On 2014/8/12 11:18, Jiang Liu wrote:
> On 2014/8/12 9:37, Yijing Wang wrote:
>> On 2014/8/11 22:59, Linda Knippers wrote:
>>> On 8/11/2014 12:43 AM, Alex Williamson wrote:
>>>> On Mon, 2014-08-11 at 10:54 +0800, Yijing Wang wrote:
>>>>> We found some strange devices in HP C7000 and Huawei Server. These devices
>>>>> can not be enumerated by OS, but they still did DMA read/write without OS
>>>>> management. Because iommu will not create the DMA mapping for these
>>>>> devices,
>>>>> the DMA read/write will be blocked by iommu hardware.
>>>>>
>>>>> Eg.
>>>>> \-[0000:00]-+-00.0 Intel Corporation Xeon E5/Core i7 DMI2
>>>>> +-01.0-[11]--
>>>>> +-01.1-[02]--
>>>>> +-02.0-[04]--+-00.0 Emulex Corporation OneConnect
>>>>> 10Gb NIC (be3)
>>>>> | +-00.1 Emulex Corporation OneConnect 10Gb NIC
>>>>> (be3)
>>>>> | +-00.2 Emulex Corporation OneConnect 10Gb iSCSI
>>>>> Initiator (be3)
>>>>> | \-00.3 Emulex Corporation OneConnect 10Gb iSCSI
>>>>> Initiator (be3)
>>>>> +-02.1-[12]--
>>>>> Kernel only found four devices in bus 0x04, but we found following DMA
>>>>> errors in dmesg.
>>>>>
>>>>> [ 1438.477262] DRHD: handling fault status reg 402
>>>>> [ 1438.498278] DMAR:[DMA Write] Request device [04:00.4] fault addr
>>>>> bdf70000
>>>>> [ 1438.498280] DMAR:[fault reason 02] Present bit in context entry is
>>>>> clear
>>>>> [ 1438.566458] DMAR:[DMA Write] Request device [04:00.5] fault addr
>>>>> bdf70000
>>>>> [ 1438.566460] DMAR:[fault reason 02] Present bit in context entry is
>>>>> clear
>>>>> [ 1438.635211] DMAR:[DMA Write] Request device [04:00.6] fault addr
>>>>> bdf70000
>>>>> [ 1438.635213] DMAR:[fault reason 02] Present bit in context entry is
>>>>> clear
>>>>> [ 1438.703849] DMAR:[DMA Write] Request device [04:00.7] fault addr
>>>>> bdf70000
>>>>> [ 1438.703851] DMAR:[fault reason 02] Present bit in context entry is
>>>>> clear
>>>>>
>>>>> Signed-off-by: Yijing Wang <wangyij...@huawei.com>
>>>>> ---
>>>>> arch/x86/include/asm/iommu.h | 2 ++
>>>>> arch/x86/kernel/pci-dma.c | 8 ++++++++
>>>>> drivers/iommu/intel-iommu.c | 41
>>>>> +++++++++++++++++++++++++++++++++++++++++
>>>>> 3 files changed, 51 insertions(+), 0 deletions(-)
>>>>>
>>>>> diff --git a/arch/x86/include/asm/iommu.h b/arch/x86/include/asm/iommu.h
>>>>> index 345c99c..5e3a2d8 100644
>>>>> --- a/arch/x86/include/asm/iommu.h
>>>>> +++ b/arch/x86/include/asm/iommu.h
>>>>> @@ -5,6 +5,8 @@ extern struct dma_map_ops nommu_dma_ops;
>>>>> extern int force_iommu, no_iommu;
>>>>> extern int iommu_detected;
>>>>> extern int iommu_pass_through;
>>>>> +extern int iommu_pt_force_bus;
>>>>> +extern int iommu_pt_force_domain;
>>>>>
>>>>> /* 10 seconds */
>>>>> #define DMAR_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000)
>>>>> diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
>>>>> index a25e202..bf21d97 100644
>>>>> --- a/arch/x86/kernel/pci-dma.c
>>>>> +++ b/arch/x86/kernel/pci-dma.c
>>>>> @@ -44,6 +44,8 @@ int iommu_detected __read_mostly = 0;
>>>>> * guests and not for driver dma translation.
>>>>> */
>>>>> int iommu_pass_through __read_mostly;
>>>>> +int iommu_pt_force_bus = -1;
>>>>> +int iommu_pt_force_domain = -1;
>>>>>
>>>>> extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
>>>>>
>>>>> @@ -146,6 +148,7 @@ void dma_generic_free_coherent(struct device *dev,
>>>>> size_t size, void *vaddr,
>>>>> */
>>>>> static __init int iommu_setup(char *p)
>>>>> {
>>>>> + char *end;
>>>>> iommu_merge = 1;
>>>>>
>>>>> if (!p)
>>>>> @@ -192,6 +195,11 @@ static __init int iommu_setup(char *p)
>>>>> #endif
>>>>> if (!strncmp(p, "pt", 2))
>>>>> iommu_pass_through = 1;
>>>>> + if (!strncmp(p, "pt_force=", 9)) {
>>>>> + iommu_pass_through = 1;
>>>>> + iommu_pt_force_domain = simple_strtol(p+9, &end, 0);
>>>>> + iommu_pt_force_bus = simple_strtol(end+1, NULL, 0);
>>>>
>>>> Documentation/kernel-parameters.txt?
>>>>
>>>>> + }
>>>>>
>>>>> gart_parse_options(p);
>>>>>
>>>>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>>>>> index d1f5caa..49757f1 100644
>>>>> --- a/drivers/iommu/intel-iommu.c
>>>>> +++ b/drivers/iommu/intel-iommu.c
>>>>> @@ -2705,6 +2705,47 @@ static int __init
>>>>> iommu_prepare_static_identity_mapping(int hw)
>>>>> return ret;
>>>>> }
>>>>>
>>>>> + /* We found some strange devices in HP c7000 and other platforms that
>>>>> + * can not be enumerated by OS, but they did DMA read/write without
>>>>> + * driver management, so we should create the pt mapping for these
>>>>> + * devices to avoid DMA errors. Add iommu=pt_force=segment:busnum to
>>>>> + * force to do pt context mapping in the bus number.
>>>>> + */
>>>>
>>>> So best case with this patch is that the user needs to discover that
>>>> this option exists, figure out the undocumented parameters, be running
>>>> on VT-d, permanently add a kernel commandline option, and never have any
>>>> intention of assigning the device to userspace or a VM...
>>>>
>>>> Can't we handle this with the DMA alias quirks that are now in 3.17? Or
>>>> can the vendor fix this with a firmware update? This device behavior is
>>>> really quite broken for this kind of server class product.
>>>
>>> Yeah, something doesn't sound right here.
>>>
>>> I would like to hear more about this configuration, off list if you prefer.
>>> What servers? What firmware revisions?
>>
>> Hi Linda, we found this issue in HP C7000 server. I attached the dmesg and
>> lspci info,
>> because the machine is in product department, so I don't know the firmware
>> revision.
>>
>> Thanks!
>> Yijing.
> Hi Yijing,
> I still suspect something is wrong with ARI support
> instead of Phantom Function.
> According to lspci output:
> 1) Root port 00:02.0 has ARIFwd enabled in DevCtl2
> 2) Function 04:00.[0-3] all have Alternative Routing-ID Interpretation
> capability.
> So could you please try to clear ARIFwd bit in devctl2 when enumerating
> root port 00:02.0?
>
> BTW, do function 04:00.[0-3] encounter any other issues except the
> IOMMU warnings?
Hi Gerry, I cleared the ARIFwd bit and rescan pci device(echo 1 >
/sys/bus/pci/rescan), but nothing changed.
Because the 04:00.0/1/2/3 are ARI devices, so the root port will be forced to
set ARIFwd bit. There has some
problem to change and rebuild the kernel now.
Other, 04:00.0-3 are 10Ge net devices, I guess no one uses it now, so no other
errors found yet.
Gerry, what ARI problem do you suspect ?
>
> Thanks!
>
>
>>
>>
>>>>
>>>>> + if (iommu_pt_force_bus >= 0 && iommu_pt_force_bus >= 0) {
>>>>> + int found = 0;
>>>>> +
>>>>> + iommu = NULL;
>>>>> + for_each_active_iommu(iommu, drhd) {
>>>>> + if (iommu_pt_force_domain != drhd->segment)
>>>>> + continue;
>>>>> +
>>>>> + for_each_active_dev_scope(drhd->devices,
>>>>> drhd->devices_cnt, i, dev) {
>>>>> + if (!dev_is_pci(dev))
>>>>> + continue;
>>>>> +
>>>>> + pdev = to_pci_dev(dev);
>>>>> + if (pdev->bus->number == iommu_pt_force_bus ||
>>>>> + (pdev->subordinate
>>>>> + && pdev->subordinate->number
>>>>> <= iommu_pt_force_bus
>>>>> + &&
>>>>> pdev->subordinate->busn_res.end >= iommu_pt_force_bus)) {
>>>>> + found = 1;
>>>>> + break;
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + if (drhd->include_all) {
>>>>> + found = 1;
>>>>> + break;
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + if (found && iommu)
>>>>> + for (i = 0; i < 256; i++)
>>>>> + domain_context_mapping_one(si_domain, iommu,
>>>>> iommu_pt_force_bus,
>>>>> + i, hw ?
>>>>> CONTEXT_TT_PASS_THROUGH :
>>>>> + CONTEXT_TT_MULTI_LEVEL);
>>>>> + }
>>>>> +
>>>>> return 0;
>>>>> }
>>>>>
>>>>
>>>>
>>>>
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>>>> iommu@lists.linux-foundation.org
>>>> https://lists.linuxfoundation.org/mailman/listinfo/iommu
>>>>
>>>
>>>
>>> .
>>>
>>
>>
>
> .
>
--
Thanks!
Yijing
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