Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-11 Thread Dave Young
On 05/12/15 at 01:57pm, Dave Young wrote: > On 05/11/15 at 12:11pm, Joerg Roedel wrote: > > On Thu, May 07, 2015 at 09:56:00PM +0800, Dave Young wrote: > > > Joreg, I can not find the last reply from you, so just reply here about > > > my worries here. > > > > > > I said that the patchset will cau

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-11 Thread Dave Young
On 05/11/15 at 12:11pm, Joerg Roedel wrote: > On Thu, May 07, 2015 at 09:56:00PM +0800, Dave Young wrote: > > Joreg, I can not find the last reply from you, so just reply here about > > my worries here. > > > > I said that the patchset will cause more problems, let me explain about > > it more her

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-11 Thread Joerg Roedel
On Thu, May 07, 2015 at 09:56:00PM +0800, Dave Young wrote: > Joreg, I can not find the last reply from you, so just reply here about > my worries here. > > I said that the patchset will cause more problems, let me explain about > it more here: > > Suppose page table was corrupted, ie. original m

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-10 Thread Don Dutile
On 05/07/2015 09:21 PM, Dave Young wrote: On 05/07/15 at 10:25am, Don Dutile wrote: On 05/07/2015 10:00 AM, Dave Young wrote: On 04/07/15 at 10:12am, Don Dutile wrote: On 04/06/2015 11:46 PM, Dave Young wrote: On 04/05/15 at 09:54am, Baoquan He wrote: On 04/03/15 at 05:21pm, Dave Young wrote

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-10 Thread Don Dutile
On 05/07/2015 10:00 AM, Dave Young wrote: On 04/07/15 at 10:12am, Don Dutile wrote: On 04/06/2015 11:46 PM, Dave Young wrote: On 04/05/15 at 09:54am, Baoquan He wrote: On 04/03/15 at 05:21pm, Dave Young wrote: On 04/03/15 at 05:01pm, Li, ZhenHua wrote: Hi Dave, There may be some possibiliti

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-07 Thread Dave Young
On 05/07/15 at 10:25am, Don Dutile wrote: > On 05/07/2015 10:00 AM, Dave Young wrote: > >On 04/07/15 at 10:12am, Don Dutile wrote: > >>On 04/06/2015 11:46 PM, Dave Young wrote: > >>>On 04/05/15 at 09:54am, Baoquan He wrote: > On 04/03/15 at 05:21pm, Dave Young wrote: > >On 04/03/15 at 05:01

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-07 Thread Don Dutile
On 05/07/2015 10:00 AM, Dave Young wrote: On 04/07/15 at 10:12am, Don Dutile wrote: On 04/06/2015 11:46 PM, Dave Young wrote: On 04/05/15 at 09:54am, Baoquan He wrote: On 04/03/15 at 05:21pm, Dave Young wrote: On 04/03/15 at 05:01pm, Li, ZhenHua wrote: Hi Dave, There may be some possibiliti

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-07 Thread Dave Young
On 04/07/15 at 10:12am, Don Dutile wrote: > On 04/06/2015 11:46 PM, Dave Young wrote: > >On 04/05/15 at 09:54am, Baoquan He wrote: > >>On 04/03/15 at 05:21pm, Dave Young wrote: > >>>On 04/03/15 at 05:01pm, Li, ZhenHua wrote: > Hi Dave, > > There may be some possibilities that the old i

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-07 Thread Dave Young
On 05/04/15 at 01:05pm, Joerg Roedel wrote: > On Fri, Apr 03, 2015 at 04:40:31PM +0800, Dave Young wrote: > > Have not read all the patches, but I have a question, not sure this > > has been answered before. Old memory is not reliable, what if the old > > memory get corrupted before panic? Is it sa

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-07 Thread Dave Young
On 05/06/15 at 10:16am, Joerg Roedel wrote: > On Wed, May 06, 2015 at 09:46:49AM +0800, Dave Young wrote: > > For the original problem, the key issue is dmar faults cause kdump kernel > > hang so that vmcore can not be saved. I do not know the reason why it hangs > > I think it is acceptable if kdu

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-06 Thread Joerg Roedel
On Wed, May 06, 2015 at 09:46:49AM +0800, Dave Young wrote: > For the original problem, the key issue is dmar faults cause kdump kernel > hang so that vmcore can not be saved. I do not know the reason why it hangs > I think it is acceptable if kdump kernel boot ok with some dma errors.. It hangs b

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-05 Thread Dave Young
On 05/05/15 at 05:23pm, Joerg Roedel wrote: > On Tue, May 05, 2015 at 02:09:31PM +0800, Dave Young wrote: > > I agree that we can do nothing with the old corrupted data, but I worry > > about the future corruption after using the old corrupted data. I wonder > > if we can mark all the oldmem as rea

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-05 Thread Joerg Roedel
On Tue, May 05, 2015 at 02:09:31PM +0800, Dave Young wrote: > I agree that we can do nothing with the old corrupted data, but I worry > about the future corruption after using the old corrupted data. I wonder > if we can mark all the oldmem as readonly so that we can lower the risk. > Is it resonab

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-04 Thread Dave Young
On 05/04/15 at 01:05pm, Joerg Roedel wrote: > On Fri, Apr 03, 2015 at 04:40:31PM +0800, Dave Young wrote: > > Have not read all the patches, but I have a question, not sure this > > has been answered before. Old memory is not reliable, what if the old > > memory get corrupted before panic? Is it sa

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-04 Thread Don Dutile
On 05/04/2015 07:05 AM, Joerg Roedel wrote: On Fri, Apr 03, 2015 at 04:40:31PM +0800, Dave Young wrote: Have not read all the patches, but I have a question, not sure this has been answered before. Old memory is not reliable, what if the old memory get corrupted before panic? Is it safe to conti

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-05-04 Thread Joerg Roedel
On Fri, Apr 03, 2015 at 04:40:31PM +0800, Dave Young wrote: > Have not read all the patches, but I have a question, not sure this > has been answered before. Old memory is not reliable, what if the old > memory get corrupted before panic? Is it safe to continue using it in > 2nd kernel, I worry tha

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-07 Thread Dave Young
On 04/07/15 at 05:55pm, Li, ZhenHua wrote: > On 04/07/2015 05:08 PM, Dave Young wrote: > >On 04/07/15 at 11:46am, Dave Young wrote: > >>On 04/05/15 at 09:54am, Baoquan He wrote: > >>>On 04/03/15 at 05:21pm, Dave Young wrote: > On 04/03/15 at 05:01pm, Li, ZhenHua wrote: > >Hi Dave, > > >

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-07 Thread Don Dutile
On 04/06/2015 11:46 PM, Dave Young wrote: On 04/05/15 at 09:54am, Baoquan He wrote: On 04/03/15 at 05:21pm, Dave Young wrote: On 04/03/15 at 05:01pm, Li, ZhenHua wrote: Hi Dave, There may be some possibilities that the old iommu data is corrupted by some other modules. Currently we do not hav

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-07 Thread Li, ZhenHua
On 04/07/2015 05:08 PM, Dave Young wrote: On 04/07/15 at 11:46am, Dave Young wrote: On 04/05/15 at 09:54am, Baoquan He wrote: On 04/03/15 at 05:21pm, Dave Young wrote: On 04/03/15 at 05:01pm, Li, ZhenHua wrote: Hi Dave, There may be some possibilities that the old iommu data is corrupted by

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-07 Thread Dave Young
On 04/07/15 at 11:46am, Dave Young wrote: > On 04/05/15 at 09:54am, Baoquan He wrote: > > On 04/03/15 at 05:21pm, Dave Young wrote: > > > On 04/03/15 at 05:01pm, Li, ZhenHua wrote: > > > > Hi Dave, > > > > > > > > There may be some possibilities that the old iommu data is corrupted by > > > > some

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-06 Thread Dave Young
On 04/03/15 at 02:05pm, Li, Zhen-Hua wrote: > The hardware will do some verification, but not completely. If people think > the OS should also do this, then it should be another patchset, I think. If there is chance to corrupt more memory I think it is not a right way. We should think about a be

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-06 Thread Dave Young
On 04/05/15 at 09:54am, Baoquan He wrote: > On 04/03/15 at 05:21pm, Dave Young wrote: > > On 04/03/15 at 05:01pm, Li, ZhenHua wrote: > > > Hi Dave, > > > > > > There may be some possibilities that the old iommu data is corrupted by > > > some other modules. Currently we do not have a better soluti

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-04 Thread Baoquan He
On 04/03/15 at 05:21pm, Dave Young wrote: > On 04/03/15 at 05:01pm, Li, ZhenHua wrote: > > Hi Dave, > > > > There may be some possibilities that the old iommu data is corrupted by > > some other modules. Currently we do not have a better solution for the > > dmar faults. > > > > But I think when

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-03 Thread Li, Zhen-Hua
The hardware will do some verification, but not completely. If people think the OS should also do this, then it should be another patchset, I think. Thanks Zhenhua > 在 2015年4月3日,17:21,Dave Young 写道: > >> On 04/03/15 at 05:01pm, Li, ZhenHua wrote: >> Hi Dave, >> >> There may be some possibil

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-03 Thread Dave Young
On 04/03/15 at 05:01pm, Li, ZhenHua wrote: > Hi Dave, > > There may be some possibilities that the old iommu data is corrupted by > some other modules. Currently we do not have a better solution for the > dmar faults. > > But I think when this happens, we need to fix the module that corrupted > t

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-03 Thread Li, ZhenHua
Hi Dave, There may be some possibilities that the old iommu data is corrupted by some other modules. Currently we do not have a better solution for the dmar faults. But I think when this happens, we need to fix the module that corrupted the old iommu data. I once met a similar problem in normal

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-03 Thread Dave Young
> 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 r

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-03 Thread Li, ZhenHua
On 04/03/2015 04:28 PM, Dave Young wrote: On 03/19/15 at 01:36pm, 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 thes

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-03 Thread Dave Young
On 03/19/15 at 01:36pm, 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: handlin

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-03 Thread Li, ZhenHua
Hi Joerg, This is quite strange. I checked the patches from patch 01 to 10 using ./scripts/checkpatch.pl under the kernel source directory, but got 0 errors and 0 warning. Only some white spaces in the cover letter 00, but is could not be checked by this script. But I checked the intel-iommu

Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-04-02 Thread Joerg Roedel
Hi Zhen-Hua, On Thu, Mar 19, 2015 at 01:36:18PM +0800, 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 faul

[PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel

2015-03-18 Thread Li, Zhen-Hua
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] Reque