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

[Eric Auger <eric.auger@linaro.org>]

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


Eric Auger (2):
  kvm: introduce kvm_arch_msi_data_to_gsi
  arm_gicv2m: set kvm_gsi_direct_mapping and kvm_msi_via_irqfd_allowed

 hw/intc/arm_gicv2m.c | 2 ++
 include/sysemu/kvm.h | 2 ++
 kvm-all.c            | 2 +-
 target-arm/kvm.c     | 5 +++++
 target-i386/kvm.c    | 5 +++++
 target-mips/kvm.c    | 5 +++++
 target-ppc/kvm.c     | 5 +++++
 target-s390x/kvm.c   | 5 +++++
 8 files changed, 30 insertions(+), 1 deletion(-)

-- 
1.8.3.2