From: Christoph Schlameuss Date: Mon, 24 Jun 2024 09:59:02 +0000 (+0200) Subject: kvm: s390: Reject memory region operations for ucontrol VMs X-Git-Tag: v6.11-rc1~89^2~19^2 X-Git-Url: https://repo.jachan.dev/linux.git/commitdiff_plain/7816e58967d0 kvm: s390: Reject memory region operations for ucontrol VMs This change rejects the KVM_SET_USER_MEMORY_REGION and KVM_SET_USER_MEMORY_REGION2 ioctls when called on a ucontrol VM. This is necessary since ucontrol VMs have kvm->arch.gmap set to 0 and would thus result in a null pointer dereference further in. Memory management needs to be performed in userspace and using the ioctls KVM_S390_UCAS_MAP and KVM_S390_UCAS_UNMAP. Also improve s390 specific documentation for KVM_SET_USER_MEMORY_REGION and KVM_SET_USER_MEMORY_REGION2. Signed-off-by: Christoph Schlameuss Fixes: 27e0393f15fc ("KVM: s390: ucontrol: per vcpu address spaces") Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/r/20240624095902.29375-1-schlameuss@linux.ibm.com Signed-off-by: Janosch Frank [frankja@linux.ibm.com: commit message spelling fix, subject prefix fix] Message-ID: <20240624095902.29375-1-schlameuss@linux.ibm.com> --- diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index a71d91978d9e..eec8df1dde06 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -1403,6 +1403,12 @@ Instead, an abort (data abort if the cause of the page-table update was a load or a store, instruction abort if it was an instruction fetch) is injected in the guest. +S390: +^^^^^ + +Returns -EINVAL if the VM has the KVM_VM_S390_UCONTROL flag set. +Returns -EINVAL if called on a protected VM. + 4.36 KVM_SET_TSS_ADDR --------------------- @@ -6273,6 +6279,12 @@ state. At VM creation time, all memory is shared, i.e. the PRIVATE attribute is '0' for all gfns. Userspace can control whether memory is shared/private by toggling KVM_MEMORY_ATTRIBUTE_PRIVATE via KVM_SET_MEMORY_ATTRIBUTES as needed. +S390: +^^^^^ + +Returns -EINVAL if the VM has the KVM_VM_S390_UCONTROL flag set. +Returns -EINVAL if called on a protected VM. + 4.141 KVM_SET_MEMORY_ATTRIBUTES ------------------------------- diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 82e9631cd9ef..854d0d1410be 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -5748,6 +5748,9 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, { gpa_t size; + if (kvm_is_ucontrol(kvm)) + return -EINVAL; + /* When we are protected, we should not change the memory slots */ if (kvm_s390_pv_get_handle(kvm)) return -EINVAL;