[PATCH v5.5 17/30] KVM: s390: Skip gfn/size sanity checks on memslot DELETE or FLAGS_ONLY
From: Sean Christopherson <seanjc@google.com>
Date: 2021-11-04 00:28:50
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-riscv, lkml
Subsystem:
kernel virtual machine for s390 (kvm/s390), s390 architecture, the rest · Maintainers:
Christian Borntraeger, Janosch Frank, Claudio Imbrenda, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds
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 <seanjc@google.com> --- 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