Re: [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework
在 2018年08月06日 星期一 08:27 下午, Pavel Machek 写道: Hi! WarpDrive is a common user space accelerator framework. Its main component in Kernel is called spimdev, Share Parent IOMMU Mediated Device. It exposes spimdev is really unfortunate name. It looks like it has something to do with SPI, but it does not. Yes. Let me change it to Share (IOMMU) Domain MDev, SDMdev:) +++ b/Documentation/warpdrive/warpdrive.rst @@ -0,0 +1,153 @@ +Introduction of WarpDrive += + +*WarpDrive* is a general accelerator framework built on top of vfio. +It can be taken as a light weight virtual function, which you can use without +*SR-IOV* like facility and can be shared among multiple processes. + +It can be used as the quick channel for accelerators, network adaptors or +other hardware in user space. It can make some implementation simpler. E.g. +you can reuse most of the *netdev* driver and just share some ring buffer to +the user space driver for *DPDK* or *ODP*. Or you can combine the RSA +accelerator with the *netdev* in the user space as a Web reversed proxy, etc. What is DPDK? ODP? DPDK：https://www.dpdk.org/about/ ODP: https://www.opendataplane.org/ will add the reference in the next RFC +How does it work + + +*WarpDrive* takes the Hardware Accelerator as a heterogeneous processor which +can share some load for the CPU: + +.. image:: wd.svg +:alt: This is a .svg image, if your browser cannot show it, +try to download and view it locally + +So it provides the capability to the user application to: + +1. Send request to the hardware +2. Share memory with the application and other accelerators + +These requirements can be fulfilled by VFIO if the accelerator can serve each +application with a separated Virtual Function. But a *SR-IOV* like VF (we will +call it *HVF* hereinafter) design is too heavy for the accelerator which +service thousands of processes. VFIO? VF? HVF? Also "gup" might be worth spelling out. But I think the reference [1] has explained this. +References +== +.. [1] Accroding to the comment in in mm/gup.c, The *gup* is only safe within + a syscall. Because it can only keep the physical memory in place + without making sure the VMA will always point to it. Maybe we should + raise the VM_PINNED patchset (see + https://lists.gt.net/linux/kernel/1931993) again to solve this probl I went through the docs, but I still don't know what it does. Will refine the doc in next RFC, hope it will help. Pavel ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework
Hi! > WarpDrive is a common user space accelerator framework. Its main component > in Kernel is called spimdev, Share Parent IOMMU Mediated Device. It exposes spimdev is really unfortunate name. It looks like it has something to do with SPI, but it does not. > +++ b/Documentation/warpdrive/warpdrive.rst > @@ -0,0 +1,153 @@ > +Introduction of WarpDrive > += > + > +*WarpDrive* is a general accelerator framework built on top of vfio. > +It can be taken as a light weight virtual function, which you can use without > +*SR-IOV* like facility and can be shared among multiple processes. > + > +It can be used as the quick channel for accelerators, network adaptors or > +other hardware in user space. It can make some implementation simpler. E.g. > +you can reuse most of the *netdev* driver and just share some ring buffer to > +the user space driver for *DPDK* or *ODP*. Or you can combine the RSA > +accelerator with the *netdev* in the user space as a Web reversed proxy, etc. What is DPDK? ODP? > +How does it work > + > + > +*WarpDrive* takes the Hardware Accelerator as a heterogeneous processor which > +can share some load for the CPU: > + > +.. image:: wd.svg > +:alt: This is a .svg image, if your browser cannot show it, > +try to download and view it locally > + > +So it provides the capability to the user application to: > + > +1. Send request to the hardware > +2. Share memory with the application and other accelerators > + > +These requirements can be fulfilled by VFIO if the accelerator can serve each > +application with a separated Virtual Function. But a *SR-IOV* like VF (we > will > +call it *HVF* hereinafter) design is too heavy for the accelerator which > +service thousands of processes. VFIO? VF? HVF? Also "gup" might be worth spelling out. > +References > +== > +.. [1] Accroding to the comment in in mm/gup.c, The *gup* is only safe within > + a syscall. Because it can only keep the physical memory in place > + without making sure the VMA will always point to it. Maybe we should > + raise the VM_PINNED patchset (see > + https://lists.gt.net/linux/kernel/1931993) again to solve this probl I went through the docs, but I still don't know what it does. Pavel ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
RE: [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework
> From: Kenneth Lee > Sent: Thursday, August 2, 2018 12:23 PM > > On Thu, Aug 02, 2018 at 03:14:38AM +, Tian, Kevin wrote: > > > > > From: Kenneth Lee > > > Sent: Wednesday, August 1, 2018 6:22 PM > > > > > > From: Kenneth Lee > > > > > > WarpDrive is a common user space accelerator framework. Its main > > > component > > > in Kernel is called spimdev, Share Parent IOMMU Mediated Device. It > > > > Not sure whether "share parent IOMMU" is a good term here. better > > stick to what capabity you bring to user space, instead of describing > > internal trick... > Agree. The "SPI" is also strongly hint to "Share Peripheral Interrupt" or > "Serial > Peripheral Interface". Personally I hate this name. But I cannot find a better > one. In the user space, we can use a impassible name (WarpDrive). But > kernel > require a name point to its feature... maybe I should use "Process-Shared > Mdev" > in next version? or maybe no new name. Just stick to mdev but introducing some new attribute/capability to indicate such purpose. Thanks Kevin ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework
On Thu, Aug 02, 2018 at 03:14:38AM +, Tian, Kevin wrote: > Date: Thu, 2 Aug 2018 03:14:38 + > From: "Tian, Kevin" > To: Kenneth Lee , Jonathan Corbet , > Herbert Xu , "David S . Miller" > , Joerg Roedel , Alex Williamson > , Kenneth Lee , Hao > Fang , Zhou Wang , Zaibo Xu > , Philippe Ombredanne , Greg > Kroah-Hartman , Thomas Gleixner > , "linux-...@vger.kernel.org" > , "linux-ker...@vger.kernel.org" > , "linux-cry...@vger.kernel.org" > , "iommu@lists.linux-foundation.org" > , "k...@vger.kernel.org" > , "linux-accelerat...@lists.ozlabs.org" > , Lu Baolu > , "Kumar, Sanjay K" > CC: "linux...@huawei.com" > Subject: RE: [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive > framework > Message-ID: > > > > From: Kenneth Lee > > Sent: Wednesday, August 1, 2018 6:22 PM > > > > From: Kenneth Lee > > > > WarpDrive is a common user space accelerator framework. Its main > > component > > in Kernel is called spimdev, Share Parent IOMMU Mediated Device. It > > Not sure whether "share parent IOMMU" is a good term here. better > stick to what capabity you bring to user space, instead of describing > internal trick... Agree. The "SPI" is also strongly hint to "Share Peripheral Interrupt" or "Serial Peripheral Interface". Personally I hate this name. But I cannot find a better one. In the user space, we can use a impassible name (WarpDrive). But kernel require a name point to its feature... maybe I should use "Process-Shared Mdev" in next version? > > > exposes > > the hardware capabilities to the user space via vfio-mdev. So processes in > > user land can obtain a "queue" by open the device and direct access the > > hardware MMIO space or do DMA operation via VFIO interface. > > > > WarpDrive is intended to be used with Jean Philippe Brucker's SVA patchset > > (it is still in RFC stage) to support multi-process. But This is not a must. > > Without the SVA patches, WarpDrive can still work for one process for > > every > > hardware device. > > > > This patch add detail documents for the framework. > > > > Signed-off-by: Kenneth Lee > > --- > > Documentation/00-INDEX| 2 + > > Documentation/warpdrive/warpdrive.rst | 153 ++ > > Documentation/warpdrive/wd-arch.svg | 732 > > ++ > > Documentation/warpdrive/wd.svg| 526 ++ > > 4 files changed, 1413 insertions(+) > > create mode 100644 Documentation/warpdrive/warpdrive.rst > > create mode 100644 Documentation/warpdrive/wd-arch.svg > > create mode 100644 Documentation/warpdrive/wd.svg > > > > diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX > > index 2754fe83f0d4..9959affab599 100644 > > --- a/Documentation/00-INDEX > > +++ b/Documentation/00-INDEX > > @@ -410,6 +410,8 @@ vm/ > > - directory with info on the Linux vm code. > > w1/ > > - directory with documents regarding the 1-wire (w1) subsystem. > > +warpdrive/ > > + - directory with documents about WarpDrive accelerator > > framework. > > watchdog/ > > - how to auto-reboot Linux if it has "fallen and can't get up". ;-) > > wimax/ > > diff --git a/Documentation/warpdrive/warpdrive.rst > > b/Documentation/warpdrive/warpdrive.rst > > new file mode 100644 > > index ..3792b2780ea6 > > --- /dev/null > > +++ b/Documentation/warpdrive/warpdrive.rst > > @@ -0,0 +1,153 @@ > > +Introduction of WarpDrive > > += > > + > > +*WarpDrive* is a general accelerator framework built on top of vfio. > > +It can be taken as a light weight virtual function, which you can use > > without > > +*SR-IOV* like facility and can be shared among multiple processes. > > + > > +It can be used as the quick channel for accelerators, network adaptors or > > +other hardware in user space. It can make some implementation simpler. > > E.g. > > +you can reuse most of the *netdev* driver and just share some ring buffer > > to > > +the user space driver for *DPDK* or *ODP*. Or you can combine the RSA > > +accelerator with the *netdev* in the user space as a Web reversed proxy, > > etc. > > + > > +The name *WarpDrive* is simply a cool and general name meaning the > > framework > > +makes the application faster. In kernel, the framework is called SPIMDEV, > > +namely "Share Parent IOMMU
RE: [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework
> From: Kenneth Lee > Sent: Wednesday, August 1, 2018 6:22 PM > > From: Kenneth Lee > > WarpDrive is a common user space accelerator framework. Its main > component > in Kernel is called spimdev, Share Parent IOMMU Mediated Device. It Not sure whether "share parent IOMMU" is a good term here. better stick to what capabity you bring to user space, instead of describing internal trick... > exposes > the hardware capabilities to the user space via vfio-mdev. So processes in > user land can obtain a "queue" by open the device and direct access the > hardware MMIO space or do DMA operation via VFIO interface. > > WarpDrive is intended to be used with Jean Philippe Brucker's SVA patchset > (it is still in RFC stage) to support multi-process. But This is not a must. > Without the SVA patches, WarpDrive can still work for one process for > every > hardware device. > > This patch add detail documents for the framework. > > Signed-off-by: Kenneth Lee > --- > Documentation/00-INDEX| 2 + > Documentation/warpdrive/warpdrive.rst | 153 ++ > Documentation/warpdrive/wd-arch.svg | 732 > ++ > Documentation/warpdrive/wd.svg| 526 ++ > 4 files changed, 1413 insertions(+) > create mode 100644 Documentation/warpdrive/warpdrive.rst > create mode 100644 Documentation/warpdrive/wd-arch.svg > create mode 100644 Documentation/warpdrive/wd.svg > > diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX > index 2754fe83f0d4..9959affab599 100644 > --- a/Documentation/00-INDEX > +++ b/Documentation/00-INDEX > @@ -410,6 +410,8 @@ vm/ > - directory with info on the Linux vm code. > w1/ > - directory with documents regarding the 1-wire (w1) subsystem. > +warpdrive/ > + - directory with documents about WarpDrive accelerator > framework. > watchdog/ > - how to auto-reboot Linux if it has "fallen and can't get up". ;-) > wimax/ > diff --git a/Documentation/warpdrive/warpdrive.rst > b/Documentation/warpdrive/warpdrive.rst > new file mode 100644 > index ..3792b2780ea6 > --- /dev/null > +++ b/Documentation/warpdrive/warpdrive.rst > @@ -0,0 +1,153 @@ > +Introduction of WarpDrive > += > + > +*WarpDrive* is a general accelerator framework built on top of vfio. > +It can be taken as a light weight virtual function, which you can use > without > +*SR-IOV* like facility and can be shared among multiple processes. > + > +It can be used as the quick channel for accelerators, network adaptors or > +other hardware in user space. It can make some implementation simpler. > E.g. > +you can reuse most of the *netdev* driver and just share some ring buffer > to > +the user space driver for *DPDK* or *ODP*. Or you can combine the RSA > +accelerator with the *netdev* in the user space as a Web reversed proxy, > etc. > + > +The name *WarpDrive* is simply a cool and general name meaning the > framework > +makes the application faster. In kernel, the framework is called SPIMDEV, > +namely "Share Parent IOMMU Mediated Device". > + > + > +How does it work > + > + > +*WarpDrive* takes the Hardware Accelerator as a heterogeneous > processor which > +can share some load for the CPU: > + > +.. image:: wd.svg > +:alt: This is a .svg image, if your browser cannot show it, > +try to download and view it locally > + > +So it provides the capability to the user application to: > + > +1. Send request to the hardware > +2. Share memory with the application and other accelerators > + > +These requirements can be fulfilled by VFIO if the accelerator can serve > each > +application with a separated Virtual Function. But a *SR-IOV* like VF (we > will > +call it *HVF* hereinafter) design is too heavy for the accelerator which > +service thousands of processes. > + > +And the *HVF* is not good for the scenario that a device keep most of its > +resource but share partial of the function to the user space. E.g. a *NIC* > +works as a *netdev* but share some hardware queues to the user > application to > +send packets direct to the hardware. > + > +*VFIO-mdev* can solve some of the problem here. But *VFIO-mdev* has > two problem: > + > +1. it cannot make use of its parent device's IOMMU. > +2. it is assumed to be openned only once. > + > +So it will need some add-on for better resource control and let the VFIO > +driver be aware of this. > + > + > +Architecture > + > + > +The full *WarpDrive* architecture is represented in the following class > +diagram: > + > +.. image:: wd-arch.svg > +:alt: This is a .svg image, if your browser cannot show it, > +try to download and view it locally > + > +The idea is: when a device is probed, it can be registered to the general > +framework, e.g. *netdev* or *crypto*, and the *SPIMDEV* at the same > time. > + > +If *SPIMDEV* is registered. A *mdev* creation interface is created. Then > the > +system administrator can create
[RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework
From: Kenneth Lee WarpDrive is a common user space accelerator framework. Its main component in Kernel is called spimdev, Share Parent IOMMU Mediated Device. It exposes the hardware capabilities to the user space via vfio-mdev. So processes in user land can obtain a "queue" by open the device and direct access the hardware MMIO space or do DMA operation via VFIO interface. WarpDrive is intended to be used with Jean Philippe Brucker's SVA patchset (it is still in RFC stage) to support multi-process. But This is not a must. Without the SVA patches, WarpDrive can still work for one process for every hardware device. This patch add detail documents for the framework. Signed-off-by: Kenneth Lee --- Documentation/00-INDEX| 2 + Documentation/warpdrive/warpdrive.rst | 153 ++ Documentation/warpdrive/wd-arch.svg | 732 ++ Documentation/warpdrive/wd.svg| 526 ++ 4 files changed, 1413 insertions(+) create mode 100644 Documentation/warpdrive/warpdrive.rst create mode 100644 Documentation/warpdrive/wd-arch.svg create mode 100644 Documentation/warpdrive/wd.svg diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX index 2754fe83f0d4..9959affab599 100644 --- a/Documentation/00-INDEX +++ b/Documentation/00-INDEX @@ -410,6 +410,8 @@ vm/ - directory with info on the Linux vm code. w1/ - directory with documents regarding the 1-wire (w1) subsystem. +warpdrive/ + - directory with documents about WarpDrive accelerator framework. watchdog/ - how to auto-reboot Linux if it has "fallen and can't get up". ;-) wimax/ diff --git a/Documentation/warpdrive/warpdrive.rst b/Documentation/warpdrive/warpdrive.rst new file mode 100644 index ..3792b2780ea6 --- /dev/null +++ b/Documentation/warpdrive/warpdrive.rst @@ -0,0 +1,153 @@ +Introduction of WarpDrive += + +*WarpDrive* is a general accelerator framework built on top of vfio. +It can be taken as a light weight virtual function, which you can use without +*SR-IOV* like facility and can be shared among multiple processes. + +It can be used as the quick channel for accelerators, network adaptors or +other hardware in user space. It can make some implementation simpler. E.g. +you can reuse most of the *netdev* driver and just share some ring buffer to +the user space driver for *DPDK* or *ODP*. Or you can combine the RSA +accelerator with the *netdev* in the user space as a Web reversed proxy, etc. + +The name *WarpDrive* is simply a cool and general name meaning the framework +makes the application faster. In kernel, the framework is called SPIMDEV, +namely "Share Parent IOMMU Mediated Device". + + +How does it work + + +*WarpDrive* takes the Hardware Accelerator as a heterogeneous processor which +can share some load for the CPU: + +.. image:: wd.svg +:alt: This is a .svg image, if your browser cannot show it, +try to download and view it locally + +So it provides the capability to the user application to: + +1. Send request to the hardware +2. Share memory with the application and other accelerators + +These requirements can be fulfilled by VFIO if the accelerator can serve each +application with a separated Virtual Function. But a *SR-IOV* like VF (we will +call it *HVF* hereinafter) design is too heavy for the accelerator which +service thousands of processes. + +And the *HVF* is not good for the scenario that a device keep most of its +resource but share partial of the function to the user space. E.g. a *NIC* +works as a *netdev* but share some hardware queues to the user application to +send packets direct to the hardware. + +*VFIO-mdev* can solve some of the problem here. But *VFIO-mdev* has two problem: + +1. it cannot make use of its parent device's IOMMU. +2. it is assumed to be openned only once. + +So it will need some add-on for better resource control and let the VFIO +driver be aware of this. + + +Architecture + + +The full *WarpDrive* architecture is represented in the following class +diagram: + +.. image:: wd-arch.svg +:alt: This is a .svg image, if your browser cannot show it, +try to download and view it locally + +The idea is: when a device is probed, it can be registered to the general +framework, e.g. *netdev* or *crypto*, and the *SPIMDEV* at the same time. + +If *SPIMDEV* is registered. A *mdev* creation interface is created. Then the +system administrator can create a *mdev* in the user space and set its +parameters via its sysfs interfacev. But not like the other mdev +implementation, hardware resource will not be allocated until it is opened by +an application. + +With this strategy, the hardware resource can be easily scheduled among +multiple processes. + + +The user API + + +We adopt a polling style interface in the user space: :: + +int wd_request_queue(int container, struct wd_queue *q, +
