diff options
| author | Dominik Dingel <dingel@linux.vnet.ibm.com> | 2014-10-31 14:10:41 +0100 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2015-01-23 13:25:30 +0100 |
| commit | 8c0a7ce60676caa89c204a1a3b748e065f3d7182 (patch) | |
| tree | 8f3b3f85b3c99edb88933dd27c210916752aa75e /arch/s390/include/uapi/asm | |
| parent | dafd032a15f8f165a7d10e00217d3b74f70a7b0f (diff) | |
| download | blackbird-op-linux-8c0a7ce60676caa89c204a1a3b748e065f3d7182.tar.gz blackbird-op-linux-8c0a7ce60676caa89c204a1a3b748e065f3d7182.zip | |
KVM: s390: Allow userspace to limit guest memory size
With commit c6c956b80bdf ("KVM: s390/mm: support gmap page tables with less
than 5 levels") we are able to define a limit for the guest memory size.
As we round up the guest size in respect to the levels of page tables
we get to guest limits of: 2048 MB, 4096 GB, 8192 TB and 16384 PB.
We currently limit the guest size to 16 TB, which means we end up
creating a page table structure supporting guest sizes up to 8192 TB.
This patch introduces an interface that allows userspace to tune
this limit. This may bring performance improvements for small guests.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/include/uapi/asm')
| -rw-r--r-- | arch/s390/include/uapi/asm/kvm.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 48eda3ab4944..9c01159cf667 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -61,6 +61,7 @@ struct kvm_s390_io_adapter_req { /* kvm attributes for mem_ctrl */ #define KVM_S390_VM_MEM_ENABLE_CMMA 0 #define KVM_S390_VM_MEM_CLR_CMMA 1 +#define KVM_S390_VM_MEM_LIMIT_SIZE 2 /* for KVM_GET_REGS and KVM_SET_REGS */ struct kvm_regs { |
