[PATCH] x86/mm: split struct sh_dirty_vram and make results private

[Jan Beulich <jbeulich@xxxxxxxx>]

The types are local to the shadow and HAP subsystems respectively, and
HAP has no need for the shadow-specific fields (i.e. it can get away with
smaller allocations). In struct hvm_domain it therefore suffices to have
a union of two (generally opaque) pointers.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/include/asm/hvm/domain.h
+++ b/xen/arch/x86/include/asm/hvm/domain.h
@@ -95,7 +95,10 @@ struct hvm_domain {
     struct list_head       pinned_cacheattr_ranges;
 
     /* VRAM dirty support.  Protect with the domain paging lock. */
-    struct sh_dirty_vram *dirty_vram;
+    union {
+        struct sh_dirty_vram *sh;
+        struct hap_dirty_vram *hap;
+    }                      dirty_vram;
 
     /* If one of vcpus of this domain is in no_fill_mode or
      * mtrr/pat between vcpus is not the same, set is_in_uc_mode
--- a/xen/arch/x86/include/asm/paging.h
+++ b/xen/arch/x86/include/asm/paging.h
@@ -133,19 +133,6 @@ struct paging_mode {
     (DIV_ROUND_UP(PADDR_BITS - PAGE_SHIFT - (PAGE_SHIFT + 3), \
                   PAGE_SHIFT - ilog2(sizeof(mfn_t))) + 1)
 
-#ifdef CONFIG_HVM
-/* VRAM dirty tracking support */
-struct sh_dirty_vram {
-    unsigned long begin_pfn;
-    unsigned long end_pfn;
-#ifdef CONFIG_SHADOW_PAGING
-    paddr_t *sl1ma;
-    uint8_t *dirty_bitmap;
-    s_time_t last_dirty;
-#endif
-};
-#endif
-
 #if PG_log_dirty
 
 /* log dirty initialization */
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -36,6 +36,11 @@
 /*          HAP VRAM TRACKING SUPPORT           */
 /************************************************/
 
+struct hap_dirty_vram {
+    unsigned long begin_pfn;
+    unsigned long end_pfn;
+};
+
 /*
  * hap_track_dirty_vram()
  * Create the domain's dv_dirty_vram struct on demand.
@@ -52,7 +57,7 @@ int hap_track_dirty_vram(struct domain *
                          XEN_GUEST_HANDLE(void) guest_dirty_bitmap)
 {
     long rc = 0;
-    struct sh_dirty_vram *dirty_vram;
+    struct hap_dirty_vram *dirty_vram;
     uint8_t *dirty_bitmap = NULL;
 
     if ( nr_frames )
@@ -66,17 +71,17 @@ int hap_track_dirty_vram(struct domain *
 
         paging_lock(d);
 
-        dirty_vram = d->arch.hvm.dirty_vram;
+        dirty_vram = d->arch.hvm.dirty_vram.hap;
         if ( !dirty_vram )
         {
             rc = -ENOMEM;
-            if ( (dirty_vram = xzalloc(struct sh_dirty_vram)) == NULL )
+            if ( (dirty_vram = xzalloc(struct hap_dirty_vram)) == NULL )
             {
                 paging_unlock(d);
                 goto out;
             }
 
-            d->arch.hvm.dirty_vram = dirty_vram;
+            d->arch.hvm.dirty_vram.hap = dirty_vram;
         }
 
         if ( begin_pfn != dirty_vram->begin_pfn ||
@@ -132,7 +137,7 @@ int hap_track_dirty_vram(struct domain *
     {
         paging_lock(d);
 
-        dirty_vram = d->arch.hvm.dirty_vram;
+        dirty_vram = d->arch.hvm.dirty_vram.hap;
         if ( dirty_vram )
         {
             /*
@@ -142,7 +147,7 @@ int hap_track_dirty_vram(struct domain *
             begin_pfn = dirty_vram->begin_pfn;
             nr_frames = dirty_vram->end_pfn - dirty_vram->begin_pfn;
             xfree(dirty_vram);
-            d->arch.hvm.dirty_vram = NULL;
+            d->arch.hvm.dirty_vram.hap = NULL;
         }
 
         paging_unlock(d);
@@ -630,7 +635,7 @@ void hap_teardown(struct domain *d, bool
 
     d->arch.paging.mode &= ~PG_log_dirty;
 
-    XFREE(d->arch.hvm.dirty_vram);
+    XFREE(d->arch.hvm.dirty_vram.hap);
 
 out:
     paging_unlock(d);
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -2886,11 +2886,11 @@ void shadow_teardown(struct domain *d, b
     d->arch.paging.mode &= ~PG_log_dirty;
 
 #ifdef CONFIG_HVM
-    if ( is_hvm_domain(d) && d->arch.hvm.dirty_vram )
+    if ( is_hvm_domain(d) && d->arch.hvm.dirty_vram.sh )
     {
-        xfree(d->arch.hvm.dirty_vram->sl1ma);
-        xfree(d->arch.hvm.dirty_vram->dirty_bitmap);
-        XFREE(d->arch.hvm.dirty_vram);
+        xfree(d->arch.hvm.dirty_vram.sh->sl1ma);
+        xfree(d->arch.hvm.dirty_vram.sh->dirty_bitmap);
+        XFREE(d->arch.hvm.dirty_vram.sh);
     }
 #endif
 
--- a/xen/arch/x86/mm/shadow/hvm.c
+++ b/xen/arch/x86/mm/shadow/hvm.c
@@ -1033,7 +1033,7 @@ int shadow_track_dirty_vram(struct domai
     p2m_lock(p2m_get_hostp2m(d));
     paging_lock(d);
 
-    dirty_vram = d->arch.hvm.dirty_vram;
+    dirty_vram = d->arch.hvm.dirty_vram.sh;
 
     if ( dirty_vram && (!nr_frames ||
              ( begin_pfn != dirty_vram->begin_pfn
@@ -1043,8 +1043,8 @@ int shadow_track_dirty_vram(struct domai
         gdprintk(XENLOG_INFO, "stopping tracking VRAM %lx - %lx\n", 
dirty_vram->begin_pfn, dirty_vram->end_pfn);
         xfree(dirty_vram->sl1ma);
         xfree(dirty_vram->dirty_bitmap);
-        xfree(dirty_vram);
-        dirty_vram = d->arch.hvm.dirty_vram = NULL;
+        XFREE(dirty_vram);
+        d->arch.hvm.dirty_vram.sh = NULL;
     }
 
     if ( !nr_frames )
@@ -1075,7 +1075,7 @@ int shadow_track_dirty_vram(struct domai
             goto out;
         dirty_vram->begin_pfn = begin_pfn;
         dirty_vram->end_pfn = end_pfn;
-        d->arch.hvm.dirty_vram = dirty_vram;
+        d->arch.hvm.dirty_vram.sh = dirty_vram;
 
         if ( (dirty_vram->sl1ma = xmalloc_array(paddr_t, nr_frames)) == NULL )
             goto out_dirty_vram;
@@ -1202,8 +1202,8 @@ int shadow_track_dirty_vram(struct domai
  out_sl1ma:
     xfree(dirty_vram->sl1ma);
  out_dirty_vram:
-    xfree(dirty_vram);
-    dirty_vram = d->arch.hvm.dirty_vram = NULL;
+    XFREE(dirty_vram);
+    d->arch.hvm.dirty_vram.sh = NULL;
 
  out:
     paging_unlock(d);
@@ -1226,7 +1226,7 @@ void shadow_vram_get_mfn(mfn_t mfn, unsi
                          const struct domain *d)
 {
     unsigned long gfn;
-    struct sh_dirty_vram *dirty_vram = d->arch.hvm.dirty_vram;
+    struct sh_dirty_vram *dirty_vram = d->arch.hvm.dirty_vram.sh;
 
     ASSERT(is_hvm_domain(d));
 
@@ -1256,7 +1256,7 @@ void shadow_vram_put_mfn(mfn_t mfn, unsi
                          const struct domain *d)
 {
     unsigned long gfn;
-    struct sh_dirty_vram *dirty_vram = d->arch.hvm.dirty_vram;
+    struct sh_dirty_vram *dirty_vram = d->arch.hvm.dirty_vram.sh;
 
     ASSERT(is_hvm_domain(d));
 
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -608,7 +608,7 @@ _sh_propagate(struct vcpu *v,
 #ifdef CONFIG_HVM
     if ( unlikely(level == 1) && is_hvm_domain(d) )
     {
-        struct sh_dirty_vram *dirty_vram = d->arch.hvm.dirty_vram;
+        struct sh_dirty_vram *dirty_vram = d->arch.hvm.dirty_vram.sh;
 
         if ( dirty_vram && dirty_vram->last_dirty == -1 &&
              gfn_x(target_gfn) >= dirty_vram->begin_pfn &&
--- a/xen/arch/x86/mm/shadow/private.h
+++ b/xen/arch/x86/mm/shadow/private.h
@@ -424,7 +424,15 @@ mfn_t sh_make_monitor_table(const struct
 void sh_destroy_monitor_table(const struct vcpu *v, mfn_t mmfn,
                               unsigned int shadow_levels);
 
-/* VRAM dirty tracking helpers. */
+/* VRAM dirty tracking support */
+struct sh_dirty_vram {
+    unsigned long begin_pfn;
+    unsigned long end_pfn;
+    paddr_t *sl1ma;
+    uint8_t *dirty_bitmap;
+    s_time_t last_dirty;
+};
+
 void shadow_vram_get_mfn(mfn_t mfn, unsigned int l1f,
                          mfn_t sl1mfn, const void *sl1e,
                          const struct domain *d);