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-rw-r--r--tools/testing/selftests/kvm/demand_paging_test.c112
1 files changed, 79 insertions, 33 deletions
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index 8c03484a5784..fcba527c29a6 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -73,33 +73,48 @@ static void *vcpu_worker(void *data)
return NULL;
}
-static int handle_uffd_page_request(int uffd, uint64_t addr)
+static int handle_uffd_page_request(int uffd_mode, int uffd, uint64_t addr)
{
- pid_t tid;
+ pid_t tid = syscall(__NR_gettid);
struct timespec start;
struct timespec ts_diff;
- struct uffdio_copy copy;
int r;
- tid = syscall(__NR_gettid);
+ clock_gettime(CLOCK_MONOTONIC, &start);
- copy.src = (uint64_t)guest_data_prototype;
- copy.dst = addr;
- copy.len = demand_paging_size;
- copy.mode = 0;
+ if (uffd_mode == UFFDIO_REGISTER_MODE_MISSING) {
+ struct uffdio_copy copy;
- clock_gettime(CLOCK_MONOTONIC, &start);
+ copy.src = (uint64_t)guest_data_prototype;
+ copy.dst = addr;
+ copy.len = demand_paging_size;
+ copy.mode = 0;
+
+ r = ioctl(uffd, UFFDIO_COPY, &copy);
+ if (r == -1) {
+ pr_info("Failed UFFDIO_COPY in 0x%lx from thread %d with errno: %d\n",
+ addr, tid, errno);
+ return r;
+ }
+ } else if (uffd_mode == UFFDIO_REGISTER_MODE_MINOR) {
+ struct uffdio_continue cont = {0};
+
+ cont.range.start = addr;
+ cont.range.len = demand_paging_size;
- r = ioctl(uffd, UFFDIO_COPY, &copy);
- if (r == -1) {
- pr_info("Failed Paged in 0x%lx from thread %d with errno: %d\n",
- addr, tid, errno);
- return r;
+ r = ioctl(uffd, UFFDIO_CONTINUE, &cont);
+ if (r == -1) {
+ pr_info("Failed UFFDIO_CONTINUE in 0x%lx from thread %d with errno: %d\n",
+ addr, tid, errno);
+ return r;
+ }
+ } else {
+ TEST_FAIL("Invalid uffd mode %d", uffd_mode);
}
ts_diff = timespec_elapsed(start);
- PER_PAGE_DEBUG("UFFDIO_COPY %d \t%ld ns\n", tid,
+ PER_PAGE_DEBUG("UFFD page-in %d \t%ld ns\n", tid,
timespec_to_ns(ts_diff));
PER_PAGE_DEBUG("Paged in %ld bytes at 0x%lx from thread %d\n",
demand_paging_size, addr, tid);
@@ -110,6 +125,7 @@ static int handle_uffd_page_request(int uffd, uint64_t addr)
bool quit_uffd_thread;
struct uffd_handler_args {
+ int uffd_mode;
int uffd;
int pipefd;
useconds_t delay;
@@ -186,7 +202,7 @@ static void *uffd_handler_thread_fn(void *arg)
if (delay)
usleep(delay);
addr = msg.arg.pagefault.address;
- r = handle_uffd_page_request(uffd, addr);
+ r = handle_uffd_page_request(uffd_args->uffd_mode, uffd, addr);
if (r < 0)
return NULL;
pages++;
@@ -202,13 +218,32 @@ static void *uffd_handler_thread_fn(void *arg)
static void setup_demand_paging(struct kvm_vm *vm,
pthread_t *uffd_handler_thread, int pipefd,
- useconds_t uffd_delay,
+ int uffd_mode, useconds_t uffd_delay,
struct uffd_handler_args *uffd_args,
- void *hva, uint64_t len)
+ void *hva, void *alias, uint64_t len)
{
+ bool is_minor = (uffd_mode == UFFDIO_REGISTER_MODE_MINOR);
int uffd;
struct uffdio_api uffdio_api;
struct uffdio_register uffdio_register;
+ uint64_t expected_ioctls = ((uint64_t) 1) << _UFFDIO_COPY;
+
+ PER_PAGE_DEBUG("Userfaultfd %s mode, faults resolved with %s\n",
+ is_minor ? "MINOR" : "MISSING",
+ is_minor ? "UFFDIO_CONINUE" : "UFFDIO_COPY");
+
+ /* In order to get minor faults, prefault via the alias. */
+ if (is_minor) {
+ size_t p;
+
+ expected_ioctls = ((uint64_t) 1) << _UFFDIO_CONTINUE;
+
+ TEST_ASSERT(alias != NULL, "Alias required for minor faults");
+ for (p = 0; p < (len / demand_paging_size); ++p) {
+ memcpy(alias + (p * demand_paging_size),
+ guest_data_prototype, demand_paging_size);
+ }
+ }
uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
TEST_ASSERT(uffd >= 0, "uffd creation failed, errno: %d", errno);
@@ -221,12 +256,13 @@ static void setup_demand_paging(struct kvm_vm *vm,
uffdio_register.range.start = (uint64_t)hva;
uffdio_register.range.len = len;
- uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
+ uffdio_register.mode = uffd_mode;
TEST_ASSERT(ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) != -1,
"ioctl UFFDIO_REGISTER failed");
- TEST_ASSERT((uffdio_register.ioctls & UFFD_API_RANGE_IOCTLS) ==
- UFFD_API_RANGE_IOCTLS, "unexpected userfaultfd ioctl set");
+ TEST_ASSERT((uffdio_register.ioctls & expected_ioctls) ==
+ expected_ioctls, "missing userfaultfd ioctls");
+ uffd_args->uffd_mode = uffd_mode;
uffd_args->uffd = uffd;
uffd_args->pipefd = pipefd;
uffd_args->delay = uffd_delay;
@@ -238,7 +274,7 @@ static void setup_demand_paging(struct kvm_vm *vm,
}
struct test_params {
- bool use_uffd;
+ int uffd_mode;
useconds_t uffd_delay;
enum vm_mem_backing_src_type src_type;
bool partition_vcpu_memory_access;
@@ -275,7 +311,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
p->partition_vcpu_memory_access);
- if (p->use_uffd) {
+ if (p->uffd_mode) {
uffd_handler_threads =
malloc(nr_vcpus * sizeof(*uffd_handler_threads));
TEST_ASSERT(uffd_handler_threads, "Memory allocation failed");
@@ -289,6 +325,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
vm_paddr_t vcpu_gpa;
void *vcpu_hva;
+ void *vcpu_alias;
uint64_t vcpu_mem_size;
@@ -303,8 +340,9 @@ static void run_test(enum vm_guest_mode mode, void *arg)
PER_VCPU_DEBUG("Added VCPU %d with test mem gpa [%lx, %lx)\n",
vcpu_id, vcpu_gpa, vcpu_gpa + vcpu_mem_size);
- /* Cache the HVA pointer of the region */
+ /* Cache the host addresses of the region */
vcpu_hva = addr_gpa2hva(vm, vcpu_gpa);
+ vcpu_alias = addr_gpa2alias(vm, vcpu_gpa);
/*
* Set up user fault fd to handle demand paging
@@ -315,8 +353,9 @@ static void run_test(enum vm_guest_mode mode, void *arg)
TEST_ASSERT(!r, "Failed to set up pipefd");
setup_demand_paging(vm, &uffd_handler_threads[vcpu_id],
- pipefds[vcpu_id * 2], p->uffd_delay,
- &uffd_args[vcpu_id], vcpu_hva,
+ pipefds[vcpu_id * 2], p->uffd_mode,
+ p->uffd_delay, &uffd_args[vcpu_id],
+ vcpu_hva, vcpu_alias,
vcpu_mem_size);
}
}
@@ -345,7 +384,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
pr_info("All vCPU threads joined\n");
- if (p->use_uffd) {
+ if (p->uffd_mode) {
char c;
/* Tell the user fault fd handler threads to quit */
@@ -367,7 +406,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
free(guest_data_prototype);
free(vcpu_threads);
- if (p->use_uffd) {
+ if (p->uffd_mode) {
free(uffd_handler_threads);
free(uffd_args);
free(pipefds);
@@ -377,11 +416,11 @@ static void run_test(enum vm_guest_mode mode, void *arg)
static void help(char *name)
{
puts("");
- printf("usage: %s [-h] [-m mode] [-u] [-d uffd_delay_usec]\n"
+ printf("usage: %s [-h] [-m vm_mode] [-u uffd_mode] [-d uffd_delay_usec]\n"
" [-b memory] [-t type] [-v vcpus] [-o]\n", name);
guest_modes_help();
- printf(" -u: use User Fault FD to handle vCPU page\n"
- " faults.\n");
+ printf(" -u: use userfaultfd to handle vCPU page faults. Mode is a\n"
+ " UFFD registration mode: 'MISSING' or 'MINOR'.\n");
printf(" -d: add a delay in usec to the User Fault\n"
" FD handler to simulate demand paging\n"
" overheads. Ignored without -u.\n");
@@ -408,13 +447,17 @@ int main(int argc, char *argv[])
guest_modes_append_default();
- while ((opt = getopt(argc, argv, "hm:ud:b:t:v:o")) != -1) {
+ while ((opt = getopt(argc, argv, "hm:u:d:b:t:v:o")) != -1) {
switch (opt) {
case 'm':
guest_modes_cmdline(optarg);
break;
case 'u':
- p.use_uffd = true;
+ if (!strcmp("MISSING", optarg))
+ p.uffd_mode = UFFDIO_REGISTER_MODE_MISSING;
+ else if (!strcmp("MINOR", optarg))
+ p.uffd_mode = UFFDIO_REGISTER_MODE_MINOR;
+ TEST_ASSERT(p.uffd_mode, "UFFD mode must be 'MISSING' or 'MINOR'.");
break;
case 'd':
p.uffd_delay = strtoul(optarg, NULL, 0);
@@ -441,6 +484,9 @@ int main(int argc, char *argv[])
}
}
+ TEST_ASSERT(p.uffd_mode != UFFDIO_REGISTER_MODE_MINOR || p.src_type == VM_MEM_SRC_SHMEM,
+ "userfaultfd MINOR mode requires shared memory; pick a different -t");
+
for_each_guest_mode(run_test, &p);
return 0;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 06:22:48 +0000