Re: [Qemu-devel] [PATCH v2 0/2] ARM adaptations for vhost irqfd setup

[Paolo Bonzini <pbonzini@redhat.com>]

On 10/04/2015 09:48, Eric Auger wrote:
> After the introduction of gicv2m, this series adds missing pieces to
> run VIRTIO-PCI with vhost back-end on ARM.
> 
> It is proposed to use the kvm_gsi_direct_mapping modality that sets
> the irqfd gsi to the MSI data value. With that trick there is no need
> to create a KVM MSI routing entry featuring a different gsi.
> 
> The only adaptation needed for ARM consists in adding an architecture
> specific function that converts the MSI data field into the actual
> gsi index: there is an offset of 32 between the MSI data content
> (SPI ID) and the SPI index that is passed to KVM_IRQFD ioctl. Once
> this is done we can set the requested flags to enable vhost:
> kvm_gsi_direct_mapping, kvm_msi_via_irqfd_allowed.
> 
> This was tested on XGene, on top of Christoffer's series,
> [PATCH 0/3] Add support for for GICv2m and MSIs to arm-virt
> (https://lists.gnu.org/archive/html/qemu-devel/2015-04/msg00881.html)
> 
> Best Regards
> 
> Eric
> 
> v1 -> v2:
> - abort on i386/mips/s390x since those archs do not support
>   kvm_gsi_direct_mapping

Patch 1 is okay.  I guess this series will go through some ARM tree.

Paolo