For HPC usage case, it will create a huge VM with vcpus number as same as host
cpus and this requires more vcpus support in a single VM. This patch is to
increase max vcpu number from 288 to 8192 which is current default maximum cpu
number for Linux kernel.
Signed-off-by: Lan Tianyu <[email protected]>
---
arch/x86/include/asm/kvm_host.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 87ac4fb..7946394 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -35,7 +35,7 @@
#include <asm/asm.h>
#include <asm/kvm_page_track.h>
-#define KVM_MAX_VCPUS 288
+#define KVM_MAX_VCPUS 8192
#define KVM_SOFT_MAX_VCPUS 240
#define KVM_MAX_VCPU_ID 1023
#define KVM_USER_MEM_SLOTS 509
--
1.8.3.1
2017-08-15 20:43-0400, Lan Tianyu:
> For HPC usage case, it will create a huge VM with vcpus number as same as host
> cpus and this requires more vcpus support in a single VM. This patch is to
> increase max vcpu number from 288 to 8192 which is current default maximum cpu
> number for Linux kernel.
>
> Signed-off-by: Lan Tianyu <[email protected]>
> ---
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> @@ -35,7 +35,7 @@
> #include <asm/asm.h>
> #include <asm/kvm_page_track.h>
>
> -#define KVM_MAX_VCPUS 288
> +#define KVM_MAX_VCPUS 8192
> #define KVM_SOFT_MAX_VCPUS 240
> #define KVM_MAX_VCPU_ID 1023
We will also need to raise KVM_MAX_VCPU_ID to actually allow that many
VCPUs. If I count correctly, it is impossible to have ID bigger than
this:
#define KVM_MAX_VCPU_ID (KVM_MAX_VCPUS * 4)
(And we can also use NR_CPUS instead of 8192.)
Thanks.