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Diffstat (limited to 'tools/testing/selftests/kvm/lib/userfaultfd_util.c')
-rw-r--r--tools/testing/selftests/kvm/lib/userfaultfd_util.c156
1 files changed, 88 insertions, 68 deletions
diff --git a/tools/testing/selftests/kvm/lib/userfaultfd_util.c b/tools/testing/selftests/kvm/lib/userfaultfd_util.c
index f4eef6eb2dc2..7c9de8414462 100644
--- a/tools/testing/selftests/kvm/lib/userfaultfd_util.c
+++ b/tools/testing/selftests/kvm/lib/userfaultfd_util.c
@@ -6,9 +6,6 @@
* Copyright (C) 2018, Red Hat, Inc.
* Copyright (C) 2019-2022 Google LLC
*/
-
-#define _GNU_SOURCE /* for pipe2 */
-
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
@@ -16,6 +13,7 @@
#include <poll.h>
#include <pthread.h>
#include <linux/userfaultfd.h>
+#include <sys/epoll.h>
#include <sys/syscall.h>
#include "kvm_util.h"
@@ -27,76 +25,69 @@
static void *uffd_handler_thread_fn(void *arg)
{
- struct uffd_desc *uffd_desc = (struct uffd_desc *)arg;
- int uffd = uffd_desc->uffd;
- int pipefd = uffd_desc->pipefds[0];
- useconds_t delay = uffd_desc->delay;
+ struct uffd_reader_args *reader_args = (struct uffd_reader_args *)arg;
+ int uffd = reader_args->uffd;
int64_t pages = 0;
struct timespec start;
struct timespec ts_diff;
+ struct epoll_event evt;
+ int epollfd;
+
+ epollfd = epoll_create(1);
+ TEST_ASSERT(epollfd >= 0, "Failed to create epollfd.");
+
+ evt.events = EPOLLIN | EPOLLEXCLUSIVE;
+ evt.data.u32 = 0;
+ TEST_ASSERT(!epoll_ctl(epollfd, EPOLL_CTL_ADD, uffd, &evt),
+ "Failed to add uffd to epollfd");
+
+ evt.events = EPOLLIN;
+ evt.data.u32 = 1;
+ TEST_ASSERT(!epoll_ctl(epollfd, EPOLL_CTL_ADD, reader_args->pipe, &evt),
+ "Failed to add pipe to epollfd");
clock_gettime(CLOCK_MONOTONIC, &start);
while (1) {
struct uffd_msg msg;
- struct pollfd pollfd[2];
- char tmp_chr;
int r;
- pollfd[0].fd = uffd;
- pollfd[0].events = POLLIN;
- pollfd[1].fd = pipefd;
- pollfd[1].events = POLLIN;
+ r = epoll_wait(epollfd, &evt, 1, -1);
+ TEST_ASSERT(r == 1,
+ "Unexpected number of events (%d) from epoll, errno = %d",
+ r, errno);
- r = poll(pollfd, 2, -1);
- switch (r) {
- case -1:
- pr_info("poll err");
- continue;
- case 0:
- continue;
- case 1:
- break;
- default:
- pr_info("Polling uffd returned %d", r);
- return NULL;
- }
-
- if (pollfd[0].revents & POLLERR) {
- pr_info("uffd revents has POLLERR");
- return NULL;
- }
+ if (evt.data.u32 == 1) {
+ char tmp_chr;
- if (pollfd[1].revents & POLLIN) {
- r = read(pollfd[1].fd, &tmp_chr, 1);
+ TEST_ASSERT(!(evt.events & (EPOLLERR | EPOLLHUP)),
+ "Reader thread received EPOLLERR or EPOLLHUP on pipe.");
+ r = read(reader_args->pipe, &tmp_chr, 1);
TEST_ASSERT(r == 1,
- "Error reading pipefd in UFFD thread");
+ "Error reading pipefd in uffd reader thread");
break;
}
- if (!(pollfd[0].revents & POLLIN))
- continue;
+ TEST_ASSERT(!(evt.events & (EPOLLERR | EPOLLHUP)),
+ "Reader thread received EPOLLERR or EPOLLHUP on uffd.");
r = read(uffd, &msg, sizeof(msg));
if (r == -1) {
- if (errno == EAGAIN)
- continue;
- pr_info("Read of uffd got errno %d\n", errno);
- return NULL;
+ TEST_ASSERT(errno == EAGAIN,
+ "Error reading from UFFD: errno = %d", errno);
+ continue;
}
- if (r != sizeof(msg)) {
- pr_info("Read on uffd returned unexpected size: %d bytes", r);
- return NULL;
- }
+ TEST_ASSERT(r == sizeof(msg),
+ "Read on uffd returned unexpected number of bytes (%d)", r);
if (!(msg.event & UFFD_EVENT_PAGEFAULT))
continue;
- if (delay)
- usleep(delay);
- r = uffd_desc->handler(uffd_desc->uffd_mode, uffd, &msg);
- if (r < 0)
- return NULL;
+ if (reader_args->delay)
+ usleep(reader_args->delay);
+ r = reader_args->handler(reader_args->uffd_mode, uffd, &msg);
+ TEST_ASSERT(r >= 0,
+ "Reader thread handler fn returned negative value %d", r);
pages++;
}
@@ -110,6 +101,7 @@ static void *uffd_handler_thread_fn(void *arg)
struct uffd_desc *uffd_setup_demand_paging(int uffd_mode, useconds_t delay,
void *hva, uint64_t len,
+ uint64_t num_readers,
uffd_handler_t handler)
{
struct uffd_desc *uffd_desc;
@@ -118,14 +110,25 @@ struct uffd_desc *uffd_setup_demand_paging(int uffd_mode, useconds_t delay,
struct uffdio_api uffdio_api;
struct uffdio_register uffdio_register;
uint64_t expected_ioctls = ((uint64_t) 1) << _UFFDIO_COPY;
- int ret;
+ int ret, i;
PER_PAGE_DEBUG("Userfaultfd %s mode, faults resolved with %s\n",
is_minor ? "MINOR" : "MISSING",
is_minor ? "UFFDIO_CONINUE" : "UFFDIO_COPY");
uffd_desc = malloc(sizeof(struct uffd_desc));
- TEST_ASSERT(uffd_desc, "malloc failed");
+ TEST_ASSERT(uffd_desc, "Failed to malloc uffd descriptor");
+
+ uffd_desc->pipefds = calloc(sizeof(int), num_readers);
+ TEST_ASSERT(uffd_desc->pipefds, "Failed to alloc pipes");
+
+ uffd_desc->readers = calloc(sizeof(pthread_t), num_readers);
+ TEST_ASSERT(uffd_desc->readers, "Failed to alloc reader threads");
+
+ uffd_desc->reader_args = calloc(sizeof(struct uffd_reader_args), num_readers);
+ TEST_ASSERT(uffd_desc->reader_args, "Failed to alloc reader_args");
+
+ uffd_desc->num_readers = num_readers;
/* In order to get minor faults, prefault via the alias. */
if (is_minor)
@@ -148,18 +151,28 @@ struct uffd_desc *uffd_setup_demand_paging(int uffd_mode, useconds_t delay,
TEST_ASSERT((uffdio_register.ioctls & expected_ioctls) ==
expected_ioctls, "missing userfaultfd ioctls");
- ret = pipe2(uffd_desc->pipefds, O_CLOEXEC | O_NONBLOCK);
- TEST_ASSERT(!ret, "Failed to set up pipefd");
-
- uffd_desc->uffd_mode = uffd_mode;
uffd_desc->uffd = uffd;
- uffd_desc->delay = delay;
- uffd_desc->handler = handler;
- pthread_create(&uffd_desc->thread, NULL, uffd_handler_thread_fn,
- uffd_desc);
+ for (i = 0; i < uffd_desc->num_readers; ++i) {
+ int pipes[2];
- PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n",
- hva, hva + len);
+ ret = pipe2((int *) &pipes, O_CLOEXEC | O_NONBLOCK);
+ TEST_ASSERT(!ret, "Failed to set up pipefd %i for uffd_desc %p",
+ i, uffd_desc);
+
+ uffd_desc->pipefds[i] = pipes[1];
+
+ uffd_desc->reader_args[i].uffd_mode = uffd_mode;
+ uffd_desc->reader_args[i].uffd = uffd;
+ uffd_desc->reader_args[i].delay = delay;
+ uffd_desc->reader_args[i].handler = handler;
+ uffd_desc->reader_args[i].pipe = pipes[0];
+
+ pthread_create(&uffd_desc->readers[i], NULL, uffd_handler_thread_fn,
+ &uffd_desc->reader_args[i]);
+
+ PER_VCPU_DEBUG("Created uffd thread %i for HVA range [%p, %p)\n",
+ i, hva, hva + len);
+ }
return uffd_desc;
}
@@ -167,19 +180,26 @@ struct uffd_desc *uffd_setup_demand_paging(int uffd_mode, useconds_t delay,
void uffd_stop_demand_paging(struct uffd_desc *uffd)
{
char c = 0;
- int ret;
+ int i;
- ret = write(uffd->pipefds[1], &c, 1);
- TEST_ASSERT(ret == 1, "Unable to write to pipefd");
+ for (i = 0; i < uffd->num_readers; ++i)
+ TEST_ASSERT(write(uffd->pipefds[i], &c, 1) == 1,
+ "Unable to write to pipefd %i for uffd_desc %p", i, uffd);
- ret = pthread_join(uffd->thread, NULL);
- TEST_ASSERT(ret == 0, "Pthread_join failed.");
+ for (i = 0; i < uffd->num_readers; ++i)
+ TEST_ASSERT(!pthread_join(uffd->readers[i], NULL),
+ "Pthread_join failed on reader %i for uffd_desc %p", i, uffd);
close(uffd->uffd);
- close(uffd->pipefds[1]);
- close(uffd->pipefds[0]);
+ for (i = 0; i < uffd->num_readers; ++i) {
+ close(uffd->pipefds[i]);
+ close(uffd->reader_args[i].pipe);
+ }
+ free(uffd->pipefds);
+ free(uffd->readers);
+ free(uffd->reader_args);
free(uffd);
}
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