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.

1 files changed, 10 insertions, 2 deletions

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 0f5197548da7..ad00e4761886 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -4,11 +4,10 @@
  *
  * Copyright (C) 2018, Google LLC.
  */
-
-#define _GNU_SOURCE /* for program_invocation_name */
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
+#include "ucall_common.h"
 
 #include <assert.h>
 #include <sched.h>
@@ -20,6 +19,9 @@
 
 #define KVM_UTIL_MIN_PFN	2
 
+uint32_t guest_random_seed;
+struct guest_random_state guest_rng;
+
 static int vcpu_mmap_sz(void);
 
 int open_path_or_exit(const char *path, int flags)
@@ -432,6 +434,10 @@ struct kvm_vm *__vm_create(struct vm_shape shape, uint32_t nr_runnable_vcpus,
 	slot0 = memslot2region(vm, 0);
 	ucall_init(vm, slot0->region.guest_phys_addr + slot0->region.memory_size);
 
+	pr_info("Random seed: 0x%x\n", guest_random_seed);
+	guest_rng = new_guest_random_state(guest_random_seed);
+	sync_global_to_guest(vm, guest_rng);
+
 	kvm_arch_vm_post_create(vm);
 
 	return vm;
@@ -2313,6 +2319,8 @@ void __attribute((constructor)) kvm_selftest_init(void)
 	/* Tell stdout not to buffer its content. */
 	setbuf(stdout, NULL);
 
+	guest_random_seed = random();
+
 	kvm_selftest_arch_init();
 }