(d);
-    }
-    break;
-
     case XEN_DOMCTL_ioport_mapping:
     {
 #define MAX_IOPORTS    0x10000
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index af3614b..866338b 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -822,6 +822,77 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
     }
     break;
 
+    case XEN_DOMCTL_memory_mapping:
+    {
+        unsigned long gfn = op->u.memory_mapping.first_gfn;
+        unsigned long mfn = op->u.memory_mapping.first_mfn;
+        unsigned long nr_mfns = op->u.memory_mapping.nr_mfns;
+        unsigned long mfn_end = mfn + nr_mfns - 1;
+        unsigned long gfn_end = gfn + nr_mfns - 1;
+        int add = op->u.memory_mapping.add_mapping;
+
+        ret = -EINVAL;
+        if ( mfn_end < mfn || /* wrap? */
+             ((mfn | mfn_end) >> (paddr_bits - PAGE_SHIFT)) ||
+             gfn_end < gfn ) /* wrap? */
+            break;
+
+        ret = -EPERM;
+        if ( !iomem_access_permitted(current->domain, mfn, mfn_end) )
+            break;
+
+        ret = xsm_iomem_mapping(XSM_HOOK, d, mfn, mfn_end, add);
+        if ( ret )
+            break;
+
+        if ( add )
+        {
+            printk(XENLOG_G_INFO
+                   "memory_map:add: dom%d gfn=%lx mfn=%lx nr=%lx\n",
+                   d->domain_id, gfn, mfn, nr_mfns);
+
+            ret = iomem_permit_access(d, mfn, mfn_end);
+            if ( !ret )
+            {
+                ret = map_mmio_regions(d, gfn, nr_mfns, _mfn(mfn));
+                if ( ret )
+                {
+                    printk(XENLOG_G_WARNING
+                           "memory_map:fail: dom%d gfn=%lx mfn=%lx ret:%ld\n",
+                           d->domain_id, gfn, mfn, ret);
+                    if ( iomem_deny_access(d, mfn, mfn_end) &&
+                         is_hardware_domain(current->domain) )
+                        printk(XENLOG_ERR
+                               "memory_map: failed to deny dom%d access to [%lx,%lx]\n",
+                               d->domain_id, mfn, mfn_end);
+                }
+            }
+        }
+        else
+        {
+            int rc;
+
+            printk(XENLOG_G_INFO
+                   "memory_map:remove: dom%d gfn=%lx mfn=%lx nr=%lx\n",
+                   d->domain_id, gfn, mfn, nr_mfns);
+
+            rc = unmap_mmio_regions(d, gfn, nr_mfns, _mfn(mfn));
+            ret = iomem_deny_access(d, mfn, mfn_end);
+            if ( !ret )
+                ret = rc;
+            if ( ret && is_hardware_domain(current->domain) )
+                printk(XENLOG_ERR
+                       "memory_map: error %ld %s dom%d access to [%lx,%lx]\n",
+                       ret, rc ? "removing" : "denying", d->domain_id,
+                       mfn, mfn_end);
+        }
+#ifdef CONFIG_X86
+        /* Do this unconditionally to cover errors on above failure paths. */
+        memory_type_changed(d);
+#endif
+    }
+    break;
+
     case XEN_DOMCTL_settimeoffset:
     {
         domain_set_time_offset(d, op->u.settimeoffset.time_offset_seconds);
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index 6d56daa..5e135bf 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -3,6 +3,12 @@
 
 #include <xen/mm.h>
 
+#define mfn_t unsigned long
+#include <xen/p2m-common.h>
+
+#define paddr_bits PADDR_BITS
+#define _mfn(pfn) (pfn)
+
 struct domain;
 
 /* Per-p2m-table state */
@@ -84,13 +90,6 @@ int p2m_cache_flush(struct domain *d, xen_pfn_t start_mfn, xen_pfn_t end_mfn);
 
 /* Setup p2m RAM mapping for domain d from start-end. */
 int p2m_populate_ram(struct domain *d, paddr_t start, paddr_t end);
-/* Map MMIO regions in the p2m: start_gfn and nr_mfns describe the range
- * in the guest physical address space to map, starting from the machine
- * frame number mfn. */
-int map_mmio_regions(struct domain *d,
-                     unsigned long start_gfn,
-                     unsigned long nr_mfns,
-                     unsigned long mfn);
 
 int guest_physmap_add_entry(struct domain *d,
                             unsigned long gfn,
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index e712916..9b0f08b 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -29,21 +29,10 @@
 
 #include <xen/config.h>
 #include <xen/paging.h>
+#include <xen/p2m-common.h>
 #include <asm/mem_sharing.h>
 #include <asm/page.h>    /* for pagetable_t */
 
-/* Map MMIO regions in the p2m: start_gfn and nr_mfns describe the range
- * in the guest physical address space to map, starting from the machine
- * frame number mfn. */
-int map_mmio_regions(struct domain *d,
-                     unsigned long start_gfn,
-                     unsigned long nr_mfns,
-                     mfn_t mfn);
-int unmap_mmio_regions(struct domain *d,
-                       unsigned long start_gfn,
-                       unsigned long nr_mfns,
-                       mfn_t mfn);
-
 extern bool_t opt_hap_1gb, opt_hap_2mb;
 
 /*
diff --git a/xen/include/xen/p2m-common.h b/xen/include/xen/p2m-common.h
new file mode 100644
index 0000000..8760b9d
--- /dev/null
+++ b/xen/include/xen/p2m-common.h
@@ -0,0 +1,16 @@
+#ifndef _XEN_P2M_COMMON_H
+#define _XEN_P2M_COMMON_H
+
+/* Map MMIO regions in the p2m: start_gfn and nr_mfns describe the range
+ * in the guest physical address space to map, starting from the machine
+ * frame number mfn. */
+int map_mmio_regions(struct domain *d,
+                     unsigned long start_gfn,
+                     unsigned long nr_mfns,
+                     mfn_t mfn);
+int unmap_mmio_regions(struct domain *d,
+                       unsigned long start_gfn,
+                       unsigned long nr_mfns,
+                       mfn_t mfn);
+
+#endif /* _XEN_P2M_COMMON_H */
-- 
1.9.2