[PATCH] x86/hap: Initialise HAP logdirty function pointers once in hap_domain_init()

[PATCH] x86/hap: Initialise HAP logdirty function pointers once in hap_domain_init()

[Andrew Cooper]

rather than repeatedly initialising them each time logdirty is enabled or the
vram tracking area changes.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Jan Beulich <JBeulich@suse.com>
CC: Tim Deegan <tim@xen.org>
---
 xen/arch/x86/mm/hap/hap.c |   15 +++++----------
 xen/arch/x86/mm/paging.c  |    2 --
 xen/include/asm-x86/hap.h |    1 -
 3 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index 21f57c1..abf3d7a 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -81,7 +81,6 @@ int hap_track_dirty_vram(struct domain *d,
 
         if ( !paging_mode_log_dirty(d) )
         {
-            hap_logdirty_init(d);
             rc = paging_log_dirty_enable(d, 0);
             if ( rc )
                 goto out;
@@ -219,15 +218,6 @@ static void hap_clean_dirty_bitmap(struct domain *d)
     flush_tlb_mask(d->domain_dirty_cpumask);
 }
 
-void hap_logdirty_init(struct domain *d)
-{
-
-    /* Reinitialize logdirty mechanism */
-    paging_log_dirty_init(d, hap_enable_log_dirty,
-                          hap_disable_log_dirty,
-                          hap_clean_dirty_bitmap);
-}
-
 /************************************************/
 /*             HAP SUPPORT FUNCTIONS            */
 /************************************************/
@@ -438,6 +428,11 @@ static void hap_destroy_monitor_table(struct vcpu* v, mfn_t mmfn)
 void hap_domain_init(struct domain *d)
 {
     INIT_PAGE_LIST_HEAD(&d->arch.paging.hap.freelist);
+
+    /* Use HAP logdirty mechanism. */
+    paging_log_dirty_init(d, hap_enable_log_dirty,
+                          hap_disable_log_dirty,
+                          hap_clean_dirty_bitmap);
 }
 
 /* return 0 for success, -errno for failure */
diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c
index 32764ba..455000d 100644
--- a/xen/arch/x86/mm/paging.c
+++ b/xen/arch/x86/mm/paging.c
@@ -594,8 +594,6 @@ int paging_domctl(struct domain *d, xen_domctl_shadow_op_t *sc,
             break;
         /* Else fall through... */
     case XEN_DOMCTL_SHADOW_OP_ENABLE_LOGDIRTY:
-        if ( hap_enabled(d) )
-            hap_logdirty_init(d);
         return paging_log_dirty_enable(d, 1);
 
     case XEN_DOMCTL_SHADOW_OP_OFF:
diff --git a/xen/include/asm-x86/hap.h b/xen/include/asm-x86/hap.h
index 5161927..7876527 100644
--- a/xen/include/asm-x86/hap.h
+++ b/xen/include/asm-x86/hap.h
@@ -56,7 +56,6 @@ int   hap_enable(struct domain *d, u32 mode);
 void  hap_final_teardown(struct domain *d);
 void  hap_teardown(struct domain *d);
 void  hap_vcpu_init(struct vcpu *v);
-void  hap_logdirty_init(struct domain *d);
 int   hap_track_dirty_vram(struct domain *d,
                            unsigned long begin_pfn,
                            unsigned long nr,
-- 
1.7.10.4

Re: [PATCH] x86/hap: Initialise HAP logdirty function pointers once in hap_domain_init()

[Tim Deegan]

At 15:12 +0100 on 08 Aug (1407507141), Andrew Cooper wrote:
> rather than repeatedly initialising them each time logdirty is enabled or the
> vram tracking area changes.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

I thought there was some subtlety of the ordering here, but I can't
see it now so maybe other changes have made it irrelevant.  So,

Reviewed-by: Tim Deegan <tim@xen.org>