06013b647c
The SR-IOV specification requires both PFs and VFs to implement a PCIe
capability. Generally this is sufficient to assume extended config space
is present, but we generally also perform additional tests to make sure the
extended config space is reachable and not simply an alias of standard
config space. For a VF to exist extended config space must be accessible
on the PF, therefore we can also assume it to be accessible on the VF.
This enables a micro performance optimization previously implemented in
commit 975bb8b4dc93 ("PCI/IOV: Use VF0 cached config space size for other
VFs") to speed up probing of VFs.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: Hao Zheng <yinhe@linux.alibaba.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.