[PATCH 13/17] PVH xen: p2m related changes.

[Mukesh Rathor <mukesh.rathor@oracle.com>]

In this patch, I introduce  a new type p2m_map_foreign for pages that a
dom0 maps from foreign domains its creating. Also, add
set_foreign_p2m_entry() to map p2m_map_foreign type pages. Other misc changes
related to p2m.

Changes in V2:
   - Make guest_physmap_add_entry() same for PVH in terms of overwriting old
     entry.
   - In set_foreign_p2m_entry() do locked get_gfn and not unlocked.
   - Replace ASSERT with return -EINVAL in do_physdev_op.
   - Remove unnecessary check for PVH in do_physdev_op().

Changes in V3:
   - remove changes unrelated to this patch.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
---
 xen/arch/x86/domctl.c     |   14 ++++++++------
 xen/arch/x86/mm/p2m-ept.c |    3 ++-
 xen/arch/x86/mm/p2m-pt.c  |    3 ++-
 xen/arch/x86/mm/p2m.c     |   31 ++++++++++++++++++++++++++++++-
 xen/include/asm-x86/p2m.h |    4 ++++
 5 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 88fe868..dc161c7 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -68,9 +68,10 @@ long domctl_memory_mapping(struct domain *d, unsigned long gfn,
 
     if ( add_map )
     {
-        printk(XENLOG_G_INFO
-               "memory_map:add: dom%d gfn=%lx mfn=%lx nr=%lx\n",
-               d->domain_id, gfn, mfn, nr_mfns);
+        if ( !is_pvh_domain(d) )     /* PVH maps lots and lots */
+            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 + nr_mfns - 1);
         if ( !ret && paging_mode_translate(d) )
@@ -93,9 +94,10 @@ long domctl_memory_mapping(struct domain *d, unsigned long gfn,
             }
         }
     } else {
-        printk(XENLOG_G_INFO
-               "memory_map:remove: dom%d gfn=%lx mfn=%lx nr=%lx\n",
-               d->domain_id, gfn, mfn, nr_mfns);
+        if ( !is_pvh_domain(d) )     /* PVH unmaps lots and lots */
+            printk(XENLOG_G_INFO
+                   "memory_map:remove: dom%d gfn=%lx mfn=%lx nr=%lx\n",
+                   d->domain_id, gfn, mfn, nr_mfns);
 
         if ( paging_mode_translate(d) )
             for ( i = 0; i < nr_mfns; i++ )
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 595c6e7..cb8c2df 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -75,6 +75,7 @@ static void ept_p2m_type_to_flags(ept_entry_t *entry, p2m_type_t type, p2m_acces
             entry->w = 0;
             break;
         case p2m_grant_map_rw:
+        case p2m_map_foreign:
             entry->r = entry->w = 1;
             entry->x = 0;
             break;
@@ -431,7 +432,7 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn,
     }
 
     /* Track the highest gfn for which we have ever had a valid mapping */
-    if ( p2mt != p2m_invalid &&
+    if ( p2mt != p2m_invalid && p2mt != p2m_mmio_dm &&
          (gfn + (1UL << order) - 1 > p2m->max_mapped_pfn) )
         p2m->max_mapped_pfn = gfn + (1UL << order) - 1;
 
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index 302b621..3f46418 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -89,6 +89,7 @@ static unsigned long p2m_type_to_flags(p2m_type_t t, mfn_t mfn)
     case p2m_ram_rw:
         return flags | P2M_BASE_FLAGS | _PAGE_RW;
     case p2m_grant_map_rw:
+    case p2m_map_foreign:
         return flags | P2M_BASE_FLAGS | _PAGE_RW | _PAGE_NX_BIT;
     case p2m_mmio_direct:
         if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn_x(mfn)) )
@@ -429,7 +430,7 @@ p2m_set_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn,
     }
 
     /* Track the highest gfn for which we have ever had a valid mapping */
-    if ( p2mt != p2m_invalid
+    if ( p2mt != p2m_invalid && p2mt != p2m_mmio_dm
          && (gfn + (1UL << page_order) - 1 > p2m->max_mapped_pfn) )
         p2m->max_mapped_pfn = gfn + (1UL << page_order) - 1;
 
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index f5ddd20..17cb78f 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -523,7 +523,7 @@ p2m_remove_page(struct p2m_domain *p2m, unsigned long gfn, unsigned long mfn,
         for ( i = 0; i < (1UL << page_order); i++ )
         {
             mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, 0, NULL);
-            if ( !p2m_is_grant(t) && !p2m_is_shared(t) )
+            if ( !p2m_is_grant(t) && !p2m_is_shared(t) && !p2m_is_foreign(t) )
                 set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY);
             ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) );
         }
@@ -754,7 +754,36 @@ void p2m_change_type_range(struct domain *d,
     p2m_unlock(p2m);
 }
 
+/* Returns: True for success. 0 for failure */
+int set_foreign_p2m_entry(struct domain *dp, unsigned long gfn, mfn_t mfn)
+{
+    int rc = 0;
+    p2m_type_t ot;
+    mfn_t omfn;
+    struct p2m_domain *p2m = p2m_get_hostp2m(dp);
 
+    if ( !paging_mode_translate(dp) )
+        return 0;
+
+    omfn = get_gfn_query(dp, gfn, &ot);
+    if ( mfn_valid(omfn) )
+    {
+        gdprintk(XENLOG_ERR, "Already mapped mfn %lx at gfn:%lx\n",
+                 mfn_x(omfn), gfn);
+        set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
+    }
+    put_gfn(dp, gfn);
+
+    P2M_DEBUG("set foreign %lx %lx\n", gfn, mfn_x(mfn));
+    p2m_lock(p2m);
+    rc = set_p2m_entry(p2m, gfn, mfn, 0, p2m_map_foreign, p2m->default_access);
+    p2m_unlock(p2m);
+    if ( rc == 0 )
+        gdprintk(XENLOG_ERR,
+            "set_foreign_p2m_entry: set_p2m_entry failed! gfn:%lx mfn=%08lx\n",
+            gfn, mfn_x(get_gfn_query(dp, gfn, &ot)));
+    return rc;
+}
 
 int
 set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 43583b2..b76dc33 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -70,6 +70,7 @@ typedef enum {
     p2m_ram_paging_in = 11,       /* Memory that is being paged in */
     p2m_ram_shared = 12,          /* Shared or sharable memory */
     p2m_ram_broken = 13,          /* Broken page, access cause domain crash */
+    p2m_map_foreign  = 14,        /* ram pages from foreign domain */
 } p2m_type_t;
 
 /*
@@ -180,6 +181,7 @@ typedef unsigned int p2m_query_t;
 #define p2m_is_sharable(_t) (p2m_to_mask(_t) & P2M_SHARABLE_TYPES)
 #define p2m_is_shared(_t)   (p2m_to_mask(_t) & P2M_SHARED_TYPES)
 #define p2m_is_broken(_t)   (p2m_to_mask(_t) & P2M_BROKEN_TYPES)
+#define p2m_is_foreign(_t)  (p2m_to_mask(_t) & p2m_to_mask(p2m_map_foreign))
 
 /* Per-p2m-table state */
 struct p2m_domain {
@@ -510,6 +512,8 @@ p2m_type_t p2m_change_type(struct domain *d, unsigned long gfn,
 int set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn);
 int clear_mmio_p2m_entry(struct domain *d, unsigned long gfn);
 
+/* Set foreign mfn in the current guest's p2m table (for pvh dom0) */
+int set_foreign_p2m_entry(struct domain *domp, unsigned long gfn, mfn_t mfn);
 
 /* 
  * Populate-on-demand
-- 
1.7.2.3