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Groups > linux.kernel > #1310289
| From | Sinan Kaya <okaya@codeaurora.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver |
| Date | 2016-01-15 18:20 +0100 |
| Message-ID | <qRgcy-Lu-5@gated-at.bofh.it> (permalink) |
| References | <qPLXc-3He-21@gated-at.bofh.it> <qPLXd-3He-55@gated-at.bofh.it> <qReaK-7SU-23@gated-at.bofh.it> <qRekq-7Xi-25@gated-at.bofh.it> <qReu6-80G-19@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
>>> This doesn't seem to tie into KVM or VFIO, and as far as I can tell >>> there's no mechanism for associating channels with a particular virtual >>> address space (i.e. no configuration of an external or internal IOMMU), >>> nor pinning of guest pages to allow for DMA to occur safely. >> >> I'm using VFIO platform driver for this purpose. VFIO platform driver is >> capable of assigning any platform device to a guest machine with this driver. > > Typically VFIO-platform also comes with a corresponding reset driver. > You don't need one? The HIDMA channel driver resets the channel before using it. That's why, I never bothered with writing a reset driver on the hypervisor. > >> You just unbind the HIDMA channel driver from the hypervisor and bind to vfio >> driver using the very same approach you'd use with PCIe. >> >> Of course, this all assumes the presence of an IOMMU driver on the system. VFIO >> driver uses the IOMMU driver to create the mappings. > > No IOMMU was described in the DT binding. It sounds like you'd need an > optional (not present in the guest) iommus property per-channel You are right. I missed that part. I'll update the device-tree binding documentation. > >> The mechanism used here is not different from VFIO PCI from user perspective. >> >>> >>> Given that, I'm at a loss as to how this would be used in a hypervisor >>> context. What am I missing? >>> >>> Are there additional patches, or do you have some userspace that works >>> with this in some limited configuration? >> >> No, these are the only patches. We have one patch for the QEMU but from kernel >> perspective this is it. > > Do you have a link to that? Seeing it would help to ease my concerns. The QEMU driver has not been posted yet. As far as I know, it just discovers the memory resources on the platform object and creates mappings for the guest machine only. Shanker Donthineni and Vikram Sethi will post the QEMU patch later. > > Thanks, > Mark. > -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
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[PATCH v12 0/7] dma: add Qualcomm Technologies HIDMA driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-11 15:50 +0100
[PATCH V12 4/7] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-11 15:50 +0100
[PATCH V12 2/7] dma: hidma: Add Device Tree support Sinan Kaya <okaya@codeaurora.org> - 2016-01-11 15:50 +0100
Re: [PATCH V12 2/7] dma: hidma: Add Device Tree support Mark Rutland <mark.rutland@arm.com> - 2016-01-15 16:20 +0100
Re: [PATCH V12 2/7] dma: hidma: Add Device Tree support Mark Rutland <mark.rutland@arm.com> - 2016-01-15 16:40 +0100
Re: [PATCH V12 2/7] dma: hidma: Add Device Tree support Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 18:10 +0100
Re: [PATCH V12 2/7] dma: hidma: Add Device Tree support Mark Rutland <mark.rutland@arm.com> - 2016-01-18 12:50 +0100
Re: [PATCH V12 2/7] dma: hidma: Add Device Tree support Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 18:00 +0100
Re: [PATCH V12 2/7] dma: hidma: Add Device Tree support Mark Rutland <mark.rutland@arm.com> - 2016-01-18 13:00 +0100
Re: [PATCH V12 2/7] dma: hidma: Add Device Tree support Sinan Kaya <okaya@codeaurora.org> - 2016-01-18 15:10 +0100
[PATCH V12 6/7] dma: qcom_hidma: add debugfs hooks Sinan Kaya <okaya@codeaurora.org> - 2016-01-11 15:50 +0100
[PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-11 15:50 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Mark Rutland <mark.rutland@arm.com> - 2016-01-15 16:10 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 16:20 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Mark Rutland <mark.rutland@arm.com> - 2016-01-15 16:30 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 18:20 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Marc Zyngier <marc.zyngier@arm.com> - 2016-01-15 18:40 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 23:50 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Marc Zyngier <marc.zyngier@arm.com> - 2016-01-18 10:10 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-22 19:40 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Marc Zyngier <marc.zyngier@arm.com> - 2016-01-15 16:20 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Mark Rutland <mark.rutland@arm.com> - 2016-01-15 16:40 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 17:10 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-20 23:20 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 16:50 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Marc Zyngier <marc.zyngier@arm.com> - 2016-01-15 18:30 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2016-01-15 18:50 +0100
Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Marc Zyngier <marc.zyngier@arm.com> - 2016-01-15 19:10 +0100
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