Hi all,

Today's linux-next merge of the kvm-arm tree got conflicts in:

  tools/testing/selftests/kvm/Makefile
  tools/testing/selftests/kvm/demand_paging_test.c

between commit:

  7812d80c0f89 ("KVM: selftests: Rename perf_test_util symbols to memstress")
  7046638192d5 ("KVM: selftests: Consolidate common code for populating ucall struct")

from the kvm tree and commit:

  a93871d0ea9f ("KVM: selftests: Add a userfaultfd library")

from the kvm-arm tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc tools/testing/selftests/kvm/Makefile
index 2275ba861e0e,1d85b8e218a0..000000000000
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@@ -47,7 -47,7 +47,8 @@@ LIBKVM += lib/memstress.
  LIBKVM += lib/rbtree.c
  LIBKVM += lib/sparsebit.c
  LIBKVM += lib/test_util.c
 +LIBKVM += lib/ucall_common.c
+ LIBKVM += lib/userfaultfd_util.c
  
  LIBKVM_STRING += lib/string_override.c
  
diff --cc tools/testing/selftests/kvm/demand_paging_test.c
index 3a977ddf07b2,8e1fe4ffcccd..000000000000
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@@ -20,8 -20,9 +20,9 @@@
  
  #include "kvm_util.h"
  #include "test_util.h"
 -#include "perf_test_util.h"
 +#include "memstress.h"
  #include "guest_modes.h"
+ #include "userfaultfd_util.h"
  
  #ifdef __NR_userfaultfd
  
@@@ -270,22 -129,13 +129,13 @@@ static void prefault_mem(void *alias, u
  static void run_test(enum vm_guest_mode mode, void *arg)
  {
  	struct test_params *p = arg;
- 	pthread_t *uffd_handler_threads = NULL;
- 	struct uffd_handler_args *uffd_args = NULL;
+ 	struct uffd_desc **uffd_descs = NULL;
  	struct timespec start;
  	struct timespec ts_diff;
- 	int *pipefds = NULL;
  	struct kvm_vm *vm;
- 	int r, i;
+ 	int i;
  
 -	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
 +	vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
  				 p->src_type, p->partition_vcpu_memory_access);
  
  	demand_paging_size = get_backing_src_pagesz(p->src_type);
@@@ -296,18 -146,11 +146,11 @@@
  	memset(guest_data_prototype, 0xAB, demand_paging_size);
  
  	if (p->uffd_mode) {
- 		uffd_handler_threads =
- 			malloc(nr_vcpus * sizeof(*uffd_handler_threads));
- 		TEST_ASSERT(uffd_handler_threads, "Memory allocation failed");
- 
- 		uffd_args = malloc(nr_vcpus * sizeof(*uffd_args));
- 		TEST_ASSERT(uffd_args, "Memory allocation failed");
- 
- 		pipefds = malloc(sizeof(int) * nr_vcpus * 2);
- 		TEST_ASSERT(pipefds, "Unable to allocate memory for pipefd");
+ 		uffd_descs = malloc(nr_vcpus * sizeof(struct uffd_desc *));
+ 		TEST_ASSERT(uffd_descs, "Memory allocation failed");
  
  		for (i = 0; i < nr_vcpus; i++) {
 -			struct perf_test_vcpu_args *vcpu_args;
 +			struct memstress_vcpu_args *vcpu_args;
  			void *vcpu_hva;
  			void *vcpu_alias;
  
@@@ -321,15 -167,10 +167,10 @@@
  			 * Set up user fault fd to handle demand paging
  			 * requests.
  			 */
- 			r = pipe2(&pipefds[i * 2],
- 				  O_CLOEXEC | O_NONBLOCK);
- 			TEST_ASSERT(!r, "Failed to set up pipefd");
- 
- 			setup_demand_paging(vm, &uffd_handler_threads[i],
- 					    pipefds[i * 2], p->uffd_mode,
- 					    p->uffd_delay, &uffd_args[i],
- 					    vcpu_hva, vcpu_alias,
- 					    vcpu_args->pages * memstress_args.guest_page_size);
+ 			uffd_descs[i] = uffd_setup_demand_paging(
+ 				p->uffd_mode, p->uffd_delay, vcpu_hva,
 -				vcpu_args->pages * perf_test_args.guest_page_size,
++				vcpu_args->pages * memstress_args.guest_page_size,
+ 				&handle_uffd_page_request);
  		}
  	}
  
@@@ -358,17 -193,14 +193,14 @@@
  	pr_info("Total guest execution time: %ld.%.9lds\n",
  		ts_diff.tv_sec, ts_diff.tv_nsec);
  	pr_info("Overall demand paging rate: %f pgs/sec\n",
 -		perf_test_args.vcpu_args[0].pages * nr_vcpus /
 +		memstress_args.vcpu_args[0].pages * nr_vcpus /
  		((double)ts_diff.tv_sec + (double)ts_diff.tv_nsec / 100000000.0));
  
 -	perf_test_destroy_vm(vm);
 +	memstress_destroy_vm(vm);
  
  	free(guest_data_prototype);
- 	if (p->uffd_mode) {
- 		free(uffd_handler_threads);
- 		free(uffd_args);
- 		free(pipefds);
- 	}
+ 	if (p->uffd_mode)
+ 		free(uffd_descs);
  }
  
  static void help(char *name)