Hi, Alex
On 2016/6/2 21:11, Alex Williamson wrote:
AFAICT, you posted this *3* days ago, has something changed here or is
this just expedited nagging for review? This also depends on a
non-upstream series and crosses multiple functional areas, all of which
make it difficult for maintainers to actually do anything with this
series. Thanks,
Alex
I resend this series because I found the message-id of the previous email
is changed unexpectedly. The cover letter is not in the same thread as other
patches. It would be a little hard for people to review.
Thanks,
Yongji
On Thu, 2 Jun 2016 14:09:57 +0800
Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx> wrote:
Current vfio-pci implementation disallows to mmap the page
containing MSI-X table in case that users can write directly
to MSI-X table and generate an incorrect MSIs.
However, this will cause some performance issue when there
are some critical device registers in the same page as the
MSI-X table. We have to handle the mmio access to these
registers in QEMU emulation rather than in guest.
To solve this issue, this series allows to expose MSI-X table
to userspace when hardware enables the capability of interrupt
remapping which can ensure that a given PCI device can only
shoot the MSIs assigned for it. And we introduce a new bus_flags
PCI_BUS_FLAGS_MSI_REMAP to test this capability on PCI side
for different archs.
The patch 3 are based on the proposed patchset[1].
Changelog v2:
- Make the commit log more clear
- Replace pci_bus_check_msi_remapping() with pci_bus_msi_isolated()
so that we could clearly know what the function does
- Set PCI_BUS_FLAGS_MSI_REMAP in pci_create_root_bus() instead
of iommu_bus_notifier()
- Reserve VFIO_REGION_INFO_FLAG_CAPS when we allow to mmap MSI-X
table so that we can know whether we allow to mmap MSI-X table
in QEMU
[1] https://www.mail-archive.com/linux-kernel%40vger.kernel.org/msg1138820.html
Yongji Xie (6):
PCI: Add a new PCI_BUS_FLAGS_MSI_REMAP flag
PCI: Set PCI_BUS_FLAGS_MSI_REMAP if MSI controller enables IRQ remapping
PCI: Set PCI_BUS_FLAGS_MSI_REMAP if IOMMU have capability of IRQ remapping
iommu: Set PCI_BUS_FLAGS_MSI_REMAP on iommu driver initialization
pci-ioda: Set PCI_BUS_FLAGS_MSI_REMAP for IODA host bridge
vfio-pci: Allow to expose MSI-X table to userspace if interrupt remapping is enabled
arch/powerpc/platforms/powernv/pci-ioda.c | 8 ++++++++
drivers/iommu/iommu.c | 8 ++++++++
drivers/pci/msi.c | 15 +++++++++++++++
drivers/pci/probe.c | 7 +++++++
drivers/vfio/pci/vfio_pci.c | 17 ++++++++++++++---
drivers/vfio/pci/vfio_pci_rdwr.c | 3 ++-
include/linux/msi.h | 5 ++++-
include/linux/pci.h | 1 +
8 files changed, 59 insertions(+), 5 deletions(-)
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