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* [PATCH 0/9] Support using MSI interrupts in ntb_transport
@ 2019-01-31 18:56 Logan Gunthorpe
  2019-01-31 18:56 ` [PATCH 1/9] iommu/vt-d: Allow interrupts from the entire bus for aliased devices Logan Gunthorpe
                   ` (9 more replies)
  0 siblings, 10 replies; 26+ messages in thread
From: Logan Gunthorpe @ 2019-01-31 18:56 UTC (permalink / raw)
  To: linux-kernel, linux-ntb, linux-pci, iommu, linux-kselftest,
	Jon Mason, Bjorn Helgaas, Joerg Roedel
  Cc: Allen Hubbe, Dave Jiang, Serge Semin, Eric Pilmore, Logan Gunthorpe

Hi,

This patch series adds optional support for using MSI interrupts instead
of NTB doorbells in ntb_transport. This is desirable seeing doorbells on
current hardware are quite slow and therefore switching to MSI interrupts
provides a significant performance gain. On switchtec hardware, a simple
apples-to-apples comparison shows ntb_netdev/iperf numbers going from
3.88Gb/s to 14.1Gb/s when switching to MSI interrupts.

To do this, a couple changes are required outside of the NTB tree:

1) The IOMMU must know to accept MSI requests from aliased bused numbers
seeing NTB hardware typically sends proxied request IDs through
additional requester IDs. The first patch in this series adds support
for the Intel IOMMU. A quirk to add these aliases for switchtec hardware
was already accepted. See commit ad281ecf1c7d ("PCI: Add DMA alias quirk
for Microsemi Switchtec NTB") for a description of NTB proxy IDs and why
this is necessary.

2) NTB transport (and other clients) may often need more MSI interrupts
than the NTB hardware actually advertises support for. However, seeing
these interrupts will not be triggered by the hardware but through an
NTB memory window, the hardware does not actually need support or need
to know about them. Therefore we add the concept of Virtual MSI
interrupts which are allocated just like any other MSI interrupt but
are not programmed into the hardware's MSI table. This is done in
Patch 2 and then made use of in Patch 3.

The remaining patches in this series add a library for dealing with MSI
interrupts, a test client and finally support in ntb_transport.

The series is based off of v5.0-rc4 and I've tested it on top of a
of the patches I've already sent to the NTB tree (though they are
independent changes). A git repo is available here:

https://github.com/sbates130272/linux-p2pmem/ ntb_transport_msi_v1

Thanks,

Logan

--

Logan Gunthorpe (9):
  iommu/vt-d: Allow interrupts from the entire bus for aliased devices
  PCI/MSI: Support allocating virtual MSI interrupts
  PCI/switchtec: Add module parameter to request more interrupts
  NTB: Introduce functions to calculate multi-port resource index
  NTB: Rename ntb.c to support multiple source files in the module
  NTB: Introduce MSI library
  NTB: Introduce NTB MSI Test Client
  NTB: Add ntb_msi_test support to ntb_test
  NTB: Add MSI interrupt support to ntb_transport

 drivers/iommu/intel_irq_remapping.c     |  12 +
 drivers/ntb/Kconfig                     |  10 +
 drivers/ntb/Makefile                    |   3 +
 drivers/ntb/{ntb.c => core.c}           |   0
 drivers/ntb/msi.c                       | 313 ++++++++++++++++++
 drivers/ntb/ntb_transport.c             | 134 +++++++-
 drivers/ntb/test/Kconfig                |   9 +
 drivers/ntb/test/Makefile               |   1 +
 drivers/ntb/test/ntb_msi_test.c         | 416 ++++++++++++++++++++++++
 drivers/pci/msi.c                       |  51 ++-
 drivers/pci/switch/switchtec.c          |  12 +-
 include/linux/msi.h                     |   1 +
 include/linux/ntb.h                     | 139 ++++++++
 include/linux/pci.h                     |   9 +
 tools/testing/selftests/ntb/ntb_test.sh |  54 ++-
 15 files changed, 1150 insertions(+), 14 deletions(-)
 rename drivers/ntb/{ntb.c => core.c} (100%)
 create mode 100644 drivers/ntb/msi.c
 create mode 100644 drivers/ntb/test/ntb_msi_test.c

--
2.19.0

^ permalink raw reply	[flat|nested] 26+ messages in thread

end of thread, other threads:[~2019-02-05 23:57 UTC | newest]

Thread overview: 26+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-01-31 18:56 [PATCH 0/9] Support using MSI interrupts in ntb_transport Logan Gunthorpe
2019-01-31 18:56 ` [PATCH 1/9] iommu/vt-d: Allow interrupts from the entire bus for aliased devices Logan Gunthorpe
2019-02-01 16:44   ` Joerg Roedel
2019-02-01 17:27     ` Logan Gunthorpe
2019-02-05 19:19       ` Jacob Pan
2019-02-05 20:40         ` Logan Gunthorpe
2019-02-05 23:58           ` Jacob Pan
2019-01-31 18:56 ` [PATCH 2/9] PCI/MSI: Support allocating virtual MSI interrupts Logan Gunthorpe
2019-01-31 22:39   ` Bjorn Helgaas
2019-01-31 22:52     ` Logan Gunthorpe
2019-02-01 19:23       ` Bjorn Helgaas
2019-01-31 18:56 ` [PATCH 3/9] PCI/switchtec: Add module parameter to request more interrupts Logan Gunthorpe
2019-01-31 18:56 ` [PATCH 4/9] NTB: Introduce functions to calculate multi-port resource index Logan Gunthorpe
2019-01-31 18:56 ` [PATCH 5/9] NTB: Rename ntb.c to support multiple source files in the module Logan Gunthorpe
2019-01-31 18:56 ` [PATCH 6/9] NTB: Introduce MSI library Logan Gunthorpe
2019-01-31 18:56 ` [PATCH 7/9] NTB: Introduce NTB MSI Test Client Logan Gunthorpe
2019-01-31 18:56 ` [PATCH 8/9] NTB: Add ntb_msi_test support to ntb_test Logan Gunthorpe
2019-01-31 18:56 ` [PATCH 9/9] NTB: Add MSI interrupt support to ntb_transport Logan Gunthorpe
2019-01-31 20:20 ` [PATCH 0/9] Support using MSI interrupts in ntb_transport Dave Jiang
2019-01-31 20:48   ` Logan Gunthorpe
2019-01-31 20:58     ` Dave Jiang
2019-01-31 22:39       ` Logan Gunthorpe
2019-01-31 22:46         ` Dave Jiang
2019-01-31 23:41           ` Logan Gunthorpe
2019-01-31 23:48             ` Dave Jiang
2019-01-31 23:52               ` Logan Gunthorpe

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