From: Razvan Cojocaru <rcojocaru@bitdefender.com>
Date: Thu, 15 Nov 2018 12:35:08 +0000 (+0100)
Subject: x86/altp2m: propagate ept.ad changes to all active altp2ms
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~2922
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=303cee10a677dd8c5c130e50ddad6517c12e0276;p=xen.git

x86/altp2m: propagate ept.ad changes to all active altp2ms

This patch is a pre-requisite for fixing the logdirty VGA issue
(display freezes when switching to a new altp2m view early in a
domain's lifetime).

The new ept_set_ad_sync() function has been added to update all
active altp2ms' ept.ad. New altp2ms will inherit the hostp2m's
ept.ad value.

The p2m_{en,dis}able_hardware_log_dirty() hostp2m locking has
been moved to the new ept_{en,dis}able_hardware_log_dirty()
functions as part of the code refactoring, while locks for the
individual altp2ms are taken in ept_set_ad_sync() (called by
ept_{en,dis}able_pml()).

Suggested-by: George Dunlap <george.dunlap@citrix.com>
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Tested-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---

diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 407e299e50..fabcd06f07 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -17,6 +17,7 @@
 
 #include <xen/domain_page.h>
 #include <xen/sched.h>
+#include <asm/altp2m.h>
 #include <asm/current.h>
 #include <asm/paging.h>
 #include <asm/types.h>
@@ -1222,6 +1223,34 @@ static void ept_tlb_flush(struct p2m_domain *p2m)
     ept_sync_domain_mask(p2m, p2m->domain->dirty_cpumask);
 }
 
+static void ept_set_ad_sync(struct domain *d, bool value)
+{
+    struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
+
+    ASSERT(p2m_locked_by_me(hostp2m));
+
+    hostp2m->ept.ad = value;
+
+    if ( unlikely(altp2m_active(d)) )
+    {
+        unsigned int i;
+
+        for ( i = 0; i < MAX_ALTP2M; i++ )
+        {
+            struct p2m_domain *p2m;
+
+            if ( d->arch.altp2m_eptp[i] == mfn_x(INVALID_MFN) )
+                continue;
+
+            p2m = d->arch.altp2m_p2m[i];
+
+            p2m_lock(p2m);
+            p2m->ept.ad = value;
+            p2m_unlock(p2m);
+        }
+    }
+}
+
 static void ept_enable_pml(struct p2m_domain *p2m)
 {
     /* Domain must have been paused */
@@ -1236,7 +1265,7 @@ static void ept_enable_pml(struct p2m_domain *p2m)
         return;
 
     /* Enable EPT A/D bit for PML */
-    p2m->ept.ad = 1;
+    ept_set_ad_sync(p2m->domain, true);
     vmx_domain_update_eptp(p2m->domain);
 }
 
@@ -1248,10 +1277,28 @@ static void ept_disable_pml(struct p2m_domain *p2m)
     vmx_domain_disable_pml(p2m->domain);
 
     /* Disable EPT A/D bit */
-    p2m->ept.ad = 0;
+    ept_set_ad_sync(p2m->domain, false);
     vmx_domain_update_eptp(p2m->domain);
 }
 
+static void ept_enable_hardware_log_dirty(struct p2m_domain *p2m)
+{
+    struct p2m_domain *hostp2m = p2m_get_hostp2m(p2m->domain);
+
+    p2m_lock(hostp2m);
+    ept_enable_pml(hostp2m);
+    p2m_unlock(hostp2m);
+}
+
+static void ept_disable_hardware_log_dirty(struct p2m_domain *p2m)
+{
+    struct p2m_domain *hostp2m = p2m_get_hostp2m(p2m->domain);
+
+    p2m_lock(hostp2m);
+    ept_disable_pml(hostp2m);
+    p2m_unlock(hostp2m);
+}
+
 static void ept_flush_pml_buffers(struct p2m_domain *p2m)
 {
     /* Domain must have been paused */
@@ -1281,8 +1328,8 @@ int ept_p2m_init(struct p2m_domain *p2m)
 
     if ( cpu_has_vmx_pml )
     {
-        p2m->enable_hardware_log_dirty = ept_enable_pml;
-        p2m->disable_hardware_log_dirty = ept_disable_pml;
+        p2m->enable_hardware_log_dirty = ept_enable_hardware_log_dirty;
+        p2m->disable_hardware_log_dirty = ept_disable_hardware_log_dirty;
         p2m->flush_hardware_cached_dirty = ept_flush_pml_buffers;
     }
 
@@ -1390,8 +1437,10 @@ void setup_ept_dump(void)
 void 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;
 
+    p2m->ept.ad = hostp2m->ept.ad;
     p2m->min_remapped_gfn = gfn_x(INVALID_GFN);
     p2m->max_remapped_gfn = 0;
     ept = &p2m->ept;
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 4bdc5e34e0..6a1abb6df5 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -360,11 +360,7 @@ void p2m_enable_hardware_log_dirty(struct domain *d)
     struct p2m_domain *p2m = p2m_get_hostp2m(d);
 
     if ( p2m->enable_hardware_log_dirty )
-    {
-        p2m_lock(p2m);
         p2m->enable_hardware_log_dirty(p2m);
-        p2m_unlock(p2m);
-    }
 }
 
 void p2m_disable_hardware_log_dirty(struct domain *d)
@@ -372,11 +368,7 @@ void p2m_disable_hardware_log_dirty(struct domain *d)
     struct p2m_domain *p2m = p2m_get_hostp2m(d);
 
     if ( p2m->disable_hardware_log_dirty )
-    {
-        p2m_lock(p2m);
         p2m->disable_hardware_log_dirty(p2m);
-        p2m_unlock(p2m);
-    }
 }
 
 void p2m_flush_hardware_cached_dirty(struct domain *d)