From 438a496b9041402736e164c8ebf1368599903958 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Fri, 14 Jun 2024 22:28:59 +0200 Subject: [PATCH] KVM: selftests: Test vCPU boot IDs above 2^32 and MAX_VCPU_ID The KVM_SET_BOOT_CPU_ID ioctl missed to reject invalid vCPU IDs. Verify this no longer works and gets rejected with an appropriate error code. Signed-off-by: Mathias Krause Link: https://lore.kernel.org/r/20240614202859.3597745-6-minipli@grsecurity.net [sean: add test for MAX_VCPU_ID+1, always do negative test] Signed-off-by: Sean Christopherson --- .../selftests/kvm/x86_64/set_boot_cpu_id.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c b/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c index d691d86e5bc3..49913784bc82 100644 --- a/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c +++ b/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c @@ -33,6 +33,20 @@ static void guest_not_bsp_vcpu(void *arg) GUEST_DONE(); } +static void test_set_invalid_bsp(struct kvm_vm *vm) +{ + unsigned long max_vcpu_id = vm_check_cap(vm, KVM_CAP_MAX_VCPU_ID); + int r; + + if (max_vcpu_id) { + r = __vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(max_vcpu_id + 1)); + TEST_ASSERT(r == -1 && errno == EINVAL, "BSP with ID > MAX should fail"); + } + + r = __vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(1L << 32)); + TEST_ASSERT(r == -1 && errno == EINVAL, "BSP with ID[63:32]!=0 should fail"); +} + static void test_set_bsp_busy(struct kvm_vcpu *vcpu, const char *msg) { int r = __vm_ioctl(vcpu->vm, KVM_SET_BOOT_CPU_ID, @@ -80,6 +94,8 @@ static struct kvm_vm *create_vm(uint32_t nr_vcpus, uint32_t bsp_vcpu_id, vm = vm_create(nr_vcpus); + test_set_invalid_bsp(vm); + vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(unsigned long)bsp_vcpu_id); for (i = 0; i < nr_vcpus; i++)