[XEN] Get rid of gva_to_gpa translation

It didn't have any sensible error checking.  Make all callers
use gva_to_gfn translation and check the result.  MMIO and PIO
callers inject pagefaults to the guest iof the non-IO address is
not mapped.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 8d369b3b49..43d1343d5f 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -371,7 +371,20 @@ static void hvm_pio_assist(struct cpu_user_regs *regs, ioreq_t *p,
             {
                 unsigned long addr = pio_opp->addr;
                 if ( hvm_paging_enabled(current) )
-                    (void)hvm_copy_to_guest_virt(addr, &p->data, p->size);
+                {
+                    int rv = hvm_copy_to_guest_virt(addr, &p->data, p->size);
+                    if ( rv != 0 ) 
+                    {
+                        /* Failed on the page-spanning copy.  Inject PF into
+                         * the guest for the address where we failed. */
+                        addr += p->size - rv;
+                        gdprintk(XENLOG_DEBUG, "Pagefault writing non-io side "
+                                 "of a page-spanning PIO: va=%#lx\n", addr);
+                        hvm_inject_exception(TRAP_page_fault, 
+                                             PFEC_write_access, addr);
+                        return;
+                    }
+                }
                 else
                     (void)hvm_copy_to_guest_phys(addr, &p->data, p->size);
             }
@@ -489,7 +502,20 @@ static void hvm_mmio_assist(struct cpu_user_regs *regs, ioreq_t *p,
             unsigned long addr = mmio_opp->addr;
 
             if (hvm_paging_enabled(current))
-                (void)hvm_copy_to_guest_virt(addr, &p->data, p->size);
+            {
+                int rv = hvm_copy_to_guest_virt(addr, &p->data, p->size);
+                if ( rv != 0 ) 
+                {
+                    /* Failed on the page-spanning copy.  Inject PF into
+                     * the guest for the address where we failed. */
+                    addr += p->size - rv;
+                    gdprintk(XENLOG_DEBUG, "Pagefault writing non-io side of "
+                             "a page-spanning MMIO: va=%#lx\n", addr);
+                    hvm_inject_exception(TRAP_page_fault, 
+                                         PFEC_write_access, addr);
+                    return;
+                }
+            }
             else
                 (void)hvm_copy_to_guest_phys(addr, &p->data, p->size);
         }