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Groups > linux.kernel > #1517230
| From | Kirti Wankhede <kwankhede@nvidia.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v11 09/22] vfio iommu type1: Add task structure to vfio_dma |
| Date | 2016-11-08 15:20 +0100 |
| Message-ID | <sBfpL-20X-7@gated-at.bofh.it> (permalink) |
| References | <szTUm-6Y7-25@gated-at.bofh.it> <szU42-71A-33@gated-at.bofh.it> <sAZkZ-8k-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 11/8/2016 2:33 AM, Alex Williamson wrote:
> On Sat, 5 Nov 2016 02:40:43 +0530
> Kirti Wankhede <kwankhede@nvidia.com> wrote:
>
...
>> static int vfio_dma_do_map(struct vfio_iommu *iommu,
>> struct vfio_iommu_type1_dma_map *map)
>> {
>> dma_addr_t iova = map->iova;
>> unsigned long vaddr = map->vaddr;
>> size_t size = map->size;
>> - long npage;
>> int ret = 0, prot = 0;
>> uint64_t mask;
>> struct vfio_dma *dma;
>> - unsigned long pfn;
>> + struct vfio_addr_space *addr_space;
>> + struct mm_struct *mm;
>> + bool free_addr_space_on_err = false;
>>
>> /* Verify that none of our __u64 fields overflow */
>> if (map->size != size || map->vaddr != vaddr || map->iova != iova)
>> @@ -608,47 +685,56 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
>> mutex_lock(&iommu->lock);
>>
>> if (vfio_find_dma(iommu, iova, size)) {
>> - mutex_unlock(&iommu->lock);
>> - return -EEXIST;
>> + ret = -EEXIST;
>> + goto do_map_err;
>> + }
>> +
>> + mm = get_task_mm(current);
>> + if (!mm) {
>> + ret = -ENODEV;
>
> -EFAULT?
>
-ENODEV return is in original code from vfio_pin_pages()
if (!current->mm)
return -ENODEV;
Once I thought of changing it to -EFAULT, but then again changed to
-ENODEV to be consistent with original error code.
Should I still change this return to -EFAULT?
>> + goto do_map_err;
>> + }
>> +
>> + addr_space = vfio_find_addr_space(iommu, mm);
>> + if (addr_space) {
>> + atomic_inc(&addr_space->ref_count);
>> + mmput(mm);
>> + } else {
>> + addr_space = kzalloc(sizeof(*addr_space), GFP_KERNEL);
>> + if (!addr_space) {
>> + ret = -ENOMEM;
>> + goto do_map_err;
>> + }
>> + addr_space->mm = mm;
>> + atomic_set(&addr_space->ref_count, 1);
>> + list_add(&addr_space->next, &iommu->addr_space_list);
>> + free_addr_space_on_err = true;
>> }
>>
>> dma = kzalloc(sizeof(*dma), GFP_KERNEL);
>> if (!dma) {
>> - mutex_unlock(&iommu->lock);
>> - return -ENOMEM;
>> + if (free_addr_space_on_err) {
>> + mmput(mm);
>> + list_del(&addr_space->next);
>> + kfree(addr_space);
>> + }
>> + ret = -ENOMEM;
>> + goto do_map_err;
>> }
>>
>> dma->iova = iova;
>> dma->vaddr = vaddr;
>> dma->prot = prot;
>> + dma->addr_space = addr_space;
>> + get_task_struct(current);
>> + dma->task = current;
>> + dma->mlock_cap = capable(CAP_IPC_LOCK);
>
>
> How do you reason we can cache this? Does the fact that the process
> had this capability at the time that it did a DMA_MAP imply that it
> necessarily still has this capability when an external user (vendor
> driver) tries to pin pages? I don't see how we can make that
> assumption.
>
>
Will process change MEMLOCK limit at runtime? I think it shouldn't,
correct me if I'm wrong. QEMU doesn't do that, right?
The function capable() determines current task's capability. But when
vfio_pin_pages() is called, it could come from other task but pages are
pinned from address space of task who mapped it. So we can't use
capable() in vfio_pin_pages()
If this capability shouldn't be cached, we have to use has_capability()
with dma->task as argument in vfio_pin_pages()
bool has_capability(struct task_struct *t, int cap)
Thanks,
Kirti
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v11 00/22] Add Mediated device support Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:10 +0100
[PATCH v11 12/22] vfio: Add notifier callback to parent's ops structure of mdev Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 12/22] vfio: Add notifier callback to parent's ops structure of mdev Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 01:00 +0100
[PATCH v11 06/22] vfio iommu type1: Update arguments of vfio_lock_acct Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 17/22] vfio_platform: Updated to use vfio_set_irqs_validate_and_prepare() Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 17/22] vfio_platform: Updated to use vfio_set_irqs_validate_and_prepare() Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-08 11:00 +0100
Re: [PATCH v11 17/22] vfio_platform: Updated to use vfio_set_irqs_validate_and_prepare() Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 21:50 +0100
[PATCH v11 20/22] docs: Sysfs ABI for mediated device framework Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 16/22] vfio_pci: Updated to use vfio_set_irqs_validate_and_prepare() Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 04/22] vfio: Common function to increment container_users Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 19/22] docs: Add Documentation for Mediated devices Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 13/22] vfio: Introduce common function to add capabilities Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 13/22] vfio: Introduce common function to add capabilities Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-08 08:30 +0100
Re: [PATCH v11 13/22] vfio: Introduce common function to add capabilities Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 21:50 +0100
Re: [PATCH v11 13/22] vfio: Introduce common function to add capabilities Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 22:50 +0100
Re: [PATCH v11 13/22] vfio: Introduce common function to add capabilities Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-09 03:30 +0100
[PATCH v11 03/22] vfio: Rearrange functions to get vfio_group from dev Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 14/22] vfio_pci: Update vfio_pci to use vfio_info_add_capability() Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 09/22] vfio iommu type1: Add task structure to vfio_dma Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 09/22] vfio iommu type1: Add task structure to vfio_dma Alex Williamson <alex.williamson@redhat.com> - 2016-11-07 22:10 +0100
Re: [PATCH v11 09/22] vfio iommu type1: Add task structure to vfio_dma Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 15:20 +0100
Re: [PATCH v11 09/22] vfio iommu type1: Add task structure to vfio_dma Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 17:50 +0100
[PATCH v11 02/22] vfio: VFIO based driver for Mediated devices Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 18/22] vfio: Define device_api strings Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 07/22] vfio iommu type1: Update argument of vaddr_get_pfn() Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 07/22] vfio iommu type1: Update argument of vaddr_get_pfn() Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-07 09:50 +0100
[PATCH v11 15/22] vfio: Introduce vfio_set_irqs_validate_and_prepare() Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 15/22] vfio: Introduce vfio_set_irqs_validate_and_prepare() Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-08 09:50 +0100
Re: [PATCH v11 15/22] vfio: Introduce vfio_set_irqs_validate_and_prepare() Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 21:30 +0100
Re: [PATCH v11 15/22] vfio: Introduce vfio_set_irqs_validate_and_prepare() Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-09 04:10 +0100
Re: [PATCH v11 15/22] vfio: Introduce vfio_set_irqs_validate_and_prepare() Alex Williamson <alex.williamson@redhat.com> - 2016-11-09 04:40 +0100
[PATCH v11 10/22] vfio iommu type1: Add support for mediated devices Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 00:20 +0100
Re: [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices Jike Song <jike.song@intel.com> - 2016-11-08 03:30 +0100
Re: [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 17:20 +0100
Re: [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 16:10 +0100
Re: [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 18:10 +0100
Re: [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-08 08:00 +0100
[PATCH v11 22/22] MAINTAINERS: Add entry VFIO based Mediated device drivers Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 08/22] vfio iommu type1: Add find_iommu_group() function Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
[PATCH v11 11/22] vfio iommu: Add blocking notifier to notify DMA_UNMAP Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 11/22] vfio iommu: Add blocking notifier to notify DMA_UNMAP Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 00:50 +0100
Re: [PATCH v11 11/22] vfio iommu: Add blocking notifier to notify DMA_UNMAP Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 17:30 +0100
Re: [PATCH v11 11/22] vfio iommu: Add blocking notifier to notify DMA_UNMAP Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 18:50 +0100
Re: [PATCH v11 11/22] vfio iommu: Add blocking notifier to notify DMA_UNMAP Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 21:10 +0100
Re: [PATCH v11 11/22] vfio iommu: Add blocking notifier to notify DMA_UNMAP Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 22:30 +0100
[PATCH v11 01/22] vfio: Mediated device Core driver Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
RE: [PATCH v11 01/22] vfio: Mediated device Core driver "Tian, Kevin" <kevin.tian@intel.com> - 2016-11-07 07:50 +0100
Re: [PATCH v11 01/22] vfio: Mediated device Core driver Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 22:20 +0100
[PATCH v11 05/22] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-04 22:20 +0100
Re: [PATCH v11 05/22] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops Alex Williamson <alex.williamson@redhat.com> - 2016-11-07 20:40 +0100
Re: [PATCH v11 05/22] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 15:00 +0100
Re: [PATCH v11 05/22] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 17:50 +0100
Re: [PATCH v11 05/22] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-08 20:00 +0100
Re: [PATCH v11 05/22] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops Alex Williamson <alex.williamson@redhat.com> - 2016-11-08 20:20 +0100
Re: [PATCH v11 00/22] Add Mediated device support Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-07 04:50 +0100
Re: [PATCH v11 00/22] Add Mediated device support Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-07 05:00 +0100
Re: [PATCH v11 00/22] Add Mediated device support Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-07 06:10 +0100
Re: [PATCH v11 00/22] Add Mediated device support Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-07 07:20 +0100
Re: [PATCH v11 00/22] Add Mediated device support Kirti Wankhede <kwankhede@nvidia.com> - 2016-11-07 07:40 +0100
Re: [PATCH v11 00/22] Add Mediated device support Alexey Kardashevskiy <aik@ozlabs.ru> - 2016-11-07 07:50 +0100
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