Merged.

16 files changed, 190 insertions, 173 deletions

diff --git a/linux-2.6-xen-sparse/arch/i386/kernel/quirks-xen.c b/linux-2.6-xen-sparse/arch/i386/kernel/quirks-xen.c
index 39d9ed110a..7e44d81bdc 100644
--- a/linux-2.6-xen-sparse/arch/i386/kernel/quirks-xen.c
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/quirks-xen.c
@@ -5,7 +5,7 @@
 #include <linux/pci.h>
 #include <linux/irq.h>
 
-#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
+#if defined(CONFIG_X86_IO_APIC) && (defined(CONFIG_SMP) || defined(CONFIG_XEN)) && defined(CONFIG_PCI)
 
 static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
 {
diff --git a/tools/examples/block b/tools/examples/block
index 5a43560eff..dae32dc234 100644
--- a/tools/examples/block
+++ b/tools/examples/block
@@ -72,7 +72,7 @@ check_sharing()
   then
     toskip="^$"
   else
-    toskip="^[^ ]* [^ ]* [^ ]* ro "
+    toskip="^[^ ]* [^ ]* [^ ]* ro[, ]"
   fi
 
   for file in $(cat /proc/mounts | grep -v "$toskip" | cut -f 1 -d ' ')
diff --git a/tools/libxc/xc_ptrace.c b/tools/libxc/xc_ptrace.c
index 715cb73b39..f83005b45c 100644
--- a/tools/libxc/xc_ptrace.c
+++ b/tools/libxc/xc_ptrace.c
@@ -153,6 +153,79 @@ online_vcpus_changed(cpumap_t cpumap)
 }
 
 /* --------------------- */
+/* XXX application state */
+static long                     nr_pages = 0;
+static unsigned long           *page_array = NULL;
+
+static void *
+map_domain_va_32(
+    int xc_handle,
+    int cpu,
+    void *guest_va,
+    int perm)
+{
+    unsigned long pde, page;
+    unsigned long va = (unsigned long)guest_va;
+
+    static unsigned long  cr3_phys[MAX_VIRT_CPUS];
+    static uint32_t *cr3_virt[MAX_VIRT_CPUS];
+    static unsigned long  pde_phys[MAX_VIRT_CPUS];
+    static uint32_t *pde_virt[MAX_VIRT_CPUS];
+    static unsigned long  page_phys[MAX_VIRT_CPUS];
+    static uint32_t *page_virt[MAX_VIRT_CPUS];    
+    static int            prev_perm[MAX_VIRT_CPUS];
+
+   if (ctxt[cpu].ctrlreg[3] == 0)
+       return NULL;
+   if ( ctxt[cpu].ctrlreg[3] != cr3_phys[cpu] )
+    {
+        cr3_phys[cpu] = ctxt[cpu].ctrlreg[3];
+        if ( cr3_virt[cpu] )
+            munmap(cr3_virt[cpu], PAGE_SIZE);
+        cr3_virt[cpu] = xc_map_foreign_range(
+            xc_handle, current_domid, PAGE_SIZE, PROT_READ,
+            cr3_phys[cpu] >> PAGE_SHIFT);
+        if ( cr3_virt[cpu] == NULL )
+            return NULL;
+    }
+    if ( (pde = cr3_virt[cpu][vtopdi(va)]) == 0 )
+        return NULL;
+    if ( (ctxt[cpu].flags & VGCF_HVM_GUEST) && paging_enabled(&ctxt[cpu]) )
+        pde = page_array[pde >> PAGE_SHIFT] << PAGE_SHIFT;
+    if ( pde != pde_phys[cpu] )
+    {
+        pde_phys[cpu] = pde;
+        if ( pde_virt[cpu] )
+            munmap(pde_virt[cpu], PAGE_SIZE);
+        pde_virt[cpu] = xc_map_foreign_range(
+            xc_handle, current_domid, PAGE_SIZE, PROT_READ,
+            pde_phys[cpu] >> PAGE_SHIFT);
+        if ( pde_virt[cpu] == NULL )
+            return NULL;
+    }
+    if ( (page = pde_virt[cpu][vtopti(va)]) == 0 )
+        return NULL;
+    if (ctxt[cpu].flags & VGCF_HVM_GUEST)
+        page = page_array[page >> PAGE_SHIFT] << PAGE_SHIFT;
+    if ( (page != page_phys[cpu]) || (perm != prev_perm[cpu]) )
+    {
+        page_phys[cpu] = page;
+        if ( page_virt[cpu] )
+            munmap(page_virt[cpu], PAGE_SIZE);
+        page_virt[cpu] = xc_map_foreign_range(
+            xc_handle, current_domid, PAGE_SIZE, perm,
+            page_phys[cpu] >> PAGE_SHIFT);
+        if ( page_virt[cpu] == NULL )
+        {
+            page_phys[cpu] = 0;
+            return NULL;
+        }
+        prev_perm[cpu] = perm;
+    } 
+
+    return (void *)(((unsigned long)page_virt[cpu]) | (va & BSD_PAGE_MASK));
+}
+
 
 static void *
 map_domain_va_pae(
@@ -165,28 +238,31 @@ map_domain_va_pae(
     uint64_t *l3, *l2, *l1;
     static void *v;
 
-    if (fetch_regs(xc_handle, cpu, NULL))
-        return NULL;
-
     l3 = xc_map_foreign_range(
         xc_handle, current_domid, PAGE_SIZE, PROT_READ, ctxt[cpu].ctrlreg[3] >> PAGE_SHIFT);
     if ( l3 == NULL )
         return NULL;
 
     l2p = l3[l3_table_offset_pae(va)] >> PAGE_SHIFT;
+    l2p = page_array[l2p];
     l2 = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, PROT_READ, l2p);
+    munmap(l3, PAGE_SIZE);
     if ( l2 == NULL )
         return NULL;
 
     l1p = l2[l2_table_offset_pae(va)] >> PAGE_SHIFT;
+    l1p = page_array[l1p];
     l1 = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, perm, l1p);
+    munmap(l2, PAGE_SIZE);
     if ( l1 == NULL )
         return NULL;
 
     p = l1[l1_table_offset_pae(va)] >> PAGE_SHIFT;
+    p = page_array[p];
     if ( v != NULL )
         munmap(v, PAGE_SIZE);
     v = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, perm, p);
+    munmap(l1, PAGE_SIZE);
     if ( v == NULL )
         return NULL;
 
@@ -195,46 +271,58 @@ map_domain_va_pae(
 
 #ifdef __x86_64__
 static void *
-map_domain_va(
+map_domain_va_64(
     int xc_handle,
     int cpu,
     void *guest_va,
     int perm)
 {
-    unsigned long l3p, l2p, l1p, p, va = (unsigned long)guest_va;
+    unsigned long l3p, l2p, l1p, l1e, p, va = (unsigned long)guest_va;
     uint64_t *l4, *l3, *l2, *l1;
     static void *v;
 
     if ((ctxt[cpu].ctrlreg[4] & 0x20) == 0 ) /* legacy ia32 mode */
-        return map_domain_va_pae(xc_handle, cpu, guest_va, perm);
-
-    if (fetch_regs(xc_handle, cpu, NULL))
-        return NULL;
+        return map_domain_va_32(xc_handle, cpu, guest_va, perm);
 
-    l4 = xc_map_foreign_range(
-        xc_handle, current_domid, PAGE_SIZE, PROT_READ, ctxt[cpu].ctrlreg[3] >> PAGE_SHIFT);
+    l4 = xc_map_foreign_range( xc_handle, current_domid, PAGE_SIZE, 
+            PROT_READ, ctxt[cpu].ctrlreg[3] >> PAGE_SHIFT);
     if ( l4 == NULL )
         return NULL;
 
     l3p = l4[l4_table_offset(va)] >> PAGE_SHIFT;
+    l3p = page_array[l3p];
     l3 = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, PROT_READ, l3p);
+    munmap(l4, PAGE_SIZE);
     if ( l3 == NULL )
         return NULL;
 
     l2p = l3[l3_table_offset(va)] >> PAGE_SHIFT;
+    l2p = page_array[l2p];
     l2 = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, PROT_READ, l2p);
+    munmap(l3, PAGE_SIZE);
     if ( l2 == NULL )
         return NULL;
 
-    l1p = l2[l2_table_offset(va)] >> PAGE_SHIFT;
-    l1 = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, perm, l1p);
-    if ( l1 == NULL )
-        return NULL;
+    l1 = NULL;
+    l1e = l2[l2_table_offset(va)];
+    l1p = l1e >> PAGE_SHIFT;
+    if (l1e & 0x80)  { /* 2M pages */
+        p = (l1p + l1_table_offset(va));
+    } else { /* 4K pages */
+        l1p = page_array[l1p];
+        l1 = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, perm, l1p);
+        munmap(l2, PAGE_SIZE);
+        if ( l1 == NULL )
+            return NULL;
 
-    p = l1[l1_table_offset(va)] >> PAGE_SHIFT;
+        p = l1[l1_table_offset(va)] >> PAGE_SHIFT;
+    }
+    p = page_array[p];
     if ( v != NULL )
         munmap(v, PAGE_SIZE);
     v = xc_map_foreign_range(xc_handle, current_domid, PAGE_SIZE, perm, p);
+    if (l1)
+        munmap(l1, PAGE_SIZE);
     if ( v == NULL )
         return NULL;
 
@@ -242,11 +330,6 @@ map_domain_va(
 }
 #endif
 
-#ifdef __i386__
-/* XXX application state */
-static long                     nr_pages = 0;
-static unsigned long           *page_array = NULL;
-
 static void *
 map_domain_va(
     int xc_handle,
@@ -254,20 +337,9 @@ map_domain_va(
     void *guest_va,
     int perm)
 {
-
-    unsigned long pde, page;
-    unsigned long va = (unsigned long)guest_va;
+    unsigned long va = (unsigned long) guest_va;
     long npgs = xc_get_tot_pages(xc_handle, current_domid);
-
-
-    static uint32_t  cr3_phys[MAX_VIRT_CPUS];
-    static unsigned long *cr3_virt[MAX_VIRT_CPUS];
-    static unsigned long  pde_phys[MAX_VIRT_CPUS];
-    static unsigned long *pde_virt[MAX_VIRT_CPUS];
-    static unsigned long  page_phys[MAX_VIRT_CPUS];
-    static unsigned long *page_virt[MAX_VIRT_CPUS];    
-    static int            prev_perm[MAX_VIRT_CPUS];
-    static enum { MODE_UNKNOWN, MODE_32, MODE_PAE, MODE_64 } mode;
+    static enum { MODE_UNKNOWN, MODE_64, MODE_32, MODE_PAE } mode;
 
     if ( mode == MODE_UNKNOWN )
     {
@@ -281,9 +353,6 @@ map_domain_va(
             mode = MODE_32;
     }
 
-    if ( mode == MODE_PAE )
-        return map_domain_va_pae(xc_handle, cpu, guest_va, perm);
-
     if ( nr_pages != npgs )
     {
         if ( nr_pages > 0 )
@@ -305,60 +374,32 @@ map_domain_va(
     if (fetch_regs(xc_handle, cpu, NULL))
         return NULL;
 
-    if (paging_enabled(&ctxt[cpu])) {
-       if ( ctxt[cpu].ctrlreg[3] != cr3_phys[cpu] )
-        {
-            cr3_phys[cpu] = ctxt[cpu].ctrlreg[3];
-            if ( cr3_virt[cpu] )
-                munmap(cr3_virt[cpu], PAGE_SIZE);
-            cr3_virt[cpu] = xc_map_foreign_range(
-                xc_handle, current_domid, PAGE_SIZE, PROT_READ,
-                cr3_phys[cpu] >> PAGE_SHIFT);
-            if ( cr3_virt[cpu] == NULL )
-                return NULL;
-        }
-        if ( (pde = cr3_virt[cpu][vtopdi(va)]) == 0 )
-            return NULL;
-        if ( (ctxt[cpu].flags & VGCF_HVM_GUEST) && paging_enabled(&ctxt[cpu]) )
-            pde = page_array[pde >> PAGE_SHIFT] << PAGE_SHIFT;
-        if ( pde != pde_phys[cpu] )
-        {
-            pde_phys[cpu] = pde;
-            if ( pde_virt[cpu] )
-                munmap(pde_virt[cpu], PAGE_SIZE);
-            pde_virt[cpu] = xc_map_foreign_range(
-                xc_handle, current_domid, PAGE_SIZE, PROT_READ,
-                pde_phys[cpu] >> PAGE_SHIFT);
-            if ( pde_virt[cpu] == NULL )
-                return NULL;
-        }
-        if ( (page = pde_virt[cpu][vtopti(va)]) == 0 )
-            return NULL;
-    } else {
-        page = va;
-    }
-    if (ctxt[cpu].flags & VGCF_HVM_GUEST)
-        page = page_array[page >> PAGE_SHIFT] << PAGE_SHIFT;
-    if ( (page != page_phys[cpu]) || (perm != prev_perm[cpu]) )
-    {
-        page_phys[cpu] = page;
-        if ( page_virt[cpu] )
-            munmap(page_virt[cpu], PAGE_SIZE);
-        page_virt[cpu] = xc_map_foreign_range(
-            xc_handle, current_domid, PAGE_SIZE, perm,
-            page_phys[cpu] >> PAGE_SHIFT);
-        if ( page_virt[cpu] == NULL )
-        {
-            page_phys[cpu] = 0;
-            return NULL;
-        }
-        prev_perm[cpu] = perm;
-    } 
+    if (!paging_enabled(&ctxt[cpu])) { 
+        static void * v;
+        unsigned long page;
 
-    return (void *)(((unsigned long)page_virt[cpu]) | (va & BSD_PAGE_MASK));
-}
+        if ( v != NULL )
+            munmap(v, PAGE_SIZE);
+
+        page = page_array[va >> PAGE_SHIFT] << PAGE_SHIFT;
 
+        v = xc_map_foreign_range( xc_handle, current_domid, PAGE_SIZE, 
+                perm, page >> PAGE_SHIFT);
+    
+        if ( v == NULL )
+            return NULL;
+
+        return (void *)(((unsigned long)v) | (va & BSD_PAGE_MASK));
+    }
+#ifdef __x86_64__
+    if ( mode == MODE_64 )
+        return map_domain_va_64(xc_handle, cpu, guest_va, perm);
 #endif
+    if ( mode == MODE_PAE )
+        return map_domain_va_pae(xc_handle, cpu, guest_va, perm);
+    /* else ( mode == MODE_32 ) */
+    return map_domain_va_32(xc_handle, cpu, guest_va, perm);
+}
 
 static int 
 __xc_waitdomain(
@@ -470,7 +511,7 @@ xc_ptrace(
         break;
 
     case PTRACE_SETREGS:
-        if (!current_isfile)
+        if (current_isfile)
                 goto out_unspported; /* XXX not yet supported */
         SET_XC_REGS(((struct gdb_regs *)data), ctxt[cpu].user_regs);
         if ((retval = xc_vcpu_setcontext(xc_handle, current_domid, cpu, 
@@ -492,7 +533,7 @@ xc_ptrace(
 
     case PTRACE_CONT:
     case PTRACE_DETACH:
-        if (!current_isfile)
+        if (current_isfile)
             goto out_unspported; /* XXX not yet supported */
         if ( request != PTRACE_SINGLESTEP )
         {
diff --git a/tools/libxc/xc_ptrace.h b/tools/libxc/xc_ptrace.h
index 2119d9c984..b6d5bea314 100644
--- a/tools/libxc/xc_ptrace.h
+++ b/tools/libxc/xc_ptrace.h
@@ -31,7 +31,7 @@ struct gdb_regs
   unsigned long orig_rax;
   unsigned long rip;
   unsigned long xcs;
-  unsigned long eflags;
+  unsigned long rflags;
   unsigned long rsp;
   unsigned long xss;
   unsigned long fs_base;
@@ -61,7 +61,7 @@ struct gdb_regs
     pt.rax = xc.rax;                            \
     pt.rip = xc.rip;                            \
     pt.xcs = xc.cs;                             \
-    pt.eflags = xc.eflags;                      \
+    pt.rflags = xc.rflags;                      \
     pt.rsp = xc.rsp;                            \
     pt.xss = xc.ss;                             \
     pt.xes = xc.es;                             \
@@ -89,7 +89,7 @@ struct gdb_regs
     xc.rax = pt->rax;                           \
     xc.rip = pt->rip;                           \
     xc.cs = pt->xcs;                            \
-    xc.eflags = pt->eflags;                     \
+    xc.rflags = pt->rflags & 0xffffffff;        \
     xc.rsp = pt->rsp;                           \
     xc.ss = pt->xss;                            \
     xc.es = pt->xes;                            \
diff --git a/xen/Rules.mk b/xen/Rules.mk
index f887ea44f5..ade8b87a1e 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -55,11 +55,14 @@ ifneq ($(max_phys_cpus),)
 CFLAGS-y               += -DMAX_PHYS_CPUS=$(max_phys_cpus)
 endif
 
+AFLAGS-y               += -D__ASSEMBLY__
+
 ALL_OBJS := $(ALL_OBJS-y)
 CFLAGS   := $(strip $(CFLAGS) $(CFLAGS-y))
+AFLAGS   := $(strip $(AFLAGS) $(AFLAGS-y))
 
 %.o: %.c $(HDRS) Makefile
 	$(CC) $(CFLAGS) -c $< -o $@
 
 %.o: %.S $(HDRS) Makefile
-	$(CC) $(CFLAGS) -D__ASSEMBLY__ -c $< -o $@
+	$(CC) $(CFLAGS) $(AFLAGS) -c $< -o $@
diff --git a/xen/arch/ia64/Makefile b/xen/arch/ia64/Makefile
index 444f4eb30b..381c6d739b 100644
--- a/xen/arch/ia64/Makefile
+++ b/xen/arch/ia64/Makefile
@@ -76,7 +76,7 @@ $(BASEDIR)/include/asm-ia64/.offsets.h.stamp:
 
 # I'm sure a Makefile wizard would know a better way to do this
 xen.lds.s: xen/xen.lds.S
-	$(CC) -E $(CPPFLAGS) -P -DXEN -D__ASSEMBLY__ \
+	$(CC) -E $(CPPFLAGS) -P -DXEN $(AFLAGS) \
 		-o xen.lds.s xen/xen.lds.S
 
 clean:: FORCE
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 3fa20dd7d0..c7a2e6ae1d 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -72,7 +72,7 @@ asm-offsets.s: $(TARGET_SUBARCH)/asm-offsets.c $(HDRS)
 	$(CC) $(CFLAGS) -S -o $@ $<
 
 xen.lds: $(TARGET_SUBARCH)/xen.lds.S $(HDRS)
-	$(CC) $(CFLAGS) -P -E -Ui386 -D__ASSEMBLY__ -o $@ $<
+	$(CC) $(CFLAGS) -P -E -Ui386 $(AFLAGS) -o $@ $<
 
 boot/mkelf32: boot/mkelf32.c
 	$(HOSTCC) $(HOSTCFLAGS) -o $@ $<
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index b8e6ce9708..8cb91ead4d 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -393,7 +393,7 @@ int arch_set_info_guest(
     }
     else if ( test_bit(_VCPUF_initialised, &v->vcpu_flags) )
     {
-        hvm_modify_guest_state(v);
+        hvm_load_cpu_guest_regs(v, &v->arch.guest_context.user_regs);
     }
 
     if ( test_bit(_VCPUF_initialised, &v->vcpu_flags) )
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index d43bfb08d8..77ba3f8089 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -382,11 +382,6 @@ static inline int long_mode_do_msr_write(struct cpu_user_regs *regs)
     return 1;
 }
 
-void svm_modify_guest_state(struct vcpu *v)
-{
-    svm_modify_vmcb(v, &v->arch.guest_context.user_regs);
-}
-
 int svm_realmode(struct vcpu *v)
 {
     unsigned long cr0 = v->arch.hvm_svm.cpu_shadow_cr0;
@@ -449,8 +444,6 @@ int start_svm(void)
     hvm_funcs.store_cpu_guest_regs = svm_store_cpu_guest_regs;
     hvm_funcs.load_cpu_guest_regs = svm_load_cpu_guest_regs;
 
-    hvm_funcs.modify_guest_state = svm_modify_guest_state;
-
     hvm_funcs.realmode = svm_realmode;
     hvm_funcs.paging_enabled = svm_paging_enabled;
     hvm_funcs.instruction_length = svm_instruction_length;
diff --git a/xen/arch/x86/hvm/svm/vmcb.c b/xen/arch/x86/hvm/svm/vmcb.c
index 0d101206b6..33c995a6f6 100644
--- a/xen/arch/x86/hvm/svm/vmcb.c
+++ b/xen/arch/x86/hvm/svm/vmcb.c
@@ -161,23 +161,6 @@ static int construct_vmcb_controls(struct arch_svm_struct *arch_svm)
 
 
 /*
- * modify guest eflags and execption bitmap for gdb
- */
-int svm_modify_vmcb(struct vcpu *v, struct cpu_user_regs *regs)
-{
-    int error;
-    if ((error = load_vmcb(&v->arch.hvm_svm, v->arch.hvm_svm.host_save_pa))) 
-    {
-        printk("svm_modify_vmcb: load_vmcb failed: VMCB = %lx\n",
-                (unsigned long) v->arch.hvm_svm.host_save_pa);
-        return -EINVAL; 
-    }
-    svm_load_cpu_user_regs(v,regs);
-    return 0;
-}
-
-
-/*
  * Initially set the same environement as host.
  */
 static int construct_init_vmcb_guest(struct arch_svm_struct *arch_svm, 
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index a4e09344c4..7a2f50bb27 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -487,32 +487,6 @@ void destroy_vmcs(struct arch_vmx_struct *arch_vmx)
     arch_vmx->io_bitmap_b = NULL;
 }
 
-/*
- * modify guest eflags and execption bitmap for gdb
- */
-int modify_vmcs(struct arch_vmx_struct *arch_vmx,
-                struct cpu_user_regs *regs)
-{
-    int error;
-    u64 vmcs_phys_ptr, old, old_phys_ptr;
-    vmcs_phys_ptr = (u64) virt_to_maddr(arch_vmx->vmcs);
-
-    old_phys_ptr = virt_to_maddr(&old);
-    __vmptrst(old_phys_ptr);
-    if ((error = load_vmcs(arch_vmx, vmcs_phys_ptr))) {
-        printk("modify_vmcs: load_vmcs failed: VMCS = %lx\n",
-               (unsigned long) vmcs_phys_ptr);
-        return -EINVAL;
-    }
-
-/* XXX VMX change modify_vmcs arg to v */
-    hvm_load_cpu_guest_regs(current, regs);
-
-    __vmptrld(old_phys_ptr);
-
-    return 0;
-}
-
 void vm_launch_fail(unsigned long eflags)
 {
     unsigned long error;
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 9e146477cc..623fb22922 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -400,7 +400,7 @@ void vmx_migrate_timers(struct vcpu *v)
         migrate_timer(&(VLAPIC(v)->vlapic_timer), v->processor);
 }
 
-struct vmx_store_cpu_guest_regs_callback_info {
+struct vmx_cpu_guest_regs_callback_info {
     struct vcpu *v;
     struct cpu_user_regs *regs;
     unsigned long *crs;
@@ -409,12 +409,21 @@ struct vmx_store_cpu_guest_regs_callback_info {
 static void vmx_store_cpu_guest_regs(
     struct vcpu *v, struct cpu_user_regs *regs, unsigned long *crs);
 
+static void vmx_load_cpu_guest_regs(
+    struct vcpu *v, struct cpu_user_regs *regs);
+
 static void vmx_store_cpu_guest_regs_callback(void *data)
 {
-    struct vmx_store_cpu_guest_regs_callback_info *info = data;
+    struct vmx_cpu_guest_regs_callback_info *info = data;
     vmx_store_cpu_guest_regs(info->v, info->regs, info->crs);
 }
 
+static void vmx_load_cpu_guest_regs_callback(void *data)
+{
+    struct vmx_cpu_guest_regs_callback_info *info = data;
+    vmx_load_cpu_guest_regs(info->v, info->regs);
+}
+
 static void vmx_store_cpu_guest_regs(
     struct vcpu *v, struct cpu_user_regs *regs, unsigned long *crs)
 {
@@ -426,7 +435,7 @@ static void vmx_store_cpu_guest_regs(
         if ( v->arch.hvm_vmx.launch_cpu != smp_processor_id() )
         {
             /* Get register details from remote CPU. */
-            struct vmx_store_cpu_guest_regs_callback_info info = {
+            struct vmx_cpu_guest_regs_callback_info info = {
                 .v = v, .regs = regs, .crs = crs };
             cpumask_t cpumask = cpumask_of_cpu(v->arch.hvm_vmx.launch_cpu);
             on_selected_cpus(cpumask, vmx_store_cpu_guest_regs_callback,
@@ -479,8 +488,33 @@ static void vmx_store_cpu_guest_regs(
 
 void vmx_load_cpu_guest_regs(struct vcpu *v, struct cpu_user_regs *regs)
 {
+    if ( v != current )
+    {
+        /* Non-current VCPUs must be paused to set the register snapshot. */
+        ASSERT(atomic_read(&v->pausecnt) != 0);
+
+        if ( v->arch.hvm_vmx.launch_cpu != smp_processor_id() )
+        {
+            struct vmx_cpu_guest_regs_callback_info info = {
+                .v = v, .regs = regs };
+            cpumask_t cpumask = cpumask_of_cpu(v->arch.hvm_vmx.launch_cpu);
+            on_selected_cpus(cpumask, vmx_load_cpu_guest_regs_callback,
+                             &info, 1, 1);
+            return;
+        }
+
+        /* Register details are on this CPU. Load the correct VMCS. */
+        __vmptrld(virt_to_maddr(v->arch.hvm_vmx.vmcs));
+    }
+
+    ASSERT(v->arch.hvm_vmx.launch_cpu == smp_processor_id());
+
 #if defined (__x86_64__)
     __vmwrite(GUEST_SS_SELECTOR, regs->ss);
+    __vmwrite(GUEST_DS_SELECTOR, regs->ds);
+    __vmwrite(GUEST_ES_SELECTOR, regs->es);
+    __vmwrite(GUEST_GS_SELECTOR, regs->gs);
+    __vmwrite(GUEST_FS_SELECTOR, regs->fs);
     __vmwrite(GUEST_RSP, regs->rsp);
 
     __vmwrite(GUEST_RFLAGS, regs->rflags);
@@ -493,6 +527,11 @@ void vmx_load_cpu_guest_regs(struct vcpu *v, struct cpu_user_regs *regs)
     __vmwrite(GUEST_RIP, regs->rip);
 #elif defined (__i386__)
     __vmwrite(GUEST_SS_SELECTOR, regs->ss);
+    __vmwrite(GUEST_DS_SELECTOR, regs->ds);
+    __vmwrite(GUEST_ES_SELECTOR, regs->es);
+    __vmwrite(GUEST_GS_SELECTOR, regs->gs);
+    __vmwrite(GUEST_FS_SELECTOR, regs->fs);
+
     __vmwrite(GUEST_RSP, regs->esp);
 
     __vmwrite(GUEST_RFLAGS, regs->eflags);
@@ -503,14 +542,11 @@ void vmx_load_cpu_guest_regs(struct vcpu *v, struct cpu_user_regs *regs)
 
     __vmwrite(GUEST_CS_SELECTOR, regs->cs);
     __vmwrite(GUEST_RIP, regs->eip);
-#else
-#error Unsupported architecture
 #endif
-}
 
-void vmx_modify_guest_state(struct vcpu *v)
-{
-    modify_vmcs(&v->arch.hvm_vmx, &v->arch.guest_context.user_regs);
+    /* Reload current VCPU's VMCS if it was temporarily unloaded. */
+    if ( (v != current) && hvm_guest(current) )
+        __vmptrld(virt_to_maddr(current->arch.hvm_vmx.vmcs));
 }
 
 int vmx_realmode(struct vcpu *v)
@@ -661,8 +697,6 @@ int start_vmx(void)
     hvm_funcs.store_cpu_guest_regs = vmx_store_cpu_guest_regs;
     hvm_funcs.load_cpu_guest_regs = vmx_load_cpu_guest_regs;
 
-    hvm_funcs.modify_guest_state = vmx_modify_guest_state;
-
     hvm_funcs.realmode = vmx_realmode;
     hvm_funcs.paging_enabled = vmx_paging_enabled;
     hvm_funcs.instruction_length = vmx_instruction_length;
diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index 3360a2a5a0..23aabeb2b9 100644
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -212,13 +212,13 @@ extern unsigned long _end; /* standard ELF symbol */
  *                                                       ------ ------
  *  I/O remapping area                                   ( 4MB)
  *  Direct-map (1:1) area [Xen code/data/heap]           (12MB)
- *  Per-domain mappings (inc. 4MB map_domain_page cache) ( 4MB)
+ *  Per-domain mappings (inc. 4MB map_domain_page cache) ( 8MB)
  *  Shadow linear pagetable                              ( 4MB) ( 8MB)
  *  Guest linear pagetable                               ( 4MB) ( 8MB)
  *  Machine-to-physical translation table [writable]     ( 4MB) (16MB)
  *  Frame-info table                                     (24MB) (96MB)
  *   * Start of guest inaccessible area
- *  Machine-to-physical translation table [read-only]    ( 4MB)
+ *  Machine-to-physical translation table [read-only]    ( 4MB) (16MB)
  *   * Start of guest unmodifiable area
  */
 
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index eff373996c..8e830977cc 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -47,8 +47,6 @@ struct hvm_function_table {
         struct vcpu *v, struct cpu_user_regs *r, unsigned long *crs);
     void (*load_cpu_guest_regs)(
         struct vcpu *v, struct cpu_user_regs *r);
-    void (*modify_guest_state)(struct vcpu *v);
-
     /*
      * Examine specifics of the guest state:
      * 1) determine whether the guest is in real or vm8086 mode,
@@ -105,12 +103,6 @@ hvm_load_cpu_guest_regs(struct vcpu *v, struct cpu_user_regs *r)
     hvm_funcs.load_cpu_guest_regs(v, r);
 }
 
-static inline void
-hvm_modify_guest_state(struct vcpu *v)
-{
-    hvm_funcs.modify_guest_state(v);
-}
-
 static inline int
 hvm_realmode(struct vcpu *v)
 {
diff --git a/xen/include/asm-x86/hvm/svm/svm.h b/xen/include/asm-x86/hvm/svm/svm.h
index b74ed8c759..30d20238cf 100644
--- a/xen/include/asm-x86/hvm/svm/svm.h
+++ b/xen/include/asm-x86/hvm/svm/svm.h
@@ -39,7 +39,6 @@ extern unsigned int cpu_rev;
 extern void svm_stop(void);
 extern void svm_save_cpu_user_regs(struct vcpu *v, struct cpu_user_regs *regs);
 extern void svm_load_cpu_user_regs(struct vcpu *v, struct cpu_user_regs *regs);
-extern int svm_modify_vmcb(struct vcpu *v, struct cpu_user_regs *regs);
 extern void svm_vmread(struct vcpu *v, int index, unsigned long *value);
 extern void svm_vmwrite(struct vcpu *v, int index, unsigned long value);
 extern void svm_final_setup_guest(struct vcpu *v); 
diff --git a/xen/include/asm-x86/hvm/vmx/vmcs.h b/xen/include/asm-x86/hvm/vmx/vmcs.h
index c77e665463..b2545bbd26 100644
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -89,8 +89,6 @@ struct arch_vmx_struct {
 
 void vmx_do_resume(struct vcpu *);
 struct vmcs_struct *alloc_vmcs(void);
-int modify_vmcs(struct arch_vmx_struct *arch_vmx,
-                struct cpu_user_regs *regs);
 void destroy_vmcs(struct arch_vmx_struct *arch_vmx);
 
 extern void vmx_request_clear_vmcs(struct vcpu *v);