>>> On 13.09.11 at 11:12, George Dunlap <George.Dunlap@xxxxxxxxxxxxx> wrote:
> So what was the verdict on this one? Is someone going to commit to
> doing a "fake pdev" thing? If that's not going to happen before the
> 4.2 release, I suggest we take this patch in the mean time.
Isn't this -unstable c/s 23813:5535d7ce2673?
Jan
> On Thu, Sep 1, 2011 at 3:20 PM, George Dunlap
> <george.dunlap@xxxxxxxxxxxxx> wrote:
>> On some systems, requests devices behind a PCIe-to-PCI bridge all
>> appear to the IOMMU as though they come from from slot 0, function
>> 0 on that device; so the mapping code much punch a hole for X:0.0
>> in the IOMMU for such devices. When punching the hole, if that device
>> has already been mapped once, we simply need to check ownership to
>> make sure it's legal. To do so, domain_context_mapping_one() will look
>> up the device for the mapping with pci_get_pdev() and look for the owner.
>>
>> However, if there is no device in X:0.0, this look up will fail.
>>
>> Rather than returning -ENODEV in this situation (causing a failure in
>> mapping the device), try to get the domain ownership from the iommu context
>> mapping itself.
>>
>> Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
>>
>> diff -r 4a4882df5649 -r ede81b0552be xen/drivers/passthrough/vtd/iommu.c
>> --- a/xen/drivers/passthrough/vtd/iommu.c Wed Aug 31 15:23:49 2011
>> +0100
>> +++ b/xen/drivers/passthrough/vtd/iommu.c Thu Sep 01 15:18:18 2011
> +0100
>> @@ -113,6 +113,27 @@ static int context_set_domain_id(struct
>> return 0;
>> }
>>
>> +static int context_get_domain_id(struct context_entry *context,
>> + struct iommu *iommu)
>> +{
>> + unsigned long dom_index, nr_dom;
>> + int domid = -1;
>> +
>> + if (iommu && context)
>> + {
>> + nr_dom = cap_ndoms(iommu->cap);
>> +
>> + dom_index = context_domain_id(*context);
>> +
>> + if ( dom_index < nr_dom && iommu->domid_map)
>> + domid = iommu->domid_map[dom_index];
>> + else
>> + dprintk(XENLOG_DEBUG VTDPREFIX, "%s: dom_index %lu exceeds
> nr_dom %lu or iommu has no domid_map\n",
>> + __func__, dom_index, nr_dom);
>> + }
>> + return domid;
>> +}
>> +
>> static struct intel_iommu *__init alloc_intel_iommu(void)
>> {
>> struct intel_iommu *intel;
>> @@ -1237,7 +1258,6 @@ int domain_context_mapping_one(
>> struct hvm_iommu *hd = domain_hvm_iommu(domain);
>> struct context_entry *context, *context_entries;
>> u64 maddr, pgd_maddr;
>> - struct pci_dev *pdev = NULL;
>> int agaw;
>>
>> ASSERT(spin_is_locked(&pcidevs_lock));
>> @@ -1249,12 +1269,45 @@ int domain_context_mapping_one(
>> if ( context_present(*context) )
>> {
>> int res = 0;
>> + struct pci_dev *pdev = NULL;
>>
>> + /* First try to get domain ownership from device structure. If
> that's
>> + * not available, try to read it from the context itself. */
>> pdev = pci_get_pdev(bus, devfn);
>> - if (!pdev)
>> - res = -ENODEV;
>> - else if (pdev->domain != domain)
>> - res = -EINVAL;
>> + if ( pdev )
>> + {
>> + if ( pdev->domain != domain )
>> + {
>> + dprintk(XENLOG_INFO VTDPREFIX, "d%d: bdf = %x:%x.%x owned
> by d%d!",
>> + domain->domain_id,
>> + bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
>> + (pdev->domain)
>> + ? pdev->domain->domain_id : -1);
>> + res = -EINVAL;
>> + }
>> + }
>> + else
>> + {
>> + int cdomain;
>> + cdomain = context_get_domain_id(context, iommu);
>> +
>> + if ( cdomain < 0 )
>> + {
>> + dprintk(VTDPREFIX, "d%d: bdf = %x:%x.%x mapped, but can't
> find owner!\n",
>> + domain->domain_id,
>> + bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
>> + res = -EINVAL;
>> + }
>> + else if ( cdomain != domain->domain_id )
>> + {
>> + dprintk(XENLOG_INFO VTDPREFIX, "d%d: bdf = %x:%x.%x already
> mapped to d%d!",
>> + domain->domain_id,
>> + bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
>> + cdomain);
>> + res = -EINVAL;
>> + }
>> + }
>> +
>> unmap_vtd_domain_page(context_entries);
>> spin_unlock(&iommu->lock);
>> return res;
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel
>>
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