Well, that's quite good news. Looking forward Takao's testing on his system. Regards Zhenhua On 01/07/2015 04:28 PM, Baoquan He wrote: > On 01/07/15 at 01:25pm, Li, ZhenHua wrote: >> It is same as the last one I send to you yesterday. >> >> The continuous memory that needed for data in this patchset: >> RE: PAGE_SIZE, 4096 Bytes; >> IRTE: 65536 * 16 ; 1M Bytes; >> >> It should use same memory as the old versions of this patchset. The >> changes for the last version do not need more memory. > > Hi Zhenhua, > > It was my mistake because I didn't strip the debug info of modules, then > initramfs is bloated very big. Just now I tested the latest version, it > works well and dump is successful. No dmar fault and intr-remap fault > seen any more, good job! > > Thanks > Baoquan > > >> >> Regards >> Zhenhua >> >> On 01/07/2015 01:02 PM, Baoquan He wrote: >>> On 01/07/15 at 12:11pm, Li, ZhenHua wrote: >>>> Many thanks to Takao Indoh and Baoquan He, for your testing on more >>>> different systems. >>>> >>>> The calling of flush functions are added to this version. >>>> >>>> The usage of __iommu_flush_cache function : >>>> 1. Fixes a dump on Takao's system. >>>> 2. Reduces the count of faults on Baoquan's system. >>> >>> I am testing the version you sent to me yesterday afternoon. Is that >>> different with this patchset? I found your patchset man reserve a big >>> contiguous memory region under 896M, this will cause the crashkernel >>> reservation failed when I set crashkernel=320M. The reason I increase >>> the crashkerenl reservation to 320M is 256M is not enough and cause OOM >>> when that patchset is tested. >>> >>> I am checking what happened. >>> >>> >>> Thanks >>> Baoquan >>> >>>> >>>> Regards >>>> Zhenhua >>>> >>>> On 01/07/2015 12:04 PM, 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 updates: >>>>> https://lkml.org/lkml/2014/10/21/134 >>>>> https://lkml.org/lkml/2014/12/15/121 >>>>> https://lkml.org/lkml/2014/12/22/53 >>>>> >>>>> Changelog[v7]: >>>>> 1. Use __iommu_flush_cache to flush the data to hardware. >>>>> >>>>> Changelog[v6]: >>>>> 1. Use "unsigned long" as type of physical address. >>>>> 2. Use new function unmap_device_dma to unmap the old dma. >>>>> 3. Some small incorrect bits order for aw shift. >>>>> >>>>> Changelog[v5]: >>>>> 1. Do not disable and re-enable traslation and interrupt remapping. >>>>> 2. Use old root entry table. >>>>> 3. Use old interrupt remapping table. >>>>> 4. New functions to copy data from old kernel, and save to old kernel mem. >>>>> 5. New functions to save updated root entry table and irte table. >>>>> 6. Use intel_unmap to unmap the old dma; >>>>> 7. Allocate new pages while driver is being loaded. >>>>> >>>>> Changelog[v4]: >>>>> 1. Cut off the patches that move some defines and functions to new files. >>>>> 2. Reduce the numbers of patches to five, make it more easier to read. >>>>> 3. Changed the name of functions, make them consistent with current context >>>>> get/set functions. >>>>> 4. Add change to function __iommu_attach_domain. >>>>> >>>>> Changelog[v3]: >>>>> 1. Commented-out "#define DEBUG 1" to eliminate debug messages. >>>>> 2. Updated the comments about changes in each version. >>>>> 3. Fixed: one-line added to Copy-Translations patch to initialize the iovad >>>>> struct as recommended by Baoquan He [bhe at redhat.com] >>>>> init_iova_domain(&domain->iovad, DMA_32BIT_PFN); >>>>> >>>>> Changelog[v2]: >>>>> The following series implements a fix for: >>>>> A kdump problem about DMA that has been discussed for a long time. That is, >>>>> when a kernel panics and boots into the kdump kernel, DMA started by the >>>>> panicked kernel is not stopped before the kdump kernel is booted and the >>>>> kdump kernel disables the IOMMU while this DMA continues. This causes the >>>>> IOMMU to stop translating the DMA addresses as IOVAs and begin to treat >>>>> them as physical memory addresses -- which causes the DMA to either: >>>>> (1) generate DMAR errors or >>>>> (2) generate PCI SERR errors or >>>>> (3) transfer data to or from incorrect areas of memory. Often this >>>>> causes the dump to fail. >>>>> >>>>> Changelog[v1]: >>>>> The original version. >>>>> >>>>> 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; >>>>> >>>>> Baoquan He <bhe at redhat.com> helps testing this patchset. >>>>> >>>>> 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/vt-d: assign new page table for dma_map >>>>> iommu/vt-d: Copy functions for irte >>>>> iommu/vt-d: Use old irte in kdump kernel >>>>> >>>>> Signed-off-by: Bill Sumner <billsumnerlinux at gmail.com> >>>>> Signed-off-by: Li, Zhen-Hua <zhen-hual at hp.com> >>>>> Signed-off-by: Takao Indoh <indou.takao at jp.fujitsu.com> >>>>> Tested-by: Baoquan He <bhe at redhat.com> >>>>> --- >>>>> drivers/iommu/intel-iommu.c | 1050 +++++++++++++++++++++++++++++++++-- >>>>> drivers/iommu/intel_irq_remapping.c | 104 +++- >>>>> include/linux/intel-iommu.h | 18 + >>>>> 3 files changed, 1130 insertions(+), 42 deletions(-) >>>>> >>>> >>
