>>> On 16.08.17 at 18:47, <andrew.coop...@citrix.com> wrote: > On 16/08/17 16:23, Jan Beulich wrote: >>>>> On 16.08.17 at 13:22, <andrew.coop...@citrix.com> wrote: >>> --- a/xen/arch/x86/mm/shadow/multi.c >>> +++ b/xen/arch/x86/mm/shadow/multi.c >>> @@ -3112,7 +3112,6 @@ static int sh_page_fault(struct vcpu *v, >>> * will make sure no inconsistent mapping being translated into >>> * shadow page table. */ >>> version = atomic_read(&d->arch.paging.shadow.gtable_dirty_version); >>> - rmb(); >>> walk_ok = sh_walk_guest_tables(v, va, &gw, error_code); >> Isn't this supposed to make sure version is being read first? I.e. >> doesn't this at least need to be barrier()? > > atomic_read() is not free to be reordered by the compiler. It is an asm > volatile with a volatile memory reference.
Oh, right - I did forget about the volatiles there (since generally, like in Linux, we appear to try to avoid volatile). Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
