[PATCH v2 04/14] x86/mm: split set_identity_p2m_entry() into PV and HVM parts

[Jan Beulich <jbeulich@xxxxxxxx>]

..., moving the former into the new physmap.c. Also call the new
functions directly from arch_iommu_hwdom_init() and
vpci_make_msix_hole(), as the PV/HVM split is explicit there.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: George Dunlap <george.dunlap@xxxxxxxxxx>
---
v2: Change arch_iommu_hwdom_init() and vpci_make_msix_hole().

--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1473,12 +1473,9 @@ static int clear_mmio_p2m_entry(struct d
     return rc;
 }
 
-#endif /* CONFIG_HVM */
-
-int set_identity_p2m_entry(struct domain *d, unsigned long gfn_l,
+int p2m_add_identity_entry(struct domain *d, unsigned long gfn_l,
                            p2m_access_t p2ma, unsigned int flag)
 {
-#ifdef CONFIG_HVM
     p2m_type_t p2mt;
     p2m_access_t a;
     gfn_t gfn = _gfn(gfn_l);
@@ -1488,13 +1485,8 @@ int set_identity_p2m_entry(struct domain
 
     if ( !paging_mode_translate(d) )
     {
-#endif
-        if ( !is_iommu_enabled(d) )
-            return 0;
-        return iommu_legacy_map(d, _dfn(gfn_l), _mfn(gfn_l),
-                                1ul << PAGE_ORDER_4K,
-                                p2m_access_to_iommu_flags(p2ma));
-#ifdef CONFIG_HVM
+        ASSERT_UNREACHABLE();
+        return -EPERM;
     }
 
     gfn_lock(p2m, gfn, 0);
@@ -1520,12 +1512,10 @@ int set_identity_p2m_entry(struct domain
 
     gfn_unlock(p2m, gfn, 0);
     return ret;
-#endif
 }
 
-int clear_identity_p2m_entry(struct domain *d, unsigned long gfn_l)
+int p2m_remove_identity_entry(struct domain *d, unsigned long gfn_l)
 {
-#ifdef CONFIG_HVM
     p2m_type_t p2mt;
     p2m_access_t a;
     gfn_t gfn = _gfn(gfn_l);
@@ -1535,11 +1525,8 @@ int clear_identity_p2m_entry(struct doma
 
     if ( !paging_mode_translate(d) )
     {
-#endif
-        if ( !is_iommu_enabled(d) )
-            return 0;
-        return iommu_legacy_unmap(d, _dfn(gfn_l), 1ul << PAGE_ORDER_4K);
-#ifdef CONFIG_HVM
+        ASSERT_UNREACHABLE();
+        return -EPERM;
     }
 
     gfn_lock(p2m, gfn, 0);
@@ -1561,7 +1548,6 @@ int clear_identity_p2m_entry(struct doma
     }
 
     return ret;
-#endif
 }
 
 #ifdef CONFIG_MEM_SHARING
@@ -1606,8 +1592,6 @@ int set_shared_p2m_entry(struct domain *
 
 #endif /* CONFIG_MEM_SHARING */
 
-#ifdef CONFIG_HVM
-
 static struct p2m_domain *
 p2m_getlru_nestedp2m(struct domain *d, struct p2m_domain *p2m)
 {
--- a/xen/arch/x86/mm/physmap.c
+++ b/xen/arch/x86/mm/physmap.c
@@ -21,6 +21,7 @@
  * along with this program; If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <xen/iommu.h>
 #include <asm/p2m.h>
 
 #include "mm-locks.h"
@@ -75,6 +76,33 @@ guest_physmap_remove_page(struct domain
     return p2m_remove_page(d, gfn, mfn, page_order);
 }
 
+int set_identity_p2m_entry(struct domain *d, unsigned long gfn,
+                           p2m_access_t p2ma, unsigned int flag)
+{
+    if ( !paging_mode_translate(d) )
+    {
+        if ( !is_iommu_enabled(d) )
+            return 0;
+        return iommu_legacy_map(d, _dfn(gfn), _mfn(gfn),
+                                1ul << PAGE_ORDER_4K,
+                                p2m_access_to_iommu_flags(p2ma));
+    }
+
+    return p2m_add_identity_entry(d, gfn, p2ma, flag);
+}
+
+int clear_identity_p2m_entry(struct domain *d, unsigned long gfn)
+{
+    if ( !paging_mode_translate(d) )
+    {
+        if ( !is_iommu_enabled(d) )
+            return 0;
+        return iommu_legacy_unmap(d, _dfn(gfn), 1ul << PAGE_ORDER_4K);
+    }
+
+    return p2m_remove_identity_entry(d, gfn);
+}
+
 /*
  * Local variables:
  * mode: C
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -373,7 +373,7 @@ void __hwdom_init arch_iommu_hwdom_init(
         if ( !hwdom_iommu_map(d, pfn, max_pfn) )
             rc = 0;
         else if ( paging_mode_translate(d) )
-            rc = set_identity_p2m_entry(d, pfn, p2m_access_rw, 0);
+            rc = p2m_add_identity_entry(d, pfn, p2m_access_rw, 0);
         else
             rc = iommu_map(d, _dfn(pfn), _mfn(pfn), 1ul << PAGE_ORDER_4K,
                            IOMMUF_readable | IOMMUF_writable, &flush_flags);
--- a/xen/drivers/vpci/msix.c
+++ b/xen/drivers/vpci/msix.c
@@ -409,7 +409,7 @@ int vpci_make_msix_hole(const struct pci
             case p2m_mmio_direct:
                 if ( mfn_x(mfn) == start )
                 {
-                    clear_identity_p2m_entry(d, start);
+                    p2m_remove_identity_entry(d, start);
                     break;
                 }
                 /* fallthrough. */
--- a/xen/arch/x86/include/asm/p2m.h
+++ b/xen/arch/x86/include/asm/p2m.h
@@ -637,6 +637,10 @@ int set_mmio_p2m_entry(struct domain *d,
 int set_identity_p2m_entry(struct domain *d, unsigned long gfn,
                            p2m_access_t p2ma, unsigned int flag);
 int clear_identity_p2m_entry(struct domain *d, unsigned long gfn);
+/* HVM-only callers can use these directly: */
+int p2m_add_identity_entry(struct domain *d, unsigned long gfn,
+                           p2m_access_t p2ma, unsigned int flag);
+int p2m_remove_identity_entry(struct domain *d, unsigned long gfn);
 
 /* 
  * Populate-on-demand