vt-d: Fix crash on x86/32.

On 32-bit xen, dom0 crashes when using VT-d to assign devices. It is
caused by setting m2p in clear_mmio_p2m_entry(), because
machine_to_phys_map[] entry for mmio address is not mapped.

Signed-off-by: Weidong Han <weidong.han@intel.com>

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index a241d7cbb3e5f87838b0308f73b9d18b4ac7b9d7..fb0394282af540a4799468a72fd52a7f1d848b39 100644 (file)
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -912,11 +912,6 @@ clear_mmio_p2m_entry(struct domain *d, unsigned long gfn)
     }
     rc = set_p2m_entry(d, gfn, _mfn(INVALID_MFN), 0);
 
-#if !defined(__x86_64__)
-    /* x86_64 xen does not map mmio entries in machine_to_phys_mapp[] */
-    set_gpfn_from_mfn(mfn, INVALID_M2P_ENTRY);
-#endif
-
     return rc;
 }