On Thu, Oct 23, 2008 at 10:03:55AM +0800, Xu, Anthony wrote:
> Isaku Yamahata wrote:
> > On Wed, Oct 22, 2008 at 05:35:36PM +0800, Xu, Anthony wrote:
> >> The new one,
> >>
> >>
> >>>> - if (phy_pte.ma != VA_MATTR_NATPAGE)
> >>>> + /* if a device is assigned to a domain through VTD, the MMIO
> >>>> for this + * device needs to retain to UC attribute + */
> >>>> + if (phy_pte.ma == VA_MATTR_WC)
> >>>> phy_pte.ma = VA_MATTR_WB;
> >>>>
> >>>
> >>> Doesn't this break the intention of the c/s 15134:466f71b1e831?a
> >>> To be honest, I'm not sure. Kyouya or Akio, do you have any
> >>> comments?
> >>>
> >> This section is not included, need kyouya or akio confirmation.
> >>
> >> Patches about mm.c is not inculded,
> >> I'll send out a separate patch.
> >
> > Sounds good. the stuff in mm.c seems very tough.
> > However the following patch still touches mm.c.
> > Did you forget to remove it accidently?
>
> I didn't remove all mm.c small patches,
> I just removed the difficult part, which is related to atomic operation
>
> Please, check in this patch first, I had tested it by booting linux guest.
There is a race.
guest_physmap_{add, remove}_page() can be called for PV domain
simultaneously.
The p2m table and the iommu table are updated without any lock.
So they can be inconsistent with each other.
thanks,
> >> diff -r 02c8733e2d91 xen/arch/ia64/vmx/viosapic.c
> >> --- a/xen/arch/ia64/vmx/viosapic.c Wed Oct 22 17:20:15 2008 +0900
> >> +++ b/xen/arch/ia64/vmx/viosapic.c Wed Oct 22 17:08:32 2008 +0800
> >> @@ -121,6 +121,13 @@ redir_num, vector);
> >> return;
> >> }
> >> + if ( iommu_enabled )
> >> + {
> >> + spin_unlock(&viosapic->lock);
> >> + hvm_dpci_eoi(current->domain, redir_num,
> >> &viosapic->redirtbl[redir_num]); + spin_lock(&viosapic->lock);
> >> + }
> >> +
> >> service_iosapic(viosapic);
> >> spin_unlock(&viosapic->lock);
> >> }
> >
> > viosapic->isr and irr must handled atomically.
> > So unlocking and locking again breaks the requirement.
> > (I haven't looked the viosapic code very closely, though.
> > So I may be wrong.)
> >
> >
> >> diff -r 02c8733e2d91 xen/arch/ia64/xen/mm.c
> >> --- a/xen/arch/ia64/xen/mm.c Wed Oct 22 17:20:15 2008 +0900
> >> +++ b/xen/arch/ia64/xen/mm.c Wed Oct 22 17:08:32 2008 +0800 @@
> >> -1427,6 +1427,8 @@ if (mfn == INVALID_MFN) {
> >> // clear pte
> >> old_pte = ptep_get_and_clear(mm, mpaddr, pte);
> >> + if(!pte_mem(old_pte))
> >> + return;
> >> mfn = pte_pfn(old_pte);
> >> } else {
> >> unsigned long old_arflags;
> >> @@ -1463,6 +1465,13 @@
> >> perfc_incr(zap_domain_page_one);
> >> if(!mfn_valid(mfn))
> >> return;
> >> +
> >> + {
> >> + int i, j;
> >> + j = 1 << (PAGE_SHIFT-PAGE_SHIFT_4K);
> >> + for(i = 0 ; i < j; i++)
> >> + iommu_unmap_page(d, (mpaddr>>PAGE_SHIFT)*j + i); + }
> >>
> >> page = mfn_to_page(mfn);
> >> BUG_ON((page->count_info & PGC_count_mask) == 0); @@ -2844,10
> >> +2853,16 @@ __guest_physmap_add_page(struct domain *d, unsigned
> >> long gpfn, unsigned long mfn)
> >> {
> >> + int i, j;
> >> +
> >> set_gpfn_from_mfn(mfn, gpfn);
> >> smp_mb();
> >> assign_domain_page_replace(d, gpfn << PAGE_SHIFT, mfn,
> >> ASSIGN_writable |
> >> ASSIGN_pgc_allocated); + j = 1 << (PAGE_SHIFT-PAGE_SHIFT_4K);
> >> + for(i = 0 ; i < j; i++)
> >> + iommu_map_page(d, gpfn*j + i, mfn*j + i);
> >> +
> >> }
> >>
> >> int
> >
> > The same loop logic. Introducing a helper function would help?
>
--
yamahata
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