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[v5,0/3] support both PIO and MMIO BAR for virtio PMD

Message ID 1603381885-88819-1-git-send-email-huawei.xhw@alibaba-inc.com (mailing list archive)
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谢华伟(此时此刻） Oct. 22, 2020, 3:51 p.m. UTC 
  From: "huawei.xhw" <huawei.xhw@alibaba-inc.com>

Legacy virtio-pci only supports PIO BAR resource. As we need to create lots of
virtio devices and PIO resource on x86 is very limited, we expose MMIO BAR.

Kernel supports both PIO  and MMIO BAR for legacy virtio-pci device. We handles
different type of BAR in the similar way.

In previous implementation, with igb_uio we get PIO address from igb_uio
sysfs entry; with uio_pci_generic, we get PIO address from
/proc/ioports.
For PIO/MMIO RW, there is different path for different drivers and arch.
For VFIO, PIO/MMIO RW is through syscall, which has big performance
issue.
On X86, it assumes only PIO is supported.

All of the above is too much twisted.
This patch unifies the way to get both PIO and MMIO address for different driver
and arch, all from standard resource attr under pci sysfs.

We distinguish PIO and MMIO by their address like how kernel does. It is ugly but works.

v2 changes:
	 - add more explanation in the commit message

v3 changes:
	 - fix patch format issues

v4 changes:
	 - fixes for RTE_KDRV_UIO_GENERIC -> RTE_PCI_KDRV_UIO_GENERIC

v5 changes:
	 - split into three seperate patches

huawei.xhw (3):
  PCI: use PCI standard sysfs entry to get PIO address
  PCI: support MMIO in rte_pci_ioport_map/unap/read/write
  PCI: don't use vfio ioctl call to access PIO resource

 drivers/bus/pci/linux/pci.c     |  89 +-------------------
 drivers/bus/pci/linux/pci_uio.c | 177 ++++++++++++++++++++++++++++------------
 2 files changed, 128 insertions(+), 138 deletions(-)