From: Claudio Imbrenda Date: Tue, 9 Jun 2026 15:09:30 +0000 (+0200) Subject: KVM: s390: Document the KVM_CAP_S390_HPAGE_2G capability X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9030da050c9fe7d10150c9f93765e464f6c7da3c;p=thirdparty%2Fkernel%2Flinux.git KVM: s390: Document the KVM_CAP_S390_HPAGE_2G capability Document the KVM_CAP_S390_HPAGE_2G capability, which behaves very similarly to the existing KVM_CAP_S390_HPAGE_1M. Signed-off-by: Claudio Imbrenda Message-ID: <20260609150930.665370-5-imbrenda@linux.ibm.com> --- diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index e7998feaa940..dfde0bfcbce6 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8905,6 +8905,21 @@ helpful if user space wants to emulate instructions which are not This capability can be enabled dynamically even if VCPUs were already created and are running. +7.47 KVM_CAP_S390_HPAGE_2G +-------------------------- + +:Architectures: s390 +:Parameters: none +:Returns: 0 on success; -EINVAL if hpage_2g module parameter was not set, + cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL + flag set; -EBUSY if vCPUs were already created for the VM. + +With this capability the KVM support for memory backing with 2g pages +through hugetlbfs can be enabled for a VM. After the capability is +enabled, cmma can't be enabled anymore and pfmfi and the storage key +interpretation are disabled. If cmma has already been enabled or the +hpage_2g module parameter is not set to 1, -EINVAL is returned. + 8. Other capabilities. ======================