On Fri, 25 Jan 2013 12:59:12 +0900
Takuya Yoshikawa <yoshikawa_takuya...@lab.ntt.co.jp> wrote:

> > The commit c972f3b1 changed the write-protect behaviour - it does
> > wirte-protection only when dirty flag is set.
> > [ I did not see this commit when we discussed the problem before. ]
> 
> I'll look at the commit later, after the lunch break.

I've done!

So we need to do:

        if (npages && (GET_DIRTY || RDONLY))
                write protect

About sync_page, I'm not sure what is the best fix.

        Takuya

> 
> > Further more, i notice that write-protect is not enough, when do sync
> > shadow page:
> > 
> > FNAME(sync_page):
> > 
> >             host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE;
> > 
> >             set_spte(vcpu, &sp->spt[i], pte_access,
> >                      PT_PAGE_TABLE_LEVEL, gfn,
> >                      spte_to_pfn(sp->spt[i]), true, false,
> >                      host_writable);
> > 
> > It sets spte based on the old value that means the readonly flag check
> > is missed. We need to call kvm_arch_flush_shadow_all under this case.
> 
> So the change needed will be in arch/x86.
>       in arch_commit_* one.
> 
> Right?
> 
> Note: I'm not touching arch_* memory slot APIs now because ARM KVM
> is coming now.  So no problem, the flags will be passed as before.
> 
>       Takuya


-- 
Takuya Yoshikawa <yoshikawa_takuya...@lab.ntt.co.jp>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to