[PATCH 10/16] x86/mapcache: initialise the mapcache for the idle domain

[Hongyan Xia <hx242@xen.org>]

From: Hongyan Xia <hongyxia@amazon.com>

In order to use the mapcache in the idle domain, we also have to
populate its page tables in the PERDOMAIN region, and we need to move
mapcache_domain_init() earlier in arch_domain_create().

Note, commit 'x86: lift mapcache variable to the arch level' has
initialised the mapcache for HVM domains. With this patch, PV, HVM,
idle domains now all initialise the mapcache.

Signed-off-by: Wei Wang <wawei@amazon.de>
Signed-off-by: Hongyan Xia <hongyxia@amazon.com>
---
 xen/arch/x86/domain.c | 4 ++--
 xen/arch/x86/mm.c     | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index e73f1efe85..c7e90c50e6 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -539,6 +539,8 @@ int arch_domain_create(struct domain *d,
 
     spin_lock_init(&d->arch.e820_lock);
 
+    mapcache_domain_init(d);
+
     /* Minimal initialisation for the idle domain. */
     if ( unlikely(is_idle_domain(d)) )
     {
@@ -634,8 +636,6 @@ int arch_domain_create(struct domain *d,
 
     psr_domain_init(d);
 
-    mapcache_domain_init(d);
-
     if ( is_hvm_domain(d) )
     {
         if ( (rc = hvm_domain_initialise(d)) != 0 )
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index a17ae0004a..b3530d2763 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5828,6 +5828,9 @@ int create_perdomain_mapping(struct domain *d, unsigned long va,
         l3tab = __map_domain_page(pg);
         clear_page(l3tab);
         d->arch.perdomain_l3_pg = pg;
+        if ( is_idle_domain(d) )
+            idle_pg_table[l4_table_offset(PERDOMAIN_VIRT_START)] =
+                l4e_from_page(pg, __PAGE_HYPERVISOR_RW);
         if ( !nr )
         {
             unmap_domain_page(l3tab);
-- 
2.24.1.AMZN