[Xen-devel] [PATCH V2 2/3] x86/mm: allocate logdirty_ranges for altp2ms

[Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>]

This patch is a pre-requisite for the one fixing VGA logdirty
freezes when using altp2m. It only concerns itself with the
ranges allocation / deallocation / initialization part. While
touching the code, I've switched global_logdirty from bool_t
to bool.

Signed-off-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
---
 xen/arch/x86/mm/p2m-ept.c         | 15 ++++++++++-
 xen/arch/x86/mm/p2m.c             | 55 ++++++++++++++++++++++++++-------------
 xen/include/asm-x86/hvm/vmx/vmx.h |  2 +-
 xen/include/asm-x86/p2m.h         |  5 +++-
 4 files changed, 56 insertions(+), 21 deletions(-)

diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index fabcd06..989917c 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -1348,6 +1348,8 @@ int ept_p2m_init(struct p2m_domain *p2m)
 void ept_p2m_uninit(struct p2m_domain *p2m)
 {
     struct ept_data *ept = &p2m->ept;
+
+    p2m_free_logdirty(p2m);
     free_cpumask_var(ept->invalidate);
 }
 
@@ -1434,11 +1436,20 @@ void setup_ept_dump(void)
     register_keyhandler('D', ept_dump_p2m_table, "dump VT-x EPT tables", 0);
 }
 
-void p2m_init_altp2m_ept(struct domain *d, unsigned int i)
+int p2m_init_altp2m_ept(struct domain *d, unsigned int i)
 {
     struct p2m_domain *p2m = d->arch.altp2m_p2m[i];
     struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
     struct ept_data *ept;
+    int rc = p2m_init_logdirty(p2m);
+
+    if ( rc )
+        return rc;
+
+    rc = rangeset_merge(p2m->logdirty_ranges, hostp2m->logdirty_ranges);
+
+    if ( rc )
+        return rc;
 
     p2m->ept.ad = hostp2m->ept.ad;
     p2m->min_remapped_gfn = gfn_x(INVALID_GFN);
@@ -1446,6 +1457,8 @@ void p2m_init_altp2m_ept(struct domain *d, unsigned int i)
     ept = &p2m->ept;
     ept->mfn = pagetable_get_pfn(p2m_get_pagetable(p2m));
     d->arch.altp2m_eptp[i] = ept->eptp;
+
+    return 0;
 }
 
 unsigned int p2m_find_altp2m_by_eptp(struct domain *d, uint64_t eptp)
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 42b9ef4..b37db06 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -113,22 +113,44 @@ static void p2m_free_one(struct p2m_domain *p2m)
     xfree(p2m);
 }
 
+int p2m_init_logdirty(struct p2m_domain *p2m)
+{
+    if ( p2m->logdirty_ranges )
+        return 0;
+
+    p2m->logdirty_ranges = rangeset_new(p2m->domain, "log-dirty",
+                                        RANGESETF_prettyprint_hex);
+    if ( !p2m->logdirty_ranges )
+        return -ENOMEM;
+
+    return 0;
+}
+
+void p2m_free_logdirty(struct p2m_domain *p2m)
+{
+    if ( !p2m->logdirty_ranges )
+        return;
+
+    rangeset_destroy(p2m->logdirty_ranges);
+    p2m->logdirty_ranges = NULL;
+}
+
 static int p2m_init_hostp2m(struct domain *d)
 {
     struct p2m_domain *p2m = p2m_init_one(d);
+    int rc;
 
-    if ( p2m )
-    {
-        p2m->logdirty_ranges = rangeset_new(d, "log-dirty",
-                                            RANGESETF_prettyprint_hex);
-        if ( p2m->logdirty_ranges )
-        {
-            d->arch.p2m = p2m;
-            return 0;
-        }
+    if ( !p2m )
+        return -ENOMEM;
+
+    rc = p2m_init_logdirty(p2m);
+
+    if ( !rc )
+        d->arch.p2m = p2m;
+    else
         p2m_free_one(p2m);
-    }
-    return -ENOMEM;
+
+    return rc;
 }
 
 static void p2m_teardown_hostp2m(struct domain *d)
@@ -138,7 +160,7 @@ static void p2m_teardown_hostp2m(struct domain *d)
 
     if ( p2m )
     {
-        rangeset_destroy(p2m->logdirty_ranges);
+        p2m_free_logdirty(p2m);
         p2m_free_one(p2m);
         d->arch.p2m = NULL;
     }
@@ -194,6 +216,7 @@ static void p2m_teardown_altp2m(struct domain *d)
             continue;
         p2m = d->arch.altp2m_p2m[i];
         d->arch.altp2m_p2m[i] = NULL;
+        p2m_free_logdirty(p2m);
         p2m_free_one(p2m);
     }
 }
@@ -2289,10 +2312,7 @@ int p2m_init_altp2m_by_id(struct domain *d, unsigned int 
idx)
     altp2m_list_lock(d);
 
     if ( d->arch.altp2m_eptp[idx] == mfn_x(INVALID_MFN) )
-    {
-        p2m_init_altp2m_ept(d, idx);
-        rc = 0;
-    }
+        rc = p2m_init_altp2m_ept(d, idx);
 
     altp2m_list_unlock(d);
     return rc;
@@ -2310,9 +2330,8 @@ int p2m_init_next_altp2m(struct domain *d, uint16_t *idx)
         if ( d->arch.altp2m_eptp[i] != mfn_x(INVALID_MFN) )
             continue;
 
-        p2m_init_altp2m_ept(d, i);
+        rc = p2m_init_altp2m_ept(d, i);
         *idx = i;
-        rc = 0;
 
         break;
     }
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h 
b/xen/include/asm-x86/hvm/vmx/vmx.h
index b110e16..19730c7 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -598,7 +598,7 @@ void ept_p2m_uninit(struct p2m_domain *p2m);
 void ept_walk_table(struct domain *d, unsigned long gfn);
 bool_t ept_handle_misconfig(uint64_t gpa);
 void setup_ept_dump(void);
-void p2m_init_altp2m_ept(struct domain *d, unsigned int i);
+int p2m_init_altp2m_ept(struct domain *d, unsigned int i);
 /* Locate an alternate p2m by its EPTP */
 unsigned int p2m_find_altp2m_by_eptp(struct domain *d, uint64_t eptp);
 
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index d08c595..aa52212 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -223,7 +223,7 @@ struct p2m_domain {
     struct rangeset   *logdirty_ranges;
 
     /* Host p2m: Global log-dirty mode enabled for the domain. */
-    bool_t             global_logdirty;
+    bool               global_logdirty;
 
     /* Host p2m: when this flag is set, don't flush all the nested-p2m 
      * tables on every host-p2m change.  The setter of this flag 
@@ -581,6 +581,9 @@ int p2m_alloc_table(struct p2m_domain *p2m);
 void p2m_teardown(struct p2m_domain *p2m);
 void p2m_final_teardown(struct domain *d);
 
+int p2m_init_logdirty(struct p2m_domain *p2m);
+void p2m_free_logdirty(struct p2m_domain *p2m);
+
 /* Add a page to a domain's p2m table */
 int guest_physmap_add_entry(struct domain *d, gfn_t gfn,
                             mfn_t mfn, unsigned int page_order,
-- 
2.7.4


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