From: Keir Fraser <keir.fraser@citrix.com>
Date: Tue, 4 May 2010 11:41:11 +0000 (+0100)
Subject: x86: add support for domain-initiated global cache flush
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~12271
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=c499509ef2595a5daa8ef804168c94291e90ec48;p=xen.git

x86: add support for domain-initiated global cache flush

Newer Linux' AGP code wants to flush caches on all CPUs under certain
circumstances. Since doing this on all vCPU-s of the domain in
question doesn't yield the intended effect, this needs to be done in
the hypervisor. Add a new MMUEXT operation for this.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
---

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 8002c3d67f..700188e406 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -2888,6 +2888,27 @@ int do_mmuext_op(
             }
             break;
 
+        case MMUEXT_FLUSH_CACHE_GLOBAL:
+            if ( unlikely(foreigndom != DOMID_SELF) )
+                okay = 0;
+            else if ( likely(cache_flush_permitted(d)) )
+            {
+                unsigned int cpu;
+                cpumask_t mask = CPU_MASK_NONE;
+
+                for_each_online_cpu(cpu)
+                    if ( !cpus_intersects(mask,
+                                          per_cpu(cpu_sibling_map, cpu)) )
+                        cpu_set(cpu, mask);
+                flush_mask(&mask, FLUSH_CACHE);
+            }
+            else
+            {
+                MEM_LOG("Non-physdev domain tried to FLUSH_CACHE_GLOBAL");
+                okay = 0;
+            }
+            break;
+
         case MMUEXT_SET_LDT:
         {
             unsigned long ptr  = op.arg1.linear_addr;
diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index 1a5e3e840c..b3a9056602 100644
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -239,6 +239,10 @@ DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
  * 
  * cmd: MMUEXT_FLUSH_CACHE
  * No additional arguments. Writes back and flushes cache contents.
+ *
+ * cmd: MMUEXT_FLUSH_CACHE_GLOBAL
+ * No additional arguments. Writes back and flushes cache contents
+ * on all CPUs in the system.
  * 
  * cmd: MMUEXT_SET_LDT
  * linear_addr: Linear address of LDT base (NB. must be page-aligned).
@@ -268,6 +272,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
 #define MMUEXT_NEW_USER_BASEPTR 15
 #define MMUEXT_CLEAR_PAGE       16
 #define MMUEXT_COPY_PAGE        17
+#define MMUEXT_FLUSH_CACHE_GLOBAL 18
 
 #ifndef __ASSEMBLY__
 struct mmuext_op {