[Xen-devel] [PATCH v3 06/18] x86/mem_sharing: define mem_sharing_domain to hold some scattered variables

[Tamas K Lengyel <tamas.lengyel@xxxxxxxxx>]

Create struct mem_sharing_domain under hvm_domain and move mem sharing
variables into it from p2m_domain and hvm_domain.

Expose the mem_sharing_enabled macro to be used consistently across Xen.

Remove some duplicate calls to mem_sharing_enabled in mem_sharing.c

Signed-off-by: Tamas K Lengyel <tamas.lengyel@xxxxxxxxx>
---
 xen/arch/x86/mm/mem_sharing.c     | 10 ++++------
 xen/drivers/passthrough/pci.c     |  3 +--
 xen/include/asm-x86/hvm/domain.h  |  6 +++++-
 xen/include/asm-x86/mem_sharing.h | 16 ++++++++++++++++
 xen/include/asm-x86/p2m.h         |  4 ----
 5 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index f6187403a0..3aa61c30e6 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -197,9 +197,6 @@ static shr_handle_t get_next_handle(void)
     return x + 1;
 }
 
-#define mem_sharing_enabled(d) \
-    (is_hvm_domain(d) && (d)->arch.hvm.mem_sharing_enabled)
-
 static atomic_t nr_saved_mfns   = ATOMIC_INIT(0);
 static atomic_t nr_shared_mfns  = ATOMIC_INIT(0);
 
@@ -1309,6 +1306,7 @@ int __mem_sharing_unshare_page(struct domain *d,
 int relinquish_shared_pages(struct domain *d)
 {
     int rc = 0;
+    struct mem_sharing_domain *msd = &d->arch.hvm.mem_sharing;
     struct p2m_domain *p2m = p2m_get_hostp2m(d);
     unsigned long gfn, count = 0;
 
@@ -1316,7 +1314,7 @@ int relinquish_shared_pages(struct domain *d)
         return 0;
 
     p2m_lock(p2m);
-    for ( gfn = p2m->next_shared_gfn_to_relinquish;
+    for ( gfn = msd->next_shared_gfn_to_relinquish;
           gfn <= p2m->max_mapped_pfn; gfn++ )
     {
         p2m_access_t a;
@@ -1351,7 +1349,7 @@ int relinquish_shared_pages(struct domain *d)
         {
             if ( hypercall_preempt_check() )
             {
-                p2m->next_shared_gfn_to_relinquish = gfn + 1;
+                msd->next_shared_gfn_to_relinquish = gfn + 1;
                 rc = -ERESTART;
                 break;
             }
@@ -1437,7 +1435,7 @@ int 
mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
 
     /* Only HAP is supported */
     rc = -ENODEV;
-    if ( !hap_enabled(d) || !d->arch.hvm.mem_sharing_enabled )
+    if ( !mem_sharing_enabled(d) )
         goto out;
 
     switch ( mso.op )
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index c07a63981a..65d1d457ff 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -1498,8 +1498,7 @@ static int assign_device(struct domain *d, u16 seg, u8 
bus, u8 devfn, u32 flag)
     /* Prevent device assign if mem paging or mem sharing have been 
      * enabled for this domain */
     if ( d != dom_io &&
-         unlikely((is_hvm_domain(d) &&
-                   d->arch.hvm.mem_sharing_enabled) ||
+         unlikely(mem_sharing_enabled(d) ||
                   vm_event_check_ring(d->vm_event_paging) ||
                   p2m_get_hostp2m(d)->global_logdirty) )
         return -EXDEV;
diff --git a/xen/include/asm-x86/hvm/domain.h b/xen/include/asm-x86/hvm/domain.h
index bcc5621797..8f70ba2b1a 100644
--- a/xen/include/asm-x86/hvm/domain.h
+++ b/xen/include/asm-x86/hvm/domain.h
@@ -29,6 +29,7 @@
 #include <asm/hvm/viridian.h>
 #include <asm/hvm/vmx/vmcs.h>
 #include <asm/hvm/svm/vmcb.h>
+#include <asm/mem_sharing.h>
 #include <public/grant_table.h>
 #include <public/hvm/params.h>
 #include <public/hvm/save.h>
@@ -156,7 +157,6 @@ struct hvm_domain {
 
     struct viridian_domain *viridian;
 
-    bool_t                 mem_sharing_enabled;
     bool_t                 qemu_mapcache_invalidate;
     bool_t                 is_s3_suspended;
 
@@ -192,6 +192,10 @@ struct hvm_domain {
         struct vmx_domain vmx;
         struct svm_domain svm;
     };
+
+#ifdef CONFIG_MEM_SHARING
+    struct mem_sharing_domain mem_sharing;
+#endif
 };
 
 #endif /* __ASM_X86_HVM_DOMAIN_H__ */
diff --git a/xen/include/asm-x86/mem_sharing.h 
b/xen/include/asm-x86/mem_sharing.h
index cf7848709f..13114b6346 100644
--- a/xen/include/asm-x86/mem_sharing.h
+++ b/xen/include/asm-x86/mem_sharing.h
@@ -26,6 +26,20 @@
 
 #ifdef CONFIG_MEM_SHARING
 
+struct mem_sharing_domain
+{
+    bool enabled;
+
+    /*
+     * When releasing shared gfn's in a preemptible manner, recall where
+     * to resume the search.
+     */
+    unsigned long next_shared_gfn_to_relinquish;
+};
+
+#define mem_sharing_enabled(d) \
+    (hap_enabled(d) && (d)->arch.hvm.mem_sharing.enabled)
+
 /* Auditing of memory sharing code? */
 #ifndef NDEBUG
 #define MEM_SHARING_AUDIT 1
@@ -104,6 +118,8 @@ int relinquish_shared_pages(struct domain *d);
 
 #else
 
+#define mem_sharing_enabled(d) false
+
 static inline unsigned int mem_sharing_get_nr_saved_mfns(void)
 {
     return 0;
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 7399c4a897..8defa90306 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -305,10 +305,6 @@ struct p2m_domain {
     unsigned long min_remapped_gfn;
     unsigned long max_remapped_gfn;
 
-    /* When releasing shared gfn's in a preemptible manner, recall where
-     * to resume the search */
-    unsigned long next_shared_gfn_to_relinquish;
-
 #ifdef CONFIG_HVM
     /* Populate-on-demand variables
      * All variables are protected with the pod lock. We cannot rely on
-- 
2.20.1


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