| Message ID | 20210903211600.2002377-3-ehabkost@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kvm: x86: Set KVM_MAX_VCPUS=1024, KVM_SOFT_MAX_VCPUS=710 | expand |
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f4cbc08b8d4d..e30e40399092 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -37,7 +37,7 @@ #define __KVM_HAVE_ARCH_VCPU_DEBUGFS -#define KVM_MAX_VCPUS 288 +#define KVM_MAX_VCPUS 1024 #define KVM_SOFT_MAX_VCPUS 240 /*
Increase KVM_MAX_VCPUS to 1024, so we can test larger VMs. I'm not changing KVM_SOFT_MAX_VCPUS yet because I'm afraid it might involve complicated questions around the meaning of "supported" and "recommended" in the upstream tree. KVM_SOFT_MAX_VCPUS will be changed in a separate patch. For reference, visible effects of this change are: - KVM_CAP_MAX_VCPUS will now return 1024 (of course) - Default value for CPUID[HYPERV_CPUID_IMPLEMENT_LIMITS (00x40000005)].EAX will now be 1024 - KVM_MAX_VCPU_ID will change from 1151 to 4096 - Size of struct kvm will increase from 19328 to 22272 bytes (in x86_64) - Size of struct kvm_ioapic will increase from 1780 to 5084 bytes (in x86_64) - 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 Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> --- Note: this conflicts with: https://lore.kernel.org/lkml/20210903130808.30142-7-jgross@suse.com Date: Fri, 3 Sep 2021 15:08:07 +0200 From: Juergen Gross <jgross@suse.com> Subject: [PATCH v2 6/6] x86/kvm: add boot parameter for setting max number of vcpus per guest Message-Id: <20210903130808.30142-7-jgross@suse.com> I don't intend this to block Juergen's work. If Juergen's series is merged first, I can redo this patch to change KVM_DEFAULT_MAX_VCPUS instead. --- arch/x86/include/asm/kvm_host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)