Merge tag 'kvm-x86-generic-6.11' of https://github.com/kvm-x86/linux into HEAD

KVM generic changes for 6.11

 - Enable halt poll shrinking by default, as Intel found it to be a clear win.

 - Setup empty IRQ routing when creating a VM to avoid having to synchronize
   SRCU when creating a split IRQCHIP on x86.

 - Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag
   that arch code can use for hooking both sched_in() and sched_out().

 - Take the vCPU @id as an "unsigned long" instead of "u32" to avoid
   truncating a bogus value from userspace, e.g. to help userspace detect bugs.

 - Mark a vCPU as preempted if and only if it's scheduled out while in the
   KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest
   memory when retrieving guest state during live migration blackout.

 - A few minor cleanups

2 files changed, 36 insertions, 2 deletions

diff --git a/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c b/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c
index 3cc4b86832fe..7e2bfb3c3f3b 100644
--- a/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c
+++ b/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c
@@ -26,19 +26,37 @@ int main(int argc, char *argv[])
 	TEST_ASSERT(ret < 0,
 		    "Setting KVM_CAP_MAX_VCPU_ID beyond KVM cap should fail");
 
+	/* Test BOOT_CPU_ID interaction (MAX_VCPU_ID cannot be lower) */
+	if (kvm_has_cap(KVM_CAP_SET_BOOT_CPU_ID)) {
+		vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)MAX_VCPU_ID);
+
+		/* Try setting KVM_CAP_MAX_VCPU_ID below BOOT_CPU_ID */
+		ret = __vm_enable_cap(vm, KVM_CAP_MAX_VCPU_ID, MAX_VCPU_ID - 1);
+		TEST_ASSERT(ret < 0,
+			    "Setting KVM_CAP_MAX_VCPU_ID below BOOT_CPU_ID should fail");
+	}
+
 	/* Set KVM_CAP_MAX_VCPU_ID */
 	vm_enable_cap(vm, KVM_CAP_MAX_VCPU_ID, MAX_VCPU_ID);
 
-
 	/* Try to set KVM_CAP_MAX_VCPU_ID again */
 	ret = __vm_enable_cap(vm, KVM_CAP_MAX_VCPU_ID, MAX_VCPU_ID + 1);
 	TEST_ASSERT(ret < 0,
 		    "Setting KVM_CAP_MAX_VCPU_ID multiple times should fail");
 
-	/* Create vCPU with id beyond KVM_CAP_MAX_VCPU_ID cap*/
+	/* Create vCPU with id beyond KVM_CAP_MAX_VCPU_ID cap */
 	ret = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)MAX_VCPU_ID);
 	TEST_ASSERT(ret < 0, "Creating vCPU with ID > MAX_VCPU_ID should fail");
 
+	/* Create vCPU with bits 63:32 != 0, but an otherwise valid id */
+	ret = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)(1L << 32));
+	TEST_ASSERT(ret < 0, "Creating vCPU with ID[63:32] != 0 should fail");
+
+	/* Create vCPU with id within bounds */
+	ret = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)0);
+	TEST_ASSERT(ret >= 0, "Creating vCPU with ID 0 should succeed");
+
+	close(ret);
 	kvm_vm_free(vm);
 	return 0;
 }
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++)