This: - Increases KVM_MAX_VCPUS 288 to 1024. - Increases KVM_MAX_VCPU_ID from 1023 to 4096. - Increases KVM_SOFT_MAX_VCPUS from 240 to 710. Note that this conflicts with: https://lore.kernel.org/lkml/20210903130808.30142-1-jgross@xxxxxxxx Date: Fri, 3 Sep 2021 15:08:01 +0200 From: Juergen Gross <jgross@xxxxxxxx> Subject: [PATCH v2 0/6] x86/kvm: add boot parameters for max vcpu configs Message-Id: <20210903130808.30142-1-jgross@xxxxxxxx> I don't intend to block Juergen's work. I will be happy to rebase and resubmit in case Juergen's series is merged first. However, I do propose that we set the values above as the default even if Juergen's series is merged. The additional overhead (on x86_64) of the new defaults will be: - struct kvm_ioapic will grow from 1628 to 5084 bytes. - struct kvm will grow from 19328 to 22272 bytes. - Bitmap stack variables that will grow: - At kvm_hv_flush_tlb() & kvm_hv_send_ipi(), vp_bitmap[] and vcpu_bitmap[] will now be 128 bytes long - vcpu_bitmap at bioapic_write_indirect() will be 128 bytes long once patch "KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()" is applied Changes v1 -> v2: * KVM_MAX_VCPUS is now 1024 (v1 set it to 710) * KVM_MAX_VCPU_ID is now 4096 (v1 left it unchanged, at 1023) v1 of this series was: https://lore.kernel.org/lkml/20210831204535.1594297-1-ehabkost@xxxxxxxxxx Date: Tue, 31 Aug 2021 16:45:35 -0400 From: Eduardo Habkost <ehabkost@xxxxxxxxxx> Subject: [PATCH] kvm: x86: Increase MAX_VCPUS to 710 Message-Id: <20210831204535.1594297-1-ehabkost@xxxxxxxxxx> Eduardo Habkost (3): kvm: x86: Set KVM_MAX_VCPU_ID to 4*KVM_MAX_VCPUS kvm: x86: Increase MAX_VCPUS to 1024 kvm: x86: Increase KVM_SOFT_MAX_VCPUS to 710 arch/x86/include/asm/kvm_host.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) -- 2.31.1
