diff options
-rw-r--r-- | xen/arch/x86/mm/guest_walk.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/xen/arch/x86/mm/guest_walk.c b/xen/arch/x86/mm/guest_walk.c index bc4a82f878..88fc4f8cf4 100644 --- a/xen/arch/x86/mm/guest_walk.c +++ b/xen/arch/x86/mm/guest_walk.c @@ -179,8 +179,11 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, l4p = (guest_l4e_t *) top_map; gw->l4e = l4p[guest_l4_table_offset(va)]; gflags = guest_l4e_get_flags(gw->l4e) ^ iflags; + if ( !(gflags & _PAGE_PRESENT) ) { + rc |= _PAGE_PRESENT; + goto out; + } rc |= ((gflags & mflags) ^ mflags); - if ( rc & _PAGE_PRESENT ) goto out; /* Map the l3 table */ l3p = map_domain_gfn(p2m, @@ -193,9 +196,11 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, /* Get the l3e and check its flags*/ gw->l3e = l3p[guest_l3_table_offset(va)]; gflags = guest_l3e_get_flags(gw->l3e) ^ iflags; - rc |= ((gflags & mflags) ^ mflags); - if ( rc & _PAGE_PRESENT ) + if ( !(gflags & _PAGE_PRESENT) ) { + rc |= _PAGE_PRESENT; goto out; + } + rc |= ((gflags & mflags) ^ mflags); pse1G = (gflags & _PAGE_PSE) && guest_supports_1G_superpages(v); @@ -261,9 +266,11 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, #endif /* All levels... */ gflags = guest_l2e_get_flags(gw->l2e) ^ iflags; - rc |= ((gflags & mflags) ^ mflags); - if ( rc & _PAGE_PRESENT ) + if ( !(gflags & _PAGE_PRESENT) ) { + rc |= _PAGE_PRESENT; goto out; + } + rc |= ((gflags & mflags) ^ mflags); pse2M = (gflags & _PAGE_PSE) && guest_supports_superpages(v); @@ -321,6 +328,10 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, goto out; gw->l1e = l1p[guest_l1_table_offset(va)]; gflags = guest_l1e_get_flags(gw->l1e) ^ iflags; + if ( !(gflags & _PAGE_PRESENT) ) { + rc |= _PAGE_PRESENT; + goto out; + } rc |= ((gflags & mflags) ^ mflags); } |