4 files changed, 19 insertions, 5 deletions

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 4bd990ee43df..1a918dde46b5 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -164,6 +164,7 @@ static inline pte_t __pte_ma(pteval_t x)
 
 
 xmaddr_t arbitrary_virt_to_machine(void *address);
+unsigned long arbitrary_virt_to_mfn(void *vaddr);
 void make_lowmem_page_readonly(void *vaddr);
 void make_lowmem_page_readwrite(void *vaddr);
 
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 86497d5f44cd..352ea6830659 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -103,7 +103,7 @@ static void xen_vcpu_setup(int cpu)
 
         vcpup = &per_cpu(xen_vcpu_info, cpu);
 
-        info.mfn = virt_to_mfn(vcpup);
+        info.mfn = arbitrary_virt_to_mfn(vcpup);
         info.offset = offset_in_page(vcpup);
 
         printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
@@ -301,8 +301,10 @@ static void xen_load_gdt(const struct desc_ptr *dtr)
         frames = mcs.args;
 
         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
-                frames[f] = virt_to_mfn(va);
+                frames[f] = arbitrary_virt_to_mfn((void *)va);
+
                 make_lowmem_page_readonly((void *)va);
+                make_lowmem_page_readonly(mfn_to_virt(frames[f]));
         }
 
         MULTI_set_gdt(mcs.mc, frames, size / sizeof(struct desc_struct));
@@ -314,7 +316,7 @@ static void load_TLS_descriptor(struct thread_struct *t,
                                 unsigned int cpu, unsigned int i)
 {
         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
-        xmaddr_t maddr = virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
+        xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
         struct multicall_space mc = __xen_mc_entry(0);
 
         MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
@@ -488,7 +490,7 @@ static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
                 break;
 
         default: {
-                xmaddr_t maddr = virt_to_machine(&dt[entry]);
+                xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
 
                 xen_mc_flush();
                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 319bd40a57c2..cb6afa4ec95c 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -276,6 +276,13 @@ void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
         p2m_top[topidx][idx] = mfn;
 }
 
+unsigned long arbitrary_virt_to_mfn(void *vaddr)
+{
+        xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);
+
+        return PFN_DOWN(maddr.maddr);
+}
+
 xmaddr_t arbitrary_virt_to_machine(void *vaddr)
 {
         unsigned long address = (unsigned long)vaddr;
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 035582ae815d..8d470562ffc9 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -219,6 +219,7 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 {
         struct vcpu_guest_context *ctxt;
         struct desc_struct *gdt;
+        unsigned long gdt_mfn;
 
         if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
                 return 0;
@@ -248,9 +249,12 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
         ctxt->ldt_ents = 0;
 
         BUG_ON((unsigned long)gdt & ~PAGE_MASK);
+
+        gdt_mfn = arbitrary_virt_to_mfn(gdt);
         make_lowmem_page_readonly(gdt);
+        make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
 
-        ctxt->gdt_frames[0] = virt_to_mfn(gdt);
+        ctxt->gdt_frames[0] = gdt_mfn;
         ctxt->gdt_ents      = GDT_ENTRIES;
 
         ctxt->user_regs.cs = __KERNEL_CS;