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: barrier me harder
  lguest: use bool instead of int
  lguest: use KVM hypercalls
  lguest: wire up pte_update/pte_update_defer
  lguest: fix spurious BUG_ON() on invalid guest stack.
  virtio: more neatening of virtio_ring macros.
  virtio: fix BAD_RING, START_US and END_USE macros

1 files changed, 12 insertions, 10 deletions

diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index 576a8318221c..a059cf9980f7 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -199,7 +199,7 @@ static void check_gpgd(struct lg_cpu *cpu, pgd_t gpgd)
  *
  * If we fixed up the fault (ie. we mapped the address), this routine returns
  * true.  Otherwise, it was a real fault and we need to tell the Guest. */
-int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
+bool demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 {
         pgd_t gpgd;
         pgd_t *spgd;
@@ -211,7 +211,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
         gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
         /* Toplevel not present?  We can't map it in. */
         if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
-                return 0;
+                return false;
 
         /* Now look at the matching shadow entry. */
         spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
@@ -222,7 +222,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
                  * simple for this corner case. */
                 if (!ptepage) {
                         kill_guest(cpu, "out of memory allocating pte page");
-                        return 0;
+                        return false;
                 }
                 /* We check that the Guest pgd is OK. */
                 check_gpgd(cpu, gpgd);
@@ -238,16 +238,16 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 
         /* If this page isn't in the Guest page tables, we can't page it in. */
         if (!(pte_flags(gpte) & _PAGE_PRESENT))
-                return 0;
+                return false;
 
         /* Check they're not trying to write to a page the Guest wants
          * read-only (bit 2 of errcode == write). */
         if ((errcode & 2) && !(pte_flags(gpte) & _PAGE_RW))
-                return 0;
+                return false;
 
         /* User access to a kernel-only page? (bit 3 == user access) */
         if ((errcode & 4) && !(pte_flags(gpte) & _PAGE_USER))
-                return 0;
+                return false;
 
         /* Check that the Guest PTE flags are OK, and the page number is below
          * the pfn_limit (ie. not mapping the Launcher binary). */
@@ -283,7 +283,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
          * manipulated, the result returned and the code complete.  A small
          * delay and a trace of alliteration are the only indications the Guest
          * has that a page fault occurred at all. */
-        return 1;
+        return true;
 }
 
 /*H:360
@@ -296,7 +296,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
  *
  * This is a quick version which answers the question: is this virtual address
  * mapped by the shadow page tables, and is it writable? */
-static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
+static bool page_writable(struct lg_cpu *cpu, unsigned long vaddr)
 {
         pgd_t *spgd;
         unsigned long flags;
@@ -304,7 +304,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
         /* Look at the current top level entry: is it present? */
         spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
         if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
-                return 0;
+                return false;
 
         /* Check the flags on the pte entry itself: it must be present and
          * writable. */
@@ -373,8 +373,10 @@ unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr)
         /* First step: get the top-level Guest page table entry. */
         gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
         /* Toplevel not present?  We can't map it in. */
-        if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
+        if (!(pgd_flags(gpgd) & _PAGE_PRESENT)) {
                 kill_guest(cpu, "Bad address %#lx", vaddr);
+                return -1UL;
+        }
 
         gpte = lgread(cpu, gpte_addr(gpgd, vaddr), pte_t);
         if (!(pte_flags(gpte) & _PAGE_PRESENT))