Merge tag 'kvm-x86-selftests_utils-6.10' of https://github.com/kvm-x86/linux into HEAD

KVM selftests treewide updates for 6.10:

 - Define _GNU_SOURCE for all selftests to fix a warning that was introduced by
   a change to kselftest_harness.h late in the 6.9 cycle, and because forcing
   every test to #define _GNU_SOURCE is painful.

 - Provide a global psuedo-RNG instance for all tests, so that library code can
   generate random, but determinstic numbers.

 - Use the global pRNG to randomly force emulation of select writes from guest
   code on x86, e.g. to help validate KVM's emulation of locked accesses.

 - Rename kvm_util_base.h back to kvm_util.h, as the weird layer of indirection
   was added purely to avoid manually #including ucall_common.h in a handful of
   locations.

 - Allocate and initialize x86's GDT, IDT, TSS, segments, and default exception
   handlers at VM creation, instead of forcing tests to manually trigger the
   related setup.

86 files changed, 1420 insertions, 447 deletions

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index c54dc692fbbd..ce8ff8e8ce3a 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -230,8 +230,8 @@ LINUX_TOOL_ARCH_INCLUDE = $(top_srcdir)/tools/arch/$(ARCH)/include
 endif
 CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \
 	-Wno-gnu-variable-sized-type-not-at-end -MD -MP -DCONFIG_64BIT \
-	-fno-builtin-memcmp -fno-builtin-memcpy -fno-builtin-memset \
-	-fno-builtin-strnlen \
+	-D_GNU_SOURCE -fno-builtin-memcmp -fno-builtin-memcpy \
+	-fno-builtin-memset -fno-builtin-strnlen \
 	-fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \
 	-I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \
 	-I$(<D) -Iinclude/$(ARCH_DIR) -I ../rseq -I.. $(EXTRA_CFLAGS) \
diff --git a/tools/testing/selftests/kvm/aarch64/arch_timer.c b/tools/testing/selftests/kvm/aarch64/arch_timer.c
index 89be559cdb7e..eeba1cc87ff8 100644
--- a/tools/testing/selftests/kvm/aarch64/arch_timer.c
+++ b/tools/testing/selftests/kvm/aarch64/arch_timer.c
@@ -5,13 +5,12 @@
  *
  * Copyright (c) 2021, Google LLC.
  */
-#define _GNU_SOURCE
-
 #include "arch_timer.h"
 #include "delay.h"
 #include "gic.h"
 #include "processor.h"
 #include "timer_test.h"
+#include "ucall_common.h"
 #include "vgic.h"
 
 enum guest_stage {
diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index a2a158e2c0b8..d29b08198b42 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -7,7 +7,6 @@
  * hugetlbfs with a hole). It checks that the expected handling method is
  * called (e.g., uffd faults with the right address and write/read flag).
  */
-#define _GNU_SOURCE
 #include <linux/bitmap.h>
 #include <fcntl.h>
 #include <test_util.h>
diff --git a/tools/testing/selftests/kvm/aarch64/psci_test.c b/tools/testing/selftests/kvm/aarch64/psci_test.c
index 9fa3578d47d5..61731a950def 100644
--- a/tools/testing/selftests/kvm/aarch64/psci_test.c
+++ b/tools/testing/selftests/kvm/aarch64/psci_test.c
@@ -11,8 +11,6 @@
  *    KVM_SYSTEM_EVENT_SUSPEND UAPI.
  */
 
-#define _GNU_SOURCE
-
 #include <linux/kernel.h>
 #include <linux/psci.h>
 #include <asm/cputype.h>
diff --git a/tools/testing/selftests/kvm/aarch64/vgic_init.c b/tools/testing/selftests/kvm/aarch64/vgic_init.c
index ca917c71ff60..b3b5fb0ff0a9 100644
--- a/tools/testing/selftests/kvm/aarch64/vgic_init.c
+++ b/tools/testing/selftests/kvm/aarch64/vgic_init.c
@@ -4,7 +4,6 @@
  *
  * Copyright (C) 2020, Red Hat, Inc.
  */
-#define _GNU_SOURCE
 #include <linux/kernel.h>
 #include <sys/syscall.h>
 #include <asm/kvm.h>
diff --git a/tools/testing/selftests/kvm/arch_timer.c b/tools/testing/selftests/kvm/arch_timer.c
index ae1f1a6d8312..acb2cb596332 100644
--- a/tools/testing/selftests/kvm/arch_timer.c
+++ b/tools/testing/selftests/kvm/arch_timer.c
@@ -19,9 +19,6 @@
  *
  * Copyright (c) 2021, Google LLC.
  */
-
-#define _GNU_SOURCE
-
 #include <stdlib.h>
 #include <pthread.h>
 #include <linux/sizes.h>
@@ -29,6 +26,7 @@
 #include <sys/sysinfo.h>
 
 #include "timer_test.h"
+#include "ucall_common.h"
 
 struct test_args test_args = {
 	.nr_vcpus = NR_VCPUS_DEF,
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index 056ff1c87345..0202b78f8680 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -6,9 +6,6 @@
  * Copyright (C) 2018, Red Hat, Inc.
  * Copyright (C) 2019, Google, Inc.
  */
-
-#define _GNU_SOURCE /* for pipe2 */
-
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -21,6 +18,7 @@
 #include "test_util.h"
 #include "memstress.h"
 #include "guest_modes.h"
+#include "ucall_common.h"
 #include "userfaultfd_util.h"
 
 #ifdef __NR_userfaultfd
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index 61535c4f3405..9f24303acb8c 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -18,6 +18,7 @@
 #include "test_util.h"
 #include "memstress.h"
 #include "guest_modes.h"
+#include "ucall_common.h"
 
 #ifdef __aarch64__
 #include "aarch64/vgic.h"
@@ -129,7 +130,6 @@ struct test_params {
 	enum vm_mem_backing_src_type backing_src;
 	int slots;
 	uint32_t write_percent;
-	uint32_t random_seed;
 	bool random_access;
 };
 
@@ -153,8 +153,6 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 				 p->slots, p->backing_src,
 				 p->partition_vcpu_memory_access);
 
-	pr_info("Random seed: %u\n", p->random_seed);
-	memstress_set_random_seed(vm, p->random_seed);
 	memstress_set_write_percent(vm, p->write_percent);
 
 	guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm->page_shift;
@@ -343,11 +341,13 @@ int main(int argc, char *argv[])
 		.partition_vcpu_memory_access = true,
 		.backing_src = DEFAULT_VM_MEM_SRC,
 		.slots = 1,
-		.random_seed = 1,
 		.write_percent = 100,
 	};
 	int opt;
 
+	/* Override the seed to be deterministic by default. */
+	guest_random_seed = 1;
+
 	dirty_log_manual_caps =
 		kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 	dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
@@ -392,7 +392,7 @@ int main(int argc, char *argv[])
 			p.phys_offset = strtoull(optarg, NULL, 0);
 			break;
 		case 'r':
-			p.random_seed = atoi_positive("Random seed", optarg);
+			guest_random_seed = atoi_positive("Random seed", optarg);
 			break;
 		case 's':
 			p.backing_src = parse_backing_src_type(optarg);
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index eaad5b20854c..aacf80f57439 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -4,9 +4,6 @@
  *
  * Copyright (C) 2018, Red Hat, Inc.
  */
-
-#define _GNU_SOURCE /* for program_invocation_name */
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <pthread.h>
@@ -23,6 +20,7 @@
 #include "test_util.h"
 #include "guest_modes.h"
 #include "processor.h"
+#include "ucall_common.h"
 
 #define DIRTY_MEM_BITS 30 /* 1G */
 #define PAGE_SHIFT_4K  12
@@ -76,7 +74,6 @@
 static uint64_t host_page_size;
 static uint64_t guest_page_size;
 static uint64_t guest_num_pages;
-static uint64_t random_array[TEST_PAGES_PER_LOOP];
 static uint64_t iteration;
 
 /*
@@ -109,19 +106,19 @@ static void guest_code(void)
 	 */
 	for (i = 0; i < guest_num_pages; i++) {
 		addr = guest_test_virt_mem + i * guest_page_size;
-		*(uint64_t *)addr = READ_ONCE(iteration);
+		vcpu_arch_put_guest(*(uint64_t *)addr, READ_ONCE(iteration));
 	}
 
 	while (true) {
 		for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
 			addr = guest_test_virt_mem;
-			addr += (READ_ONCE(random_array[i]) % guest_num_pages)
+			addr += (guest_random_u64(&guest_rng) % guest_num_pages)
 				* guest_page_size;
 			addr = align_down(addr, host_page_size);
-			*(uint64_t *)addr = READ_ONCE(iteration);
+
+			vcpu_arch_put_guest(*(uint64_t *)addr, READ_ONCE(iteration));
 		}
 
-		/* Tell the host that we need more random numbers */
 		GUEST_SYNC(1);
 	}
 }
@@ -508,20 +505,10 @@ static void log_mode_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
 		mode->after_vcpu_run(vcpu, ret, err);
 }
 
-static void generate_random_array(uint64_t *guest_array, uint64_t size)
-{
-	uint64_t i;
-
-	for (i = 0; i < size; i++)
-		guest_array[i] = random();
-}
-
 static void *vcpu_worker(void *data)
 {
 	int ret;
 	struct kvm_vcpu *vcpu = data;
-	struct kvm_vm *vm = vcpu->vm;
-	uint64_t *guest_array;
 	uint64_t pages_count = 0;
 	struct kvm_signal_mask *sigmask = alloca(offsetof(struct kvm_signal_mask, sigset)
 						 + sizeof(sigset_t));
@@ -540,11 +527,8 @@ static void *vcpu_worker(void *data)
 	sigemptyset(sigset);
 	sigaddset(sigset, SIG_IPI);
 
-	guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
-
 	while (!READ_ONCE(host_quit)) {
 		/* Clear any existing kick signals */
-		generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
 		pages_count += TEST_PAGES_PER_LOOP;
 		/* Let the guest dirty the random pages */
 		ret = __vcpu_run(vcpu);
diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index 92eae206baa6..ba0c8e996035 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -4,8 +4,6 @@
  *
  * Author: Chao Peng <chao.p.peng@linux.intel.com>
  */
-
-#define _GNU_SOURCE
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -19,8 +17,8 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
+#include "kvm_util.h"
 #include "test_util.h"
-#include "kvm_util_base.h"
 
 static void test_file_read_write(int fd)
 {
diff --git a/tools/testing/selftests/kvm/guest_print_test.c b/tools/testing/selftests/kvm/guest_print_test.c
index 3502caa3590c..8092c2d0f5d6 100644
--- a/tools/testing/selftests/kvm/guest_print_test.c
+++ b/tools/testing/selftests/kvm/guest_print_test.c
@@ -13,6 +13,7 @@
 #include "test_util.h"
 #include "kvm_u