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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 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?
>
> 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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