> -----Original Message----- > From: Jan Beulich [mailto:[email protected]] > Sent: 07 September 2017 09:14 > To: xen-devel <[email protected]> > Cc: Andrew Cooper <[email protected]>; Paul Durrant > <[email protected]> > Subject: [PATCH] x86/HVM: drop bogus #PF raising from linear->phys > translation > > Translations spanning a page boundary not resulting in physically > contiguous addresses is not a reason to raise #PF. In fact by not doing > so accesses of this kind are being emulated correctly thanks to the > fallback logic in the insn emulator's REP MOVS/STOS/INS/OUTS handling > (non-string accesses to such locations are being split elsewhere and > hence have been working fine already).
Yes, it does seem like this is way too low a layer to be raising this exception. > > Signed-off-by: Jan Beulich <[email protected]> > Reviewed-by: Paul Durrant <[email protected]> > --- a/xen/arch/x86/hvm/emulate.c > +++ b/xen/arch/x86/hvm/emulate.c > @@ -566,15 +566,12 @@ static int hvmemul_linear_to_phys( > if ( pfec & (PFEC_page_paged | PFEC_page_shared) ) > return X86EMUL_RETRY; > done /= bytes_per_rep; > - *reps = done; > if ( done == 0 ) > { > ASSERT(!reverse); > - if ( npfn != gfn_x(INVALID_GFN) ) > - return X86EMUL_UNHANDLEABLE; > - x86_emul_pagefault(pfec, addr & PAGE_MASK, &hvmemul_ctxt- > >ctxt); > - return X86EMUL_EXCEPTION; > + return X86EMUL_UNHANDLEABLE; > } > + *reps = done; > break; > } > > > _______________________________________________ Xen-devel mailing list [email protected] https://lists.xen.org/xen-devel
