Merge branch 'kvm-6.15-rc2-fixes' into HEAD

Author: bonzini

arch/x86/include/asm/kvm_host.h

@@ -1472,8 +1472,13 @@ struct kvm_arch {
 	struct once nx_once;
 
 #ifdef CONFIG_X86_64
-	/* The number of TDP MMU pages across all roots. */
+#ifdef CONFIG_KVM_PROVE_MMU
+	/*
+	 * The number of TDP MMU pages across all roots.  Used only to sanity
+	 * check that KVM isn't leaking TDP MMU pages.
+	 */
 	atomic64_t tdp_mmu_pages;
+#endif
 
 	/*
 	 * List of struct kvm_mmu_pages being used as roots.

arch/x86/kvm/cpuid.c

@@ -1427,8 +1427,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		}
 		break;
 	case 0xa: { /* Architectural Performance Monitoring */
-		union cpuid10_eax eax;
-		union cpuid10_edx edx;
+		union cpuid10_eax eax = { };
+		union cpuid10_edx edx = { };
 
 		if (!enable_pmu || !static_cpu_has(X86_FEATURE_ARCH_PERFMON)) {
 			entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
@@ -1444,8 +1444,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 
 		if (kvm_pmu_cap.version)
 			edx.split.anythread_deprecated = 1;
-		edx.split.reserved1 = 0;
-		edx.split.reserved2 = 0;
 
 		entry->eax = eax.full;
 		entry->ebx = kvm_pmu_cap.events_mask;
@@ -1763,7 +1761,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		break;
 	/* AMD Extended Performance Monitoring and Debug */
 	case 0x80000022: {
-		union cpuid_0x80000022_ebx ebx;
+		union cpuid_0x80000022_ebx ebx = { };
 
 		entry->ecx = entry->edx = 0;
 		if (!enable_pmu || !kvm_cpu_cap_has(X86_FEATURE_PERFMON_V2)) {

arch/x86/kvm/mmu/tdp_mmu.c

@@ -40,7 +40,9 @@ void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
 	kvm_tdp_mmu_invalidate_roots(kvm, KVM_VALID_ROOTS);
 	kvm_tdp_mmu_zap_invalidated_roots(kvm, false);
 
-	WARN_ON(atomic64_read(&kvm->arch.tdp_mmu_pages));
+#ifdef CONFIG_KVM_PROVE_MMU
+	KVM_MMU_WARN_ON(atomic64_read(&kvm->arch.tdp_mmu_pages));
+#endif
 	WARN_ON(!list_empty(&kvm->arch.tdp_mmu_roots));
 
 	/*
@@ -325,13 +327,17 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	kvm_account_pgtable_pages((void *)sp->spt, +1);
+#ifdef CONFIG_KVM_PROVE_MMU
 	atomic64_inc(&kvm->arch.tdp_mmu_pages);
+#endif
 }
 
 static void tdp_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	kvm_account_pgtable_pages((void *)sp->spt, -1);
+#ifdef CONFIG_KVM_PROVE_MMU
 	atomic64_dec(&kvm->arch.tdp_mmu_pages);
+#endif
 }
 
 /**

arch/x86/kvm/x86.c

@@ -11786,6 +11786,8 @@ int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
 	if (kvm_mpx_supported())
 		kvm_load_guest_fpu(vcpu);
 
+	kvm_vcpu_srcu_read_lock(vcpu);
+
 	r = kvm_apic_accept_events(vcpu);
 	if (r < 0)
 		goto out;
@@ -11799,6 +11801,8 @@ int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
 		mp_state->mp_state = vcpu->arch.mp_state;
 
 out:
+	kvm_vcpu_srcu_read_unlock(vcpu);
+
 	if (kvm_mpx_supported())
 		kvm_put_guest_fpu(vcpu);
 	vcpu_put(vcpu);

include/linux/kvm_host.h

@@ -2382,7 +2382,7 @@ static inline bool kvm_is_visible_memslot(struct kvm_memory_slot *memslot)
 struct kvm_vcpu *kvm_get_running_vcpu(void);
 struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);
 
-#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+#if IS_ENABLED(CONFIG_HAVE_KVM_IRQ_BYPASS)
 bool kvm_arch_has_irq_bypass(void);
 int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *,
 			   struct irq_bypass_producer *);

tools/testing/selftests/kvm/rseq_test.c

@@ -196,25 +196,27 @@ static void calc_min_max_cpu(void)
 static void help(const char *name)
 {
 	puts("");
-	printf("usage: %s [-h] [-u]\n", name);
+	printf("usage: %s [-h] [-u] [-l latency]\n", name);
 	printf(" -u: Don't sanity check the number of successful KVM_RUNs\n");
+	printf(" -l: Set /dev/cpu_dma_latency to suppress deep sleep states\n");
 	puts("");
 	exit(0);
 }
 
 int main(int argc, char *argv[])
 {
+	int r, i, snapshot, opt, fd = -1, latency = -1;
 	bool skip_sanity_check = false;
-	int r, i, snapshot;
 	struct kvm_vm *vm;
 	struct kvm_vcpu *vcpu;
 	u32 cpu, rseq_cpu;
-	int opt;
 
-	while ((opt = getopt(argc, argv, "hu")) != -1) {
+	while ((opt = getopt(argc, argv, "hl:u")) != -1) {
 		switch (opt) {
 		case 'u':
 			skip_sanity_check = true;
+		case 'l':
+			latency = atoi_paranoid(optarg);
 			break;
 		case 'h':
 		default:
@@ -243,6 +245,20 @@ int main(int argc, char *argv[])
 	pthread_create(&migration_thread, NULL, migration_worker,
 		       (void *)(unsigned long)syscall(SYS_gettid));
 
+	if (latency >= 0) {
+		/*
+		 * Writes to cpu_dma_latency persist only while the file is
+		 * open, i.e. it allows userspace to provide guaranteed latency
+		 * while running a workload.  Keep the file open until the test
+		 * completes, otherwise writing cpu_dma_latency is meaningless.
+		 */
+		fd = open("/dev/cpu_dma_latency", O_RDWR);
+		TEST_ASSERT(fd >= 0, __KVM_SYSCALL_ERROR("open() /dev/cpu_dma_latency", fd));
+
+		r = write(fd, &latency, 4);
+		TEST_ASSERT(r >= 1, "Error setting /dev/cpu_dma_latency");
+	}
+
 	for (i = 0; !done; i++) {
 		vcpu_run(vcpu);
 		TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC,
@@ -278,6 +294,9 @@ int main(int argc, char *argv[])
 			    "rseq CPU = %d, sched CPU = %d", rseq_cpu, cpu);
 	}
 
+	if (fd > 0)
+		close(fd);
+
 	/*
 	 * Sanity check that the test was able to enter the guest a reasonable
 	 * number of times, e.g. didn't get stalled too often/long waiting for
@@ -293,8 +312,8 @@ int main(int argc, char *argv[])
 	TEST_ASSERT(skip_sanity_check || i > (NR_TASK_MIGRATIONS / 2),
 		    "Only performed %d KVM_RUNs, task stalled too much?\n\n"
 		    "  Try disabling deep sleep states to reduce CPU wakeup latency,\n"
-		    "  e.g. via cpuidle.off=1 or setting /dev/cpu_dma_latency to '0',\n"
-		    "  or run with -u to disable this sanity check.", i);
+		    "  e.g. via cpuidle.off=1 or via -l <latency>, or run with -u to\n"
+		    "  disable this sanity check.", i);
 
 	pthread_join(migration_thread, NULL);
 

virt/kvm/Kconfig

@@ -75,7 +75,7 @@ config KVM_COMPAT
        depends on KVM && COMPAT && !(S390 || ARM64 || RISCV)
 
 config HAVE_KVM_IRQ_BYPASS
-       bool
+       tristate
        select IRQ_BYPASS_MANAGER
 
 config HAVE_KVM_VCPU_ASYNC_IOCTL

virt/kvm/eventfd.c

@@ -149,7 +149,7 @@ irqfd_shutdown(struct work_struct *work)
 	/*
 	 * It is now safe to release the object's resources
 	 */
-#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+#if IS_ENABLED(CONFIG_HAVE_KVM_IRQ_BYPASS)
 	irq_bypass_unregister_consumer(&irqfd->consumer);
 #endif
 	eventfd_ctx_put(irqfd->eventfd);
@@ -274,7 +274,7 @@ static void irqfd_update(struct kvm *kvm, struct kvm_kernel_irqfd *irqfd)
 	write_seqcount_end(&irqfd->irq_entry_sc);
 }
 
-#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+#if IS_ENABLED(CONFIG_HAVE_KVM_IRQ_BYPASS)
 void __attribute__((weak)) kvm_arch_irq_bypass_stop(
 				struct irq_bypass_consumer *cons)
 {
@@ -424,7 +424,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
 	if (events & EPOLLIN)
 		schedule_work(&irqfd->inject);
 
-#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+#if IS_ENABLED(CONFIG_HAVE_KVM_IRQ_BYPASS)
 	if (kvm_arch_has_irq_bypass()) {
 		irqfd->consumer.token = (void *)irqfd->eventfd;
 		irqfd->consumer.add_producer = kvm_arch_irq_bypass_add_producer;
@@ -609,14 +609,14 @@ void kvm_irq_routing_update(struct kvm *kvm)
 	spin_lock_irq(&kvm->irqfds.lock);
 
 	list_for_each_entry(irqfd, &kvm->irqfds.items, list) {
-#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+#if IS_ENABLED(CONFIG_HAVE_KVM_IRQ_BYPASS)
 		/* Under irqfds.lock, so can read irq_entry safely */
 		struct kvm_kernel_irq_routing_entry old = irqfd->irq_entry;
 #endif
 
 		irqfd_update(kvm, irqfd);
 
-#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+#if IS_ENABLED(CONFIG_HAVE_KVM_IRQ_BYPASS)
 		if (irqfd->producer &&
 		    kvm_arch_irqfd_route_changed(&old, &irqfd->irq_entry)) {
 			int ret = kvm_arch_update_irqfd_routing(