8 files changed, 35 insertions, 23 deletions

diff --git a/Documentation/lguest/.gitignore b/Documentation/lguest/.gitignore
new file mode 100644
index 000000000000..115587fd5f65
--- /dev/null
+++ b/Documentation/lguest/.gitignore
@@ -0,0 +1 @@
+lguest
diff --git a/Documentation/lguest/lguest.txt b/Documentation/lguest/lguest.txt
index 29510dc51510..28c747362f95 100644
--- a/Documentation/lguest/lguest.txt
+++ b/Documentation/lguest/lguest.txt
@@ -3,11 +3,11 @@
  /,    /`      - or, A Young Coder's Illustrated Hypervisor
  \\"--\\    http://lguest.ozlabs.org
 
-Lguest is designed to be a minimal hypervisor for the Linux kernel, for
-Linux developers and users to experiment with virtualization with the
-minimum of complexity.  Nonetheless, it should have sufficient
-features to make it useful for specific tasks, and, of course, you are
-encouraged to fork and enhance it (see drivers/lguest/README).
+Lguest is designed to be a minimal 32-bit x86 hypervisor for the Linux kernel,
+for Linux developers and users to experiment with virtualization with the
+minimum of complexity.  Nonetheless, it should have sufficient features to
+make it useful for specific tasks, and, of course, you are encouraged to fork
+and enhance it (see drivers/lguest/README).
 
 Features:
 
@@ -37,6 +37,7 @@ Running Lguest:
      "Paravirtualized guest support" = Y
         "Lguest guest support" = Y
      "High Memory Support" = off/4GB
+     "PAE (Physical Address Extension) Support" = N
      "Alignment value to which kernel should be aligned" = 0x100000
         (CONFIG_PARAVIRT=y, CONFIG_LGUEST_GUEST=y, CONFIG_HIGHMEM64G=n and
          CONFIG_PHYSICAL_ALIGN=0x100000)
diff --git a/arch/x86/include/asm/lguest_hcall.h b/arch/x86/include/asm/lguest_hcall.h
index 0f4ee7148afe..faae1996487b 100644
--- a/arch/x86/include/asm/lguest_hcall.h
+++ b/arch/x86/include/asm/lguest_hcall.h
@@ -5,7 +5,6 @@
 #define LHCALL_FLUSH_ASYNC      0
 #define LHCALL_LGUEST_INIT      1
 #define LHCALL_SHUTDOWN         2
-#define LHCALL_LOAD_GDT         3
 #define LHCALL_NEW_PGTABLE      4
 #define LHCALL_FLUSH_TLB        5
 #define LHCALL_LOAD_IDT_ENTRY   6
@@ -17,6 +16,7 @@
 #define LHCALL_SET_PMD          15
 #define LHCALL_LOAD_TLS         16
 #define LHCALL_NOTIFY           17
+#define LHCALL_LOAD_GDT_ENTRY   18
 
 #define LGUEST_TRAP_ENTRY 0x1F
 
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index e94a11e42f98..a2085368a3dc 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -273,15 +273,15 @@ static void lguest_load_idt(const struct desc_ptr *desc)
  * controls the entire thing and the Guest asks it to make changes using the
  * LOAD_GDT hypercall.
  *
- * This is the opposite of the IDT code where we have a LOAD_IDT_ENTRY
- * hypercall and use that repeatedly to load a new IDT.  I don't think it
- * really matters, but wouldn't it be nice if they were the same?  Wouldn't
- * it be even better if you were the one to send the patch to fix it?
+ * This is the exactly like the IDT code.
  */
 static void lguest_load_gdt(const struct desc_ptr *desc)
 {
-        BUG_ON((desc->size + 1) / 8 != GDT_ENTRIES);
-        kvm_hypercall2(LHCALL_LOAD_GDT, __pa(desc->address), GDT_ENTRIES);
+        unsigned int i;
+        struct desc_struct *gdt = (void *)desc->address;
+
+        for (i = 0; i < (desc->size+1)/8; i++)
+                kvm_hypercall3(LHCALL_LOAD_GDT_ENTRY, i, gdt[i].a, gdt[i].b);
 }
 
 /* For a single GDT entry which changes, we do the lazy thing: alter our GDT,
@@ -291,7 +291,9 @@ static void lguest_write_gdt_entry(struct desc_struct *dt, int entrynum,
                                    const void *desc, int type)
 {
         native_write_gdt_entry(dt, entrynum, desc, type);
-        kvm_hypercall2(LHCALL_LOAD_GDT, __pa(dt), GDT_ENTRIES);
+        /* Tell Host about this new entry. */
+        kvm_hypercall3(LHCALL_LOAD_GDT_ENTRY, entrynum,
+                       dt[entrynum].a, dt[entrynum].b);
 }
 
 /* OK, I lied.  There are three "thread local storage" GDT entries which change
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index ac8a4a3741b8..af92a176697f 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -158,7 +158,8 @@ void free_interrupts(void);
 /* segments.c: */
 void setup_default_gdt_entries(struct lguest_ro_state *state);
 void setup_guest_gdt(struct lg_cpu *cpu);
-void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num);
+void load_guest_gdt_entry(struct lg_cpu *cpu, unsigned int i,
+                          u32 low, u32 hi);
 void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
 void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
 void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c
index 4f15439b7f12..7ede64ffeef9 100644
--- a/drivers/lguest/segments.c
+++ b/drivers/lguest/segments.c
@@ -144,18 +144,19 @@ void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt)
                         gdt[i] = cpu->arch.gdt[i];
 }
 
-/*H:620 This is where the Guest asks us to load a new GDT (LHCALL_LOAD_GDT).
- * We copy it from the Guest and tweak the entries. */
-void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
+/*H:620 This is where the Guest asks us to load a new GDT entry
+ * (LHCALL_LOAD_GDT_ENTRY).  We tweak the entry and copy it in. */
+void load_guest_gdt_entry(struct lg_cpu *cpu, u32 num, u32 lo, u32 hi)
 {
         /* We assume the Guest has the same number of GDT entries as the
          * Host, otherwise we'd have to dynamically allocate the Guest GDT. */
         if (num > ARRAY_SIZE(cpu->arch.gdt))
                 kill_guest(cpu, "too many gdt entries %i", num);
 
-        /* We read the whole thing in, then fix it up. */
-        __lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
-        fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
+        /* Set it up, then fix it. */
+        cpu->arch.gdt[num].a = lo;
+        cpu->arch.gdt[num].b = hi;
+        fixup_gdt_table(cpu, num, num+1);
         /* Mark that the GDT changed so the core knows it has to copy it again,
          * even if the Guest is run on the same CPU. */
         cpu->changed |= CHANGED_GDT;
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index a6b717644be0..1a83910f674f 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -324,6 +324,11 @@ static void rewrite_hypercall(struct lg_cpu *cpu)
         u8 insn[3] = {0xcd, 0x1f, 0x90};
 
         __lgwrite(cpu, guest_pa(cpu, cpu->regs->eip), insn, sizeof(insn));
+        /* The above write might have caused a copy of that page to be made
+         * (if it was read-only).  We need to make sure the Guest has
+         * up-to-date pagetables.  As this doesn't happen often, we can just
+         * drop them all. */
+        guest_pagetable_clear_all(cpu);
 }
 
 static bool is_hypercall(struct lg_cpu *cpu)
@@ -563,8 +568,8 @@ void __exit lguest_arch_host_fini(void)
 int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
         switch (args->arg0) {
-        case LHCALL_LOAD_GDT:
-                load_guest_gdt(cpu, args->arg1, args->arg2);
+        case LHCALL_LOAD_GDT_ENTRY:
+                load_guest_gdt_entry(cpu, args->arg1, args->arg2, args->arg3);
                 break;
         case LHCALL_LOAD_IDT_ENTRY:
                 load_guest_idt_entry(cpu, args->arg1, args->arg2, args->arg3);
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 59268266b79a..9c76a061a04d 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -190,7 +190,8 @@ static int balloon(void *_vballoon)
                 try_to_freeze();
                 wait_event_interruptible(vb->config_change,
                                          (diff = towards_target(vb)) != 0
-                                         || kthread_should_stop());
+                                         || kthread_should_stop()
+                                         || freezing(current));
                 if (diff > 0)
                         fill_balloon(vb, diff);
                 else if (diff < 0)