Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest-and-virtio

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest-and-virtio:
  lguest: document 32-bit and PAE requirements
  lguest: tell git to ignore Documentation/lguest/lguest
  virtio: fix suspend when using virtio_balloon
  lguest: fix guest crash on non-linear addresses in gdt pvops
  lguest: fix crash on vmlinux images

Documentation/lguest/.gitignore

@@ -0,0 +1 @@
+lguest

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
+Lguest is designed to be a minimal 32-bit x86 hypervisor for the Linux kernel,
-Linux developers and users to experiment with virtualization with the
+for Linux developers and users to experiment with virtualization with the
-minimum of complexity.  Nonetheless, it should have sufficient
+minimum of complexity.  Nonetheless, it should have sufficient features to
-features to make it useful for specific tasks, and, of course, you are
+make it useful for specific tasks, and, of course, you are encouraged to fork
-encouraged to fork and enhance it (see drivers/lguest/README).
+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)

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
 

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
+ * This is the exactly like the IDT code.
- * 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?
  */
 static void lguest_load_gdt(const struct desc_ptr *desc)
 {
-	BUG_ON((desc->size + 1) / 8 != GDT_ENTRIES);
+	unsigned int i;
-	kvm_hypercall2(LHCALL_LOAD_GDT, __pa(desc->address), GDT_ENTRIES);
+	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

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);

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).
+/*H:620 This is where the Guest asks us to load a new GDT entry
- * We copy it from the Guest and tweak the entries. */
+ * (LHCALL_LOAD_GDT_ENTRY).  We tweak the entry and copy it in. */
-void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
+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. */
+	/* Set it up, then fix it. */
-	__lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
+	cpu->arch.gdt[num].a = lo;
-	fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
+	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;

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:
+	case LHCALL_LOAD_GDT_ENTRY:
-		load_guest_gdt(cpu, args->arg1, args->arg2);
+		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);

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)