Re: [Qemu-devel] [PATCH 0/3] Add support for for GICv2m and MSIs to arm-virt

[Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>]

On Thu, Apr 9, 2015 at 12:20 AM, Christoffer Dall
<christoffer.dall@linaro.org> wrote:
> Now when we have a host generic PCIe controller in the virt board, it
> would be nice to be able to use MSIs so that we can eventually enable
> VHOST with KVM.
>
> With these patches you can use MSIs with TCG and with KVM, but you still
> need some fixes for the mapping of the IRQ index to the GSI number for
> IRQFD to work.  A separate patch series will follow this one to enable
> that.
>
> Tested with KVM on XGene and with TCG by configuring a virtio-pci
> network adapter for the guest and verifying MSIs going through as
> expected.

Christofer, have you measured the network performance difference with KVM.
Probably the next patchseries (with IRQFD) makes bigger difference.

In any case, sharing some numbers will be great.
Thanks.

regards,
Nikolay Nikolaev

>
> Christoffer Dall (3):
>   target-arm: Add GIC phandle to VirtBoardInfo
>   arm_gicv2m: Add GICv2m widget to support MSIs
>   target-arm: Add the GICv2m to the virt board
>
>  hw/arm/virt.c         |  69 +++++++++++++++----
>  hw/intc/Makefile.objs |   1 +
>  hw/intc/arm_gicv2m.c  | 180 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  pixman                |   2 +-
>  4 files changed, 237 insertions(+), 15 deletions(-)
>  create mode 100644 hw/intc/arm_gicv2m.c
>
> --
> 2.1.2.330.g565301e.dirty
>
>