Changes from V2:
1. Enabling and disabling SR-IOV is now done
through the sysfs interface, requiring
admin privileges.
2. Since admin privileges are now required
to enable SR-IOV most of the the security
measures introduced in RFC V2 were removed.
Unfortunately we still need a mutex to prevent
the VFIO user from changing the number of
VFs while enable_sriov is in progress.
Changes from V1:
1. The VF are no longer assigned to PFs iommu group
2. Add a pci_enable_sriov_with_override API to allow
enablind sriov without probing the VFs with the
default driver
Changes from RFC V2:
1. pci_disable_sriov() is now called from a workqueue
To avoid the situation where a process is blocked
in pci_disable_sriov() wating for itself to relase the VFs.
2. a mutex was added to synchronize calls to
pci_enable_sriov() and pci_disable_sriov()
Changes from RFC V1:
Due to the security concern raised in RFC V1, we add two patches
to make sure the VFs belong to the same IOMMU group as
the PF and are probed by VFIO.
Today the QEMU hypervisor allows assigning a physical device to a VM,
facilitating driver development. However, it does not support enabling
SR-IOV by the VM kernel driver. Our goal is to implement such support,
allowing developers working on SR-IOV physical function drivers to work
inside VMs as well.
This patch series implements the kernel side of our solution. It extends
the VFIO driver to support the PCIE SRIOV extended capability with
following features:
1. The ability to probe SR-IOV BAR sizes.
2. The ability to enable and disable SR-IOV.
This patch series is going to be used by QEMU to expose SR-IOV capabilities
to VM. We already have an early prototype based on Knut Omang's patches for
SR-IOV[1].
Limitations:
1. Per SR-IOV spec section 3.3.12, PFs are required to support
4-KB, 8-KB, 64-KB, 256-KB, 1-MB, and 4-MB page sizes.
Unfourtently the kernel currently initializes the System Page Size register once
and assumes it doesn't change therefore we cannot allow guests to change this
register at will. We currently map both the Supported Page sizes and
System Page Size as virtualized and read only in violation of the spec.
In practice this is not an issue since both the hypervisor and the
guest typically select the same System Page Size.
[1] https://github.com/knuto/qemu/tree/sriov_patches_v6
Ilya Lesokhin (3):
pci: Extend PCI IOV API
vfio/pci: Allow control SR-IOV through sysfs interface
vfio/pci: Add support for SR-IOV extended capablity
drivers/pci/iov.c | 41 ++++++++--
drivers/vfio/pci/vfio_pci.c | 43 ++++++++--
drivers/vfio/pci/vfio_pci_config.c | 151 ++++++++++++++++++++++++++++++++----
drivers/vfio/pci/vfio_pci_private.h | 2 +
include/linux/pci.h | 13 +++-
5 files changed, 219 insertions(+), 31 deletions(-)
--
1.8.3.1
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