Re: [PATCH v6 10/14] KVM: selftests: Use a single binary for dirty/clear log test

From: Andrew Jones
Date: Tue Mar 10 2020 - 04:10:25 EST

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In reply to: Peter Xu: "[PATCH v6 10/14] KVM: selftests: Use a single binary for dirty/clear log test"
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On Mon, Mar 09, 2020 at 06:25:19PM -0400, Peter Xu wrote:
> Remove the clear_dirty_log test, instead merge it into the existing
> dirty_log_test. It should be cleaner to use this single binary to do
> both tests, also it's a preparation for the upcoming dirty ring test.
>
> The default behavior will run all the modes in sequence.
>
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/Makefile | 2 -
> .../selftests/kvm/clear_dirty_log_test.c | 2 -
> tools/testing/selftests/kvm/dirty_log_test.c | 169 +++++++++++++++---
> 3 files changed, 146 insertions(+), 27 deletions(-)
> delete mode 100644 tools/testing/selftests/kvm/clear_dirty_log_test.c
>
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index d91c53b726e6..941bfcd48eaa 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -27,11 +27,9 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test
> TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
> TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test
> TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_test
> -TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
> TEST_GEN_PROGS_x86_64 += dirty_log_test
> TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
>
> -TEST_GEN_PROGS_aarch64 += clear_dirty_log_test
> TEST_GEN_PROGS_aarch64 += dirty_log_test
> TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
>
> diff --git a/tools/testing/selftests/kvm/clear_dirty_log_test.c b/tools/testing/selftests/kvm/clear_dirty_log_test.c
> deleted file mode 100644
> index 749336937d37..000000000000
> --- a/tools/testing/selftests/kvm/clear_dirty_log_test.c
> +++ /dev/null
> @@ -1,2 +0,0 @@
> -#define USE_CLEAR_DIRTY_LOG
> -#include "dirty_log_test.c"
> diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
> index 3c0ffd34b3b0..642886394e34 100644
> --- a/tools/testing/selftests/kvm/dirty_log_test.c
> +++ b/tools/testing/selftests/kvm/dirty_log_test.c
> @@ -128,6 +128,73 @@ static uint64_t host_dirty_count;
> static uint64_t host_clear_count;
> static uint64_t host_track_next_count;
>
> +enum log_mode_t {
> + /* Only use KVM_GET_DIRTY_LOG for logging */
> + LOG_MODE_DIRTY_LOG = 0,
> +
> + /* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */
> + LOG_MODE_CLEAR_LOG = 1,
> +
> + LOG_MODE_NUM,
> +
> + /* Run all supported modes */
> + LOG_MODE_ALL = LOG_MODE_NUM,
> +};
> +
> +/* Mode of logging to test. Default is to run all supported modes */
> +static enum log_mode_t host_log_mode_option = LOG_MODE_ALL;
> +/* Logging mode for current run */
> +static enum log_mode_t host_log_mode;
> +
> +static bool clear_log_supported(void)
> +{
> + return kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
> +}
> +
> +static void clear_log_create_vm_done(struct kvm_vm *vm)
> +{
> + struct kvm_enable_cap cap = {};
> +
> + cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
> + cap.args[0] = 1;
> + vm_enable_cap(vm, &cap);
> +}
> +
> +static void dirty_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
> + void *bitmap, uint32_t num_pages)
> +{
> + kvm_vm_get_dirty_log(vm, slot, bitmap);
> +}
> +
> +static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
> + void *bitmap, uint32_t num_pages)
> +{
> + kvm_vm_get_dirty_log(vm, slot, bitmap);
> + kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages);
> +}
> +
> +struct log_mode {
> + const char *name;
> + /* Return true if this mode is supported, otherwise false */
> + bool (*supported)(void);
> + /* Hook when the vm creation is done (before vcpu creation) */
> + void (*create_vm_done)(struct kvm_vm *vm);
> + /* Hook to collect the dirty pages into the bitmap provided */
> + void (*collect_dirty_pages) (struct kvm_vm *vm, int slot,
> + void *bitmap, uint32_t num_pages);
> +} log_modes[LOG_MODE_NUM] = {
> + {
> + .name = "dirty-log",
> + .collect_dirty_pages = dirty_log_collect_dirty_pages,
> + },
> + {
> + .name = "clear-log",
> + .supported = clear_log_supported,
> + .create_vm_done = clear_log_create_vm_done,
> + .collect_dirty_pages = clear_log_collect_dirty_pages,
> + },
> +};
> +
> /*
> * We use this bitmap to track some pages that should have its dirty
> * bit set in the _next_ iteration. For example, if we detected the
> @@ -137,6 +204,43 @@ static uint64_t host_track_next_count;
> */
> static unsigned long *host_bmap_track;
>
> +static void log_modes_dump(void)
> +{
> + int i;
> +
> + for (i = 0; i < LOG_MODE_NUM; i++)
> + printf("%s, ", log_modes[i].name);
> + puts("\b\b \b\b");

This will be ugly when the output is redirected to a file.
How about just

printf("%s", log_modes[0].name);
for (i = 1; i < LOG_MODE_NUM; i++)
printf(", %s", log_modes[i].name);
printf("\n");

> +}
> +
> +static bool log_mode_supported(void)
> +{
> + struct log_mode *mode = &log_modes[host_log_mode];
> +
> + if (mode->supported)
> + return mode->supported();
> +
> + return true;
> +}
> +
> +static void log_mode_create_vm_done(struct kvm_vm *vm)
> +{
> + struct log_mode *mode = &log_modes[host_log_mode];
> +
> + if (mode->create_vm_done)
> + mode->create_vm_done(vm);
> +}
> +
> +static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot,
> + void *bitmap, uint32_t num_pages)
> +{
> + struct log_mode *mode = &log_modes[host_log_mode];
> +
> + TEST_ASSERT(mode->collect_dirty_pages != NULL,
> + "collect_dirty_pages() is required for any log mode!");
> + mode->collect_dirty_pages(vm, slot, bitmap, num_pages);
> +}
> +
> static void generate_random_array(uint64_t *guest_array, uint64_t size)
> {
> uint64_t i;
> @@ -257,6 +361,7 @@ static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
> #ifdef __x86_64__
> vm_create_irqchip(vm);
> #endif
> + log_mode_create_vm_done(vm);
> vm_vcpu_add_default(vm, vcpuid, guest_code);
> return vm;
> }
> @@ -271,6 +376,12 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
> struct kvm_vm *vm;
> unsigned long *bmap;
>
> + if (!log_mode_supported()) {
> + fprintf(stderr, "Log mode '%s' not supported, skip\n",
> + log_modes[host_log_mode].name);

I think kvm selftests needs a skip_test() function that outputs a more
consistent test skip message. It seems we mostly do

fprintf(stderr, "%s, skipping test\n", custom_message);

but here we have ', skip'. Also, I see a few places were we output
skipping to stderr and others to stdout. I think I like stdout better.

> + return;
> + }
> +
> /*
> * We reserve page table for 2 times of extra dirty mem which
> * will definitely cover the original (1G+) test range. Here
> @@ -316,14 +427,6 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
> bmap = bitmap_alloc(host_num_pages);
> host_bmap_track = bitmap_alloc(host_num_pages);
>
> -#ifdef USE_CLEAR_DIRTY_LOG
> - struct kvm_enable_cap cap = {};
> -
> - cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
> - cap.args[0] = 1;
> - vm_enable_cap(vm, &cap);
> -#endif
> -
> /* Add an extra memory slot for testing dirty logging */
> vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
> guest_test_phys_mem,
> @@ -364,11 +467,8 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
> while (iteration < iterations) {
> /* Give the vcpu thread some time to dirty some pages */
> usleep(interval * 1000);
> - kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
> -#ifdef USE_CLEAR_DIRTY_LOG
> - kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
> - host_num_pages);
> -#endif
> + log_mode_collect_dirty_pages(vm, TEST_MEM_SLOT_INDEX,
> + bmap, host_num_pages);
> vm_dirty_log_verify(bmap);
> iteration++;
> sync_global_to_guest(vm, iteration);
> @@ -413,6 +513,9 @@ static void help(char *name)
> TEST_HOST_LOOP_INTERVAL);
> printf(" -p: specify guest physical test memory offset\n"
> " Warning: a low offset can conflict with the loaded test code.\n");
> + printf(" -M: specify the host logging mode "
> + "(default: run all log modes). Supported modes: \n\t");
> + log_modes_dump();
> printf(" -m: specify the guest mode ID to test "
> "(default: test all supported modes)\n"
> " This option may be used multiple times.\n"
> @@ -432,18 +535,11 @@ int main(int argc, char *argv[])
> bool mode_selected = false;
> uint64_t phys_offset = 0;
> unsigned int mode;
> - int opt, i;
> + int opt, i, j;
> #ifdef __aarch64__
> unsigned int host_ipa_limit;
> #endif
>
> -#ifdef USE_CLEAR_DIRTY_LOG
> - if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) {
> - fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n");
> - exit(KSFT_SKIP);
> - }
> -#endif
> -
> #ifdef __x86_64__
> vm_guest_mode_params_init(VM_MODE_PXXV48_4K, true, true);
> #endif
> @@ -463,7 +559,7 @@ int main(int argc, char *argv[])
> vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true);
> #endif
>
> - while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) {
> + while ((opt = getopt(argc, argv, "hi:I:p:m:M:")) != -1) {
> switch (opt) {
> case 'i':
> iterations = strtol(optarg, NULL, 10);
> @@ -485,6 +581,22 @@ int main(int argc, char *argv[])
> "Guest mode ID %d too big", mode);
> vm_guest_mode_params[mode].enabled = true;
> break;
> + case 'M':

Can also add

if (!strcmp(optarg, "all"))
host_log_mode_option = LOG_MODE_ALL;

> + for (i = 0; i < LOG_MODE_NUM; i++) {
> + if (!strcmp(optarg, log_modes[i].name)) {
> + DEBUG("Setting log mode to: '%s'\n",
> + optarg);

Basing this on kvm/queue won't work as DEBUG() no longer exists. This
looks like a pr_info().

> + host_log_mode_option = i;
> + break;
> + }
> + }
> + if (i == LOG_MODE_NUM) {
> + printf("Log mode '%s' is invalid. "
> + "Please choose from: ", optarg);
> + log_modes_dump();
> + exit(-1);

Exit code of 255? Probably just want exit(1);

> + }
> + break;
> case 'h':
> default:
> help(argv[0]);
> @@ -506,7 +618,18 @@ int main(int argc, char *argv[])
> TEST_ASSERT(vm_guest_mode_params[i].supported,
> "Guest mode ID %d (%s) not supported.",
> i, vm_guest_mode_string(i));
> - run_test(i, iterations, interval, phys_offset);
> + if (host_log_mode_option == LOG_MODE_ALL) {
> + /* Run each log mode */
> + for (j = 0; j < LOG_MODE_NUM; j++) {
> + DEBUG("Testing Log Mode '%s'\n",
> + log_modes[j].name);
> + host_log_mode = j;
> + run_test(i, iterations, interval, phys_offset);
> + }
> + } else {
> + host_log_mode = host_log_mode_option;
> + run_test(i, iterations, interval, phys_offset);
> + }
> }
>
> return 0;
> --
> 2.24.1
>

Thanks,
drew

Next message: Dmitry Vyukov: "Re: general protection fault in syscall_return_slowpath"
Previous message: Masami Hiramatsu: "Re: Instrumentation and RCU"
In reply to: Peter Xu: "[PATCH v6 10/14] KVM: selftests: Use a single binary for dirty/clear log test"
Next in thread: Peter Xu: "Re: [PATCH v6 10/14] KVM: selftests: Use a single binary for dirty/clear log test"
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