Re: [Qemu-devel] [PATCH 0/3] Add support for for GICv2m and MSIs to arm-virt
On Thu, Apr 9, 2015 at 12:01 AM, Nikolay Nikolaev n.nikol...@virtualopensystems.com wrote: On Thu, Apr 9, 2015 at 12:20 AM, Christoffer Dall christoffer.d...@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. I did run numbers, and it depends greatly on the workload, but for something simple like netperf, you see a huge increase in performance (several orders of magnitude). Surprisingly, a large portion of that seems to come from using ioeventfd for the mmio accesses to vhost, possibly because it begins to use multiple queues. For latency measurements, irqfd also makes a big difference. -Christoffer
Re: [Qemu-devel] [PATCH 0/3] Add support for for GICv2m and MSIs to arm-virt
On Wed, Apr 08, 2015 at 10:31:53PM +0100, Peter Maydell wrote: On 8 April 2015 at 22:20, Christoffer Dall christoffer.d...@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. 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 +- Will review properly later, but what's pixman doing in your diffstat? :-) Whoops :) I've removed that change locally, will adjust when re-submitting after you've reviewed them. Thanks, -Christoffer
Re: [Qemu-devel] [PATCH 0/3] Add support for for GICv2m and MSIs to arm-virt
On 8 April 2015 at 22:20, Christoffer Dall christoffer.d...@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. 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 +- Will review properly later, but what's pixman doing in your diffstat? :-) -- PMM
Re: [Qemu-devel] [PATCH 0/3] Add support for for GICv2m and MSIs to arm-virt
On Thu, Apr 9, 2015 at 12:20 AM, Christoffer Dall christoffer.d...@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
