Re: [Xen-devel] [PATCH v2 2/2] x86/mm: merge ptwr and mmio_ro page fault handlers

>>> On 01.09.17 at 15:50, wrote: > On Fri, Sep 01, 2017 at 02:46:27PM +0100, Wei Liu wrote: >> On Fri, Sep 01, 2017 at 03:38:49AM -0600, Jan Beulich wrote: >> > > + struct cpu_user_regs *regs) >> > > +{ >> > > +l1_pgentry_t pte; >> > > +struct

Re: [Xen-devel] [PATCH v2 2/2] x86/mm: merge ptwr and mmio_ro page fault handlers

On Fri, Sep 01, 2017 at 02:46:27PM +0100, Wei Liu wrote: > On Fri, Sep 01, 2017 at 03:38:49AM -0600, Jan Beulich wrote: > > > /* > > > * fault handling for read-only MMIO pages > > > */ > > > > Note how you move the remains of the function above below this > >

Re: [Xen-devel] [PATCH v2 2/2] x86/mm: merge ptwr and mmio_ro page fault handlers

On Fri, Sep 01, 2017 at 03:38:49AM -0600, Jan Beulich wrote: > > /* > > * fault handling for read-only MMIO pages > > */ > > Note how you move the remains of the function above below this > comment, which isn't really correct. I can place the new function where the

Re: [Xen-devel] [PATCH v2 2/2] x86/mm: merge ptwr and mmio_ro page fault handlers

>>> On 31.08.17 at 13:22, wrote: > --- a/xen/arch/x86/mm.c > +++ b/xen/arch/x86/mm.c > @@ -5176,91 +5176,6 @@ static const struct x86_emulate_ops ptwr_emulate_ops = > { > .cpuid = pv_emul_cpuid, > }; > > -/* Write page fault handler: check if guest is trying to

[Xen-devel] [PATCH v2 2/2] x86/mm: merge ptwr and mmio_ro page fault handlers

Provide a unified entry to avoid going through pte look-up, decode and emulation cycle more than necessary. The path taken is determined by the faulting address. Note that the order of checks is changed in the new function, but the order of the checks is performed shouldn't matter. The sole