xen: Add suspend/resume support for PV on HVM guests.

[karo-tx-linux.git] / arch / x86 / xen / enlighten.c

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b211a04c4b2ccbb6f1ad2c4b2388592532dff2f0..127c95c8d15e9f7e5f777e53022303ddf49d893e 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1262,13 +1262,15 @@ static int init_hvm_pv_info(int *major, int *minor)
        return 0;
 }
 
-static void __init init_shared_info(void)
+void xen_hvm_init_shared_info(void)
 {
+       int cpu;
        struct xen_add_to_physmap xatp;
-       struct shared_info *shared_info_page;
+       static struct shared_info *shared_info_page = 0;
 
-       shared_info_page = (struct shared_info *)
-               extend_brk(PAGE_SIZE, PAGE_SIZE);
+       if (!shared_info_page)
+               shared_info_page = (struct shared_info *)
+                       extend_brk(PAGE_SIZE, PAGE_SIZE);
        xatp.domid = DOMID_SELF;
        xatp.idx = 0;
        xatp.space = XENMAPSPACE_shared_info;
@@ -1278,7 +1280,17 @@ static void __init init_shared_info(void)
 
        HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 
-       per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
+       /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
+        * page, we use it in the event channel upcall and in some pvclock
+        * related functions. We don't need the vcpu_info placement
+        * optimizations because we don't use any pv_mmu or pv_irq op on
+        * HVM.
+        * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
+        * online but xen_hvm_init_shared_info is run at resume time too and
+        * in that case multiple vcpus might be online. */
+       for_each_online_cpu(cpu) {
+               per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+       }
 }
 
 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
@@ -1308,7 +1320,7 @@ static void __init xen_hvm_guest_init(void)
        if (r < 0)
                return;
 
-       init_shared_info();
+       xen_hvm_init_shared_info();
 
        if (xen_feature(XENFEAT_hvm_callback_vector))
                xen_have_vector_callback = 1;