|
From: | Zenghui Yu |
Subject: | Re: [Qemu-devel] [RFC 0/3] KVM/ARM: Fix >256 vcpus |
Date: | Thu, 29 Aug 2019 10:06:32 +0800 |
User-agent: | Mozilla/5.0 (Windows NT 6.1; WOW64; rv:64.0) Gecko/20100101 Thunderbird/64.0 |
Hi Eric, On 2019/8/28 0:05, Eric Auger wrote:
Since 4.18, KVM/ARM exposes a KVM_MAX_VCPUS equal to 512. However it was reported [1] that a VM with more than 256 vcpus cannot be launched. 5.4 is about to fix the situation with 2 patches: - one upgrade of the KVM_IRQ_LINE API [2] supporting a vcpu id encoded on 12 bits, - the reduction of KVM IO devices consumed by each GICv3 redistributor [3] This series uses the new KVM_IRQ_LINE API and also checks the associated capability (KVM_CAP_ARM_IRQ_LINE_LAYOUT_2) in machvirt. Without the series, as soon as the -smp arguments exceeds 256, QEMU exits with "kvm_set_irq: Invalid argument".
For the series: Tested-by: Zenghui Yu <address@hidden> together with [2], [3].
Best Regards Eric References: [1] Can we boot a 512U kvm guest? https://patchwork.kernel.org/patch/11091501/ [2] [PATCH] KVM: arm/arm64: vgic: Allow more than 256 vcpus for KVM_IRQ_LINE https://patchwork.kernel.org/patch/11099609/ [3] [PATCH] KVM: arm/arm64: vgic: Use a single IO device per redistributor https://patchwork.kernel.org/patch/11112141/ This series can be found at: https://github.com/eauger/qemu/tree/v4.1.0-256fix-rfc-v1 Eric Auger (3): linux headers: update for KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 intc/arm_gic: Support PPI injection for more than 256 vpus virt: Check KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 for smp_cpus > 256
Thanks, zenghui
[Prev in Thread] | Current Thread | [Next in Thread] |