[RFC 1/2] selftests: KVM: Move dirty logging functions to memstress.(c|h)

[RFC 1/2] selftests: KVM: Move dirty logging functions to memstress.(c|h)

[Ben Gardon]

Move some helper functions from dirty_log_perf_test.c to the memstress
library so that they can be used in a future commit which tests page
splitting during dirty logging.

Signed-off-by: Ben Gardon <bgardon@google.com>
---
 .../selftests/kvm/dirty_log_perf_test.c       | 84 ++-----------------
 .../testing/selftests/kvm/include/memstress.h |  8 ++
 tools/testing/selftests/kvm/lib/memstress.c   | 72 ++++++++++++++++
 3 files changed, 87 insertions(+), 77 deletions(-)

diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index e9d6d1aecf89c..416719e205183 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -136,77 +136,6 @@ struct test_params {
 	bool random_access;
 };
 
-static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
-{
-	int i;
-
-	for (i = 0; i < slots; i++) {
-		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
-		int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;
-
-		vm_mem_region_set_flags(vm, slot, flags);
-	}
-}
-
-static inline void enable_dirty_logging(struct kvm_vm *vm, int slots)
-{
-	toggle_dirty_logging(vm, slots, true);
-}
-
-static inline void disable_dirty_logging(struct kvm_vm *vm, int slots)
-{
-	toggle_dirty_logging(vm, slots, false);
-}
-
-static void get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots)
-{
-	int i;
-
-	for (i = 0; i < slots; i++) {
-		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
-
-		kvm_vm_get_dirty_log(vm, slot, bitmaps[i]);
-	}
-}
-
-static void clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[],
-			    int slots, uint64_t pages_per_slot)
-{
-	int i;
-
-	for (i = 0; i < slots; i++) {
-		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
-
-		kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot);
-	}
-}
-
-static unsigned long **alloc_bitmaps(int slots, uint64_t pages_per_slot)
-{
-	unsigned long **bitmaps;
-	int i;
-
-	bitmaps = malloc(slots * sizeof(bitmaps[0]));
-	TEST_ASSERT(bitmaps, "Failed to allocate bitmaps array.");
-
-	for (i = 0; i < slots; i++) {
-		bitmaps[i] = bitmap_zalloc(pages_per_slot);
-		TEST_ASSERT(bitmaps[i], "Failed to allocate slot bitmap.");
-	}
-
-	return bitmaps;
-}
-
-static void free_bitmaps(unsigned long *bitmaps[], int slots)
-{
-	int i;
-
-	for (i = 0; i < slots; i++)
-		free(bitmaps[i]);
-
-	free(bitmaps);
-}
-
 static void run_test(enum vm_guest_mode mode, void *arg)
 {
 	struct test_params *p = arg;
@@ -236,7 +165,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 	pages_per_slot = host_num_pages / p->slots;
 
-	bitmaps = alloc_bitmaps(p->slots, pages_per_slot);
+	bitmaps = memstress_alloc_bitmaps(p->slots, pages_per_slot);
 
 	if (dirty_log_manual_caps)
 		vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2,
@@ -277,7 +206,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 	/* Enable dirty logging */
 	clock_gettime(CLOCK_MONOTONIC, &start);
-	enable_dirty_logging(vm, p->slots);
+	memstress_enable_dirty_logging(vm, p->slots);
 	ts_diff = timespec_elapsed(start);
 	pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);
@@ -306,7 +235,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 			iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 
 		clock_gettime(CLOCK_MONOTONIC, &start);
-		get_dirty_log(vm, bitmaps, p->slots);
+		memstress_get_dirty_log(vm, bitmaps, p->slots);
 		ts_diff = timespec_elapsed(start);
 		get_dirty_log_total = timespec_add(get_dirty_log_total,
 						   ts_diff);
@@ -315,7 +244,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 		if (dirty_log_manual_caps) {
 			clock_gettime(CLOCK_MONOTONIC, &start);
-			clear_dirty_log(vm, bitmaps, p->slots, pages_per_slot);
+			memstress_clear_dirty_log(vm, bitmaps, p->slots,
+						  pages_per_slot);
 			ts_diff = timespec_elapsed(start);
 			clear_dirty_log_total = timespec_add(clear_dirty_log_total,
 							     ts_diff);
@@ -334,7 +264,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 	/* Disable dirty logging */
 	clock_gettime(CLOCK_MONOTONIC, &start);
-	disable_dirty_logging(vm, p->slots);
+	memstress_disable_dirty_logging(vm, p->slots);
 	ts_diff = timespec_elapsed(start);
 	pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);
@@ -359,7 +289,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 			clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 	}
 
-	free_bitmaps(bitmaps, p->slots);
+	memstress_free_bitmaps(bitmaps, p->slots);
 	arch_cleanup_vm(vm);
 	memstress_destroy_vm(vm);
 }
diff --git a/tools/testing/selftests/kvm/include/memstress.h b/tools/testing/selftests/kvm/include/memstress.h
index 72e3e358ef7bd..ce4e603050eaa 100644
--- a/tools/testing/selftests/kvm/include/memstress.h
+++ b/tools/testing/selftests/kvm/include/memstress.h
@@ -72,4 +72,12 @@ void memstress_guest_code(uint32_t vcpu_id);
 uint64_t memstress_nested_pages(int nr_vcpus);
 void memstress_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vcpus[]);
 
+void memstress_enable_dirty_logging(struct kvm_vm *vm, int slots);
+void memstress_disable_dirty_logging(struct kvm_vm *vm, int slots);
+void memstress_get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots);
+void memstress_clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[],
+			       int slots, uint64_t pages_per_slot);
+unsigned long **memstress_alloc_bitmaps(int slots, uint64_t pages_per_slot);
+void memstress_free_bitmaps(unsigned long *bitmaps[], int slots);
+
 #endif /* SELFTEST_KVM_MEMSTRESS_H */
diff --git a/tools/testing/selftests/kvm/lib/memstress.c b/tools/testing/selftests/kvm/lib/memstress.c
index 5f1d3173c238c..3632956c6bcf5 100644
--- a/tools/testing/selftests/kvm/lib/memstress.c
+++ b/tools/testing/selftests/kvm/lib/memstress.c
@@ -5,6 +5,7 @@
 #define _GNU_SOURCE
 
 #include <inttypes.h>
+#include <linux/bitmap.h>
 
 #include "kvm_util.h"
 #include "memstress.h"
@@ -320,3 +321,74 @@ void memstress_join_vcpu_threads(int nr_vcpus)
 	for (i = 0; i < nr_vcpus; i++)
 		pthread_join(vcpu_threads[i].thread, NULL);
 }
+
+static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
+{
+	int i;
+
+	for (i = 0; i < slots; i++) {
+		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
+		int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;
+
+		vm_mem_region_set_flags(vm, slot, flags);
+	}
+}
+
+void memstress_enable_dirty_logging(struct kvm_vm *vm, int slots)
+{
+	toggle_dirty_logging(vm, slots, true);
+}
+
+void memstress_disable_dirty_logging(struct kvm_vm *vm, int slots)
+{
+	toggle_dirty_logging(vm, slots, false);
+}
+
+void memstress_get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots)
+{
+	int i;
+
+	for (i = 0; i < slots; i++) {
+		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
+
+		kvm_vm_get_dirty_log(vm, slot, bitmaps[i]);
+	}
+}
+
+void memstress_clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[],
+			       int slots, uint64_t pages_per_slot)
+{
+	int i;
+
+	for (i = 0; i < slots; i++) {
+		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
+
+		kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot);
+	}
+}
+
+unsigned long **memstress_alloc_bitmaps(int slots, uint64_t pages_per_slot)
+{
+	unsigned long **bitmaps;
+	int i;
+
+	bitmaps = malloc(slots * sizeof(bitmaps[0]));
+	TEST_ASSERT(bitmaps, "Failed to allocate bitmaps array.");
+
+	for (i = 0; i < slots; i++) {
+		bitmaps[i] = bitmap_zalloc(pages_per_slot);
+		TEST_ASSERT(bitmaps[i], "Failed to allocate slot bitmap.");
+	}
+
+	return bitmaps;
+}
+
+void memstress_free_bitmaps(unsigned long *bitmaps[], int slots)
+{
+	int i;
+
+	for (i = 0; i < slots; i++)
+		free(bitmaps[i]);
+
+	free(bitmaps);
+}
-- 
2.39.1.405.gd4c25cc71f-goog

[RFC 2/2] selftests: KVM: Add page splitting test

[Ben Gardon]

Add a test for page splitting during dirty logging and for hugepage
recovery after dirty logging.

Page splitting represents non-trivial behavior, which is complicated
by MANUAL_PROTECT mode, which causes pages to be split on the first
clear, instead of when dirty logging is enabled.

Add a test which makes asserions about page counts to help define the
expected behavior of page splitting and to provid needed coverage of the
behavior. This also helps ensure that a failure in eager page splitting
is not covered up by splitting in the vCPU path.

Tested by running the test on an Intel Haswell machine w/wo
MANUAL_PROTECT.

Signed-off-by: Ben Gardon <bgardon@google.com>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/include/kvm_util_base.h     |   1 +
 .../kvm/x86_64/page_splitting_test.c          | 311 ++++++++++++++++++
 3 files changed, 313 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/x86_64/page_splitting_test.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 1750f91dd9362..057ebd709e77a 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -76,6 +76,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/kvm_pv_test
 TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
 TEST_GEN_PROGS_x86_64 += x86_64/monitor_mwait_test
 TEST_GEN_PROGS_x86_64 += x86_64/nested_exceptions_test
+TEST_GEN_PROGS_x86_64 += x86_64/page_splitting_test
 TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
 TEST_GEN_PROGS_x86_64 += x86_64/pmu_event_filter_test
 TEST_GEN_PROGS_x86_64 += x86_64/set_boot_cpu_id
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index fbc2a79369b8b..98974a601b0af 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -402,6 +402,7 @@ static inline uint64_t vm_get_stat(struct kvm_vm *vm, const char *stat_name)
 	uint64_t data;
 
 	__vm_get_stat(vm, stat_name, &data, 1);
+
 	return data;
 }
 
diff --git a/tools/testing/selftests/kvm/x86_64/page_splitting_test.c b/tools/testing/selftests/kvm/x86_64/page_splitting_test.c
new file mode 100644
index 0000000000000..4b5dcd4908b5a
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/page_splitting_test.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM dirty logging page splitting test
+ *
+ * Based on dirty_log_perf.c
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ * Copyright (C) 2020, Google, Inc.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <pthread.h>
+#include <linux/bitmap.h>
+
+#include "kvm_util.h"
+#include "test_util.h"
+#include "memstress.h"
+#include "guest_modes.h"
+
+/* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/
+#define TEST_HOST_LOOP_N		2UL
+
+static int NR_VCPUS = 2;
+static int NR_SLOTS = 2;
+static int NR_ITERATIONS = 2;
+static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
+
+/* Host variables */
+static u64 dirty_log_manual_caps;
+static bool host_quit;
+static int iteration;
+static int vcpu_last_completed_iteration[KVM_MAX_VCPUS];
+
+struct kvm_page_stats {
+	uint64_t pages_4k;
+	uint64_t pages_2m;
+	uint64_t pages_1g;
+	uint64_t hugepages;
+};
+
+static void get_page_stats(struct kvm_vm *vm, struct kvm_page_stats *stats)
+{
+	stats->pages_4k = vm_get_stat(vm, "pages_4k");
+	stats->pages_2m = vm_get_stat(vm, "pages_2m");
+	stats->pages_1g = vm_get_stat(vm, "pages_1g");
+	stats->hugepages = stats->pages_2m + stats->pages_1g;
+
+	pr_debug("Page stats - 4K: %ld 2M: %ld 1G: %ld huge: %ld\n",
+		 stats->pages_4k, stats->pages_2m, stats->pages_1g,
+		 stats->hugepages);
+}
+
+static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
+{
+	struct kvm_vcpu *vcpu = vcpu_args->vcpu;
+	int vcpu_idx = vcpu_args->vcpu_idx;
+	uint64_t pages_count = 0;
+	struct kvm_run *run;
+	int ret;
+
+	run = vcpu->run;
+
+	while (!READ_ONCE(host_quit)) {
+		int current_iteration = READ_ONCE(iteration);
+
+		ret = _vcpu_run(vcpu);
+
+		TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+		TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC,
+			    "Invalid guest sync status: exit_reason=%s\n",
+			    exit_reason_str(run->exit_reason));
+
+		vcpu_last_completed_iteration[vcpu_idx] = current_iteration;
+
+		if (current_iteration)
+			pages_count += vcpu_args->pages;
+
+		/* Wait for the start of the next iteration to be signaled. */
+		while (current_iteration == READ_ONCE(iteration) &&
+		       READ_ONCE(iteration) >= 0 &&
+		       !READ_ONCE(host_quit))
+			;
+	}
+}
+
+struct test_params {
+	enum vm_mem_backing_src_type backing_src;
+};
+
+static void run_test(struct test_params *p)
+{
+	struct kvm_vm *vm;
+	unsigned long **bitmaps;
+	uint64_t guest_num_pages;
+	uint64_t host_num_pages;
+	uint64_t pages_per_slot;
+	int i;
+	uint64_t total_4k_pages;
+	struct kvm_page_stats stats_populated;
+	struct kvm_page_stats stats_dirty_logging_enabled;
+	struct kvm_page_stats stats_dirty_pass[NR_ITERATIONS];
+	struct kvm_page_stats stats_clear_pass[NR_ITERATIONS];
+	struct kvm_page_stats stats_dirty_logging_disabled;
+	struct kvm_page_stats stats_repopulated;
+
+	vm = memstress_create_vm(VM_MODE_DEFAULT, NR_VCPUS, guest_percpu_mem_size,
+				 NR_SLOTS, p->backing_src, false);
+
+	guest_num_pages = (NR_VCPUS * guest_percpu_mem_size) >> vm->page_shift;
+	guest_num_pages = vm_adjust_num_guest_pages(VM_MODE_DEFAULT, guest_num_pages);
+	host_num_pages = vm_num_host_pages(VM_MODE_DEFAULT, guest_num_pages);
+	pages_per_slot = host_num_pages / NR_SLOTS;
+
+	bitmaps = memstress_alloc_bitmaps(NR_SLOTS, pages_per_slot);
+
+	if (dirty_log_manual_caps)
+		vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2,
+			      dirty_log_manual_caps);
+
+	/* Start the iterations */
+	iteration = 0;
+	host_quit = false;
+
+	for (i = 0; i < NR_VCPUS; i++)
+		vcpu_last_completed_iteration[i] = -1;
+
+	memstress_start_vcpu_threads(NR_VCPUS, vcpu_worker);
+
+	/* Allow the vCPUs to populate memory */
+	for (i = 0; i < NR_VCPUS; i++) {
+		while (READ_ONCE(vcpu_last_completed_iteration[i]) !=
+		       iteration)
+			;
+	}
+
+	pr_debug("\nGetting stats after populating memory:\n");
+	get_page_stats(vm, &stats_populated);
+
+	/* Enable dirty logging */
+	memstress_enable_dirty_logging(vm, NR_SLOTS);
+
+	pr_debug("\nGetting stats after enabling dirty logging:\n");
+	get_page_stats(vm, &stats_dirty_logging_enabled);
+
+	while (iteration < NR_ITERATIONS) {
+		/*
+		 * Incrementing the iteration number will start the vCPUs
+		 * dirtying memory again.
+		 */
+		iteration++;
+
+		for (i = 0; i < NR_VCPUS; i++) {
+			while (READ_ONCE(vcpu_last_completed_iteration[i])
+			       != iteration)
+				;
+		}
+
+		pr_debug("\nGetting stats after dirtying memory on pass %d:\n", iteration);
+		get_page_stats(vm, &stats_dirty_pass[iteration - 1]);
+
+		memstress_get_dirty_log(vm, bitmaps, NR_SLOTS);
+
+		if (dirty_log_manual_caps) {
+			memstress_clear_dirty_log(vm, bitmaps, NR_SLOTS, pages_per_slot);
+
+			pr_debug("\nGetting stats after clearing dirty log pass %d:\n", iteration);
+			get_page_stats(vm, &stats_clear_pass[iteration - 1]);
+		}
+	}
+
+	/* Disable dirty logging */
+	memstress_disable_dirty_logging(vm, NR_SLOTS);
+
+	pr_debug("\nGetting stats after disabling dirty logging:\n");
+	get_page_stats(vm, &stats_dirty_logging_disabled);
+
+	/* Run vCPUs again to fault pages back in. */
+	iteration++;
+	for (i = 0; i < NR_VCPUS; i++) {
+		while (READ_ONCE(vcpu_last_completed_iteration[i]) != iteration)
+			;
+	}
+
+	pr_debug("\nGetting stats after repopulating memory:\n");
+	get_page_stats(vm, &stats_repopulated);
+
+	/*
+	 * Tell the vCPU threads to quit.  No need to manually check that vCPUs
+	 * have stopped running after disabling dirty logging, the join will
+	 * wait for them to exit.
+	 */
+	host_quit = true;
+	memstress_join_vcpu_threads(NR_VCPUS);
+
+	memstress_free_bitmaps(bitmaps, NR_SLOTS);
+	memstress_destroy_vm(vm);
+
+	/* Make assertions about the page counts. */
+	total_4k_pages = stats_populated.pages_4k;
+	total_4k_pages += stats_populated.pages_2m * 512;
+	total_4k_pages += stats_populated.pages_1g * 512 * 512;
+
+	/*
+	 * Check that all huge pages were split. Since large pages can only
+	 * exist in the data slot, and the vCPUs should have dirtied all pages
+	 * in the data slot, there should be no huge pages left after splitting.
+	 * Splitting happens at dirty log enable time without
+	 * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 and after the first clear pass
+	 * with that capability.
+	 */
+	if (dirty_log_manual_caps) {
+		TEST_ASSERT(stats_clear_pass[0].hugepages == 0,
+			    "Unexpected huge page count after splitting. Expected 0, got %ld",
+			    stats_clear_pass[0].hugepages);
+		TEST_ASSERT(stats_clear_pass[0].pages_4k == total_4k_pages,
+			    "All memory should be mapped at 4k. Expected %ld 4k pages, got %ld",
+			    total_4k_pages, stats_clear_pass[0].pages_4k);
+	} else {
+		TEST_ASSERT(stats_dirty_logging_enabled.hugepages == 0,
+			    "Unexpected huge page count after splitting. Expected 0, got %ld",
+			    stats_dirty_logging_enabled.hugepages);
+		TEST_ASSERT(stats_dirty_logging_enabled.pages_4k == total_4k_pages,
+			    "All memory should be mapped at 4k. Expected %ld 4k pages, got %ld",
+			    total_4k_pages, stats_dirty_logging_enabled.pages_4k);
+	}
+
+	/*
+	 * Once dirty logging is disabled and the vCPUs have touched all their
+	 * memory again, the page counts should be the same as they were
+	 * right after initial population of memory.
+	 */
+	TEST_ASSERT(stats_populated.pages_4k == stats_repopulated.pages_4k,
+		    "4k page count did not return to its initial value after "
+		    "dirty logging. Expected %ld, got %ld",
+		    stats_populated.pages_4k, stats_repopulated.pages_4k);
+	TEST_ASSERT(stats_populated.pages_2m == stats_repopulated.pages_2m,
+		    "2m page count did not return to its initial value after "
+		    "dirty logging. Expected %ld, got %ld",
+		    stats_populated.pages_2m, stats_repopulated.pages_2m);
+	TEST_ASSERT(stats_populated.pages_1g == stats_repopulated.pages_1g,
+		    "1g page count did not return to its initial value after "
+		    "dirty logging. Expected %ld, got %ld",
+		    stats_populated.pages_1g, stats_repopulated.pages_1g);
+}
+
+static void help(char *name)
+{
+	puts("");
+	printf("usage: %s [-h] [-g] [-m mode] [-b vcpu bytes] [-s mem type]\n",
+	       name);
+	puts("");
+	printf(" -g: Do not enable KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2. This\n"
+	       "     makes KVM_GET_DIRTY_LOG clear the dirty log (i.e.\n"
+	       "     KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is not enabled)\n"
+	       "     and writes will be tracked as soon as dirty logging is\n"
+	       "     enabled on the memslot (i.e. KVM_DIRTY_LOG_INITIALLY_SET\n"
+	       "     is not enabled).\n");
+	printf(" -b: specify the size of the memory region which should be\n"
+	       "     dirtied by each vCPU. e.g. 10M or 3G.\n"
+	       "     (default: 1G)\n");
+	backing_src_help("-s");
+	puts("");
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	struct test_params p = {
+		.backing_src = VM_MEM_SRC_ANONYMOUS_HUGETLB,
+	};
+	int opt;
+
+	dirty_log_manual_caps =
+		kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
+	dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
+				  KVM_DIRTY_LOG_INITIALLY_SET);
+
+	guest_modes_append_default();
+
+	while ((opt = getopt(argc, argv, "b:ghs:")) != -1) {
+		switch (opt) {
+		case 'b':
+			guest_percpu_mem_size = parse_size(optarg);
+			break;
+		case 'g':
+			dirty_log_manual_caps = 0;
+			break;
+		case 'h':
+			help(argv[0]);
+			break;
+		case 's':
+			p.backing_src = parse_backing_src_type(optarg);
+			break;
+		default:
+			help(argv[0]);
+			break;
+		}
+	}
+
+	if (!is_backing_src_hugetlb(p.backing_src)) {
+		pr_info("This test will only work reliably with HugeTLB memory. "
+			"It can work with THP, but that is best effort.");
+		return KSFT_SKIP;
+	}
+
+	run_test(&p);
+
+	return 0;
+}
-- 
2.39.1.405.gd4c25cc71f-goog

Re: [RFC 1/2] selftests: KVM: Move dirty logging functions to memstress.(c|h)

[Sean Christopherson]

Please provide cover letters for multi-patch series, regardless of how trivial
the series is.

This series especially needs a cover explaining why it's tagged "RFC".

Re: [RFC 1/2] selftests: KVM: Move dirty logging functions to memstress.(c|h)

[Ben Gardon]

Woops! I did not mean to tag this RFC. Sorry about that. I will
include a cover letter in the future and can resend these with one if
preferred.

On Thu, Jan 19, 2023 at 12:39 PM Sean Christopherson <seanjc@google.com> wrote:
>
> Please provide cover letters for multi-patch series, regardless of how trivial
> the series is.
>
> This series especially needs a cover explaining why it's tagged "RFC".

Re: [RFC 1/2] selftests: KVM: Move dirty logging functions to memstress.(c|h)

[Sean Christopherson]

On Thu, Jan 19, 2023, Ben Gardon wrote:
> Woops!

Heh, and top posting too.  Me thinks you had too long of a break ;-)

> I did not mean to tag this RFC. Sorry about that. I will include a cover
> letter in the future and can resend these with one if preferred.

Eh, no need, damage done.  I was just confused.

> On Thu, Jan 19, 2023 at 12:39 PM Sean Christopherson <seanjc@google.com> wrote:
> >
> > Please provide cover letters for multi-patch series, regardless of how trivial
> > the series is.
> >
> > This series especially needs a cover explaining why it's tagged "RFC".

Re: [RFC 1/2] selftests: KVM: Move dirty logging functions to memstress.(c|h)

[Ben Gardon]

On Thu, Jan 19, 2023 at 12:53 PM Sean Christopherson <seanjc@google.com> wrote:
>
> On Thu, Jan 19, 2023, Ben Gardon wrote:
> > Woops!
>
> Heh, and top posting too.  Me thinks you had too long of a break ;-)

Oh no, I'm in shambles (^:

>
> > I did not mean to tag this RFC. Sorry about that. I will include a cover
> > letter in the future and can resend these with one if preferred.
>
> Eh, no need, damage done.  I was just confused.

I sent a revised version anyway because I realized it probably made
sense to have test skip itself if TDP MMU or Eager Page Splitting was
disabled.

>
> > On Thu, Jan 19, 2023 at 12:39 PM Sean Christopherson <seanjc@google.com> wrote:
> > >
> > > Please provide cover letters for multi-patch series, regardless of how trivial
> > > the series is.
> > >
> > > This series especially needs a cover explaining why it's tagged "RFC".