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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-ia64-devel][PATCH][VTD]change ioports_permit_access interface
On Fri, Oct 17, 2008 at 05:58:45PM +0900, Isaku Yamahata wrote:
> On Fri, Oct 17, 2008 at 04:45:09PM +0800, Xu, Anthony wrote:
> > Hi isaku,
> >
> > If I remembered correctly, last time I encountered issue at line page =
> > mfn_to_page(mfn);
> > Page returns 0.
>
> Which line do you have trouble?
> Do you mean that mfn_to_page(mfn) returned NULL?
> or
> Did you hit BUG_ON(page_get_owner(page) == NULL)?
>
>
>
> >
> > I suspect if page_info for IOPORTs is initialized.
> > Any idea?
Ah, I think they are initialized, but they are free.
i.e. page refcount = 0, page owner = NULL.
So you may need to make them owned by DOMID_IO somewhere of the
initialization.
i.e. page refcount = 1, page owner = DOMID_IO.
> >
> > Thanks,
> > Anthony
> >
> >
> > mm_teardown_pte(struct domain* d, volatile pte_t* pte, unsigned long offset)
> > {
> > pte_t old_pte;
> > unsigned long mfn;
> > struct page_info* page;
> >
> > old_pte = ptep_get_and_clear(&d->arch.mm, offset, pte);// acquire
> > semantics
> >
> > // vmx domain use bit[58:56] to distinguish io region from memory.
> > // see vmx_build_physmap_table() in vmx_init.c
> > if (!pte_mem(old_pte))
> > return;
> >
> > // domain might map IO space or acpi table pages. check it.
> > mfn = pte_pfn(old_pte);
> > if (!mfn_valid(mfn))
> > return;
> > page = mfn_to_page(mfn);
> > BUG_ON(page_get_owner(page) == NULL);
> >
> >
> >
> >
> > Isaku Yamahata wrote:
> > > On Fri, Oct 17, 2008 at 03:22:18PM +0800, Xu, Anthony wrote:
> > >> Isaku Yamahata wrote:
> > >>> On Thu, Oct 16, 2008 at 07:37:51PM +0800, Xu, Anthony wrote:
> > >>>> use VTD to assing device, guest port may not be equal to host port.
> > >>>> Change ioports_permit_access interface
> > >>>> add deassign_domain_mmio_page interface
> > >>>>
> > >>>> Signed-off-by; Anthony Xu < anthony.xu@xxxxxxxxx >
> > >>>
> > >>> Some comments.
> > >>>
> > >>> - ioports_permit_access()
> > >>> x86 didn't change its prototype.
> > >>> Why does only ia64 need to change it?
> > >>> Or will x86 also change it?
> > >> In x86 side, only it is identity mapping, guest can access the port
> > >> directly.
> > >> If it is not identity mapping, guest can not access the port
> > >> directly, at this situation, xen will intercept io port access
> > >> first, and xen access the corresponding physical port.
> > >>
> > >> In ia64 side, guest can acess all assigned port whenever it is
> > >> identity mapping or not. So we need to change the interface.
> > >
> > > Understood. x86 have io instructions.
> > > Okay, please split out ioports_permit_access(), then I'll take it.
> > >
> > >>
> > >>
> > >>>
> > >>> I suppose, it would be nice to map the port io area
> > >>> to arbitrary guest physical area.
> > >>> But I'm not sure how x86 will go with XEN_DOMCTL_ioport_mapping.
> > >>>
> > >>> - deassign_domain_mmio_page()
> > >>> calling __assgin_domain_page() may result in page reference count
> > >>> leak because the corresponding p2m entry may be changed to
> > >>> another value. So you want to modify zap_domain_page_one() so
> > >>> that it accepts iomem page and call it from
> > >>> deassign_domain_mmio_page().
> > >>
> > >> There is no page_info for mmio page, I didn't see reference count
> > >> issue.
> > >>
> > >> If VTD is enabled, in the life of guest, p2m can not be changed,
> > >> Because it VTD operation hit a page table miss, the DMA operation
> > >> can not be resumed.
> > >
> > > Hmm, it is possible for qemu-dm (or any tools stack in dom0) can
> > > issue racy hypercall, isn't it.
> > > Anyway __assgin_domain_page() isn't assumed to use for deassigning
> > > page. (Sorry, I have to admit those functions are somewhat
> > > confusing...) How about the following patch? I did only compile
> > > test, though.
> > > With the following modification zap_domain_page_one() could be used
> > > by deassign_domain_mmio_page().
> > > Probably you may want to twist mfn_valid() with is_iomem_page() or
> > > something.
> > >
> > > thanks,
> > >
> > > diff -r 7db30bf36b0e xen/arch/ia64/xen/mm.c
> > > --- a/xen/arch/ia64/xen/mm.c Fri Oct 17 15:33:03 2008 +0900
> > > +++ b/xen/arch/ia64/xen/mm.c Fri Oct 17 16:58:34 2008 +0900
> > > @@ -1422,8 +1422,9 @@
> > > again:
> > > // memory_exchange() calls guest_physmap_remove_page() with
> > > // a stealed page. i.e. page owner = NULL.
> > > - BUG_ON(page_get_owner(mfn_to_page(mfn)) != d &&
> > > - page_get_owner(mfn_to_page(mfn)) != NULL);
> > > + BUG_ON(mfn_valid(mfn) &&
> > > + (page_get_owner(mfn_to_page(mfn)) != d &&
> > > + page_get_owner(mfn_to_page(mfn)) != NULL));
> > > old_arflags = pte_val(*pte) & ~_PAGE_PPN_MASK;
> > > old_pte = pfn_pte(mfn, __pgprot(old_arflags));
> > > new_pte = __pte(0);
> > > @@ -1445,12 +1446,15 @@
> > > BUG_ON(mfn != pte_pfn(ret_pte));
> > > }
> > >
> > > + perfc_incr(zap_domain_page_one);
> > > + if (!mfn_valid(mfn))
> > > + return;
> > > +
> > > page = mfn_to_page(mfn);
> > > BUG_ON((page->count_info & PGC_count_mask) == 0);
> > >
> > > BUG_ON(clear_PGC_allocate && (page_get_owner(page) == NULL));
> > > domain_put_page(d, mpaddr, pte, old_pte, clear_PGC_allocate);
> > > - perfc_incr(zap_domain_page_one);
> > > }
> > >
> > > unsigned long
> > >
> > >
> > >>
> > >>
> > >> Thanks,
> > >> Anthony
> > >>
> > >>>
> > >>> - probably it would better to split this patch into two ones.
> > >>>
> > >>> thanks,
> > >>>
> > >>>> use VTD to assing device, guest port may not be equal to host port.
> > >>>> Change ioports_permit_access interface
> > >>>> add deassign_domain_mmio_page interface
> > >>>>
> > >>>> Signed-off-by; Anthony Xu < anthony.xu@xxxxxxxxx >
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>> diff -r 42c7733c1a2a xen/arch/ia64/xen/dom0_ops.c
> > >>>> --- a/xen/arch/ia64/xen/dom0_ops.c Thu Oct 16 18:18:39 2008
> > >>>> +0800 +++ b/xen/arch/ia64/xen/dom0_ops.c Thu Oct 16 19:13:01
> > >>>> 2008 +0800 @@ -203,7 +203,7 @@ ret = 0;
> > >>>> else {
> > >>>> if (op->u.ioport_permission.allow_access)
> > >>>> - ret = ioports_permit_access(d, fp, lp);
> > >>>> + ret = ioports_permit_access(d, fp, fp, lp);
> > >>>> else ret = ioports_deny_access(d, fp, lp); } @@
> > >>>> -522,7 +522,7 @@ fp = space_number << IO_SPACE_BITS;
> > >>>> lp = fp | 0xffff;
> > >>>>
> > >>>> - return ioports_permit_access(d, fp, lp);
> > >>>> + return ioports_permit_access(d, fp, fp, lp);
> > >>>> }
> > >>>>
> > >>>> unsigned long
> > >>>> diff -r 42c7733c1a2a xen/arch/ia64/xen/domain.c
> > >>>> --- a/xen/arch/ia64/xen/domain.c Thu Oct 16 18:18:39 2008
> > >>>> +0800 +++ b/xen/arch/ia64/xen/domain.c Thu Oct 16 19:13:01
> > >>>> 2008 +0800 @@ -1995,7 +1995,7 @@ BUG();
> > >>>> if (irqs_permit_access(d, 0, NR_IRQS-1))
> > >>>> BUG();
> > >>>> - if (ioports_permit_access(d, 0, 0xffff))
> > >>>> + if (ioports_permit_access(d, 0, 0, 0xffff))
> > >>>> BUG();
> > >>>> }
> > >>>>
> > >>>> diff -r 42c7733c1a2a xen/arch/ia64/xen/mm.c
> > >>>> --- a/xen/arch/ia64/xen/mm.c Thu Oct 16 18:18:39 2008 +0800
> > >>>> +++ b/xen/arch/ia64/xen/mm.c Thu Oct 16 19:13:01 2008 +0800 @@
> > >>>> -984,15 +984,22 @@ ASSIGN_writable
> > >>>> | ASSIGN_pgc_allocated); }
> > >>>>
> > >>>> +/*
> > >>>> + * Inpurt
> > >>>> + * fgp: first guest port
> > >>>> + * fmp: first machine port
> > >>>> + * lmp: last machine port
> > >>>> + */
> > >>>> int
> > >>>> -ioports_permit_access(struct domain *d, unsigned int fp, unsigned
> > >>>> int lp) +ioports_permit_access(struct domain *d, unsigned int fgp,
> > >>>> + unsigned int fmp, unsigned int lmp)
> > >>>> {
> > >>>> struct io_space *space;
> > >>>> - unsigned long mmio_start, mmio_end, mach_start;
> > >>>> + unsigned long mmio_start, mach_start, mach_end; int ret;
> > >>>>
> > >>>> - if (IO_SPACE_NR(fp) >= num_io_spaces) {
> > >>>> - dprintk(XENLOG_WARNING, "Unknown I/O Port range 0x%x -
> > >>>> 0x%x\n", fp, lp); + if (IO_SPACE_NR(fmp) >= num_io_spaces) {
> > >>>> + dprintk(XENLOG_WARNING, "Unknown I/O Port range 0x%x -
> > >>>> 0x%x\n", fmp, lmp); return -EFAULT; }
> > >>>>
> > >>>> @@ -1006,42 +1013,44 @@
> > >>>> * I/O port spaces and thus will number port spaces
> > >>>> differently.
> > >>>> * This is ok, they don't make use of this interface. */
> > >>>> - ret = rangeset_add_range(d->arch.ioport_caps, fp, lp);
> > >>>> + ret = rangeset_add_range(d->arch.ioport_caps, fmp, lmp);
> > >>>> if (ret != 0) return ret;
> > >>>>
> > >>>> - space = &io_space[IO_SPACE_NR(fp)];
> > >>>> + space = &io_space[IO_SPACE_NR(fmp)];
> > >>>>
> > >>>> /* Legacy I/O on dom0 is already setup */
> > >>>> if (d == dom0 && space == &io_space[0])
> > >>>> return 0;
> > >>>>
> > >>>> - fp = IO_SPACE_PORT(fp);
> > >>>> - lp = IO_SPACE_PORT(lp);
> > >>>> + fmp = IO_SPACE_PORT(fmp);
> > >>>> + lmp = IO_SPACE_PORT(lmp);
> > >>>>
> > >>>> if (space->sparse) {
> > >>>> - mmio_start = IO_SPACE_SPARSE_ENCODING(fp) & PAGE_MASK;
> > >>>> - mmio_end = PAGE_ALIGN(IO_SPACE_SPARSE_ENCODING(lp));
> > >>>> + mach_start = IO_SPACE_SPARSE_ENCODING(fmp) & PAGE_MASK;
> > >>>> + mach_end = PAGE_ALIGN(IO_SPACE_SPARSE_ENCODING(lmp)); }
> > >>>> else {
> > >>>> - mmio_start = fp & PAGE_MASK;
> > >>>> - mmio_end = PAGE_ALIGN(lp);
> > >>>> + mach_start = fmp & PAGE_MASK;
> > >>>> + mach_end = PAGE_ALIGN(lmp);
> > >>>> }
> > >>>>
> > >>>> /*
> > >>>> * The "machine first port" is not necessarily identity mapped
> > >>>> * to the guest first port. At least for the legacy range.
> > >>>> */ - mach_start = mmio_start | __pa(space->mmio_base);
> > >>>> + mach_start = mach_start | __pa(space->mmio_base);
> > >>>> + mach_end = mach_end | __pa(space->mmio_base);
> > >>>>
> > >>>> - if (space == &io_space[0]) {
> > >>>> + mmio_start = IO_SPACE_SPARSE_ENCODING(fgp) & PAGE_MASK; +
> > >>>> + if ( VMX_DOMAIN(d->vcpu[0]))
> > >>>> + mmio_start |= LEGACY_IO_START;
> > >>>> + else if (space == &io_space[0])
> > >>>> mmio_start |= IO_PORTS_PADDR;
> > >>>> - mmio_end |= IO_PORTS_PADDR;
> > >>>> - } else {
> > >>>> + else
> > >>>> mmio_start |= __pa(space->mmio_base);
> > >>>> - mmio_end |= __pa(space->mmio_base);
> > >>>> - }
> > >>>>
> > >>>> - while (mmio_start <= mmio_end) {
> > >>>> + while (mach_start < mach_end) {
> > >>>> __assign_domain_page(d, mmio_start,
> > >>>> mach_start, ASSIGN_nocache | ASSIGN_direct_io);
> > >>>> mmio_start += PAGE_SIZE;
> > >>>> @@ -1091,7 +1100,9 @@
> > >>>> mmio_end = PAGE_ALIGN(lp_base);
> > >>>> }
> > >>>>
> > >>>> - if (space == &io_space[0] && d != dom0)
> > >>>> + if (VMX_DOMAIN(d->vcpu[0]))
> > >>>> + mmio_base = LEGACY_IO_START;
> > >>>> + else if (space == &io_space[0] && d != dom0)
> > >>>> mmio_base = IO_PORTS_PADDR;
> > >>>> else
> > >>>> mmio_base = __pa(space->mmio_base);
> > >>>> @@ -1217,6 +1228,33 @@
> > >>>>
> > >>>> return mpaddr;
> > >>>> }
> > >>>> +
> > >>>> +int
> > >>>> +deassign_domain_mmio_page(struct domain *d, unsigned long mpaddr,
> > >>>> + unsigned long phys_addr, unsigned long size ) +{
> > >>>> + unsigned long addr = mpaddr & PAGE_MASK;
> > >>>> + unsigned long end = PAGE_ALIGN(mpaddr + size); + + if
> > >>>> (size == 0) { + gdprintk(XENLOG_INFO, "%s: domain %p mpaddr
> > >>>> 0x%lx size = 0x%lx\n", + __func__, d, mpaddr,
> > >>>> size); + } + if (!efi_mmio(phys_addr, size)) {
> > >>>> +#ifndef NDEBUG
> > >>>> + gdprintk(XENLOG_INFO, "%s: domain %p mpaddr 0x%lx size =
> > >>>> 0x%lx\n", + __func__, d, mpaddr, size); +#endif
> > >>>> + return -EINVAL;
> > >>>> + }
> > >>>> +
> > >>>> + for (; addr < end; addr += PAGE_SIZE ) {
> > >>>> + __assign_domain_page(d, addr, 0,
> > >>>> + ASSIGN_nocache | ASSIGN_direct_io); + } +
> > >>>> return 0; +}
> > >>>> +
> > >>>>
> > >>>> unsigned long
> > >>>> assign_domain_mach_page(struct domain *d,
> > >>>> diff -r 42c7733c1a2a xen/include/asm-ia64/iocap.h
> > >>>> --- a/xen/include/asm-ia64/iocap.h Thu Oct 16 18:18:39 2008
> > >>>> +0800 +++ b/xen/include/asm-ia64/iocap.h Thu Oct 16 19:13:01
> > >>>> 2008 +0800 @@ -7,7 +7,7 @@ #ifndef __IA64_IOCAP_H__
> > >>>> #define __IA64_IOCAP_H__
> > >>>>
> > >>>> -extern int ioports_permit_access(struct domain *d,
> > >>>> +extern int ioports_permit_access(struct domain *d, unsigned int
> > >>>> gs, unsigned int s, unsigned int e);
> > >>>> extern int ioports_deny_access(struct domain *d,
> > >>>> unsigned int s, unsigned int e);
> > >>
> > >> _______________________________________________
> > >> Xen-ia64-devel mailing list
> > >> Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> > >> http://lists.xensource.com/xen-ia64-devel
> >
> > _______________________________________________
> > Xen-ia64-devel mailing list
> > Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-ia64-devel
> >
>
--
yamahata
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