| Message ID | 1480331616-6165-2-git-send-email-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
At 11:13 +0000 on 28 Nov (1480331598), Andrew Cooper wrote: > When translating the second frame of a write crossing a page boundary, mask > the linear address down to the page boundary. > > This causes the correct %cr2 being reported to the guest in the case that the > second frame suffers a pagefault during translation. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Tim Deegan <tim@xen.org>
>>> On 28.11.16 at 12:13, <andrew.cooper3@citrix.com> wrote: > When translating the second frame of a write crossing a page boundary, mask > the linear address down to the page boundary. > > This causes the correct %cr2 being reported to the guest in the case that the > second frame suffers a pagefault during translation. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c index ced2313..7e5b8b0 100644 --- a/xen/arch/x86/mm/shadow/common.c +++ b/xen/arch/x86/mm/shadow/common.c @@ -1808,7 +1808,8 @@ void *sh_emulate_map_dest(struct vcpu *v, unsigned long vaddr, else { /* This write crosses a page boundary. Translate the second page. */ - sh_ctxt->mfn[1] = emulate_gva_to_mfn(v, vaddr + bytes - 1, sh_ctxt); + sh_ctxt->mfn[1] = emulate_gva_to_mfn( + v, (vaddr + bytes - 1) & PAGE_MASK, sh_ctxt); if ( !mfn_valid(sh_ctxt->mfn[1]) ) return ((mfn_x(sh_ctxt->mfn[1]) == BAD_GVA_TO_GFN) ? MAPPING_EXCEPTION :
When translating the second frame of a write crossing a page boundary, mask the linear address down to the page boundary. This causes the correct %cr2 being reported to the guest in the case that the second frame suffers a pagefault during translation. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Tim Deegan <tim@xen.org> v2: * New --- xen/arch/x86/mm/shadow/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)