On 2014/12/29 12:15, Li, ZhenHua wrote: > Hi Takao Indoh, > > Happy New Year, and thank you very much for you help. The flush is quite
Happy new year! > a problem, as there are several places the flush function should be called, > I think the flush should be placed in functions like __iommu_update_old_*. > Created a small patch for this, it is attached. > > > > As I cannot reproduce your problems on my system, so could you please try > these steps? > 1. Apply the latest patchset, including 9/10 and 10/10, and then apply the > attached patch_for_flush.patch. And then test the kernel. No inter-remap fault, but there is still DMAR fault message. > > 2. If 1 does not fix the DMAR fault problems, then it might be caused by > 7/10, so please *unpatch* it from the kernel (others and the attached one > should be patched), and then test the kernel. DMAR fault still occurs. I'll dig iommu driver code to find out the reason. Thanks, Takao Indoh > > Regards > Zhenhua > > On 12/26/2014 03:27 PM, Takao Indoh wrote: >> On 2014/12/26 15:46, Li, ZhenHua wrote: >>> Hi Takao Indoh, >>> >>> Thank you very much for your testing. I will add your update in next >>> version. >>> Also I think a flush for __iommu_update_old_root_entry is also necessary. >>> >>> Currently I have no idea about your fault, does it happen before or >>> during its loading? Could you send me your full kernel log as an >>> attachment? >> Sure, see attached file. >> >> I removed 9/10 and 10/10 patches from my kernel to avoid panic problem I >> reported in previous mail, and then tested kdump. So please ignore >> intr-remap fault message in log file. Also please ignore stack trace >> starting with the following message, it's a problem of my box. >> >> Flags mismatch irq 0. 00000080 (i801_smbus) vs. 00015a00 (timer) >> >> Thanks, >> Takao Indoh >> >>> Regards and Merry Christmas. >>> Zhenhua >>> >>> On 12/26/2014 01:13 PM, Takao Indoh wrote: >>>> Hi Zhen-Hua, >>>> >>>> I tested your patch and found two problems. >>>> >>>> [1] >>>> Kenel panic occurs during 2nd kernel boot. >>>> >>>> ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 >>>> Kernel panic - not syncing: timer doesn't work through Interrupt-remapped >>>> IO-APIC >>>> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.18.0 #25 >>>> Hardware name: FUJITSU-SV PRIMERGY BX920 S2/D3030, BIOS 080015 >>>> Rev.3D81.3030 02/10/2012 >>>> 0000000000000002 ffff880036167d08 ffffffff815b1c6a 0000000000000000 >>>> ffffffff817f7670 ffff880036167d88 ffffffff815b19f1 0000000000000008 >>>> ffff880036167d98 ffff880036167d38 ffffffff810a5d2f ffff880036167d98 >>>> Call Trace: >>>> [<ffffffff815b1c6a>] dump_stack+0x48/0x5e >>>> [<ffffffff815b19f1>] panic+0xbb/0x1fa >>>> [<ffffffff810a5d2f>] ? vprintk_default+0x1f/0x30 >>>> [<ffffffff814c6a6c>] panic_if_irq_remap+0x1c/0x20 >>>> [<ffffffff81b53985>] check_timer+0x1e7/0x5ed >>>> [<ffffffff8129bd9d>] ? radix_tree_lookup+0xd/0x10 >>>> [<ffffffff81b5413b>] setup_IO_APIC+0x261/0x292 >>>> [<ffffffff81b50302>] native_smp_prepare_cpus+0x214/0x25d >>>> [<ffffffff81b41c65>] kernel_init_freeable+0x1dc/0x28c >>>> [<ffffffff815aaf00>] ? rest_init+0x80/0x80 >>>> [<ffffffff815aaf0e>] kernel_init+0xe/0xf0 >>>> [<ffffffff815b5d2c>] ret_from_fork+0x7c/0xb0 >>>> [<ffffffff815aaf00>] ? rest_init+0x80/0x80 >>>> ---[ end Kernel panic - not syncing: timer doesn't work through >>>> Interrupt-remapped IO-APIC >>>> >>>> >>>> This panic seems to be related to unflushed cache. I confirmed this >>>> problem was fixed by the following patch. >>>> >>>> --- a/drivers/iommu/intel_irq_remapping.c >>>> +++ b/drivers/iommu/intel_irq_remapping.c >>>> @@ -200,8 +200,13 @@ static int modify_irte(int irq, struct irte >>>> *irte_modified) >>>> set_64bit(&irte->high, irte_modified->high); >>>> >>>> #ifdef CONFIG_CRASH_DUMP >>>> - if (is_kdump_kernel()) >>>> + if (is_kdump_kernel()) { >>>> __iommu_update_old_irte(iommu, index); >>>> + __iommu_flush_cache(iommu, >>>> + iommu->ir_table->base_old_virt + >>>> + index * sizeof(struct irte), >>>> + sizeof(struct irte)); >>>> + } >>>> #endif >>>> __iommu_flush_cache(iommu, irte, sizeof(*irte)); >>>> >>>> >>>> [2] >>>> Some DMAR error messages are still found in 2nd kernel boot. >>>> >>>> dmar: DRHD: handling fault status reg 2 >>>> dmar: DMAR:[DMA Write] Request device [01:00.0] fault addr ffded000 >>>> DMAR:[fault reason 01] Present bit in root entry is clear >>>> >>>> I confiremd your commit 1a2262 was already applied. Any idea? >>>> >>>> Thanks, >>>> Takao Indoh >>>> >>>> >>>> On 2014/12/22 18:15, Li, Zhen-Hua wrote: >>>>> This patchset is an update of Bill Sumner's patchset, implements a fix >>>>> for: >>>>> If a kernel boots with intel_iommu=on on a system that supports intel >>>>> vt-d, >>>>> when a panic happens, the kdump kernel will boot with these faults: >>>>> >>>>> dmar: DRHD: handling fault status reg 102 >>>>> dmar: DMAR:[DMA Read] Request device [01:00.0] fault addr fff80000 >>>>> DMAR:[fault reason 01] Present bit in root entry is clear >>>>> >>>>> dmar: DRHD: handling fault status reg 2 >>>>> dmar: INTR-REMAP: Request device [[61:00.0] fault index 42 >>>>> INTR-REMAP:[fault reason 34] Present field in the IRTE entry is >>>>> clear >>>>> >>>>> On some system, the interrupt remapping fault will also happen even if the >>>>> intel_iommu is not set to on, because the interrupt remapping will be >>>>> enabled >>>>> when x2apic is needed by the system. >>>>> >>>>> The cause of the DMA fault is described in Bill's original version, and >>>>> the >>>>> INTR-Remap fault is caused by a similar reason. In short, the >>>>> initialization >>>>> of vt-d drivers causes the in-flight DMA and interrupt requests get wrong >>>>> response. >>>>> >>>>> To fix this problem, we modifies the behaviors of the intel vt-d in the >>>>> crashdump kernel: >>>>> >>>>> For DMA Remapping: >>>>> 1. To accept the vt-d hardware in an active state, >>>>> 2. Do not disable and re-enable the translation, keep it enabled. >>>>> 3. Use the old root entry table, do not rewrite the RTA register. >>>>> 4. Malloc and use new context entry table and page table, copy data from >>>>> the >>>>> old ones that used by the old kernel. >>>>> 5. to use different portions of the iova address ranges for the device >>>>> drivers >>>>> in the crashdump kernel than the iova ranges that were in-use at >>>>> the time >>>>> of the panic. >>>>> 6. After device driver is loaded, when it issues the first dma_map >>>>> command, >>>>> free the dmar_domain structure for this device, and generate a new >>>>> one, so >>>>> that the device can be assigned a new and empty page table. >>>>> 7. When a new context entry table is generated, we also save its address >>>>> to >>>>> the old root entry table. >>>>> >>>>> For Interrupt Remapping: >>>>> 1. To accept the vt-d hardware in an active state, >>>>> 2. Do not disable and re-enable the interrupt remapping, keep it enabled. >>>>> 3. Use the old interrupt remapping table, do not rewrite the IRTA >>>>> register. >>>>> 4. When ioapic entry is setup, the interrupt remapping table is changed, >>>>> and >>>>> the updated data will be stored to the old interrupt remapping >>>>> table. >>>>> >>>>> Advantages of this approach: >>>>> 1. All manipulation of the IO-device is done by the Linux device-driver >>>>> for that device. >>>>> 2. This approach behaves in a manner very similar to operation without an >>>>> active iommu. >>>>> 3. Any activity between the IO-device and its RMRR areas is handled by the >>>>> device-driver in the same manner as during a non-kdump boot. >>>>> 4. If an IO-device has no driver in the kdump kernel, it is simply left >>>>> alone. >>>>> This supports the practice of creating a special kdump kernel >>>>> without >>>>> drivers for any devices that are not required for taking a >>>>> crashdump. >>>>> 5. Minimal code-changes among the existing mainline intel vt-d code. >>>>> >>>>> Summary of changes in this patch set: >>>>> 1. Added some useful function for root entry table in code intel-iommu.c >>>>> 2. Added new members to struct root_entry and struct irte; >>>>> 3. Functions to load old root entry table to iommu->root_entry from the >>>>> memory >>>>> of old kernel. >>>>> 4. Functions to malloc new context entry table and page table and copy >>>>> the data >>>>> from the old ones to the malloced new ones. >>>>> 5. Functions to enable support for DMA remapping in kdump kernel. >>>>> 6. Functions to load old irte data from the old kernel to the kdump >>>>> kernel. >>>>> 7. Some code changes that support other behaviours that have been listed. >>>>> 8. In the new functions, use physical address as "unsigned long" type, not >>>>> pointers. >>>>> >>>>> Original version by Bill Sumner: >>>>> https://lkml.org/lkml/2014/1/10/518 >>>>> https://lkml.org/lkml/2014/4/15/716 >>>>> https://lkml.org/lkml/2014/4/24/836 >>>>> >>>>> Zhenhua's last of Bill's patchset: >>>>> https://lkml.org/lkml/2014/10/21/134 >>>>> https://lkml.org/lkml/2014/12/15/121 >>>>> >>>>> Changed in this version: >>>>> 1. Do not disable and re-enable traslation and interrupt remapping. >>>>> 2. Use old root entry table. >>>>> 3. Use old interrupt remapping table. >>>>> 4. Use "unsigned long" as physical address. >>>>> 5. Use intel_unmap to unmap the old dma; >>>>> >>>>> This patchset should be applied with this one together: >>>>> https://lkml.org/lkml/2014/11/5/43 >>>>> x86/iommu: fix incorrect bit operations in setting values >>>>> >>>>> Bill Sumner (5): >>>>> iommu/vt-d: Update iommu_attach_domain() and its callers >>>>> iommu/vt-d: Items required for kdump >>>>> iommu/vt-d: data types and functions used for kdump >>>>> iommu/vt-d: Add domain-id functions >>>>> iommu/vt-d: enable kdump support in iommu module >>>>> >>>>> Li, Zhen-Hua (10): >>>>> iommu/vt-d: Update iommu_attach_domain() and its callers >>>>> iommu/vt-d: Items required for kdump >>>>> iommu/vt-d: Add domain-id functions >>>>> iommu/vt-d: functions to copy data from old mem >>>>> iommu/vt-d: Add functions to load and save old re >>>>> iommu/vt-d: datatypes and functions used for kdump >>>>> iommu/vt-d: enable kdump support in iommu module >>>>> iommu/vtd: assign new page table for dma_map >>>>> iommu/vt-d: Copy functions for irte >>>>> iommu/vt-d: Use old irte in kdump kernel >>>>> >>>>> drivers/iommu/intel-iommu.c | 1050 >>>>> +++++++++++++++++++++++++++++++++-- >>>>> drivers/iommu/intel_irq_remapping.c | 99 +++- >>>>> include/linux/intel-iommu.h | 18 + >>>>> 3 files changed, 1123 insertions(+), 44 deletions(-) >>>>> >>> >>> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/