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From: Sumit Gupta <sumitg@nvidia.com>
To: Krishna Reddy <vdumpa@nvidia.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: "eric.auger@redhat.com" <eric.auger@redhat.com>,
	"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
	"eric.auger.pro@gmail.com" <eric.auger.pro@gmail.com>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"jiangkunkun@huawei.com" <jiangkunkun@huawei.com>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"lushenming@huawei.com" <lushenming@huawei.com>,
	"maz@kernel.org" <maz@kernel.org>,
	"robin.murphy@arm.com" <robin.murphy@arm.com>,
	"tn@semihalf.com" <tn@semihalf.com>,
	"vivek.gautam@arm.com" <vivek.gautam@arm.com>,
	Vikram Sethi <vsethi@nvidia.com>,
	"wangxingang5@huawei.com" <wangxingang5@huawei.com>,
	"will@kernel.org" <will@kernel.org>,
	"zhangfei.gao@linaro.org" <zhangfei.gao@linaro.org>,
	"zhukeqian1@huawei.com" <zhukeqian1@huawei.com>,
	Sachin Nikam <Snikam@nvidia.com>, Bibek Basu <bbasu@nvidia.com>,
	Shanker Donthineni <sdonthineni@nvidia.com>,
	Sumit Gupta <sumitg@nvidia.com>
Subject: Re: [PATCH v14 00/13] SMMUv3 Nested Stage Setup (IOMMU part)
Date: Fri, 23 Apr 2021 23:49:55 +0530	[thread overview]
Message-ID: <467c95cd-3ba5-519e-cdac-9f477da86ecb@nvidia.com> (raw)
In-Reply-To: <BY5PR12MB37642B9AC7E5D907F5A664F6B3459@BY5PR12MB3764.namprd12.prod.outlook.com>



>>> Did that patch cause any issue, or is it just not needed on your system?
>>> It fixes an hypothetical problem with the way ATS is implemented.
>>> Maybe I actually observed it on an old software model, I don't
>>> remember. Either way it's unlikely to go upstream but I'd like to know
>>> if I should drop it from my tree.
> 
>> Had to revert same patch "mm: notify remote TLBs when dirtying a PTE" to
>> avoid below crash[1]. I am not sure about the cause yet.
> 
> I have noticed this issue earlier with patch pointed here and root caused the issue as below.
> It happens after vfio_mmap request from QEMU for the PCIe device and during the access of VA when
> PTE access flags are updated.
> 
> kvm_mmu_notifier_change_pte() --> kvm_set_spte_hve() --> kvm_set_spte_hva() --> clean_dcache_guest_page()
> 
> The validation model doesn't have FWB capability supported.
> __clean_dcache_guest_page() attempts to perform dcache flush on pcie bar address(not a valid_pfn()) through page_address(),
> which doesn't have page table mapping and leads to exception.
> 
> I have worked around the issue by filtering out the request if the pfn is not valid in  __clean_dcache_guest_page().
> As the patch wasn't posted in the community, reverted it as well.

Thank you Krishna for sharing the analysis.

Best Regards,
Sumit Gupta

WARNING: multiple messages have this Message-ID (diff)
From: Sumit Gupta <sumitg@nvidia.com>
To: Krishna Reddy <vdumpa@nvidia.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"vivek.gautam@arm.com" <vivek.gautam@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	"eric.auger.pro@gmail.com" <eric.auger.pro@gmail.com>,
	"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
	"wangxingang5@huawei.com" <wangxingang5@huawei.com>,
	"maz@kernel.org" <maz@kernel.org>,
	"jiangkunkun@huawei.com" <jiangkunkun@huawei.com>,
	"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	Vikram Sethi <vsethi@nvidia.com>, Bibek Basu <bbasu@nvidia.com>,
	"zhangfei.gao@linaro.org" <zhangfei.gao@linaro.org>,
	Shanker Donthineni <sdonthineni@nvidia.com>,
	Sachin Nikam <Snikam@nvidia.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"lushenming@huawei.com" <lushenming@huawei.com>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"robin.murphy@arm.com" <robin.murphy@arm.com>
Subject: Re: [PATCH v14 00/13] SMMUv3 Nested Stage Setup (IOMMU part)
Date: Fri, 23 Apr 2021 23:49:55 +0530	[thread overview]
Message-ID: <467c95cd-3ba5-519e-cdac-9f477da86ecb@nvidia.com> (raw)
In-Reply-To: <BY5PR12MB37642B9AC7E5D907F5A664F6B3459@BY5PR12MB3764.namprd12.prod.outlook.com>



>>> Did that patch cause any issue, or is it just not needed on your system?
>>> It fixes an hypothetical problem with the way ATS is implemented.
>>> Maybe I actually observed it on an old software model, I don't
>>> remember. Either way it's unlikely to go upstream but I'd like to know
>>> if I should drop it from my tree.
> 
>> Had to revert same patch "mm: notify remote TLBs when dirtying a PTE" to
>> avoid below crash[1]. I am not sure about the cause yet.
> 
> I have noticed this issue earlier with patch pointed here and root caused the issue as below.
> It happens after vfio_mmap request from QEMU for the PCIe device and during the access of VA when
> PTE access flags are updated.
> 
> kvm_mmu_notifier_change_pte() --> kvm_set_spte_hve() --> kvm_set_spte_hva() --> clean_dcache_guest_page()
> 
> The validation model doesn't have FWB capability supported.
> __clean_dcache_guest_page() attempts to perform dcache flush on pcie bar address(not a valid_pfn()) through page_address(),
> which doesn't have page table mapping and leads to exception.
> 
> I have worked around the issue by filtering out the request if the pfn is not valid in  __clean_dcache_guest_page().
> As the patch wasn't posted in the community, reverted it as well.

Thank you Krishna for sharing the analysis.

Best Regards,
Sumit Gupta
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Sumit Gupta <sumitg@nvidia.com>
To: Krishna Reddy <vdumpa@nvidia.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"vivek.gautam@arm.com" <vivek.gautam@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	"eric.auger.pro@gmail.com" <eric.auger.pro@gmail.com>,
	"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
	"wangxingang5@huawei.com" <wangxingang5@huawei.com>,
	"maz@kernel.org" <maz@kernel.org>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	Vikram Sethi <vsethi@nvidia.com>, Bibek Basu <bbasu@nvidia.com>,
	"zhangfei.gao@linaro.org" <zhangfei.gao@linaro.org>,
	Sumit Gupta <sumitg@nvidia.com>,
	Shanker Donthineni <sdonthineni@nvidia.com>,
	Sachin Nikam <Snikam@nvidia.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"lushenming@huawei.com" <lushenming@huawei.com>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"robin.murphy@arm.com" <robin.murphy@arm.com>
Subject: Re: [PATCH v14 00/13] SMMUv3 Nested Stage Setup (IOMMU part)
Date: Fri, 23 Apr 2021 23:49:55 +0530	[thread overview]
Message-ID: <467c95cd-3ba5-519e-cdac-9f477da86ecb@nvidia.com> (raw)
In-Reply-To: <BY5PR12MB37642B9AC7E5D907F5A664F6B3459@BY5PR12MB3764.namprd12.prod.outlook.com>



>>> Did that patch cause any issue, or is it just not needed on your system?
>>> It fixes an hypothetical problem with the way ATS is implemented.
>>> Maybe I actually observed it on an old software model, I don't
>>> remember. Either way it's unlikely to go upstream but I'd like to know
>>> if I should drop it from my tree.
> 
>> Had to revert same patch "mm: notify remote TLBs when dirtying a PTE" to
>> avoid below crash[1]. I am not sure about the cause yet.
> 
> I have noticed this issue earlier with patch pointed here and root caused the issue as below.
> It happens after vfio_mmap request from QEMU for the PCIe device and during the access of VA when
> PTE access flags are updated.
> 
> kvm_mmu_notifier_change_pte() --> kvm_set_spte_hve() --> kvm_set_spte_hva() --> clean_dcache_guest_page()
> 
> The validation model doesn't have FWB capability supported.
> __clean_dcache_guest_page() attempts to perform dcache flush on pcie bar address(not a valid_pfn()) through page_address(),
> which doesn't have page table mapping and leads to exception.
> 
> I have worked around the issue by filtering out the request if the pfn is not valid in  __clean_dcache_guest_page().
> As the patch wasn't posted in the community, reverted it as well.

Thank you Krishna for sharing the analysis.

Best Regards,
Sumit Gupta
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  reply	other threads:[~2021-04-23 18:20 UTC|newest]

Thread overview: 140+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-23 20:56 [PATCH v14 00/13] SMMUv3 Nested Stage Setup (IOMMU part) Eric Auger
2021-02-23 20:56 ` Eric Auger
2021-02-23 20:56 ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 01/13] iommu: Introduce attach/detach_pasid_table API Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 02/13] iommu: Introduce bind/unbind_guest_msi Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 03/13] iommu/smmuv3: Allow s1 and s2 configs to coexist Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 04/13] iommu/smmuv3: Get prepared for nested stage support Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 05/13] iommu/smmuv3: Implement attach/detach_pasid_table Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-03-02  8:35   ` Keqian Zhu
2021-03-02  8:35     ` Keqian Zhu
2021-03-02  8:35     ` Keqian Zhu
2021-03-19 13:15     ` Auger Eric
2021-03-19 13:15       ` Auger Eric
2021-03-19 13:15       ` Auger Eric
2021-03-22  6:23       ` Keqian Zhu
2021-03-22  6:23         ` Keqian Zhu
2021-03-22  6:23         ` Keqian Zhu
2021-02-23 20:56 ` [PATCH v14 06/13] iommu/smmuv3: Allow stage 1 invalidation with unmanaged ASIDs Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-03-30  9:17   ` Zenghui Yu
2021-03-30  9:17     ` Zenghui Yu
2021-03-30  9:17     ` Zenghui Yu
2021-04-01  9:38     ` Auger Eric
2021-04-01  9:38       ` Auger Eric
2021-04-01  9:38       ` Auger Eric
2021-04-01 12:37   ` Kunkun Jiang
2021-04-01 12:37     ` Kunkun Jiang
2021-04-01 12:37     ` Kunkun Jiang
2021-04-08 12:30     ` Auger Eric
2021-04-08 12:30       ` Auger Eric
2021-04-08 12:30       ` Auger Eric
2021-04-09  4:48       ` Kunkun Jiang
2021-04-09  4:48         ` Kunkun Jiang
2021-04-09  4:48         ` Kunkun Jiang
2021-04-09  8:31         ` Auger Eric
2021-04-09  8:31           ` Auger Eric
2021-04-09  8:31           ` Auger Eric
2021-04-09  9:43           ` Kunkun Jiang
2021-04-09  9:43             ` Kunkun Jiang
2021-04-09  9:43             ` Kunkun Jiang
2021-02-23 20:56 ` [PATCH v14 07/13] iommu/smmuv3: Implement cache_invalidate Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-03-04  7:55   ` chenxiang (M)
2021-03-04  7:55     ` chenxiang (M)
2021-03-19 17:36     ` Auger Eric
2021-03-19 17:36       ` Auger Eric
2021-03-19 17:36       ` Auger Eric
2021-03-22  6:40       ` [Linuxarm] " chenxiang (M)
2021-03-22  6:40         ` chenxiang (M)
2021-03-22  6:40         ` chenxiang (M)
2021-03-22  9:05         ` Auger Eric
2021-03-22  9:05           ` Auger Eric
2021-03-22  9:05           ` Auger Eric
2021-03-23  1:28           ` chenxiang (M)
2021-03-23  1:28             ` chenxiang (M)
2021-03-23  1:28             ` chenxiang (M)
2021-04-01  6:11   ` Zenghui Yu
2021-04-01  6:11     ` Zenghui Yu
2021-04-01  6:11     ` Zenghui Yu
2021-04-01 12:06     ` Auger Eric
2021-04-01 12:06       ` Auger Eric
2021-04-01 12:06       ` Auger Eric
2021-02-23 20:56 ` [PATCH v14 08/13] dma-iommu: Implement NESTED_MSI cookie Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-04-07  7:39   ` Zenghui Yu
2021-04-07  7:39     ` Zenghui Yu
2021-04-07  7:39     ` Zenghui Yu
2021-04-10 13:34     ` Auger Eric
2021-04-10 13:34       ` Auger Eric
2021-04-10 13:34       ` Auger Eric
2021-02-23 20:56 ` [PATCH v14 09/13] iommu/smmuv3: Nested mode single MSI doorbell per domain enforcement Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 10/13] iommu/smmuv3: Enforce incompatibility between nested mode and HW MSI regions Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 11/13] iommu/smmuv3: Implement bind/unbind_guest_msi Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 12/13] iommu/smmuv3: report additional recoverable faults Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56 ` [PATCH v14 13/13] iommu/smmuv3: Accept configs with more than one context descriptor Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-02-23 20:56   ` Eric Auger
2021-03-30  9:23   ` Zenghui Yu
2021-03-30  9:23     ` Zenghui Yu
2021-03-30  9:23     ` Zenghui Yu
2021-04-01 11:48     ` Auger Eric
2021-04-01 11:48       ` Auger Eric
2021-04-01 11:48       ` Auger Eric
2021-04-01 12:38       ` Shameerali Kolothum Thodi
2021-04-01 12:38         ` Shameerali Kolothum Thodi
2021-04-01 12:38         ` Shameerali Kolothum Thodi
2021-04-01 13:20         ` Auger Eric
2021-04-01 13:20           ` Auger Eric
2021-04-01 13:20           ` Auger Eric
2021-02-25 16:06 ` [PATCH v14 00/13] SMMUv3 Nested Stage Setup (IOMMU part) Auger Eric
2021-02-25 16:06   ` Auger Eric
2021-02-25 16:06   ` Auger Eric
2021-04-22 15:04   ` Sumit Gupta
2021-04-22 15:04     ` Sumit Gupta
2021-04-22 15:04     ` Sumit Gupta
2021-04-23 13:00     ` Jean-Philippe Brucker
2021-04-23 13:00       ` Jean-Philippe Brucker
2021-04-23 13:00       ` Jean-Philippe Brucker
2021-04-23 17:16       ` Sumit Gupta
2021-04-23 17:16         ` Sumit Gupta
2021-04-23 17:16         ` Sumit Gupta
2021-04-23 17:58         ` Krishna Reddy
2021-04-23 17:58           ` Krishna Reddy
2021-04-23 17:58           ` Krishna Reddy
2021-04-23 18:19           ` Sumit Gupta [this message]
2021-04-23 18:19             ` Sumit Gupta
2021-04-23 18:19             ` Sumit Gupta
2021-04-24  9:06           ` Marc Zyngier
2021-04-24  9:06             ` Marc Zyngier
2021-04-24  9:06             ` Marc Zyngier
2021-04-24 11:29             ` Sumit Gupta
2021-04-24 11:29               ` Sumit Gupta
2021-04-24 11:29               ` Sumit Gupta
2021-03-18  0:16 ` Krishna Reddy
2021-03-18  0:16   ` Krishna Reddy
2021-03-18  0:16   ` Krishna Reddy
2021-03-19 13:17   ` Auger Eric
2021-03-19 13:17     ` Auger Eric
2021-03-19 13:17     ` Auger Eric

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