From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Date: Thu, 04 Nov 2021 00:25:18 +0000 Subject: [PATCH v5.5 17/30] KVM: s390: Skip gfn/size sanity checks on memslot DELETE or FLAGS_ONLY Message-Id: <20211104002531.1176691-18-seanjc@google.com> List-Id: References: <20211104002531.1176691-1-seanjc@google.com> In-Reply-To: <20211104002531.1176691-1-seanjc@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Paolo Bonzini Cc: Wanpeng Li , kvm@vger.kernel.org, David Hildenbrand , linux-kernel@vger.kernel.org, Atish Patra , Ben Gardon , "Maciej S . Szmigiero" , Claudio Imbrenda , linux-riscv@lists.infradead.org, Joerg Roedel , kvmarm@lists.cs.columbia.edu, kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jim Mattson , Cornelia Huck , linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, Vitaly Kuznetsov Sanity check the hva, gfn, and size of a userspace memory region only if any of those properties can change, i.e. skip the checks for DELETE and FLAGS_ONLY. KVM doesn't allow moving the hva or changing the size, a gfn change shows up as a MOVE even if flags are being modified, and the checks are pointless for the DELETE case as userspace_addr and gfn_base are zeroed by common KVM. No functional change intended. Signed-off-by: Sean Christopherson --- arch/s390/kvm/kvm-s390.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 81f90891db0f..c4d0ed5f3400 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -5020,7 +5020,14 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, struct kvm_memory_slot *new, enum kvm_mr_change change) { - gpa_t size = new->npages * PAGE_SIZE; + gpa_t size; + + /* When we are protected, we should not change the memory slots */ + if (kvm_s390_pv_get_handle(kvm)) + return -EINVAL; + + if (change = KVM_MR_DELETE || change = KVM_MR_FLAGS_ONLY) + return 0; /* A few sanity checks. We can have memory slots which have to be located/ended at a segment boundary (1MB). The memory in userland is @@ -5030,15 +5037,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if (new->userspace_addr & 0xffffful) return -EINVAL; + size = new->npages * PAGE_SIZE; if (size & 0xffffful) return -EINVAL; if ((new->base_gfn * PAGE_SIZE) + size > kvm->arch.mem_limit) return -EINVAL; - /* When we are protected, we should not change the memory slots */ - if (kvm_s390_pv_get_handle(kvm)) - return -EINVAL; return 0; } -- 2.33.1.1089.g2158813163f-goog