Re: [Xen-devel] [PATCH] add SMEP support to HVM guest

["Jan Beulich" <jbeulich@xxxxxxxxxx>]

>>> "Li, Xin" <xin.li@xxxxxxxxx> 06/05/11 2:12 AM >>>
>--- a/xen/arch/x86/hvm/hvm.c    Fri Jun 03 21:39:00 2011 +0100
>+++ b/xen/arch/x86/hvm/hvm.c    Sun Jun 05 08:07:48 2011 +0800
>@@ -1664,7 +1664,8 @@ int hvm_set_cr4(unsigned long value)
>hvm_update_guest_cr(v, 4);
>
>/* Modifying CR4.{PSE,PAE,PGE} invalidates all TLB entries, inc. Global. */
>- if ( (old_cr ^ value) & (X86_CR4_PSE | X86_CR4_PGE | X86_CR4_PAE) ) {
>+ if ( (old_cr ^ value) & (X86_CR4_PSE | X86_CR4_PGE |
>+ X86_CR4_PAE | X86_CR4_SMEP) ) {

Not having access to the specification - why?

>if ( !nestedhvm_vmswitch_in_progress(v) && nestedhvm_vcpu_in_guestmode(v) )
>paging_update_nestedmode(v);
>else
>@@ -2312,7 +2313,8 @@ enum hvm_copy_result hvm_copy_from_guest
>enum hvm_copy_result hvm_fetch_from_guest_virt(
>void *buf, unsigned long vaddr, int size, uint32_t pfec)
>{
>- if ( hvm_nx_enabled(current) )
>+ if ( hvm_nx_enabled(current) ||
>+ (!(pfec | PFEC_user_mode) && hvm_smep_enabled(current)) )

Perhaps rather "!(pfec & PFEC_user_mode)"?

>pfec |= PFEC_insn_fetch;
>return __hvm_copy(buf, vaddr, size,
>HVMCOPY_from_guest | HVMCOPY_fault | HVMCOPY_virt,
>@@ -2338,7 +2340,8 @@ enum hvm_copy_result hvm_copy_from_guest
>enum hvm_copy_result hvm_fetch_from_guest_virt_nofault(
>void *buf, unsigned long vaddr, int size, uint32_t pfec)
>{
>- if ( hvm_nx_enabled(current) )
>+ if ( hvm_nx_enabled(current) ||
>+ (!(pfec | PFEC_user_mode) && hvm_smep_enabled(current)) )

Same here.

Jan

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel