[PATCH v3 00/13] KVM: selftests: Add aarch64/page_fault_test

[PATCH v3 00/13] KVM: selftests: Add aarch64/page_fault_test

[Ricardo Koller]

This series adds a new aarch64 selftest for testing stage 2 fault handling for
various combinations of guest accesses (e.g., write, S1PTW), backing sources
(e.g., anon), and types of faults (e.g., read on hugetlbfs with a hole, write
on a readonly memslot). Each test tries a different combination and then checks
that the access results in the right behavior (e.g., uffd faults with the right
address and write/read flag). Some interesting combinations are:

- loading an instruction leads to a stage 1 page-table-walk that misses on
  stage 2 because the backing memslot for the page table it not in host memory
  (a hole was punched right there) and the fault is handled using userfaultfd.
  The expected behavior is that this leads to a userfaultfd fault marked as a
  write. See commit c4ad98e4b72c ("KVM: arm64: Assume write fault on S1PTW
  permission fault on instruction fetch") for why that's a write.
- a cas (compare-and-swap) on a readonly memslot leads to a failed vcpu run.
- write-faulting on a memslot that's marked for userfaultfd handling and dirty
  logging should result in a uffd fault and having the respective bit set in
  the dirty log.

The first 8 commits of this series add library support. The first one adds a
new userfaultfd library (out of demand_paging_test.c). The next 3 add some
library functions to get the GPA of a PTE, and to get the fd of a backing
source. Commit 6 fixes a leaked fd when using shared backing stores. The last 5
commits add the new selftest, one type of test at a time. It first adds core
tests, then uffd, then dirty logging, then readonly memslots tests, and finally
combinations of the previous ones (like uffd and dirty logging at the same
time).

v2 -> v3:
Thank you very much Oliver and Ben
- collected r-b's from Ben. [Ben]
- moved some defitions (like TCR_EL1_HA) to common headers. [Oliver]
- use FIELD_GET and ARM64_FEATURE_MASK. [Oliver]
- put test data in a macro. [Oliver]
- check for DCZID_EL1.DZP=0b0 before using "dc zva". [Oliver]
- various new comments. [Oliver]
- use 'asm' instead of hand assembly. [Oliver]
- don't copy test descriptors into the guest. [Oliver]
- rename large_page_size into backing_page_size. [Oliver]
- add enumeration for memory types (4 is MT_NORMAL). [Oliver]
- refactored the test macro definitions.

v1 -> v2: https://lore.kernel.org/kvmarm/20220323225405.267155-1-ricarkol@google.com/
- collect r-b from Ben for the memslot lib commit. [Ben]
- move userfaultfd desc struct to header. [Ben]
- move commit "KVM: selftests: Add vm_mem_region_get_src_fd library function"
  to right before it's used. [Ben]
- nit: wrong indentation in patch 6. [Ben]

Ricardo Koller (13):
  KVM: selftests: Add a userfaultfd library
  KVM: selftests: aarch64: Add vm_get_pte_gpa library function
  KVM: selftests: Add vm_alloc_page_table_in_memslot library function
  KVM: selftests: aarch64: Export _virt_pg_map with a pt_memslot arg
  KVM: selftests: Add missing close and munmap in __vm_mem_region_delete
  KVM: selftests: Add vm_mem_region_get_src_fd library function
  KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h
    macros
  tools: Copy bitfield.h from the kernel sources
  KVM: selftests: aarch64: Add aarch64/page_fault_test
  KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test
  KVM: selftests: aarch64: Add dirty logging tests into page_fault_test
  KVM: selftests: aarch64: Add readonly memslot tests into
    page_fault_test
  KVM: selftests: aarch64: Add mix of tests into page_fault_test

 tools/include/linux/bitfield.h                |  176 +++
 tools/testing/selftests/kvm/Makefile          |    3 +-
 .../selftests/kvm/aarch64/page_fault_test.c   | 1255 +++++++++++++++++
 .../selftests/kvm/demand_paging_test.c        |  227 +--
 .../selftests/kvm/include/aarch64/processor.h |   35 +-
 .../selftests/kvm/include/kvm_util_base.h     |    2 +
 .../selftests/kvm/include/userfaultfd_util.h  |   47 +
 .../selftests/kvm/lib/aarch64/processor.c     |   38 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    |   37 +-
 .../selftests/kvm/lib/userfaultfd_util.c      |  187 +++
 10 files changed, 1792 insertions(+), 215 deletions(-)
 create mode 100644 tools/include/linux/bitfield.h
 create mode 100644 tools/testing/selftests/kvm/aarch64/page_fault_test.c
 create mode 100644 tools/testing/selftests/kvm/include/userfaultfd_util.h
 create mode 100644 tools/testing/selftests/kvm/lib/userfaultfd_util.c

-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 00/13] KVM: selftests: Add aarch64/page_fault_test

[Ricardo Koller]

This series adds a new aarch64 selftest for testing stage 2 fault handling for
various combinations of guest accesses (e.g., write, S1PTW), backing sources
(e.g., anon), and types of faults (e.g., read on hugetlbfs with a hole, write
on a readonly memslot). Each test tries a different combination and then checks
that the access results in the right behavior (e.g., uffd faults with the right
address and write/read flag). Some interesting combinations are:

- loading an instruction leads to a stage 1 page-table-walk that misses on
  stage 2 because the backing memslot for the page table it not in host memory
  (a hole was punched right there) and the fault is handled using userfaultfd.
  The expected behavior is that this leads to a userfaultfd fault marked as a
  write. See commit c4ad98e4b72c ("KVM: arm64: Assume write fault on S1PTW
  permission fault on instruction fetch") for why that's a write.
- a cas (compare-and-swap) on a readonly memslot leads to a failed vcpu run.
- write-faulting on a memslot that's marked for userfaultfd handling and dirty
  logging should result in a uffd fault and having the respective bit set in
  the dirty log.

The first 8 commits of this series add library support. The first one adds a
new userfaultfd library (out of demand_paging_test.c). The next 3 add some
library functions to get the GPA of a PTE, and to get the fd of a backing
source. Commit 6 fixes a leaked fd when using shared backing stores. The last 5
commits add the new selftest, one type of test at a time. It first adds core
tests, then uffd, then dirty logging, then readonly memslots tests, and finally
combinations of the previous ones (like uffd and dirty logging at the same
time).

v2 -> v3:
Thank you very much Oliver and Ben
- collected r-b's from Ben. [Ben]
- moved some defitions (like TCR_EL1_HA) to common headers. [Oliver]
- use FIELD_GET and ARM64_FEATURE_MASK. [Oliver]
- put test data in a macro. [Oliver]
- check for DCZID_EL1.DZP=0b0 before using "dc zva". [Oliver]
- various new comments. [Oliver]
- use 'asm' instead of hand assembly. [Oliver]
- don't copy test descriptors into the guest. [Oliver]
- rename large_page_size into backing_page_size. [Oliver]
- add enumeration for memory types (4 is MT_NORMAL). [Oliver]
- refactored the test macro definitions.

v1 -> v2: https://lore.kernel.org/kvmarm/20220323225405.267155-1-ricarkol@google.com/
- collect r-b from Ben for the memslot lib commit. [Ben]
- move userfaultfd desc struct to header. [Ben]
- move commit "KVM: selftests: Add vm_mem_region_get_src_fd library function"
  to right before it's used. [Ben]
- nit: wrong indentation in patch 6. [Ben]

Ricardo Koller (13):
  KVM: selftests: Add a userfaultfd library
  KVM: selftests: aarch64: Add vm_get_pte_gpa library function
  KVM: selftests: Add vm_alloc_page_table_in_memslot library function
  KVM: selftests: aarch64: Export _virt_pg_map with a pt_memslot arg
  KVM: selftests: Add missing close and munmap in __vm_mem_region_delete
  KVM: selftests: Add vm_mem_region_get_src_fd library function
  KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h
    macros
  tools: Copy bitfield.h from the kernel sources
  KVM: selftests: aarch64: Add aarch64/page_fault_test
  KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test
  KVM: selftests: aarch64: Add dirty logging tests into page_fault_test
  KVM: selftests: aarch64: Add readonly memslot tests into
    page_fault_test
  KVM: selftests: aarch64: Add mix of tests into page_fault_test

 tools/include/linux/bitfield.h                |  176 +++
 tools/testing/selftests/kvm/Makefile          |    3 +-
 .../selftests/kvm/aarch64/page_fault_test.c   | 1255 +++++++++++++++++
 .../selftests/kvm/demand_paging_test.c        |  227 +--
 .../selftests/kvm/include/aarch64/processor.h |   35 +-
 .../selftests/kvm/include/kvm_util_base.h     |    2 +
 .../selftests/kvm/include/userfaultfd_util.h  |   47 +
 .../selftests/kvm/lib/aarch64/processor.c     |   38 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    |   37 +-
 .../selftests/kvm/lib/userfaultfd_util.c      |  187 +++
 10 files changed, 1792 insertions(+), 215 deletions(-)
 create mode 100644 tools/include/linux/bitfield.h
 create mode 100644 tools/testing/selftests/kvm/aarch64/page_fault_test.c
 create mode 100644 tools/testing/selftests/kvm/include/userfaultfd_util.h
 create mode 100644 tools/testing/selftests/kvm/lib/userfaultfd_util.c

-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 01/13] KVM: selftests: Add a userfaultfd library

[Ricardo Koller]

Move the generic userfaultfd code out of demand_paging_test.c into a
common library, userfaultfd_util. This library consists of a setup and a
stop function. The setup function starts a thread for handling page
faults using the handler callback function. This setup returns a
uffd_desc object which is then used in the stop function (to wait and
destroy the threads).

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/Makefile          |   2 +-
 .../selftests/kvm/demand_paging_test.c        | 227 +++---------------
 .../selftests/kvm/include/userfaultfd_util.h  |  47 ++++
 .../selftests/kvm/lib/userfaultfd_util.c      | 187 +++++++++++++++
 4 files changed, 264 insertions(+), 199 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/userfaultfd_util.h
 create mode 100644 tools/testing/selftests/kvm/lib/userfaultfd_util.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 0e4926bc9a58..bc5f89b3700e 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -37,7 +37,7 @@ ifeq ($(ARCH),riscv)
 	UNAME_M := riscv
 endif
 
-LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/rbtree.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c
+LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/rbtree.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c lib/userfaultfd_util.c
 LIBKVM_x86_64 = lib/x86_64/apic.c lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S
 LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handlers.S lib/aarch64/spinlock.c lib/aarch64/gic.c lib/aarch64/gic_v3.c lib/aarch64/vgic.c
 LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index 6a719d065599..b3d457cecd68 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -22,23 +22,13 @@
 #include "test_util.h"
 #include "perf_test_util.h"
 #include "guest_modes.h"
+#include "userfaultfd_util.h"
 
 #ifdef __NR_userfaultfd
 
-#ifdef PRINT_PER_PAGE_UPDATES
-#define PER_PAGE_DEBUG(...) printf(__VA_ARGS__)
-#else
-#define PER_PAGE_DEBUG(...) _no_printf(__VA_ARGS__)
-#endif
-
-#ifdef PRINT_PER_VCPU_UPDATES
-#define PER_VCPU_DEBUG(...) printf(__VA_ARGS__)
-#else
-#define PER_VCPU_DEBUG(...) _no_printf(__VA_ARGS__)
-#endif
-
 static int nr_vcpus = 1;
 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
+
 static size_t demand_paging_size;
 static char *guest_data_prototype;
 
@@ -69,9 +59,11 @@ static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
 		       ts_diff.tv_sec, ts_diff.tv_nsec);
 }
 
-static int handle_uffd_page_request(int uffd_mode, int uffd, uint64_t addr)
+static int handle_uffd_page_request(int uffd_mode, int uffd,
+		struct uffd_msg *msg)
 {
 	pid_t tid = syscall(__NR_gettid);
+	uint64_t addr = msg->arg.pagefault.address;
 	struct timespec start;
 	struct timespec ts_diff;
 	int r;
@@ -118,175 +110,32 @@ static int handle_uffd_page_request(int uffd_mode, int uffd, uint64_t addr)
 	return 0;
 }
 
-bool quit_uffd_thread;
-
-struct uffd_handler_args {
+struct test_params {
 	int uffd_mode;
-	int uffd;
-	int pipefd;
-	useconds_t delay;
+	useconds_t uffd_delay;
+	enum vm_mem_backing_src_type src_type;
+	bool partition_vcpu_memory_access;
 };
 
-static void *uffd_handler_thread_fn(void *arg)
+static void prefault_mem(void *alias, uint64_t len)
 {
-	struct uffd_handler_args *uffd_args = (struct uffd_handler_args *)arg;
-	int uffd = uffd_args->uffd;
-	int pipefd = uffd_args->pipefd;
-	useconds_t delay = uffd_args->delay;
-	int64_t pages = 0;
-	struct timespec start;
-	struct timespec ts_diff;
-
-	clock_gettime(CLOCK_MONOTONIC, &start);
-	while (!quit_uffd_thread) {
-		struct uffd_msg msg;
-		struct pollfd pollfd[2];
-		char tmp_chr;
-		int r;
-		uint64_t addr;
-
-		pollfd[0].fd = uffd;
-		pollfd[0].events = POLLIN;
-		pollfd[1].fd = pipefd;
-		pollfd[1].events = POLLIN;
-
-		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 (pollfd[1].revents & POLLIN) {
-			r = read(pollfd[1].fd, &tmp_chr, 1);
-			TEST_ASSERT(r == 1,
-				    "Error reading pipefd in UFFD thread\n");
-			return NULL;
-		}
-
-		if (!(pollfd[0].revents & POLLIN))
-			continue;
-
-		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;
-		}
-
-		if (r != sizeof(msg)) {
-			pr_info("Read on uffd returned unexpected size: %d bytes", r);
-			return NULL;
-		}
-
-		if (!(msg.event & UFFD_EVENT_PAGEFAULT))
-			continue;
+	size_t p;
 
-		if (delay)
-			usleep(delay);
-		addr =  msg.arg.pagefault.address;
-		r = handle_uffd_page_request(uffd_args->uffd_mode, uffd, addr);
-		if (r < 0)
-			return NULL;
-		pages++;
+	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);
 	}
-
-	ts_diff = timespec_elapsed(start);
-	PER_VCPU_DEBUG("userfaulted %ld pages over %ld.%.9lds. (%f/sec)\n",
-		       pages, ts_diff.tv_sec, ts_diff.tv_nsec,
-		       pages / ((double)ts_diff.tv_sec + (double)ts_diff.tv_nsec / 100000000.0));
-
-	return NULL;
 }
 
-static void setup_demand_paging(struct kvm_vm *vm,
-				pthread_t *uffd_handler_thread, int pipefd,
-				int uffd_mode, useconds_t uffd_delay,
-				struct uffd_handler_args *uffd_args,
-				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);
-
-	uffdio_api.api = UFFD_API;
-	uffdio_api.features = 0;
-	TEST_ASSERT(ioctl(uffd, UFFDIO_API, &uffdio_api) != -1,
-		    "ioctl UFFDIO_API failed: %" PRIu64,
-		    (uint64_t)uffdio_api.api);
-
-	uffdio_register.range.start = (uint64_t)hva;
-	uffdio_register.range.len = len;
-	uffdio_register.mode = uffd_mode;
-	TEST_ASSERT(ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) != -1,
-		    "ioctl UFFDIO_REGISTER failed");
-	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;
-	pthread_create(uffd_handler_thread, NULL, uffd_handler_thread_fn,
-		       uffd_args);
-
-	PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n",
-		       hva, hva + len);
-}
-
-struct test_params {
-	int uffd_mode;
-	useconds_t uffd_delay;
-	enum vm_mem_backing_src_type src_type;
-	bool partition_vcpu_memory_access;
-};
-
 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 vcpu_id;
-	int r;
 
 	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
 				 p->src_type, p->partition_vcpu_memory_access);
@@ -299,15 +148,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	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 (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 			struct perf_test_vcpu_args *vcpu_args;
@@ -320,19 +162,17 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 			vcpu_hva = addr_gpa2hva(vm, vcpu_args->gpa);
 			vcpu_alias = addr_gpa2alias(vm, vcpu_args->gpa);
 
+			prefault_mem(vcpu_alias,
+				vcpu_args->pages * perf_test_args.guest_page_size);
+
 			/*
 			 * Set up user fault fd to handle demand paging
 			 * requests.
 			 */
-			r = pipe2(&pipefds[vcpu_id * 2],
-				  O_CLOEXEC | O_NONBLOCK);
-			TEST_ASSERT(!r, "Failed to set up pipefd");
-
-			setup_demand_paging(vm, &uffd_handler_threads[vcpu_id],
-					    pipefds[vcpu_id * 2], p->uffd_mode,
-					    p->uffd_delay, &uffd_args[vcpu_id],
-					    vcpu_hva, vcpu_alias,
-					    vcpu_args->pages * perf_test_args.guest_page_size);
+			uffd_descs[vcpu_id] = uffd_setup_demand_paging(
+				p->uffd_mode, p->uffd_delay, vcpu_hva,
+				vcpu_args->pages * perf_test_args.guest_page_size,
+				&handle_uffd_page_request);
 		}
 	}
 
@@ -347,15 +187,9 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	pr_info("All vCPU threads joined\n");
 
 	if (p->uffd_mode) {
-		char c;
-
 		/* Tell the user fault fd handler threads to quit */
-		for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
-			r = write(pipefds[vcpu_id * 2 + 1], &c, 1);
-			TEST_ASSERT(r == 1, "Unable to write to pipefd");
-
-			pthread_join(uffd_handler_threads[vcpu_id], NULL);
-		}
+		for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
+			uffd_stop_demand_paging(uffd_descs[vcpu_id]);
 	}
 
 	pr_info("Total guest execution time: %ld.%.9lds\n",
@@ -367,11 +201,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	perf_test_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)
diff --git a/tools/testing/selftests/kvm/include/userfaultfd_util.h b/tools/testing/selftests/kvm/include/userfaultfd_util.h
new file mode 100644
index 000000000000..dffb4e768d56
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/userfaultfd_util.h
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM userfaultfd util
+ * Adapted from demand_paging_test.c
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ * Copyright (C) 2019, Google, Inc.
+ * Copyright (C) 2022, Google, Inc.
+ */
+
+#define _GNU_SOURCE /* for pipe2 */
+
+#include <inttypes.h>
+#include <time.h>
+#include <pthread.h>
+#include <linux/userfaultfd.h>
+
+#include "test_util.h"
+
+typedef int (*uffd_handler_t)(int uffd_mode, int uffd, struct uffd_msg *msg);
+
+struct uffd_desc {
+	int uffd_mode;
+	int uffd;
+	int pipefds[2];
+	useconds_t delay;
+	uffd_handler_t handler;
+	pthread_t thread;
+};
+
+struct uffd_desc *uffd_setup_demand_paging(int uffd_mode,
+		useconds_t uffd_delay, void *hva, uint64_t len,
+		uffd_handler_t handler);
+
+void uffd_stop_demand_paging(struct uffd_desc *uffd);
+
+#ifdef PRINT_PER_PAGE_UPDATES
+#define PER_PAGE_DEBUG(...) printf(__VA_ARGS__)
+#else
+#define PER_PAGE_DEBUG(...) _no_printf(__VA_ARGS__)
+#endif
+
+#ifdef PRINT_PER_VCPU_UPDATES
+#define PER_VCPU_DEBUG(...) printf(__VA_ARGS__)
+#else
+#define PER_VCPU_DEBUG(...) _no_printf(__VA_ARGS__)
+#endif
diff --git a/tools/testing/selftests/kvm/lib/userfaultfd_util.c b/tools/testing/selftests/kvm/lib/userfaultfd_util.c
new file mode 100644
index 000000000000..4395032ccbe4
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/userfaultfd_util.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM userfaultfd util
+ * Adapted from demand_paging_test.c
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ * Copyright (C) 2019, Google, Inc.
+ * Copyright (C) 2022, Google, Inc.
+ */
+
+#define _GNU_SOURCE /* for pipe2 */
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <poll.h>
+#include <pthread.h>
+#include <linux/userfaultfd.h>
+#include <sys/syscall.h>
+
+#include "kvm_util.h"
+#include "test_util.h"
+#include "perf_test_util.h"
+#include "userfaultfd_util.h"
+
+#ifdef __NR_userfaultfd
+
+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;
+	int64_t pages = 0;
+	struct timespec start;
+	struct timespec ts_diff;
+
+	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 = 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 (pollfd[1].revents & POLLIN) {
+			r = read(pollfd[1].fd, &tmp_chr, 1);
+			TEST_ASSERT(r == 1,
+				    "Error reading pipefd in UFFD thread\n");
+			return NULL;
+		}
+
+		if (!(pollfd[0].revents & POLLIN))
+			continue;
+
+		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;
+		}
+
+		if (r != sizeof(msg)) {
+			pr_info("Read on uffd returned unexpected size: %d bytes", r);
+			return NULL;
+		}
+
+		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;
+		pages++;
+	}
+
+	ts_diff = timespec_elapsed(start);
+	PER_VCPU_DEBUG("userfaulted %ld pages over %ld.%.9lds. (%f/sec)\n",
+		       pages, ts_diff.tv_sec, ts_diff.tv_nsec,
+		       pages / ((double)ts_diff.tv_sec + (double)ts_diff.tv_nsec / 100000000.0));
+
+	return NULL;
+}
+
+struct uffd_desc *uffd_setup_demand_paging(int uffd_mode,
+		useconds_t uffd_delay, void *hva, uint64_t len,
+		uffd_handler_t handler)
+{
+	struct uffd_desc *uffd_desc;
+	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;
+	int ret;
+
+	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");
+
+	/* In order to get minor faults, prefault via the alias. */
+	if (is_minor)
+		expected_ioctls = ((uint64_t) 1) << _UFFDIO_CONTINUE;
+
+	uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+	TEST_ASSERT(uffd >= 0, "uffd creation failed, errno: %d", errno);
+
+	uffdio_api.api = UFFD_API;
+	uffdio_api.features = 0;
+	TEST_ASSERT(ioctl(uffd, UFFDIO_API, &uffdio_api) != -1,
+		    "ioctl UFFDIO_API failed: %" PRIu64,
+		    (uint64_t)uffdio_api.api);
+
+	uffdio_register.range.start = (uint64_t)hva;
+	uffdio_register.range.len = len;
+	uffdio_register.mode = uffd_mode;
+	TEST_ASSERT(ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) != -1,
+		    "ioctl UFFDIO_REGISTER failed");
+	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 = uffd_delay;
+	uffd_desc->handler = handler;
+	pthread_create(&uffd_desc->thread, NULL, uffd_handler_thread_fn,
+		       uffd_desc);
+
+	PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n",
+		       hva, hva + len);
+
+	return uffd_desc;
+}
+
+void uffd_stop_demand_paging(struct uffd_desc *uffd)
+{
+	char c = 0;
+	int ret;
+
+	ret = write(uffd->pipefds[1], &c, 1);
+	TEST_ASSERT(ret == 1, "Unable to write to pipefd");
+
+	ret = pthread_join(uffd->thread, NULL);
+	TEST_ASSERT(ret == 0, "Pthread_join failed.");
+
+	close(uffd->uffd);
+
+	close(uffd->pipefds[1]);
+	close(uffd->pipefds[0]);
+
+	free(uffd);
+}
+
+#endif /* __NR_userfaultfd */
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 01/13] KVM: selftests: Add a userfaultfd library

[Ricardo Koller]

Move the generic userfaultfd code out of demand_paging_test.c into a
common library, userfaultfd_util. This library consists of a setup and a
stop function. The setup function starts a thread for handling page
faults using the handler callback function. This setup returns a
uffd_desc object which is then used in the stop function (to wait and
destroy the threads).

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/Makefile          |   2 +-
 .../selftests/kvm/demand_paging_test.c        | 227 +++---------------
 .../selftests/kvm/include/userfaultfd_util.h  |  47 ++++
 .../selftests/kvm/lib/userfaultfd_util.c      | 187 +++++++++++++++
 4 files changed, 264 insertions(+), 199 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/userfaultfd_util.h
 create mode 100644 tools/testing/selftests/kvm/lib/userfaultfd_util.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 0e4926bc9a58..bc5f89b3700e 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -37,7 +37,7 @@ ifeq ($(ARCH),riscv)
 	UNAME_M := riscv
 endif
 
-LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/rbtree.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c
+LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/rbtree.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c lib/userfaultfd_util.c
 LIBKVM_x86_64 = lib/x86_64/apic.c lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S
 LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handlers.S lib/aarch64/spinlock.c lib/aarch64/gic.c lib/aarch64/gic_v3.c lib/aarch64/vgic.c
 LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index 6a719d065599..b3d457cecd68 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -22,23 +22,13 @@
 #include "test_util.h"
 #include "perf_test_util.h"
 #include "guest_modes.h"
+#include "userfaultfd_util.h"
 
 #ifdef __NR_userfaultfd
 
-#ifdef PRINT_PER_PAGE_UPDATES
-#define PER_PAGE_DEBUG(...) printf(__VA_ARGS__)
-#else
-#define PER_PAGE_DEBUG(...) _no_printf(__VA_ARGS__)
-#endif
-
-#ifdef PRINT_PER_VCPU_UPDATES
-#define PER_VCPU_DEBUG(...) printf(__VA_ARGS__)
-#else
-#define PER_VCPU_DEBUG(...) _no_printf(__VA_ARGS__)
-#endif
-
 static int nr_vcpus = 1;
 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
+
 static size_t demand_paging_size;
 static char *guest_data_prototype;
 
@@ -69,9 +59,11 @@ static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
 		       ts_diff.tv_sec, ts_diff.tv_nsec);
 }
 
-static int handle_uffd_page_request(int uffd_mode, int uffd, uint64_t addr)
+static int handle_uffd_page_request(int uffd_mode, int uffd,
+		struct uffd_msg *msg)
 {
 	pid_t tid = syscall(__NR_gettid);
+	uint64_t addr = msg->arg.pagefault.address;
 	struct timespec start;
 	struct timespec ts_diff;
 	int r;
@@ -118,175 +110,32 @@ static int handle_uffd_page_request(int uffd_mode, int uffd, uint64_t addr)
 	return 0;
 }
 
-bool quit_uffd_thread;
-
-struct uffd_handler_args {
+struct test_params {
 	int uffd_mode;
-	int uffd;
-	int pipefd;
-	useconds_t delay;
+	useconds_t uffd_delay;
+	enum vm_mem_backing_src_type src_type;
+	bool partition_vcpu_memory_access;
 };
 
-static void *uffd_handler_thread_fn(void *arg)
+static void prefault_mem(void *alias, uint64_t len)
 {
-	struct uffd_handler_args *uffd_args = (struct uffd_handler_args *)arg;
-	int uffd = uffd_args->uffd;
-	int pipefd = uffd_args->pipefd;
-	useconds_t delay = uffd_args->delay;
-	int64_t pages = 0;
-	struct timespec start;
-	struct timespec ts_diff;
-
-	clock_gettime(CLOCK_MONOTONIC, &start);
-	while (!quit_uffd_thread) {
-		struct uffd_msg msg;
-		struct pollfd pollfd[2];
-		char tmp_chr;
-		int r;
-		uint64_t addr;
-
-		pollfd[0].fd = uffd;
-		pollfd[0].events = POLLIN;
-		pollfd[1].fd = pipefd;
-		pollfd[1].events = POLLIN;
-
-		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 (pollfd[1].revents & POLLIN) {
-			r = read(pollfd[1].fd, &tmp_chr, 1);
-			TEST_ASSERT(r == 1,
-				    "Error reading pipefd in UFFD thread\n");
-			return NULL;
-		}
-
-		if (!(pollfd[0].revents & POLLIN))
-			continue;
-
-		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;
-		}
-
-		if (r != sizeof(msg)) {
-			pr_info("Read on uffd returned unexpected size: %d bytes", r);
-			return NULL;
-		}
-
-		if (!(msg.event & UFFD_EVENT_PAGEFAULT))
-			continue;
+	size_t p;
 
-		if (delay)
-			usleep(delay);
-		addr =  msg.arg.pagefault.address;
-		r = handle_uffd_page_request(uffd_args->uffd_mode, uffd, addr);
-		if (r < 0)
-			return NULL;
-		pages++;
+	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);
 	}
-
-	ts_diff = timespec_elapsed(start);
-	PER_VCPU_DEBUG("userfaulted %ld pages over %ld.%.9lds. (%f/sec)\n",
-		       pages, ts_diff.tv_sec, ts_diff.tv_nsec,
-		       pages / ((double)ts_diff.tv_sec + (double)ts_diff.tv_nsec / 100000000.0));
-
-	return NULL;
 }
 
-static void setup_demand_paging(struct kvm_vm *vm,
-				pthread_t *uffd_handler_thread, int pipefd,
-				int uffd_mode, useconds_t uffd_delay,
-				struct uffd_handler_args *uffd_args,
-				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);
-
-	uffdio_api.api = UFFD_API;
-	uffdio_api.features = 0;
-	TEST_ASSERT(ioctl(uffd, UFFDIO_API, &uffdio_api) != -1,
-		    "ioctl UFFDIO_API failed: %" PRIu64,
-		    (uint64_t)uffdio_api.api);
-
-	uffdio_register.range.start = (uint64_t)hva;
-	uffdio_register.range.len = len;
-	uffdio_register.mode = uffd_mode;
-	TEST_ASSERT(ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) != -1,
-		    "ioctl UFFDIO_REGISTER failed");
-	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;
-	pthread_create(uffd_handler_thread, NULL, uffd_handler_thread_fn,
-		       uffd_args);
-
-	PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n",
-		       hva, hva + len);
-}
-
-struct test_params {
-	int uffd_mode;
-	useconds_t uffd_delay;
-	enum vm_mem_backing_src_type src_type;
-	bool partition_vcpu_memory_access;
-};
-
 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 vcpu_id;
-	int r;
 
 	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
 				 p->src_type, p->partition_vcpu_memory_access);
@@ -299,15 +148,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	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 (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 			struct perf_test_vcpu_args *vcpu_args;
@@ -320,19 +162,17 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 			vcpu_hva = addr_gpa2hva(vm, vcpu_args->gpa);
 			vcpu_alias = addr_gpa2alias(vm, vcpu_args->gpa);
 
+			prefault_mem(vcpu_alias,
+				vcpu_args->pages * perf_test_args.guest_page_size);
+
 			/*
 			 * Set up user fault fd to handle demand paging
 			 * requests.
 			 */
-			r = pipe2(&pipefds[vcpu_id * 2],
-				  O_CLOEXEC | O_NONBLOCK);
-			TEST_ASSERT(!r, "Failed to set up pipefd");
-
-			setup_demand_paging(vm, &uffd_handler_threads[vcpu_id],
-					    pipefds[vcpu_id * 2], p->uffd_mode,
-					    p->uffd_delay, &uffd_args[vcpu_id],
-					    vcpu_hva, vcpu_alias,
-					    vcpu_args->pages * perf_test_args.guest_page_size);
+			uffd_descs[vcpu_id] = uffd_setup_demand_paging(
+				p->uffd_mode, p->uffd_delay, vcpu_hva,
+				vcpu_args->pages * perf_test_args.guest_page_size,
+				&handle_uffd_page_request);
 		}
 	}
 
@@ -347,15 +187,9 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	pr_info("All vCPU threads joined\n");
 
 	if (p->uffd_mode) {
-		char c;
-
 		/* Tell the user fault fd handler threads to quit */
-		for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
-			r = write(pipefds[vcpu_id * 2 + 1], &c, 1);
-			TEST_ASSERT(r == 1, "Unable to write to pipefd");
-
-			pthread_join(uffd_handler_threads[vcpu_id], NULL);
-		}
+		for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
+			uffd_stop_demand_paging(uffd_descs[vcpu_id]);
 	}
 
 	pr_info("Total guest execution time: %ld.%.9lds\n",
@@ -367,11 +201,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	perf_test_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)
diff --git a/tools/testing/selftests/kvm/include/userfaultfd_util.h b/tools/testing/selftests/kvm/include/userfaultfd_util.h
new file mode 100644
index 000000000000..dffb4e768d56
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/userfaultfd_util.h
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM userfaultfd util
+ * Adapted from demand_paging_test.c
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ * Copyright (C) 2019, Google, Inc.
+ * Copyright (C) 2022, Google, Inc.
+ */
+
+#define _GNU_SOURCE /* for pipe2 */
+
+#include <inttypes.h>
+#include <time.h>
+#include <pthread.h>
+#include <linux/userfaultfd.h>
+
+#include "test_util.h"
+
+typedef int (*uffd_handler_t)(int uffd_mode, int uffd, struct uffd_msg *msg);
+
+struct uffd_desc {
+	int uffd_mode;
+	int uffd;
+	int pipefds[2];
+	useconds_t delay;
+	uffd_handler_t handler;
+	pthread_t thread;
+};
+
+struct uffd_desc *uffd_setup_demand_paging(int uffd_mode,
+		useconds_t uffd_delay, void *hva, uint64_t len,
+		uffd_handler_t handler);
+
+void uffd_stop_demand_paging(struct uffd_desc *uffd);
+
+#ifdef PRINT_PER_PAGE_UPDATES
+#define PER_PAGE_DEBUG(...) printf(__VA_ARGS__)
+#else
+#define PER_PAGE_DEBUG(...) _no_printf(__VA_ARGS__)
+#endif
+
+#ifdef PRINT_PER_VCPU_UPDATES
+#define PER_VCPU_DEBUG(...) printf(__VA_ARGS__)
+#else
+#define PER_VCPU_DEBUG(...) _no_printf(__VA_ARGS__)
+#endif
diff --git a/tools/testing/selftests/kvm/lib/userfaultfd_util.c b/tools/testing/selftests/kvm/lib/userfaultfd_util.c
new file mode 100644
index 000000000000..4395032ccbe4
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/userfaultfd_util.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM userfaultfd util
+ * Adapted from demand_paging_test.c
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ * Copyright (C) 2019, Google, Inc.
+ * Copyright (C) 2022, Google, Inc.
+ */
+
+#define _GNU_SOURCE /* for pipe2 */
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <poll.h>
+#include <pthread.h>
+#include <linux/userfaultfd.h>
+#include <sys/syscall.h>
+
+#include "kvm_util.h"
+#include "test_util.h"
+#include "perf_test_util.h"
+#include "userfaultfd_util.h"
+
+#ifdef __NR_userfaultfd
+
+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;
+	int64_t pages = 0;
+	struct timespec start;
+	struct timespec ts_diff;
+
+	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 = 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 (pollfd[1].revents & POLLIN) {
+			r = read(pollfd[1].fd, &tmp_chr, 1);
+			TEST_ASSERT(r == 1,
+				    "Error reading pipefd in UFFD thread\n");
+			return NULL;
+		}
+
+		if (!(pollfd[0].revents & POLLIN))
+			continue;
+
+		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;
+		}
+
+		if (r != sizeof(msg)) {
+			pr_info("Read on uffd returned unexpected size: %d bytes", r);
+			return NULL;
+		}
+
+		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;
+		pages++;
+	}
+
+	ts_diff = timespec_elapsed(start);
+	PER_VCPU_DEBUG("userfaulted %ld pages over %ld.%.9lds. (%f/sec)\n",
+		       pages, ts_diff.tv_sec, ts_diff.tv_nsec,
+		       pages / ((double)ts_diff.tv_sec + (double)ts_diff.tv_nsec / 100000000.0));
+
+	return NULL;
+}
+
+struct uffd_desc *uffd_setup_demand_paging(int uffd_mode,
+		useconds_t uffd_delay, void *hva, uint64_t len,
+		uffd_handler_t handler)
+{
+	struct uffd_desc *uffd_desc;
+	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;
+	int ret;
+
+	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");
+
+	/* In order to get minor faults, prefault via the alias. */
+	if (is_minor)
+		expected_ioctls = ((uint64_t) 1) << _UFFDIO_CONTINUE;
+
+	uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+	TEST_ASSERT(uffd >= 0, "uffd creation failed, errno: %d", errno);
+
+	uffdio_api.api = UFFD_API;
+	uffdio_api.features = 0;
+	TEST_ASSERT(ioctl(uffd, UFFDIO_API, &uffdio_api) != -1,
+		    "ioctl UFFDIO_API failed: %" PRIu64,
+		    (uint64_t)uffdio_api.api);
+
+	uffdio_register.range.start = (uint64_t)hva;
+	uffdio_register.range.len = len;
+	uffdio_register.mode = uffd_mode;
+	TEST_ASSERT(ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) != -1,
+		    "ioctl UFFDIO_REGISTER failed");
+	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 = uffd_delay;
+	uffd_desc->handler = handler;
+	pthread_create(&uffd_desc->thread, NULL, uffd_handler_thread_fn,
+		       uffd_desc);
+
+	PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n",
+		       hva, hva + len);
+
+	return uffd_desc;
+}
+
+void uffd_stop_demand_paging(struct uffd_desc *uffd)
+{
+	char c = 0;
+	int ret;
+
+	ret = write(uffd->pipefds[1], &c, 1);
+	TEST_ASSERT(ret == 1, "Unable to write to pipefd");
+
+	ret = pthread_join(uffd->thread, NULL);
+	TEST_ASSERT(ret == 0, "Pthread_join failed.");
+
+	close(uffd->uffd);
+
+	close(uffd->pipefds[1]);
+	close(uffd->pipefds[0]);
+
+	free(uffd);
+}
+
+#endif /* __NR_userfaultfd */
-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 02/13] KVM: selftests: aarch64: Add vm_get_pte_gpa library function

[Ricardo Koller]

Add a library function (in-guest) to get the GPA of the PTE of a
particular GVA.  This will be used in a future commit by a test to clear
and check the AF (access flag) of a particular page.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/aarch64/processor.h |  2 ++
 .../selftests/kvm/lib/aarch64/processor.c     | 24 +++++++++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 8f9f46979a00..caa572d83062 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -125,6 +125,8 @@ void vm_install_exception_handler(struct kvm_vm *vm,
 void vm_install_sync_handler(struct kvm_vm *vm,
 		int vector, int ec, handler_fn handler);
 
+vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva);
+
 static inline void cpu_relax(void)
 {
 	asm volatile("yield" ::: "memory");
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 9343d82519b4..ee006d354b79 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -139,7 +139,7 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 	_virt_pg_map(vm, vaddr, paddr, attr_idx);
 }
 
-vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 {
 	uint64_t *ptep;
 
@@ -162,7 +162,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 			goto unmapped_gva;
 		/* fall through */
 	case 2:
-		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, gva) * 8;
+		ptep = (uint64_t *)(pte_addr(vm, *ptep) + pte_index(vm, gva) * 8);
 		if (!ptep)
 			goto unmapped_gva;
 		break;
@@ -170,6 +170,26 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 		TEST_FAIL("Page table levels must be 2, 3, or 4");
 	}
 
+	return (vm_paddr_t)ptep;
+
+unmapped_gva:
+	TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
+	exit(1);
+}
+
+vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+{
+	uint64_t *ptep;
+	vm_paddr_t ptep_gpa;
+
+	ptep_gpa = vm_get_pte_gpa(vm, gva);
+	if (!ptep_gpa)
+		goto unmapped_gva;
+
+	ptep = addr_gpa2hva(vm, ptep_gpa);
+	if (!ptep)
+		goto unmapped_gva;
+
 	return pte_addr(vm, *ptep) + (gva & (vm->page_size - 1));
 
 unmapped_gva:
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 02/13] KVM: selftests: aarch64: Add vm_get_pte_gpa library function

[Ricardo Koller]

Add a library function (in-guest) to get the GPA of the PTE of a
particular GVA.  This will be used in a future commit by a test to clear
and check the AF (access flag) of a particular page.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/aarch64/processor.h |  2 ++
 .../selftests/kvm/lib/aarch64/processor.c     | 24 +++++++++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 8f9f46979a00..caa572d83062 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -125,6 +125,8 @@ void vm_install_exception_handler(struct kvm_vm *vm,
 void vm_install_sync_handler(struct kvm_vm *vm,
 		int vector, int ec, handler_fn handler);
 
+vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva);
+
 static inline void cpu_relax(void)
 {
 	asm volatile("yield" ::: "memory");
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 9343d82519b4..ee006d354b79 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -139,7 +139,7 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 	_virt_pg_map(vm, vaddr, paddr, attr_idx);
 }
 
-vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 {
 	uint64_t *ptep;
 
@@ -162,7 +162,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 			goto unmapped_gva;
 		/* fall through */
 	case 2:
-		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, gva) * 8;
+		ptep = (uint64_t *)(pte_addr(vm, *ptep) + pte_index(vm, gva) * 8);
 		if (!ptep)
 			goto unmapped_gva;
 		break;
@@ -170,6 +170,26 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 		TEST_FAIL("Page table levels must be 2, 3, or 4");
 	}
 
+	return (vm_paddr_t)ptep;
+
+unmapped_gva:
+	TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
+	exit(1);
+}
+
+vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+{
+	uint64_t *ptep;
+	vm_paddr_t ptep_gpa;
+
+	ptep_gpa = vm_get_pte_gpa(vm, gva);
+	if (!ptep_gpa)
+		goto unmapped_gva;
+
+	ptep = addr_gpa2hva(vm, ptep_gpa);
+	if (!ptep)
+		goto unmapped_gva;
+
 	return pte_addr(vm, *ptep) + (gva & (vm->page_size - 1));
 
 unmapped_gva:
-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 03/13] KVM: selftests: Add vm_alloc_page_table_in_memslot library function

[Ricardo Koller]

Add a library function to allocate a page-table physical page in a
particular memslot.  The default behavior is to create new page-table
pages in memslot 0.

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/include/kvm_util_base.h | 1 +
 tools/testing/selftests/kvm/lib/kvm_util.c          | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 4ed6aa049a91..3a69b35e37cc 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -306,6 +306,7 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
 vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
 			      vm_paddr_t paddr_min, uint32_t memslot);
 vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm);
+vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot);
 
 /*
  * Create a VM with reasonable defaults
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index d8cf851ab119..e18f1c93e4b4 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2386,9 +2386,15 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
 /* Arbitrary minimum physical address used for virtual translation tables. */
 #define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000
 
+vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot)
+{
+	return vm_phy_page_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR,
+			pt_memslot);
+}
+
 vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm)
 {
-	return vm_phy_page_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR, 0);
+	return vm_alloc_page_table_in_memslot(vm, 0);
 }
 
 /*
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 03/13] KVM: selftests: Add vm_alloc_page_table_in_memslot library function

[Ricardo Koller]

Add a library function to allocate a page-table physical page in a
particular memslot.  The default behavior is to create new page-table
pages in memslot 0.

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/include/kvm_util_base.h | 1 +
 tools/testing/selftests/kvm/lib/kvm_util.c          | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 4ed6aa049a91..3a69b35e37cc 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -306,6 +306,7 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
 vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
 			      vm_paddr_t paddr_min, uint32_t memslot);
 vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm);
+vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot);
 
 /*
  * Create a VM with reasonable defaults
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index d8cf851ab119..e18f1c93e4b4 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2386,9 +2386,15 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
 /* Arbitrary minimum physical address used for virtual translation tables. */
 #define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000
 
+vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot)
+{
+	return vm_phy_page_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR,
+			pt_memslot);
+}
+
 vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm)
 {
-	return vm_phy_page_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR, 0);
+	return vm_alloc_page_table_in_memslot(vm, 0);
 }
 
 /*
-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 04/13] KVM: selftests: aarch64: Export _virt_pg_map with a pt_memslot arg

[Ricardo Koller]

Add an argument, pt_memslot, into _virt_pg_map in order to use a
specific memslot for the page-table allocations performed when creating
a new map. This will be used in a future commit to test having PTEs
stored on memslots with different setups (e.g., hugetlb with a hole).

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/aarch64/processor.h        |  3 +++
 tools/testing/selftests/kvm/lib/aarch64/processor.c  | 12 ++++++------
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index caa572d83062..3965a5ac778e 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -125,6 +125,9 @@ void vm_install_exception_handler(struct kvm_vm *vm,
 void vm_install_sync_handler(struct kvm_vm *vm,
 		int vector, int ec, handler_fn handler);
 
+void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+			 uint64_t flags, uint32_t pt_memslot);
+
 vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva);
 
 static inline void cpu_relax(void)
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index ee006d354b79..8f4ec1be4364 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -86,8 +86,8 @@ void virt_pgd_alloc(struct kvm_vm *vm)
 	}
 }
 
-static void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
-			 uint64_t flags)
+void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+			 uint64_t flags, uint32_t pt_memslot)
 {
 	uint8_t attr_idx = flags & 7;
 	uint64_t *ptep;
@@ -108,18 +108,18 @@ static void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 
 	ptep = addr_gpa2hva(vm, vm->pgd) + pgd_index(vm, vaddr) * 8;
 	if (!*ptep)
-		*ptep = vm_alloc_page_table(vm) | 3;
+		*ptep = vm_alloc_page_table_in_memslot(vm, pt_memslot) | 3;
 
 	switch (vm->pgtable_levels) {
 	case 4:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pud_index(vm, vaddr) * 8;
 		if (!*ptep)
-			*ptep = vm_alloc_page_table(vm) | 3;
+			*ptep = vm_alloc_page_table_in_memslot(vm, pt_memslot) | 3;
 		/* fall through */
 	case 3:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pmd_index(vm, vaddr) * 8;
 		if (!*ptep)
-			*ptep = vm_alloc_page_table(vm) | 3;
+			*ptep = vm_alloc_page_table_in_memslot(vm, pt_memslot) | 3;
 		/* fall through */
 	case 2:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, vaddr) * 8;
@@ -136,7 +136,7 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 {
 	uint64_t attr_idx = 4; /* NORMAL (See DEFAULT_MAIR_EL1) */
 
-	_virt_pg_map(vm, vaddr, paddr, attr_idx);
+	_virt_pg_map(vm, vaddr, paddr, attr_idx, 0);
 }
 
 vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva)
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 04/13] KVM: selftests: aarch64: Export _virt_pg_map with a pt_memslot arg

[Ricardo Koller]

Add an argument, pt_memslot, into _virt_pg_map in order to use a
specific memslot for the page-table allocations performed when creating
a new map. This will be used in a future commit to test having PTEs
stored on memslots with different setups (e.g., hugetlb with a hole).

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/aarch64/processor.h        |  3 +++
 tools/testing/selftests/kvm/lib/aarch64/processor.c  | 12 ++++++------
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index caa572d83062..3965a5ac778e 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -125,6 +125,9 @@ void vm_install_exception_handler(struct kvm_vm *vm,
 void vm_install_sync_handler(struct kvm_vm *vm,
 		int vector, int ec, handler_fn handler);
 
+void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+			 uint64_t flags, uint32_t pt_memslot);
+
 vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva);
 
 static inline void cpu_relax(void)
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index ee006d354b79..8f4ec1be4364 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -86,8 +86,8 @@ void virt_pgd_alloc(struct kvm_vm *vm)
 	}
 }
 
-static void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
-			 uint64_t flags)
+void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+			 uint64_t flags, uint32_t pt_memslot)
 {
 	uint8_t attr_idx = flags & 7;
 	uint64_t *ptep;
@@ -108,18 +108,18 @@ static void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 
 	ptep = addr_gpa2hva(vm, vm->pgd) + pgd_index(vm, vaddr) * 8;
 	if (!*ptep)
-		*ptep = vm_alloc_page_table(vm) | 3;
+		*ptep = vm_alloc_page_table_in_memslot(vm, pt_memslot) | 3;
 
 	switch (vm->pgtable_levels) {
 	case 4:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pud_index(vm, vaddr) * 8;
 		if (!*ptep)
-			*ptep = vm_alloc_page_table(vm) | 3;
+			*ptep = vm_alloc_page_table_in_memslot(vm, pt_memslot) | 3;
 		/* fall through */
 	case 3:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pmd_index(vm, vaddr) * 8;
 		if (!*ptep)
-			*ptep = vm_alloc_page_table(vm) | 3;
+			*ptep = vm_alloc_page_table_in_memslot(vm, pt_memslot) | 3;
 		/* fall through */
 	case 2:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, vaddr) * 8;
@@ -136,7 +136,7 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 {
 	uint64_t attr_idx = 4; /* NORMAL (See DEFAULT_MAIR_EL1) */
 
-	_virt_pg_map(vm, vaddr, paddr, attr_idx);
+	_virt_pg_map(vm, vaddr, paddr, attr_idx, 0);
 }
 
 vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva)
-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 05/13] KVM: selftests: Add missing close and munmap in __vm_mem_region_delete

[Ricardo Koller]

Deleting a memslot (when freeing a VM) is not closing the backing fd,
nor it's unmapping the alias mapping. Fix by adding the missing close
and munmap.

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index e18f1c93e4b4..268ad3d75fe2 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -679,6 +679,12 @@ static void __vm_mem_region_delete(struct kvm_vm *vm,
 	sparsebit_free(&region->unused_phy_pages);
 	ret = munmap(region->mmap_start, region->mmap_size);
 	TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i", ret, errno);
+	if (region->fd >= 0) {
+		/* There's an extra map shen using shared memory. */
+		ret = munmap(region->mmap_alias, region->mmap_size);
+		TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i", ret, errno);
+		close(region->fd);
+	}
 
 	free(region);
 }
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 05/13] KVM: selftests: Add missing close and munmap in __vm_mem_region_delete

[Ricardo Koller]

Deleting a memslot (when freeing a VM) is not closing the backing fd,
nor it's unmapping the alias mapping. Fix by adding the missing close
and munmap.

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index e18f1c93e4b4..268ad3d75fe2 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -679,6 +679,12 @@ static void __vm_mem_region_delete(struct kvm_vm *vm,
 	sparsebit_free(&region->unused_phy_pages);
 	ret = munmap(region->mmap_start, region->mmap_size);
 	TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i", ret, errno);
+	if (region->fd >= 0) {
+		/* There's an extra map shen using shared memory. */
+		ret = munmap(region->mmap_alias, region->mmap_size);
+		TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i", ret, errno);
+		close(region->fd);
+	}
 
 	free(region);
 }
-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 06/13] KVM: selftests: Add vm_mem_region_get_src_fd library function

[Ricardo Koller]

Add a library function to get the backing source FD of a memslot.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/kvm_util_base.h     |  1 +
 tools/testing/selftests/kvm/lib/kvm_util.c    | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 3a69b35e37cc..c8dce12a9a52 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -163,6 +163,7 @@ int _kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
 void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
 void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa);
 void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
+int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot);
 void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
 vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 268ad3d75fe2..a0a9cd575fac 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -580,6 +580,29 @@ kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start,
 	return &region->region;
 }
 
+/*
+ * KVM Userspace Memory Get Backing Source FD
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   memslot - KVM memory slot ID
+ *
+ * Output Args: None
+ *
+ * Return:
+ *   Backing source file descriptor, -1 if the memslot is an anonymous region.
+ *
+ * Returns the backing source fd of a memslot, so tests can use it to punch
+ * holes, or to setup permissions.
+ */
+int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot)
+{
+	struct userspace_mem_region *region;
+
+	region = memslot2region(vm, memslot);
+	return region->fd;
+}
+
 /*
  * VCPU Find
  *
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 06/13] KVM: selftests: Add vm_mem_region_get_src_fd library function

[Ricardo Koller]

Add a library function to get the backing source FD of a memslot.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/kvm_util_base.h     |  1 +
 tools/testing/selftests/kvm/lib/kvm_util.c    | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 3a69b35e37cc..c8dce12a9a52 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -163,6 +163,7 @@ int _kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
 void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
 void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa);
 void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
+int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot);
 void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
 vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 268ad3d75fe2..a0a9cd575fac 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -580,6 +580,29 @@ kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start,
 	return &region->region;
 }
 
+/*
+ * KVM Userspace Memory Get Backing Source FD
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   memslot - KVM memory slot ID
+ *
+ * Output Args: None
+ *
+ * Return:
+ *   Backing source file descriptor, -1 if the memslot is an anonymous region.
+ *
+ * Returns the backing source fd of a memslot, so tests can use it to punch
+ * holes, or to setup permissions.
+ */
+int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot)
+{
+	struct userspace_mem_region *region;
+
+	region = memslot2region(vm, memslot);
+	return region->fd;
+}
+
 /*
  * VCPU Find
  *
-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 07/13] KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macros

[Ricardo Koller]

Define macros for memory type indexes and construct DEFAULT_MAIR_EL1
with macros from asm/sysreg.h.  The index macros can then be used when
constructing PTEs (instead of using raw numbers).

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/aarch64/processor.h | 24 ++++++++++++++-----
 .../selftests/kvm/lib/aarch64/processor.c     |  2 +-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 3965a5ac778e..16753a1f28e3 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -38,12 +38,24 @@
  * NORMAL             4     1111:1111
  * NORMAL_WT          5     1011:1011
  */
-#define DEFAULT_MAIR_EL1 ((0x00ul << (0 * 8)) | \
-			  (0x04ul << (1 * 8)) | \
-			  (0x0cul << (2 * 8)) | \
-			  (0x44ul << (3 * 8)) | \
-			  (0xfful << (4 * 8)) | \
-			  (0xbbul << (5 * 8)))
+
+/* Linux doesn't use these memory types, so let's define them. */
+#define MAIR_ATTR_DEVICE_GRE	UL(0x0c)
+#define MAIR_NORMAL_WT		UL(0xbb)
+
+#define MT_DEVICE_nGnRnE	0
+#define MT_DEVICE_nGnRE		1
+#define MT_DEVICE_GRE		2
+#define MT_NORMAL_NC		3
+#define MT_NORMAL		4
+#define MT_NORMAL_WT		5
+
+#define DEFAULT_MAIR_EL1							\
+	(MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) |		\
+	 MAIR_ATTRIDX(MAIR_ATTR_DEVICE_GRE, MT_DEVICE_GRE) |			\
+	 MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) |			\
+	 MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) |				\
+	 MAIR_ATTRIDX(MAIR_NORMAL_WT, MT_NORMAL_WT))
 
 #define MPIDR_HWID_BITMASK (0xff00fffffful)
 
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 8f4ec1be4364..c7b899ba3e38 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -134,7 +134,7 @@ void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 
 void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 {
-	uint64_t attr_idx = 4; /* NORMAL (See DEFAULT_MAIR_EL1) */
+	uint64_t attr_idx = MT_NORMAL;
 
 	_virt_pg_map(vm, vaddr, paddr, attr_idx, 0);
 }
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 07/13] KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macros

[Ricardo Koller]

Define macros for memory type indexes and construct DEFAULT_MAIR_EL1
with macros from asm/sysreg.h.  The index macros can then be used when
constructing PTEs (instead of using raw numbers).

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/include/aarch64/processor.h | 24 ++++++++++++++-----
 .../selftests/kvm/lib/aarch64/processor.c     |  2 +-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 3965a5ac778e..16753a1f28e3 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -38,12 +38,24 @@
  * NORMAL             4     1111:1111
  * NORMAL_WT          5     1011:1011
  */
-#define DEFAULT_MAIR_EL1 ((0x00ul << (0 * 8)) | \
-			  (0x04ul << (1 * 8)) | \
-			  (0x0cul << (2 * 8)) | \
-			  (0x44ul << (3 * 8)) | \
-			  (0xfful << (4 * 8)) | \
-			  (0xbbul << (5 * 8)))
+
+/* Linux doesn't use these memory types, so let's define them. */
+#define MAIR_ATTR_DEVICE_GRE	UL(0x0c)
+#define MAIR_NORMAL_WT		UL(0xbb)
+
+#define MT_DEVICE_nGnRnE	0
+#define MT_DEVICE_nGnRE		1
+#define MT_DEVICE_GRE		2
+#define MT_NORMAL_NC		3
+#define MT_NORMAL		4
+#define MT_NORMAL_WT		5
+
+#define DEFAULT_MAIR_EL1							\
+	(MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) |		\
+	 MAIR_ATTRIDX(MAIR_ATTR_DEVICE_GRE, MT_DEVICE_GRE) |			\
+	 MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) |			\
+	 MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) |				\
+	 MAIR_ATTRIDX(MAIR_NORMAL_WT, MT_NORMAL_WT))
 
 #define MPIDR_HWID_BITMASK (0xff00fffffful)
 
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 8f4ec1be4364..c7b899ba3e38 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -134,7 +134,7 @@ void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 
 void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 {
-	uint64_t attr_idx = 4; /* NORMAL (See DEFAULT_MAIR_EL1) */
+	uint64_t attr_idx = MT_NORMAL;
 
 	_virt_pg_map(vm, vaddr, paddr, attr_idx, 0);
 }
-- 
2.35.1.1178.g4f1659d476-goog

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[PATCH v3 08/13] tools: Copy bitfield.h from the kernel sources

[Ricardo Koller]

Copy bitfield.h from include/linux/bitfield.h. It defines some
FIELD_{GET,PREP} macros that will be needed in the next patch in the
series. The header was copied as-is, no changes needed.

Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/include/linux/bitfield.h | 176 +++++++++++++++++++++++++++++++++
 1 file changed, 176 insertions(+)
 create mode 100644 tools/include/linux/bitfield.h

diff --git a/tools/include/linux/bitfield.h b/tools/include/linux/bitfield.h
new file mode 100644
index 000000000000..6093fa6db260
--- /dev/null
+++ b/tools/include/linux/bitfield.h
@@ -0,0 +1,176 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2014 Felix Fietkau <nbd@nbd.name>
+ * Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
+ */
+
+#ifndef _LINUX_BITFIELD_H
+#define _LINUX_BITFIELD_H
+
+#include <linux/build_bug.h>
+#include <asm/byteorder.h>
+
+/*
+ * Bitfield access macros
+ *
+ * FIELD_{GET,PREP} macros take as first parameter shifted mask
+ * from which they extract the base mask and shift amount.
+ * Mask must be a compilation time constant.
+ *
+ * Example:
+ *
+ *  #define REG_FIELD_A  GENMASK(6, 0)
+ *  #define REG_FIELD_B  BIT(7)
+ *  #define REG_FIELD_C  GENMASK(15, 8)
+ *  #define REG_FIELD_D  GENMASK(31, 16)
+ *
+ * Get:
+ *  a = FIELD_GET(REG_FIELD_A, reg);
+ *  b = FIELD_GET(REG_FIELD_B, reg);
+ *
+ * Set:
+ *  reg = FIELD_PREP(REG_FIELD_A, 1) |
+ *	  FIELD_PREP(REG_FIELD_B, 0) |
+ *	  FIELD_PREP(REG_FIELD_C, c) |
+ *	  FIELD_PREP(REG_FIELD_D, 0x40);
+ *
+ * Modify:
+ *  reg &= ~REG_FIELD_C;
+ *  reg |= FIELD_PREP(REG_FIELD_C, c);
+ */
+
+#define __bf_shf(x) (__builtin_ffsll(x) - 1)
+
+#define __scalar_type_to_unsigned_cases(type)				\
+		unsigned type:	(unsigned type)0,			\
+		signed type:	(unsigned type)0
+
+#define __unsigned_scalar_typeof(x) typeof(				\
+		_Generic((x),						\
+			char:	(unsigned char)0,			\
+			__scalar_type_to_unsigned_cases(char),		\
+			__scalar_type_to_unsigned_cases(short),		\
+			__scalar_type_to_unsigned_cases(int),		\
+			__scalar_type_to_unsigned_cases(long),		\
+			__scalar_type_to_unsigned_cases(long long),	\
+			default: (x)))
+
+#define __bf_cast_unsigned(type, x)	((__unsigned_scalar_typeof(type))(x))
+
+#define __BF_FIELD_CHECK(_mask, _reg, _val, _pfx)			\
+	({								\
+		BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask),		\
+				 _pfx "mask is not constant");		\
+		BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero");	\
+		BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?		\
+				 ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
+				 _pfx "value too large for the field"); \
+		BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >	\
+				 __bf_cast_unsigned(_reg, ~0ull),	\
+				 _pfx "type of reg too small for mask"); \
+		__BUILD_BUG_ON_NOT_POWER_OF_2((_mask) +			\
+					      (1ULL << __bf_shf(_mask))); \
+	})
+
+/**
+ * FIELD_MAX() - produce the maximum value representable by a field
+ * @_mask: shifted mask defining the field's length and position
+ *
+ * FIELD_MAX() returns the maximum value that can be held in the field
+ * specified by @_mask.
+ */
+#define FIELD_MAX(_mask)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_MAX: ");	\
+		(typeof(_mask))((_mask) >> __bf_shf(_mask));		\
+	})
+
+/**
+ * FIELD_FIT() - check if value fits in the field
+ * @_mask: shifted mask defining the field's length and position
+ * @_val:  value to test against the field
+ *
+ * Return: true if @_val can fit inside @_mask, false if @_val is too big.
+ */
+#define FIELD_FIT(_mask, _val)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_FIT: ");	\
+		!((((typeof(_mask))_val) << __bf_shf(_mask)) & ~(_mask)); \
+	})
+
+/**
+ * FIELD_PREP() - prepare a bitfield element
+ * @_mask: shifted mask defining the field's length and position
+ * @_val:  value to put in the field
+ *
+ * FIELD_PREP() masks and shifts up the value.  The result should
+ * be combined with other fields of the bitfield using logical OR.
+ */
+#define FIELD_PREP(_mask, _val)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");	\
+		((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask);	\
+	})
+
+/**
+ * FIELD_GET() - extract a bitfield element
+ * @_mask: shifted mask defining the field's length and position
+ * @_reg:  value of entire bitfield
+ *
+ * FIELD_GET() extracts the field specified by @_mask from the
+ * bitfield passed in as @_reg by masking and shifting it down.
+ */
+#define FIELD_GET(_mask, _reg)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: ");	\
+		(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask));	\
+	})
+
+extern void __compiletime_error("value doesn't fit into mask")
+__field_overflow(void);
+extern void __compiletime_error("bad bitfield mask")
+__bad_mask(void);
+static __always_inline u64 field_multiplier(u64 field)
+{
+	if ((field | (field - 1)) & ((field | (field - 1)) + 1))
+		__bad_mask();
+	return field & -field;
+}
+static __always_inline u64 field_mask(u64 field)
+{
+	return field / field_multiplier(field);
+}
+#define field_max(field)	((typeof(field))field_mask(field))
+#define ____MAKE_OP(type,base,to,from)					\
+static __always_inline __##type type##_encode_bits(base v, base field)	\
+{									\
+	if (__builtin_constant_p(v) && (v & ~field_mask(field)))	\
+		__field_overflow();					\
+	return to((v & field_mask(field)) * field_multiplier(field));	\
+}									\
+static __always_inline __##type type##_replace_bits(__##type old,	\
+					base val, base field)		\
+{									\
+	return (old & ~to(field)) | type##_encode_bits(val, field);	\
+}									\
+static __always_inline void type##p_replace_bits(__##type *p,		\
+					base val, base field)		\
+{									\
+	*p = (*p & ~to(field)) | type##_encode_bits(val, field);	\
+}									\
+static __always_inline base type##_get_bits(__##type v, base field)	\
+{									\
+	return (from(v) & field)/field_multiplier(field);		\
+}
+#define __MAKE_OP(size)							\
+	____MAKE_OP(le##size,u##size,cpu_to_le##size,le##size##_to_cpu)	\
+	____MAKE_OP(be##size,u##size,cpu_to_be##size,be##size##_to_cpu)	\
+	____MAKE_OP(u##size,u##size,,)
+____MAKE_OP(u8,u8,,)
+__MAKE_OP(16)
+__MAKE_OP(32)
+__MAKE_OP(64)
+#undef __MAKE_OP
+#undef ____MAKE_OP
+
+#endif
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 08/13] tools: Copy bitfield.h from the kernel sources

[Ricardo Koller]

Copy bitfield.h from include/linux/bitfield.h. It defines some
FIELD_{GET,PREP} macros that will be needed in the next patch in the
series. The header was copied as-is, no changes needed.

Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/include/linux/bitfield.h | 176 +++++++++++++++++++++++++++++++++
 1 file changed, 176 insertions(+)
 create mode 100644 tools/include/linux/bitfield.h

diff --git a/tools/include/linux/bitfield.h b/tools/include/linux/bitfield.h
new file mode 100644
index 000000000000..6093fa6db260
--- /dev/null
+++ b/tools/include/linux/bitfield.h
@@ -0,0 +1,176 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2014 Felix Fietkau <nbd@nbd.name>
+ * Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
+ */
+
+#ifndef _LINUX_BITFIELD_H
+#define _LINUX_BITFIELD_H
+
+#include <linux/build_bug.h>
+#include <asm/byteorder.h>
+
+/*
+ * Bitfield access macros
+ *
+ * FIELD_{GET,PREP} macros take as first parameter shifted mask
+ * from which they extract the base mask and shift amount.
+ * Mask must be a compilation time constant.
+ *
+ * Example:
+ *
+ *  #define REG_FIELD_A  GENMASK(6, 0)
+ *  #define REG_FIELD_B  BIT(7)
+ *  #define REG_FIELD_C  GENMASK(15, 8)
+ *  #define REG_FIELD_D  GENMASK(31, 16)
+ *
+ * Get:
+ *  a = FIELD_GET(REG_FIELD_A, reg);
+ *  b = FIELD_GET(REG_FIELD_B, reg);
+ *
+ * Set:
+ *  reg = FIELD_PREP(REG_FIELD_A, 1) |
+ *	  FIELD_PREP(REG_FIELD_B, 0) |
+ *	  FIELD_PREP(REG_FIELD_C, c) |
+ *	  FIELD_PREP(REG_FIELD_D, 0x40);
+ *
+ * Modify:
+ *  reg &= ~REG_FIELD_C;
+ *  reg |= FIELD_PREP(REG_FIELD_C, c);
+ */
+
+#define __bf_shf(x) (__builtin_ffsll(x) - 1)
+
+#define __scalar_type_to_unsigned_cases(type)				\
+		unsigned type:	(unsigned type)0,			\
+		signed type:	(unsigned type)0
+
+#define __unsigned_scalar_typeof(x) typeof(				\
+		_Generic((x),						\
+			char:	(unsigned char)0,			\
+			__scalar_type_to_unsigned_cases(char),		\
+			__scalar_type_to_unsigned_cases(short),		\
+			__scalar_type_to_unsigned_cases(int),		\
+			__scalar_type_to_unsigned_cases(long),		\
+			__scalar_type_to_unsigned_cases(long long),	\
+			default: (x)))
+
+#define __bf_cast_unsigned(type, x)	((__unsigned_scalar_typeof(type))(x))
+
+#define __BF_FIELD_CHECK(_mask, _reg, _val, _pfx)			\
+	({								\
+		BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask),		\
+				 _pfx "mask is not constant");		\
+		BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero");	\
+		BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?		\
+				 ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
+				 _pfx "value too large for the field"); \
+		BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >	\
+				 __bf_cast_unsigned(_reg, ~0ull),	\
+				 _pfx "type of reg too small for mask"); \
+		__BUILD_BUG_ON_NOT_POWER_OF_2((_mask) +			\
+					      (1ULL << __bf_shf(_mask))); \
+	})
+
+/**
+ * FIELD_MAX() - produce the maximum value representable by a field
+ * @_mask: shifted mask defining the field's length and position
+ *
+ * FIELD_MAX() returns the maximum value that can be held in the field
+ * specified by @_mask.
+ */
+#define FIELD_MAX(_mask)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_MAX: ");	\
+		(typeof(_mask))((_mask) >> __bf_shf(_mask));		\
+	})
+
+/**
+ * FIELD_FIT() - check if value fits in the field
+ * @_mask: shifted mask defining the field's length and position
+ * @_val:  value to test against the field
+ *
+ * Return: true if @_val can fit inside @_mask, false if @_val is too big.
+ */
+#define FIELD_FIT(_mask, _val)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_FIT: ");	\
+		!((((typeof(_mask))_val) << __bf_shf(_mask)) & ~(_mask)); \
+	})
+
+/**
+ * FIELD_PREP() - prepare a bitfield element
+ * @_mask: shifted mask defining the field's length and position
+ * @_val:  value to put in the field
+ *
+ * FIELD_PREP() masks and shifts up the value.  The result should
+ * be combined with other fields of the bitfield using logical OR.
+ */
+#define FIELD_PREP(_mask, _val)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");	\
+		((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask);	\
+	})
+
+/**
+ * FIELD_GET() - extract a bitfield element
+ * @_mask: shifted mask defining the field's length and position
+ * @_reg:  value of entire bitfield
+ *
+ * FIELD_GET() extracts the field specified by @_mask from the
+ * bitfield passed in as @_reg by masking and shifting it down.
+ */
+#define FIELD_GET(_mask, _reg)						\
+	({								\
+		__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: ");	\
+		(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask));	\
+	})
+
+extern void __compiletime_error("value doesn't fit into mask")
+__field_overflow(void);
+extern void __compiletime_error("bad bitfield mask")
+__bad_mask(void);
+static __always_inline u64 field_multiplier(u64 field)
+{
+	if ((field | (field - 1)) & ((field | (field - 1)) + 1))
+		__bad_mask();
+	return field & -field;
+}
+static __always_inline u64 field_mask(u64 field)
+{
+	return field / field_multiplier(field);
+}
+#define field_max(field)	((typeof(field))field_mask(field))
+#define ____MAKE_OP(type,base,to,from)					\
+static __always_inline __##type type##_encode_bits(base v, base field)	\
+{									\
+	if (__builtin_constant_p(v) && (v & ~field_mask(field)))	\
+		__field_overflow();					\
+	return to((v & field_mask(field)) * field_multiplier(field));	\
+}									\
+static __always_inline __##type type##_replace_bits(__##type old,	\
+					base val, base field)		\
+{									\
+	return (old & ~to(field)) | type##_encode_bits(val, field);	\
+}									\
+static __always_inline void type##p_replace_bits(__##type *p,		\
+					base val, base field)		\
+{									\
+	*p = (*p & ~to(field)) | type##_encode_bits(val, field);	\
+}									\
+static __always_inline base type##_get_bits(__##type v, base field)	\
+{									\
+	return (from(v) & field)/field_multiplier(field);		\
+}
+#define __MAKE_OP(size)							\
+	____MAKE_OP(le##size,u##size,cpu_to_le##size,le##size##_to_cpu)	\
+	____MAKE_OP(be##size,u##size,cpu_to_be##size,be##size##_to_cpu)	\
+	____MAKE_OP(u##size,u##size,,)
+____MAKE_OP(u8,u8,,)
+__MAKE_OP(16)
+__MAKE_OP(32)
+__MAKE_OP(64)
+#undef __MAKE_OP
+#undef ____MAKE_OP
+
+#endif
-- 
2.35.1.1178.g4f1659d476-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v3 09/13] KVM: selftests: aarch64: Add aarch64/page_fault_test

[Ricardo Koller]

Add a new test for stage 2 faults when using different combinations of
guest accesses (e.g., write, S1PTW), backing source type (e.g., anon)
and types of faults (e.g., read on hugetlbfs with a hole). The next
commits will add different handling methods and more faults (e.g., uffd
and dirty logging). This first commit starts by adding two sanity checks
for all types of accesses: AF setting by the hw, and accessing memslots
with holes.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/aarch64/page_fault_test.c   | 691 ++++++++++++++++++
 .../selftests/kvm/include/aarch64/processor.h |   6 +
 3 files changed, 698 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/page_fault_test.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index bc5f89b3700e..6a192798b217 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -103,6 +103,7 @@ TEST_GEN_PROGS_x86_64 += system_counter_offset_test
 TEST_GEN_PROGS_aarch64 += aarch64/arch_timer
 TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
+TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test
 TEST_GEN_PROGS_aarch64 += aarch64/psci_cpu_on_test
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_irq
diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
new file mode 100644
index 000000000000..04fc6007f630
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * page_fault_test.c - Test stage 2 faults.
+ *
+ * This test tries different combinations of guest accesses (e.g., write,
+ * S1PTW), backing source type (e.g., anon) and types of faults (e.g., read on
+ * hugetlbfs with a hole). It checks that the expected handling method is
+ * called (e.g., uffd faults with the right address and write/read flag).
+ */
+
+#define _GNU_SOURCE
+#include <linux/bitmap.h>
+#include <fcntl.h>
+#include <test_util.h>
+#include <kvm_util.h>
+#include <processor.h>
+#include <asm/sysreg.h>
+#include <linux/bitfield.h>
+#include "guest_modes.h"
+#include "userfaultfd_util.h"
+
+#define VCPU_ID					0
+
+#define TEST_MEM_SLOT_INDEX			1
+#define TEST_PT_SLOT_INDEX			2
+
+/* Max number of backing pages per guest page */
+#define BACKING_PG_PER_GUEST_PG			(64 / 4)
+
+/* Test memslot in backing source pages */
+#define TEST_MEMSLOT_BACKING_SRC_NPAGES		(1 * BACKING_PG_PER_GUEST_PG)
+
+/* PT memslot size in backing source pages */
+#define PT_MEMSLOT_BACKING_SRC_NPAGES		(4 * BACKING_PG_PER_GUEST_PG)
+
+/* Guest virtual addresses that point to the test page and its PTE. */
+#define TEST_GVA				0xc0000000
+#define TEST_EXEC_GVA				0xc0000008
+#define TEST_PTE_GVA				0xd0000000
+#define TEST_DATA				0x0123456789ABCDEF
+
+#define CMD_NONE				(0)
+#define CMD_SKIP_TEST				(1ULL << 1)
+#define CMD_HOLE_PT				(1ULL << 2)
+#define CMD_HOLE_TEST				(1ULL << 3)
+
+#define PREPARE_FN_NR				10
+#define CHECK_FN_NR				10
+
+uint64_t pte_gpa;
+
+enum { PT, TEST, NR_MEMSLOTS};
+
+struct memslot_desc {
+	void *hva;
+	uint64_t gpa;
+	uint64_t size;
+	uint64_t guest_pages;
+	uint64_t backing_pages;
+	enum vm_mem_backing_src_type src_type;
+	uint32_t idx;
+} memslot[NR_MEMSLOTS] = {
+	{
+		.idx = TEST_PT_SLOT_INDEX,
+		.backing_pages = PT_MEMSLOT_BACKING_SRC_NPAGES,
+	},
+	{
+		.idx = TEST_MEM_SLOT_INDEX,
+		.backing_pages = TEST_MEMSLOT_BACKING_SRC_NPAGES,
+	},
+};
+
+static struct event_cnt {
+	int aborts;
+	int fail_vcpu_runs;
+} events;
+
+struct test_desc {
+	const char *name;
+	uint64_t mem_mark_cmd;
+	/* Skip the test if any prepare function returns false */
+	bool (*guest_prepare[PREPARE_FN_NR])(void);
+	void (*guest_test)(void);
+	void (*guest_test_check[CHECK_FN_NR])(void);
+	void (*dabt_handler)(struct ex_regs *regs);
+	void (*iabt_handler)(struct ex_regs *regs);
+	uint32_t pt_memslot_flags;
+	uint32_t test_memslot_flags;
+	bool skip;
+	struct event_cnt expected_events;
+};
+
+struct test_params {
+	enum vm_mem_backing_src_type src_type;
+	struct test_desc *test_desc;
+};
+
+
+static inline void flush_tlb_page(uint64_t vaddr)
+{
+	uint64_t page = vaddr >> 12;
+
+	dsb(ishst);
+	asm volatile("tlbi vaae1is, %0" :: "r" (page));
+	dsb(ish);
+	isb();
+}
+
+static void guest_nop(void)
+{}
+
+static bool guest_prepare_nop(void)
+{
+	return true;
+}
+
+static void guest_check_nop(void)
+{}
+
+static void guest_write64(void)
+{
+	uint64_t val;
+
+	WRITE_ONCE(*((uint64_t *)TEST_GVA), TEST_DATA);
+	val = READ_ONCE(*(uint64_t *)TEST_GVA);
+	GUEST_ASSERT_EQ(val, TEST_DATA);
+}
+
+/* Check the system for atomic instructions. */
+static bool guest_check_lse(void)
+{
+	uint64_t isar0 = read_sysreg(id_aa64isar0_el1);
+	uint64_t atomic;
+
+	atomic = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR0_ATOMICS), isar0);
+	return atomic >= 2;
+}
+
+static bool guest_check_dc_zva(void)
+{
+	uint64_t dczid = read_sysreg(dczid_el0);
+	uint64_t dzp = FIELD_GET(ARM64_FEATURE_MASK(DCZID_DZP), dczid);
+
+	return dzp == 0;
+}
+
+/* Compare and swap instruction. */
+static void guest_cas(void)
+{
+	uint64_t val;
+	uint64_t addr = TEST_GVA;
+
+	GUEST_ASSERT_EQ(guest_check_lse(), 1);
+	asm volatile(".arch_extension lse\n"
+		     "casal %0, %1, [%2]\n"
+			:: "r" (0), "r" (TEST_DATA), "r" (addr));
+	val = READ_ONCE(*(uint64_t *)(addr));
+	GUEST_ASSERT_EQ(val, TEST_DATA);
+}
+
+static void guest_read64(void)
+{
+	uint64_t val;
+
+	val = READ_ONCE(*(uint64_t *)TEST_GVA);
+	GUEST_ASSERT_EQ(val, 0);
+}
+
+/* Address translation instruction */
+static void guest_at(void)
+{
+	uint64_t par;
+	uint64_t addr = 0;
+
+	asm volatile("at s1e1r, %0" :: "r" (TEST_GVA));
+	par = read_sysreg(par_el1);
+
+	/* Bit 1 indicates whether the AT was successful */
+	GUEST_ASSERT_EQ(par & 1, 0);
+	/* The PA in bits [51:12] */
+	addr = par & (((1ULL << 40) - 1) << 12);
+	GUEST_ASSERT_EQ(addr, memslot[TEST].gpa);
+}
+
+/*
+ * The size of the block written by "dc zva" is guaranteed to be between (2 <<
+ * 0) and (2 << 9), which is safe in our case as we need the write to happen
+ * for at least a word, and not more than a page.
+ */
+static void guest_dc_zva(void)
+{
+	uint16_t val;
+
+	asm volatile("dc zva, %0\n"
+			"dsb ish\n"
+			:: "r" (TEST_GVA));
+	val = READ_ONCE(*(uint16_t *)TEST_GVA);
+	GUEST_ASSERT_EQ(val, 0);
+}
+
+/*
+ * Pre-indexing loads and stores don't have a valid syndrome (ESR_EL2.ISV==0).
+ * And that's special because KVM must take special care with those: they
+ * should still count as accesses for dirty logging or user-faulting, but
+ * should be handled differently on mmio.
+ */
+static void guest_ld_preidx(void)
+{
+	uint64_t val;
+	uint64_t addr = TEST_GVA - 8;
+
+	/*
+	 * This ends up accessing "TEST_GVA + 8 - 8", where "TEST_GVA - 8" is
+	 * in a gap between memslots not backing by anything.
+	 */
+	asm volatile("ldr %0, [%1, #8]!"
+			: "=r" (val), "+r" (addr));
+	GUEST_ASSERT_EQ(val, 0);
+	GUEST_ASSERT_EQ(addr, TEST_GVA);
+}
+
+static void guest_st_preidx(void)
+{
+	uint64_t val = TEST_DATA;
+	uint64_t addr = TEST_GVA - 8;
+
+	asm volatile("str %0, [%1, #8]!"
+			: "+r" (val), "+r" (addr));
+
+	GUEST_ASSERT_EQ(addr, TEST_GVA);
+	val = READ_ONCE(*(uint64_t *)TEST_GVA);
+}
+
+static bool guest_set_ha(void)
+{
+	uint64_t mmfr1 = read_sysreg(id_aa64mmfr1_el1);
+	uint64_t hadbs, tcr;
+
+	/* Skip if HA is not supported. */
+	hadbs = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR1_HADBS), mmfr1);
+	if (hadbs == 0)
+		return false;
+
+	tcr = read_sysreg(tcr_el1) | TCR_EL1_HA;
+	write_sysreg(tcr, tcr_el1);
+	isb();
+
+	return true;
+}
+
+static bool guest_clear_pte_af(void)
+{
+	*((uint64_t *)TEST_PTE_GVA) &= ~PTE_AF;
+	flush_tlb_page(TEST_PTE_GVA);
+
+	return true;
+}
+
+static void guest_check_pte_af(void)
+{
+	flush_tlb_page(TEST_PTE_GVA);
+	GUEST_ASSERT_EQ(*((uint64_t *)TEST_PTE_GVA) & PTE_AF, PTE_AF);
+}
+
+static void guest_exec(void)
+{
+	int (*code)(void) = (int (*)(void))TEST_EXEC_GVA;
+	int ret;
+
+	ret = code();
+	GUEST_ASSERT_EQ(ret, 0x77);
+}
+
+static bool guest_prepare(struct test_desc *test)
+{
+	bool (*prepare_fn)(void);
+	int i;
+
+	for (i = 0; i < PREPARE_FN_NR; i++) {
+		prepare_fn = test->guest_prepare[i];
+		if (prepare_fn && !prepare_fn())
+			return false;
+	}
+
+	return true;
+}
+
+static void guest_test_check(struct test_desc *test)
+{
+	void (*check_fn)(void);
+	int i;
+
+	for (i = 0; i < CHECK_FN_NR; i++) {
+		check_fn = test->guest_test_check[i];
+		if (!check_fn)
+			continue;
+		check_fn();
+	}
+}
+
+static void guest_code(struct test_desc *test)
+{
+	if (!test->guest_test)
+		test->guest_test = guest_nop;
+
+	if (!guest_prepare(test))
+		GUEST_SYNC(CMD_SKIP_TEST);
+
+	GUEST_SYNC(test->mem_mark_cmd);
+	test->guest_test();
+
+	guest_test_check(test);
+	GUEST_DONE();
+}
+
+static void no_dabt_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_1(false, read_sysreg(far_el1));
+}
+
+static void no_iabt_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_1(false, regs->pc);
+}
+
+static void punch_hole_in_memslot(struct kvm_vm *vm,
+		struct memslot_desc *memslot)
+{
+	int ret, fd;
+	void *hva;
+
+	fd = vm_mem_region_get_src_fd(vm, memslot->idx);
+	if (fd != -1) {
+		ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+				0, memslot->size);
+		TEST_ASSERT(ret == 0, "fallocate failed, errno: %d\n", errno);
+	} else {
+		hva = addr_gpa2hva(vm, memslot->gpa);
+		ret = madvise(hva, memslot->size, MADV_DONTNEED);
+		TEST_ASSERT(ret == 0, "madvise failed, errno: %d\n", errno);
+	}
+}
+
+/* Returns false when the test was skipped. */
+static bool handle_cmd(struct kvm_vm *vm, int cmd)
+{
+	if (cmd == CMD_SKIP_TEST)
+		return false;
+
+	if (cmd & CMD_HOLE_PT)
+		punch_hole_in_memslot(vm, &memslot[PT]);
+	if (cmd & CMD_HOLE_TEST)
+		punch_hole_in_memslot(vm, &memslot[TEST]);
+
+	return true;
+}
+
+static void sync_stats_from_guest(struct kvm_vm *vm)
+{
+	struct event_cnt *ec = addr_gva2hva(vm, (uint64_t)&events);
+
+	events.aborts += ec->aborts;
+}
+
+void fail_vcpu_run_no_handler(int ret)
+{
+	TEST_FAIL("Unexpected vcpu run failure\n");
+}
+
+static uint64_t get_total_guest_pages(enum vm_guest_mode mode,
+		struct test_params *p)
+{
+	uint64_t backing_page_size = get_backing_src_pagesz(p->src_type);
+	uint64_t guest_page_size = vm_guest_mode_params[mode].page_size;
+	uint64_t size;
+
+	size = PT_MEMSLOT_BACKING_SRC_NPAGES * backing_page_size;
+	size += TEST_MEMSLOT_BACKING_SRC_NPAGES * backing_page_size;
+
+	return size / guest_page_size;
+}
+
+extern unsigned char __exec_test;
+
+void noinline __return_0x77(void)
+{
+	asm volatile("__exec_test: mov x0, #0x77\n"
+			"ret\n");
+}
+
+static void load_exec_code_for_test(void)
+{
+	uint64_t *code, *c;
+
+	assert(TEST_EXEC_GVA - TEST_GVA);
+	code = memslot[TEST].hva + 8;
+
+	/*
+	 * We need the cast to be separate in order for the compiler to not
+	 * complain with: "‘memcpy’ forming offset [1, 7] is out of the bounds
+	 * [0, 1] of object ‘__exec_test’ with type ‘unsigned char’"
+	 */
+	c = (uint64_t *)&__exec_test;
+	memcpy(code, c, 8);
+}
+
+static void setup_abort_handlers(struct kvm_vm *vm, struct test_desc *test)
+{
+	vm_init_descriptor_tables(vm);
+	vcpu_init_descriptor_tables(vm, VCPU_ID);
+	if (!test->dabt_handler)
+		test->dabt_handler = no_dabt_handler;
+	if (!test->iabt_handler)
+		test->iabt_handler = no_iabt_handler;
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
+			0x25, test->dabt_handler);
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
+			0x21, test->iabt_handler);
+}
+
+static void setup_memslots(struct kvm_vm *vm, enum vm_guest_mode mode,
+		struct test_params *p)
+{
+	uint64_t backing_page_size = get_backing_src_pagesz(p->src_type);
+	uint64_t guest_page_size = vm_guest_mode_params[mode].page_size;
+	struct test_desc *test = p->test_desc;
+	uint64_t hole_gpa;
+	uint64_t alignment;
+	int i;
+
+	/* Calculate the test and PT memslot sizes */
+	for (i = 0; i < NR_MEMSLOTS; i++) {
+		memslot[i].size = backing_page_size * memslot[i].backing_pages;
+		memslot[i].guest_pages = memslot[i].size / guest_page_size;
+		memslot[i].src_type = p->src_type;
+	}
+
+	TEST_ASSERT(memslot[TEST].size >= guest_page_size,
+			"The test memslot should have space one guest page.\n");
+	TEST_ASSERT(memslot[PT].size >= (4 * guest_page_size),
+			"The PT memslot sould have space for 4 guest pages.\n");
+
+	/* Place the memslots GPAs at the end of physical memory */
+	alignment = max(backing_page_size, guest_page_size);
+	memslot[TEST].gpa = (vm_get_max_gfn(vm) - memslot[TEST].guest_pages) *
+		guest_page_size;
+	memslot[TEST].gpa = align_down(memslot[TEST].gpa, alignment);
+
+	/* Add a 1-guest_page gap between the two memslots */
+	hole_gpa = memslot[TEST].gpa - guest_page_size;
+	virt_pg_map(vm, TEST_GVA - guest_page_size, hole_gpa);
+
+	memslot[PT].gpa = hole_gpa - (memslot[PT].guest_pages *
+			guest_page_size);
+	memslot[PT].gpa = align_down(memslot[PT].gpa, alignment);
+
+	/* Create memslots for the test data and a PTE. */
+	vm_userspace_mem_region_add(vm, p->src_type, memslot[PT].gpa,
+			memslot[PT].idx, memslot[PT].guest_pages,
+			test->pt_memslot_flags);
+	vm_userspace_mem_region_add(vm, p->src_type, memslot[TEST].gpa,
+			memslot[TEST].idx, memslot[TEST].guest_pages,
+			test->test_memslot_flags);
+
+	for (i = 0; i < NR_MEMSLOTS; i++)
+		memslot[i].hva = addr_gpa2hva(vm, memslot[i].gpa);
+
+	/* Map the test TEST_GVA using the PT memslot. */
+	_virt_pg_map(vm, TEST_GVA, memslot[TEST].gpa, MT_NORMAL,
+			TEST_PT_SLOT_INDEX);
+
+	/*
+	 * Find the PTE of the test page and map it in the guest so it can
+	 * clear the AF.
+	 */
+	pte_gpa = vm_get_pte_gpa(vm, TEST_GVA);
+	TEST_ASSERT(memslot[PT].gpa <= pte_gpa &&
+			pte_gpa < (memslot[PT].gpa + memslot[PT].size),
+			"The EPT should be in the PT memslot.");
+	/* This is an artibrary requirement just to make things simpler. */
+	TEST_ASSERT(pte_gpa % guest_page_size == 0,
+			"The pte_gpa (%p) should be aligned to the guest page (%lx).",
+			(void *)pte_gpa, guest_page_size);
+	virt_pg_map(vm, TEST_PTE_GVA, pte_gpa);
+}
+
+static void check_event_counts(struct test_desc *test)
+{
+	ASSERT_EQ(test->expected_events.aborts,	events.aborts);
+}
+
+static void print_test_banner(enum vm_guest_mode mode, struct test_params *p)
+{
+	struct test_desc *test = p->test_desc;
+
+	pr_debug("Test: %s\n", test->name);
+	pr_debug("Testing guest mode: %s\n", vm_guest_mode_string(mode));
+	pr_debug("Testing memory backing src type: %s\n",
+			vm_mem_backing_src_alias(p->src_type)->name);
+}
+
+static void reset_event_counts(void)
+{
+	memset(&events, 0, sizeof(events));
+}
+
+static bool vcpu_run_loop(struct kvm_vm *vm, struct test_desc *test)
+{
+	bool skip_test = false;
+	struct ucall uc;
+	int stage;
+
+	for (stage = 0; ; stage++) {
+		vcpu_run(vm, VCPU_ID);
+
+		switch (get_ucall(vm, VCPU_ID, &uc)) {
+		case UCALL_SYNC:
+			if (!handle_cmd(vm, uc.args[1])) {
+				pr_debug("Skipped.\n");
+				skip_test = true;
+				goto done;
+			}
+			break;
+		case UCALL_ABORT:
+			TEST_FAIL("%s at %s:%ld\n\tvalues: %#lx, %#lx",
+				(const char *)uc.args[0],
+				__FILE__, uc.args[1], uc.args[2], uc.args[3]);
+			break;
+		case UCALL_DONE:
+			pr_debug("Done.\n");
+			goto done;
+		default:
+			TEST_FAIL("Unknown ucall %lu", uc.cmd);
+		}
+	}
+
+done:
+	return skip_test;
+}
+
+static void run_test(enum vm_guest_mode mode, void *arg)
+{
+	struct test_params *p = (struct test_params *)arg;
+	struct test_desc *test = p->test_desc;
+	struct kvm_vm *vm;
+	bool skip_test = false;
+
+	print_test_banner(mode, p);
+
+	vm = vm_create_with_vcpus(mode, 1, DEFAULT_GUEST_PHY_PAGES,
+			get_total_guest_pages(mode, p), 0, guest_code, NULL);
+	ucall_init(vm, NULL);
+
+	reset_event_counts();
+	setup_memslots(vm, mode, p);
+
+	load_exec_code_for_test();
+	setup_abort_handlers(vm, test);
+	vcpu_args_set(vm, 0, 1, test);
+
+	sync_global_to_guest(vm, memslot);
+
+	skip_test = vcpu_run_loop(vm, test);
+
+	sync_stats_from_guest(vm);
+	ucall_uninit(vm);
+	kvm_vm_free(vm);
+
+	if (!skip_test)
+		check_event_counts(test);
+}
+
+static void for_each_test_and_guest_mode(void (*func)(enum vm_guest_mode, void *),
+		enum vm_mem_backing_src_type src_type);
+
+static void help(char *name)
+{
+	puts("");
+	printf("usage: %s [-h] [-s mem-type]\n", name);
+	puts("");
+	guest_modes_help();
+	backing_src_help("-s");
+	puts("");
+}
+
+int main(int argc, char *argv[])
+{
+	enum vm_mem_backing_src_type src_type;
+	int opt;
+
+	setbuf(stdout, NULL);
+
+	src_type = DEFAULT_VM_MEM_SRC;
+
+	guest_modes_append_default();
+
+	while ((opt = getopt(argc, argv, "hm:s:")) != -1) {
+		switch (opt) {
+		case 'm':
+			guest_modes_cmdline(optarg);
+			break;
+		case 's':
+			src_type = parse_backing_src_type(optarg);
+			break;
+		case 'h':
+		default:
+			help(argv[0]);
+			exit(0);
+		}
+	}
+
+	for_each_test_and_guest_mode(run_test, src_type);
+	return 0;
+}
+
+#define SNAME(s)			#s
+#define SCAT2(a, b)			SNAME(a ## _ ## b)
+#define SCAT3(a, b, c)			SCAT2(a, SCAT2(b, c))
+
+#define _CHECK(_test)			_CHECK_##_test
+#define _PREPARE(_test)			_PREPARE_##_test
+#define _PREPARE_guest_read64		guest_prepare_nop
+#define _PREPARE_guest_ld_preidx	guest_prepare_nop
+#define _PREPARE_guest_write64		guest_prepare_nop
+#define _PREPARE_guest_st_preidx	guest_prepare_nop
+#define _PREPARE_guest_exec		guest_prepare_nop
+#define _PREPARE_guest_at		guest_prepare_nop
+#define _PREPARE_guest_dc_zva		guest_check_dc_zva
+#define _PREPARE_guest_cas		guest_check_lse
+
+/* With or without access flag checks */
+#define _PREPARE_with_af		guest_set_ha, guest_clear_pte_af
+#define _PREPARE_no_af			guest_prepare_nop
+#define _CHECK_with_af			guest_check_pte_af
+#define _CHECK_no_af			guest_check_nop
+
+/* Performs an access and checks that no faults (no events) were triggered. */
+#define TEST_ACCESS(_access, _with_af, _mark_cmd)				\
+{										\
+	.name			= SCAT3(_access, _with_af, #_mark_cmd),		\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.mem_mark_cmd		= _mark_cmd,					\
+	.guest_test		= _access,					\
+	.guest_test_check	= { _CHECK(_with_af) },				\
+	.expected_events	= { 0 },					\
+}
+
+static struct test_desc tests[] = {
+	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
+	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
+	TEST_ACCESS(guest_ld_preidx, with_af, CMD_NONE),
+	TEST_ACCESS(guest_cas, with_af, CMD_NONE),
+	TEST_ACCESS(guest_write64, with_af, CMD_NONE),
+	TEST_ACCESS(guest_st_preidx, with_af, CMD_NONE),
+	TEST_ACCESS(guest_dc_zva, with_af, CMD_NONE),
+	TEST_ACCESS(guest_exec, with_af, CMD_NONE),
+
+	/*
+	 * Accessing a hole in the test memslot (punched with fallocate or
+	 * madvise) shouldn't fault (more sanity checks).
+	 */
+	TEST_ACCESS(guest_read64, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_cas, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_ld_preidx, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_write64, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_st_preidx, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_at, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_TEST),
+
+	{ 0 },
+};
+
+static void for_each_test_and_guest_mode(
+		void (*func)(enum vm_guest_mode m, void *a),
+		enum vm_mem_backing_src_type src_type)
+{
+	struct test_desc *t;
+
+	for (t = &tests[0]; t->name; t++) {
+		if (t->skip)
+			continue;
+
+		struct test_params p = {
+			.src_type = src_type,
+			.test_desc = t,
+		};
+
+		for_each_guest_mode(run_test, &p);
+	}
+}
diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 16753a1f28e3..cb5849fd8fd1 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -125,6 +125,12 @@ enum {
 #define ESR_EC_WP_CURRENT	0x35
 #define ESR_EC_BRK_INS		0x3c
 
+/* Access flag */
+#define PTE_AF			(1ULL << 10)
+
+/* Acces flag update enable/disable */
+#define TCR_EL1_HA		(1ULL << 39)
+
 void aarch64_get_supported_page_sizes(uint32_t ipa,
 				      bool *ps4k, bool *ps16k, bool *ps64k);
 
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 09/13] KVM: selftests: aarch64: Add aarch64/page_fault_test

[Ricardo Koller]

Add a new test for stage 2 faults when using different combinations of
guest accesses (e.g., write, S1PTW), backing source type (e.g., anon)
and types of faults (e.g., read on hugetlbfs with a hole). The next
commits will add different handling methods and more faults (e.g., uffd
and dirty logging). This first commit starts by adding two sanity checks
for all types of accesses: AF setting by the hw, and accessing memslots
with holes.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/aarch64/page_fault_test.c   | 691 ++++++++++++++++++
 .../selftests/kvm/include/aarch64/processor.h |   6 +
 3 files changed, 698 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/page_fault_test.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index bc5f89b3700e..6a192798b217 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -103,6 +103,7 @@ TEST_GEN_PROGS_x86_64 += system_counter_offset_test
 TEST_GEN_PROGS_aarch64 += aarch64/arch_timer
 TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
+TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test
 TEST_GEN_PROGS_aarch64 += aarch64/psci_cpu_on_test
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_irq
diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
new file mode 100644
index 000000000000..04fc6007f630
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * page_fault_test.c - Test stage 2 faults.
+ *
+ * This test tries different combinations of guest accesses (e.g., write,
+ * S1PTW), backing source type (e.g., anon) and types of faults (e.g., read on
+ * hugetlbfs with a hole). It checks that the expected handling method is
+ * called (e.g., uffd faults with the right address and write/read flag).
+ */
+
+#define _GNU_SOURCE
+#include <linux/bitmap.h>
+#include <fcntl.h>
+#include <test_util.h>
+#include <kvm_util.h>
+#include <processor.h>
+#include <asm/sysreg.h>
+#include <linux/bitfield.h>
+#include "guest_modes.h"
+#include "userfaultfd_util.h"
+
+#define VCPU_ID					0
+
+#define TEST_MEM_SLOT_INDEX			1
+#define TEST_PT_SLOT_INDEX			2
+
+/* Max number of backing pages per guest page */
+#define BACKING_PG_PER_GUEST_PG			(64 / 4)
+
+/* Test memslot in backing source pages */
+#define TEST_MEMSLOT_BACKING_SRC_NPAGES		(1 * BACKING_PG_PER_GUEST_PG)
+
+/* PT memslot size in backing source pages */
+#define PT_MEMSLOT_BACKING_SRC_NPAGES		(4 * BACKING_PG_PER_GUEST_PG)
+
+/* Guest virtual addresses that point to the test page and its PTE. */
+#define TEST_GVA				0xc0000000
+#define TEST_EXEC_GVA				0xc0000008
+#define TEST_PTE_GVA				0xd0000000
+#define TEST_DATA				0x0123456789ABCDEF
+
+#define CMD_NONE				(0)
+#define CMD_SKIP_TEST				(1ULL << 1)
+#define CMD_HOLE_PT				(1ULL << 2)
+#define CMD_HOLE_TEST				(1ULL << 3)
+
+#define PREPARE_FN_NR				10
+#define CHECK_FN_NR				10
+
+uint64_t pte_gpa;
+
+enum { PT, TEST, NR_MEMSLOTS};
+
+struct memslot_desc {
+	void *hva;
+	uint64_t gpa;
+	uint64_t size;
+	uint64_t guest_pages;
+	uint64_t backing_pages;
+	enum vm_mem_backing_src_type src_type;
+	uint32_t idx;
+} memslot[NR_MEMSLOTS] = {
+	{
+		.idx = TEST_PT_SLOT_INDEX,
+		.backing_pages = PT_MEMSLOT_BACKING_SRC_NPAGES,
+	},
+	{
+		.idx = TEST_MEM_SLOT_INDEX,
+		.backing_pages = TEST_MEMSLOT_BACKING_SRC_NPAGES,
+	},
+};
+
+static struct event_cnt {
+	int aborts;
+	int fail_vcpu_runs;
+} events;
+
+struct test_desc {
+	const char *name;
+	uint64_t mem_mark_cmd;
+	/* Skip the test if any prepare function returns false */
+	bool (*guest_prepare[PREPARE_FN_NR])(void);
+	void (*guest_test)(void);
+	void (*guest_test_check[CHECK_FN_NR])(void);
+	void (*dabt_handler)(struct ex_regs *regs);
+	void (*iabt_handler)(struct ex_regs *regs);
+	uint32_t pt_memslot_flags;
+	uint32_t test_memslot_flags;
+	bool skip;
+	struct event_cnt expected_events;
+};
+
+struct test_params {
+	enum vm_mem_backing_src_type src_type;
+	struct test_desc *test_desc;
+};
+
+
+static inline void flush_tlb_page(uint64_t vaddr)
+{
+	uint64_t page = vaddr >> 12;
+
+	dsb(ishst);
+	asm volatile("tlbi vaae1is, %0" :: "r" (page));
+	dsb(ish);
+	isb();
+}
+
+static void guest_nop(void)
+{}
+
+static bool guest_prepare_nop(void)
+{
+	return true;
+}
+
+static void guest_check_nop(void)
+{}
+
+static void guest_write64(void)
+{
+	uint64_t val;
+
+	WRITE_ONCE(*((uint64_t *)TEST_GVA), TEST_DATA);
+	val = READ_ONCE(*(uint64_t *)TEST_GVA);
+	GUEST_ASSERT_EQ(val, TEST_DATA);
+}
+
+/* Check the system for atomic instructions. */
+static bool guest_check_lse(void)
+{
+	uint64_t isar0 = read_sysreg(id_aa64isar0_el1);
+	uint64_t atomic;
+
+	atomic = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR0_ATOMICS), isar0);
+	return atomic >= 2;
+}
+
+static bool guest_check_dc_zva(void)
+{
+	uint64_t dczid = read_sysreg(dczid_el0);
+	uint64_t dzp = FIELD_GET(ARM64_FEATURE_MASK(DCZID_DZP), dczid);
+
+	return dzp == 0;
+}
+
+/* Compare and swap instruction. */
+static void guest_cas(void)
+{
+	uint64_t val;
+	uint64_t addr = TEST_GVA;
+
+	GUEST_ASSERT_EQ(guest_check_lse(), 1);
+	asm volatile(".arch_extension lse\n"
+		     "casal %0, %1, [%2]\n"
+			:: "r" (0), "r" (TEST_DATA), "r" (addr));
+	val = READ_ONCE(*(uint64_t *)(addr));
+	GUEST_ASSERT_EQ(val, TEST_DATA);
+}
+
+static void guest_read64(void)
+{
+	uint64_t val;
+
+	val = READ_ONCE(*(uint64_t *)TEST_GVA);
+	GUEST_ASSERT_EQ(val, 0);
+}
+
+/* Address translation instruction */
+static void guest_at(void)
+{
+	uint64_t par;
+	uint64_t addr = 0;
+
+	asm volatile("at s1e1r, %0" :: "r" (TEST_GVA));
+	par = read_sysreg(par_el1);
+
+	/* Bit 1 indicates whether the AT was successful */
+	GUEST_ASSERT_EQ(par & 1, 0);
+	/* The PA in bits [51:12] */
+	addr = par & (((1ULL << 40) - 1) << 12);
+	GUEST_ASSERT_EQ(addr, memslot[TEST].gpa);
+}
+
+/*
+ * The size of the block written by "dc zva" is guaranteed to be between (2 <<
+ * 0) and (2 << 9), which is safe in our case as we need the write to happen
+ * for at least a word, and not more than a page.
+ */
+static void guest_dc_zva(void)
+{
+	uint16_t val;
+
+	asm volatile("dc zva, %0\n"
+			"dsb ish\n"
+			:: "r" (TEST_GVA));
+	val = READ_ONCE(*(uint16_t *)TEST_GVA);
+	GUEST_ASSERT_EQ(val, 0);
+}
+
+/*
+ * Pre-indexing loads and stores don't have a valid syndrome (ESR_EL2.ISV==0).
+ * And that's special because KVM must take special care with those: they
+ * should still count as accesses for dirty logging or user-faulting, but
+ * should be handled differently on mmio.
+ */
+static void guest_ld_preidx(void)
+{
+	uint64_t val;
+	uint64_t addr = TEST_GVA - 8;
+
+	/*
+	 * This ends up accessing "TEST_GVA + 8 - 8", where "TEST_GVA - 8" is
+	 * in a gap between memslots not backing by anything.
+	 */
+	asm volatile("ldr %0, [%1, #8]!"
+			: "=r" (val), "+r" (addr));
+	GUEST_ASSERT_EQ(val, 0);
+	GUEST_ASSERT_EQ(addr, TEST_GVA);
+}
+
+static void guest_st_preidx(void)
+{
+	uint64_t val = TEST_DATA;
+	uint64_t addr = TEST_GVA - 8;
+
+	asm volatile("str %0, [%1, #8]!"
+			: "+r" (val), "+r" (addr));
+
+	GUEST_ASSERT_EQ(addr, TEST_GVA);
+	val = READ_ONCE(*(uint64_t *)TEST_GVA);
+}
+
+static bool guest_set_ha(void)
+{
+	uint64_t mmfr1 = read_sysreg(id_aa64mmfr1_el1);
+	uint64_t hadbs, tcr;
+
+	/* Skip if HA is not supported. */
+	hadbs = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR1_HADBS), mmfr1);
+	if (hadbs == 0)
+		return false;
+
+	tcr = read_sysreg(tcr_el1) | TCR_EL1_HA;
+	write_sysreg(tcr, tcr_el1);
+	isb();
+
+	return true;
+}
+
+static bool guest_clear_pte_af(void)
+{
+	*((uint64_t *)TEST_PTE_GVA) &= ~PTE_AF;
+	flush_tlb_page(TEST_PTE_GVA);
+
+	return true;
+}
+
+static void guest_check_pte_af(void)
+{
+	flush_tlb_page(TEST_PTE_GVA);
+	GUEST_ASSERT_EQ(*((uint64_t *)TEST_PTE_GVA) & PTE_AF, PTE_AF);
+}
+
+static void guest_exec(void)
+{
+	int (*code)(void) = (int (*)(void))TEST_EXEC_GVA;
+	int ret;
+
+	ret = code();
+	GUEST_ASSERT_EQ(ret, 0x77);
+}
+
+static bool guest_prepare(struct test_desc *test)
+{
+	bool (*prepare_fn)(void);
+	int i;
+
+	for (i = 0; i < PREPARE_FN_NR; i++) {
+		prepare_fn = test->guest_prepare[i];
+		if (prepare_fn && !prepare_fn())
+			return false;
+	}
+
+	return true;
+}
+
+static void guest_test_check(struct test_desc *test)
+{
+	void (*check_fn)(void);
+	int i;
+
+	for (i = 0; i < CHECK_FN_NR; i++) {
+		check_fn = test->guest_test_check[i];
+		if (!check_fn)
+			continue;
+		check_fn();
+	}
+}
+
+static void guest_code(struct test_desc *test)
+{
+	if (!test->guest_test)
+		test->guest_test = guest_nop;
+
+	if (!guest_prepare(test))
+		GUEST_SYNC(CMD_SKIP_TEST);
+
+	GUEST_SYNC(test->mem_mark_cmd);
+	test->guest_test();
+
+	guest_test_check(test);
+	GUEST_DONE();
+}
+
+static void no_dabt_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_1(false, read_sysreg(far_el1));
+}
+
+static void no_iabt_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_1(false, regs->pc);
+}
+
+static void punch_hole_in_memslot(struct kvm_vm *vm,
+		struct memslot_desc *memslot)
+{
+	int ret, fd;
+	void *hva;
+
+	fd = vm_mem_region_get_src_fd(vm, memslot->idx);
+	if (fd != -1) {
+		ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+				0, memslot->size);
+		TEST_ASSERT(ret == 0, "fallocate failed, errno: %d\n", errno);
+	} else {
+		hva = addr_gpa2hva(vm, memslot->gpa);
+		ret = madvise(hva, memslot->size, MADV_DONTNEED);
+		TEST_ASSERT(ret == 0, "madvise failed, errno: %d\n", errno);
+	}
+}
+
+/* Returns false when the test was skipped. */
+static bool handle_cmd(struct kvm_vm *vm, int cmd)
+{
+	if (cmd == CMD_SKIP_TEST)
+		return false;
+
+	if (cmd & CMD_HOLE_PT)
+		punch_hole_in_memslot(vm, &memslot[PT]);
+	if (cmd & CMD_HOLE_TEST)
+		punch_hole_in_memslot(vm, &memslot[TEST]);
+
+	return true;
+}
+
+static void sync_stats_from_guest(struct kvm_vm *vm)
+{
+	struct event_cnt *ec = addr_gva2hva(vm, (uint64_t)&events);
+
+	events.aborts += ec->aborts;
+}
+
+void fail_vcpu_run_no_handler(int ret)
+{
+	TEST_FAIL("Unexpected vcpu run failure\n");
+}
+
+static uint64_t get_total_guest_pages(enum vm_guest_mode mode,
+		struct test_params *p)
+{
+	uint64_t backing_page_size = get_backing_src_pagesz(p->src_type);
+	uint64_t guest_page_size = vm_guest_mode_params[mode].page_size;
+	uint64_t size;
+
+	size = PT_MEMSLOT_BACKING_SRC_NPAGES * backing_page_size;
+	size += TEST_MEMSLOT_BACKING_SRC_NPAGES * backing_page_size;
+
+	return size / guest_page_size;
+}
+
+extern unsigned char __exec_test;
+
+void noinline __return_0x77(void)
+{
+	asm volatile("__exec_test: mov x0, #0x77\n"
+			"ret\n");
+}
+
+static void load_exec_code_for_test(void)
+{
+	uint64_t *code, *c;
+
+	assert(TEST_EXEC_GVA - TEST_GVA);
+	code = memslot[TEST].hva + 8;
+
+	/*
+	 * We need the cast to be separate in order for the compiler to not
+	 * complain with: "‘memcpy’ forming offset [1, 7] is out of the bounds
+	 * [0, 1] of object ‘__exec_test’ with type ‘unsigned char’"
+	 */
+	c = (uint64_t *)&__exec_test;
+	memcpy(code, c, 8);
+}
+
+static void setup_abort_handlers(struct kvm_vm *vm, struct test_desc *test)
+{
+	vm_init_descriptor_tables(vm);
+	vcpu_init_descriptor_tables(vm, VCPU_ID);
+	if (!test->dabt_handler)
+		test->dabt_handler = no_dabt_handler;
+	if (!test->iabt_handler)
+		test->iabt_handler = no_iabt_handler;
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
+			0x25, test->dabt_handler);
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
+			0x21, test->iabt_handler);
+}
+
+static void setup_memslots(struct kvm_vm *vm, enum vm_guest_mode mode,
+		struct test_params *p)
+{
+	uint64_t backing_page_size = get_backing_src_pagesz(p->src_type);
+	uint64_t guest_page_size = vm_guest_mode_params[mode].page_size;
+	struct test_desc *test = p->test_desc;
+	uint64_t hole_gpa;
+	uint64_t alignment;
+	int i;
+
+	/* Calculate the test and PT memslot sizes */
+	for (i = 0; i < NR_MEMSLOTS; i++) {
+		memslot[i].size = backing_page_size * memslot[i].backing_pages;
+		memslot[i].guest_pages = memslot[i].size / guest_page_size;
+		memslot[i].src_type = p->src_type;
+	}
+
+	TEST_ASSERT(memslot[TEST].size >= guest_page_size,
+			"The test memslot should have space one guest page.\n");
+	TEST_ASSERT(memslot[PT].size >= (4 * guest_page_size),
+			"The PT memslot sould have space for 4 guest pages.\n");
+
+	/* Place the memslots GPAs at the end of physical memory */
+	alignment = max(backing_page_size, guest_page_size);
+	memslot[TEST].gpa = (vm_get_max_gfn(vm) - memslot[TEST].guest_pages) *
+		guest_page_size;
+	memslot[TEST].gpa = align_down(memslot[TEST].gpa, alignment);
+
+	/* Add a 1-guest_page gap between the two memslots */
+	hole_gpa = memslot[TEST].gpa - guest_page_size;
+	virt_pg_map(vm, TEST_GVA - guest_page_size, hole_gpa);
+
+	memslot[PT].gpa = hole_gpa - (memslot[PT].guest_pages *
+			guest_page_size);
+	memslot[PT].gpa = align_down(memslot[PT].gpa, alignment);
+
+	/* Create memslots for the test data and a PTE. */
+	vm_userspace_mem_region_add(vm, p->src_type, memslot[PT].gpa,
+			memslot[PT].idx, memslot[PT].guest_pages,
+			test->pt_memslot_flags);
+	vm_userspace_mem_region_add(vm, p->src_type, memslot[TEST].gpa,
+			memslot[TEST].idx, memslot[TEST].guest_pages,
+			test->test_memslot_flags);
+
+	for (i = 0; i < NR_MEMSLOTS; i++)
+		memslot[i].hva = addr_gpa2hva(vm, memslot[i].gpa);
+
+	/* Map the test TEST_GVA using the PT memslot. */
+	_virt_pg_map(vm, TEST_GVA, memslot[TEST].gpa, MT_NORMAL,
+			TEST_PT_SLOT_INDEX);
+
+	/*
+	 * Find the PTE of the test page and map it in the guest so it can
+	 * clear the AF.
+	 */
+	pte_gpa = vm_get_pte_gpa(vm, TEST_GVA);
+	TEST_ASSERT(memslot[PT].gpa <= pte_gpa &&
+			pte_gpa < (memslot[PT].gpa + memslot[PT].size),
+			"The EPT should be in the PT memslot.");
+	/* This is an artibrary requirement just to make things simpler. */
+	TEST_ASSERT(pte_gpa % guest_page_size == 0,
+			"The pte_gpa (%p) should be aligned to the guest page (%lx).",
+			(void *)pte_gpa, guest_page_size);
+	virt_pg_map(vm, TEST_PTE_GVA, pte_gpa);
+}
+
+static void check_event_counts(struct test_desc *test)
+{
+	ASSERT_EQ(test->expected_events.aborts,	events.aborts);
+}
+
+static void print_test_banner(enum vm_guest_mode mode, struct test_params *p)
+{
+	struct test_desc *test = p->test_desc;
+
+	pr_debug("Test: %s\n", test->name);
+	pr_debug("Testing guest mode: %s\n", vm_guest_mode_string(mode));
+	pr_debug("Testing memory backing src type: %s\n",
+			vm_mem_backing_src_alias(p->src_type)->name);
+}
+
+static void reset_event_counts(void)
+{
+	memset(&events, 0, sizeof(events));
+}
+
+static bool vcpu_run_loop(struct kvm_vm *vm, struct test_desc *test)
+{
+	bool skip_test = false;
+	struct ucall uc;
+	int stage;
+
+	for (stage = 0; ; stage++) {
+		vcpu_run(vm, VCPU_ID);
+
+		switch (get_ucall(vm, VCPU_ID, &uc)) {
+		case UCALL_SYNC:
+			if (!handle_cmd(vm, uc.args[1])) {
+				pr_debug("Skipped.\n");
+				skip_test = true;
+				goto done;
+			}
+			break;
+		case UCALL_ABORT:
+			TEST_FAIL("%s at %s:%ld\n\tvalues: %#lx, %#lx",
+				(const char *)uc.args[0],
+				__FILE__, uc.args[1], uc.args[2], uc.args[3]);
+			break;
+		case UCALL_DONE:
+			pr_debug("Done.\n");
+			goto done;
+		default:
+			TEST_FAIL("Unknown ucall %lu", uc.cmd);
+		}
+	}
+
+done:
+	return skip_test;
+}
+
+static void run_test(enum vm_guest_mode mode, void *arg)
+{
+	struct test_params *p = (struct test_params *)arg;
+	struct test_desc *test = p->test_desc;
+	struct kvm_vm *vm;
+	bool skip_test = false;
+
+	print_test_banner(mode, p);
+
+	vm = vm_create_with_vcpus(mode, 1, DEFAULT_GUEST_PHY_PAGES,
+			get_total_guest_pages(mode, p), 0, guest_code, NULL);
+	ucall_init(vm, NULL);
+
+	reset_event_counts();
+	setup_memslots(vm, mode, p);
+
+	load_exec_code_for_test();
+	setup_abort_handlers(vm, test);
+	vcpu_args_set(vm, 0, 1, test);
+
+	sync_global_to_guest(vm, memslot);
+
+	skip_test = vcpu_run_loop(vm, test);
+
+	sync_stats_from_guest(vm);
+	ucall_uninit(vm);
+	kvm_vm_free(vm);
+
+	if (!skip_test)
+		check_event_counts(test);
+}
+
+static void for_each_test_and_guest_mode(void (*func)(enum vm_guest_mode, void *),
+		enum vm_mem_backing_src_type src_type);
+
+static void help(char *name)
+{
+	puts("");
+	printf("usage: %s [-h] [-s mem-type]\n", name);
+	puts("");
+	guest_modes_help();
+	backing_src_help("-s");
+	puts("");
+}
+
+int main(int argc, char *argv[])
+{
+	enum vm_mem_backing_src_type src_type;
+	int opt;
+
+	setbuf(stdout, NULL);
+
+	src_type = DEFAULT_VM_MEM_SRC;
+
+	guest_modes_append_default();
+
+	while ((opt = getopt(argc, argv, "hm:s:")) != -1) {
+		switch (opt) {
+		case 'm':
+			guest_modes_cmdline(optarg);
+			break;
+		case 's':
+			src_type = parse_backing_src_type(optarg);
+			break;
+		case 'h':
+		default:
+			help(argv[0]);
+			exit(0);
+		}
+	}
+
+	for_each_test_and_guest_mode(run_test, src_type);
+	return 0;
+}
+
+#define SNAME(s)			#s
+#define SCAT2(a, b)			SNAME(a ## _ ## b)
+#define SCAT3(a, b, c)			SCAT2(a, SCAT2(b, c))
+
+#define _CHECK(_test)			_CHECK_##_test
+#define _PREPARE(_test)			_PREPARE_##_test
+#define _PREPARE_guest_read64		guest_prepare_nop
+#define _PREPARE_guest_ld_preidx	guest_prepare_nop
+#define _PREPARE_guest_write64		guest_prepare_nop
+#define _PREPARE_guest_st_preidx	guest_prepare_nop
+#define _PREPARE_guest_exec		guest_prepare_nop
+#define _PREPARE_guest_at		guest_prepare_nop
+#define _PREPARE_guest_dc_zva		guest_check_dc_zva
+#define _PREPARE_guest_cas		guest_check_lse
+
+/* With or without access flag checks */
+#define _PREPARE_with_af		guest_set_ha, guest_clear_pte_af
+#define _PREPARE_no_af			guest_prepare_nop
+#define _CHECK_with_af			guest_check_pte_af
+#define _CHECK_no_af			guest_check_nop
+
+/* Performs an access and checks that no faults (no events) were triggered. */
+#define TEST_ACCESS(_access, _with_af, _mark_cmd)				\
+{										\
+	.name			= SCAT3(_access, _with_af, #_mark_cmd),		\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.mem_mark_cmd		= _mark_cmd,					\
+	.guest_test		= _access,					\
+	.guest_test_check	= { _CHECK(_with_af) },				\
+	.expected_events	= { 0 },					\
+}
+
+static struct test_desc tests[] = {
+	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
+	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
+	TEST_ACCESS(guest_ld_preidx, with_af, CMD_NONE),
+	TEST_ACCESS(guest_cas, with_af, CMD_NONE),
+	TEST_ACCESS(guest_write64, with_af, CMD_NONE),
+	TEST_ACCESS(guest_st_preidx, with_af, CMD_NONE),
+	TEST_ACCESS(guest_dc_zva, with_af, CMD_NONE),
+	TEST_ACCESS(guest_exec, with_af, CMD_NONE),
+
+	/*
+	 * Accessing a hole in the test memslot (punched with fallocate or
+	 * madvise) shouldn't fault (more sanity checks).
+	 */
+	TEST_ACCESS(guest_read64, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_cas, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_ld_preidx, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_write64, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_st_preidx, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_at, no_af, CMD_HOLE_TEST),
+	TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_TEST),
+
+	{ 0 },
+};
+
+static void for_each_test_and_guest_mode(
+		void (*func)(enum vm_guest_mode m, void *a),
+		enum vm_mem_backing_src_type src_type)
+{
+	struct test_desc *t;
+
+	for (t = &tests[0]; t->name; t++) {
+		if (t->skip)
+			continue;
+
+		struct test_params p = {
+			.src_type = src_type,
+			.test_desc = t,
+		};
+
+		for_each_guest_mode(run_test, &p);
+	}
+}
diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 16753a1f28e3..cb5849fd8fd1 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -125,6 +125,12 @@ enum {
 #define ESR_EC_WP_CURRENT	0x35
 #define ESR_EC_BRK_INS		0x3c
 
+/* Access flag */
+#define PTE_AF			(1ULL << 10)
+
+/* Acces flag update enable/disable */
+#define TCR_EL1_HA		(1ULL << 39)
+
 void aarch64_get_supported_page_sizes(uint32_t ipa,
 				      bool *ps4k, bool *ps16k, bool *ps64k);
 
-- 
2.35.1.1178.g4f1659d476-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v3 10/13] KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test

[Ricardo Koller]

Add some userfaultfd tests into page_fault_test. Punch holes into the
data and/or page-table memslots, perform some accesses, and check that
the faults are taken (or not taken) when expected.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 171 +++++++++++++++++-
 1 file changed, 169 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index 04fc6007f630..bee525625956 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -52,6 +52,8 @@ uint64_t pte_gpa;
 enum { PT, TEST, NR_MEMSLOTS};
 
 struct memslot_desc {
+	size_t paging_size;
+	char *data_copy;
 	void *hva;
 	uint64_t gpa;
 	uint64_t size;
@@ -73,6 +75,9 @@ struct memslot_desc {
 static struct event_cnt {
 	int aborts;
 	int fail_vcpu_runs;
+	int uffd_faults;
+	/* uffd_faults is incremented from multiple threads. */
+	pthread_mutex_t uffd_faults_mutex;
 } events;
 
 struct test_desc {
@@ -82,6 +87,8 @@ struct test_desc {
 	bool (*guest_prepare[PREPARE_FN_NR])(void);
 	void (*guest_test)(void);
 	void (*guest_test_check[CHECK_FN_NR])(void);
+	int (*uffd_pt_handler)(int mode, int uffd, struct uffd_msg *msg);
+	int (*uffd_test_handler)(int mode, int uffd, struct uffd_msg *msg);
 	void (*dabt_handler)(struct ex_regs *regs);
 	void (*iabt_handler)(struct ex_regs *regs);
 	uint32_t pt_memslot_flags;
@@ -306,6 +313,7 @@ static void guest_code(struct test_desc *test)
 	if (!guest_prepare(test))
 		GUEST_SYNC(CMD_SKIP_TEST);
 
+	flush_tlb_page(TEST_GVA);
 	GUEST_SYNC(test->mem_mark_cmd);
 	test->guest_test();
 
@@ -323,6 +331,56 @@ static void no_iabt_handler(struct ex_regs *regs)
 	GUEST_ASSERT_1(false, regs->pc);
 }
 
+static int uffd_generic_handler(int uffd_mode, int uffd,
+		struct uffd_msg *msg, struct memslot_desc *memslot,
+		bool expect_write)
+{
+	uint64_t addr = msg->arg.pagefault.address;
+	uint64_t flags = msg->arg.pagefault.flags;
+	struct uffdio_copy copy;
+	int ret;
+
+	TEST_ASSERT(uffd_mode == UFFDIO_REGISTER_MODE_MISSING,
+			"The only expected UFFD mode is MISSING");
+	ASSERT_EQ(!!(flags & UFFD_PAGEFAULT_FLAG_WRITE), expect_write);
+	ASSERT_EQ(addr, (uint64_t)memslot->hva);
+
+	pr_debug("uffd fault: addr=%p write=%d\n",
+			(void *)addr, !!(flags & UFFD_PAGEFAULT_FLAG_WRITE));
+
+	copy.src = (uint64_t)memslot->data_copy;
+	copy.dst = addr;
+	copy.len = memslot->paging_size;
+	copy.mode = 0;
+
+	ret = ioctl(uffd, UFFDIO_COPY, &copy);
+	if (ret == -1) {
+		pr_info("Failed UFFDIO_COPY in 0x%lx with errno: %d\n",
+				addr, errno);
+		return ret;
+	}
+
+	pthread_mutex_lock(&events.uffd_faults_mutex);
+	events.uffd_faults += 1;
+	pthread_mutex_unlock(&events.uffd_faults_mutex);
+	return 0;
+}
+
+static int uffd_pt_write_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	return uffd_generic_handler(mode, uffd, msg, &memslot[PT], true);
+}
+
+static int uffd_test_write_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	return uffd_generic_handler(mode, uffd, msg, &memslot[TEST], true);
+}
+
+static int uffd_test_read_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	return uffd_generic_handler(mode, uffd, msg, &memslot[TEST], false);
+}
+
 static void punch_hole_in_memslot(struct kvm_vm *vm,
 		struct memslot_desc *memslot)
 {
@@ -332,11 +390,11 @@ static void punch_hole_in_memslot(struct kvm_vm *vm,
 	fd = vm_mem_region_get_src_fd(vm, memslot->idx);
 	if (fd != -1) {
 		ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-				0, memslot->size);
+				0, memslot->paging_size);
 		TEST_ASSERT(ret == 0, "fallocate failed, errno: %d\n", errno);
 	} else {
 		hva = addr_gpa2hva(vm, memslot->gpa);
-		ret = madvise(hva, memslot->size, MADV_DONTNEED);
+		ret = madvise(hva, memslot->paging_size, MADV_DONTNEED);
 		TEST_ASSERT(ret == 0, "madvise failed, errno: %d\n", errno);
 	}
 }
@@ -484,9 +542,60 @@ static void setup_memslots(struct kvm_vm *vm, enum vm_guest_mode mode,
 	virt_pg_map(vm, TEST_PTE_GVA, pte_gpa);
 }
 
+static void setup_uffd(enum vm_guest_mode mode, struct test_params *p,
+		struct uffd_desc **uffd)
+{
+	struct test_desc *test = p->test_desc;
+	uint64_t large_page_size = get_backing_src_pagesz(p->src_type);
+	int i;
+
+	/*
+	 * When creating the map, we might not only have created a pte page,
+	 * but also an intermediate level (pte_gpa != gpa[PT]). So, we
+	 * might need to demand page both.
+	 */
+	memslot[PT].paging_size = align_up(pte_gpa - memslot[PT].gpa,
+			large_page_size) + large_page_size;
+	memslot[TEST].paging_size = large_page_size;
+
+	for (i = 0; i < NR_MEMSLOTS; i++) {
+		memslot[i].data_copy = malloc(memslot[i].paging_size);
+		TEST_ASSERT(memslot[i].data_copy, "Failed malloc.");
+		memcpy(memslot[i].data_copy, memslot[i].hva,
+				memslot[i].paging_size);
+	}
+
+	uffd[PT] = NULL;
+	if (test->uffd_pt_handler)
+		uffd[PT] = uffd_setup_demand_paging(
+				UFFDIO_REGISTER_MODE_MISSING, 0,
+				memslot[PT].hva, memslot[PT].paging_size,
+				test->uffd_pt_handler);
+
+	uffd[TEST] = NULL;
+	if (test->uffd_test_handler)
+		uffd[TEST] = uffd_setup_demand_paging(
+				UFFDIO_REGISTER_MODE_MISSING, 0,
+				memslot[TEST].hva, memslot[TEST].paging_size,
+				test->uffd_test_handler);
+}
+
 static void check_event_counts(struct test_desc *test)
 {
 	ASSERT_EQ(test->expected_events.aborts,	events.aborts);
+	ASSERT_EQ(test->expected_events.uffd_faults, events.uffd_faults);
+}
+
+static void free_uffd(struct test_desc *test, struct uffd_desc **uffd)
+{
+	int i;
+
+	if (test->uffd_pt_handler)
+		uffd_stop_demand_paging(uffd[PT]);
+	if (test->uffd_test_handler)
+		uffd_stop_demand_paging(uffd[TEST]);
+	for (i = 0; i < NR_MEMSLOTS; i++)
+		free(memslot[i].data_copy);
 }
 
 static void print_test_banner(enum vm_guest_mode mode, struct test_params *p)
@@ -543,6 +652,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	struct test_params *p = (struct test_params *)arg;
 	struct test_desc *test = p->test_desc;
 	struct kvm_vm *vm;
+	struct uffd_desc *uffd[NR_MEMSLOTS];
 	bool skip_test = false;
 
 	print_test_banner(mode, p);
@@ -554,7 +664,14 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	reset_event_counts();
 	setup_memslots(vm, mode, p);
 
+	/*
+	 * Set some code at memslot[TEST].hva for the guest to execute (only
+	 * applicable to the EXEC tests). This has to be done before
+	 * setup_uffd() as that function copies the memslot data for the uffd
+	 * handler.
+	 */
 	load_exec_code_for_test();
+	setup_uffd(mode, p, uffd);
 	setup_abort_handlers(vm, test);
 	vcpu_args_set(vm, 0, 1, test);
 
@@ -565,7 +682,12 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	sync_stats_from_guest(vm);
 	ucall_uninit(vm);
 	kvm_vm_free(vm);
+	free_uffd(test, uffd);
 
+	/*
+	 * Make sure this is called after the uffd threads have exited (and
+	 * updated their respective event counters).
+	 */
 	if (!skip_test)
 		check_event_counts(test);
 }
@@ -616,6 +738,7 @@ int main(int argc, char *argv[])
 #define SNAME(s)			#s
 #define SCAT2(a, b)			SNAME(a ## _ ## b)
 #define SCAT3(a, b, c)			SCAT2(a, SCAT2(b, c))
+#define SCAT4(a, b, c, d)		SCAT2(a, SCAT3(b, c, d))
 
 #define _CHECK(_test)			_CHECK_##_test
 #define _PREPARE(_test)			_PREPARE_##_test
@@ -646,6 +769,20 @@ int main(int argc, char *argv[])
 	.expected_events	= { 0 },					\
 }
 
+#define TEST_UFFD(_access, _with_af, _mark_cmd,					\
+		  _uffd_test_handler, _uffd_pt_handler, _uffd_faults)		\
+{										\
+	.name			= SCAT4(uffd, _access, _with_af, #_mark_cmd),	\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.guest_test		= _access,					\
+	.mem_mark_cmd		= _mark_cmd,					\
+	.guest_test_check	= { _CHECK(_with_af) },				\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= _uffd_pt_handler,				\
+	.expected_events	= { .uffd_faults = _uffd_faults, },		\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -668,6 +805,36 @@ static struct test_desc tests[] = {
 	TEST_ACCESS(guest_at, no_af, CMD_HOLE_TEST),
 	TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_TEST),
 
+	/*
+	 * Punch holes in the test and PT memslots and mark them for
+	 * userfaultfd handling. This should result in 2 faults: the test
+	 * access and its respective S1 page table walk (S1PTW).
+	 */
+	TEST_UFFD(guest_read64, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	/* no_af should also lead to a PT write. */
+	TEST_UFFD(guest_read64, no_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	/* Note how that cas invokes the read handler. */
+	TEST_UFFD(guest_cas, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	/*
+	 * Can't test guest_at with_af as it's IMPDEF whether the AF is set.
+	 * The S1PTW fault should still be marked as a write.
+	 */
+	TEST_UFFD(guest_at, no_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 1),
+	TEST_UFFD(guest_ld_preidx, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_write64, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_write_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_dc_zva, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_write_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_st_preidx, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_write_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_exec, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 10/13] KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test

[Ricardo Koller]

Add some userfaultfd tests into page_fault_test. Punch holes into the
data and/or page-table memslots, perform some accesses, and check that
the faults are taken (or not taken) when expected.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 171 +++++++++++++++++-
 1 file changed, 169 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index 04fc6007f630..bee525625956 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -52,6 +52,8 @@ uint64_t pte_gpa;
 enum { PT, TEST, NR_MEMSLOTS};
 
 struct memslot_desc {
+	size_t paging_size;
+	char *data_copy;
 	void *hva;
 	uint64_t gpa;
 	uint64_t size;
@@ -73,6 +75,9 @@ struct memslot_desc {
 static struct event_cnt {
 	int aborts;
 	int fail_vcpu_runs;
+	int uffd_faults;
+	/* uffd_faults is incremented from multiple threads. */
+	pthread_mutex_t uffd_faults_mutex;
 } events;
 
 struct test_desc {
@@ -82,6 +87,8 @@ struct test_desc {
 	bool (*guest_prepare[PREPARE_FN_NR])(void);
 	void (*guest_test)(void);
 	void (*guest_test_check[CHECK_FN_NR])(void);
+	int (*uffd_pt_handler)(int mode, int uffd, struct uffd_msg *msg);
+	int (*uffd_test_handler)(int mode, int uffd, struct uffd_msg *msg);
 	void (*dabt_handler)(struct ex_regs *regs);
 	void (*iabt_handler)(struct ex_regs *regs);
 	uint32_t pt_memslot_flags;
@@ -306,6 +313,7 @@ static void guest_code(struct test_desc *test)
 	if (!guest_prepare(test))
 		GUEST_SYNC(CMD_SKIP_TEST);
 
+	flush_tlb_page(TEST_GVA);
 	GUEST_SYNC(test->mem_mark_cmd);
 	test->guest_test();
 
@@ -323,6 +331,56 @@ static void no_iabt_handler(struct ex_regs *regs)
 	GUEST_ASSERT_1(false, regs->pc);
 }
 
+static int uffd_generic_handler(int uffd_mode, int uffd,
+		struct uffd_msg *msg, struct memslot_desc *memslot,
+		bool expect_write)
+{
+	uint64_t addr = msg->arg.pagefault.address;
+	uint64_t flags = msg->arg.pagefault.flags;
+	struct uffdio_copy copy;
+	int ret;
+
+	TEST_ASSERT(uffd_mode == UFFDIO_REGISTER_MODE_MISSING,
+			"The only expected UFFD mode is MISSING");
+	ASSERT_EQ(!!(flags & UFFD_PAGEFAULT_FLAG_WRITE), expect_write);
+	ASSERT_EQ(addr, (uint64_t)memslot->hva);
+
+	pr_debug("uffd fault: addr=%p write=%d\n",
+			(void *)addr, !!(flags & UFFD_PAGEFAULT_FLAG_WRITE));
+
+	copy.src = (uint64_t)memslot->data_copy;
+	copy.dst = addr;
+	copy.len = memslot->paging_size;
+	copy.mode = 0;
+
+	ret = ioctl(uffd, UFFDIO_COPY, &copy);
+	if (ret == -1) {
+		pr_info("Failed UFFDIO_COPY in 0x%lx with errno: %d\n",
+				addr, errno);
+		return ret;
+	}
+
+	pthread_mutex_lock(&events.uffd_faults_mutex);
+	events.uffd_faults += 1;
+	pthread_mutex_unlock(&events.uffd_faults_mutex);
+	return 0;
+}
+
+static int uffd_pt_write_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	return uffd_generic_handler(mode, uffd, msg, &memslot[PT], true);
+}
+
+static int uffd_test_write_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	return uffd_generic_handler(mode, uffd, msg, &memslot[TEST], true);
+}
+
+static int uffd_test_read_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	return uffd_generic_handler(mode, uffd, msg, &memslot[TEST], false);
+}
+
 static void punch_hole_in_memslot(struct kvm_vm *vm,
 		struct memslot_desc *memslot)
 {
@@ -332,11 +390,11 @@ static void punch_hole_in_memslot(struct kvm_vm *vm,
 	fd = vm_mem_region_get_src_fd(vm, memslot->idx);
 	if (fd != -1) {
 		ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-				0, memslot->size);
+				0, memslot->paging_size);
 		TEST_ASSERT(ret == 0, "fallocate failed, errno: %d\n", errno);
 	} else {
 		hva = addr_gpa2hva(vm, memslot->gpa);
-		ret = madvise(hva, memslot->size, MADV_DONTNEED);
+		ret = madvise(hva, memslot->paging_size, MADV_DONTNEED);
 		TEST_ASSERT(ret == 0, "madvise failed, errno: %d\n", errno);
 	}
 }
@@ -484,9 +542,60 @@ static void setup_memslots(struct kvm_vm *vm, enum vm_guest_mode mode,
 	virt_pg_map(vm, TEST_PTE_GVA, pte_gpa);
 }
 
+static void setup_uffd(enum vm_guest_mode mode, struct test_params *p,
+		struct uffd_desc **uffd)
+{
+	struct test_desc *test = p->test_desc;
+	uint64_t large_page_size = get_backing_src_pagesz(p->src_type);
+	int i;
+
+	/*
+	 * When creating the map, we might not only have created a pte page,
+	 * but also an intermediate level (pte_gpa != gpa[PT]). So, we
+	 * might need to demand page both.
+	 */
+	memslot[PT].paging_size = align_up(pte_gpa - memslot[PT].gpa,
+			large_page_size) + large_page_size;
+	memslot[TEST].paging_size = large_page_size;
+
+	for (i = 0; i < NR_MEMSLOTS; i++) {
+		memslot[i].data_copy = malloc(memslot[i].paging_size);
+		TEST_ASSERT(memslot[i].data_copy, "Failed malloc.");
+		memcpy(memslot[i].data_copy, memslot[i].hva,
+				memslot[i].paging_size);
+	}
+
+	uffd[PT] = NULL;
+	if (test->uffd_pt_handler)
+		uffd[PT] = uffd_setup_demand_paging(
+				UFFDIO_REGISTER_MODE_MISSING, 0,
+				memslot[PT].hva, memslot[PT].paging_size,
+				test->uffd_pt_handler);
+
+	uffd[TEST] = NULL;
+	if (test->uffd_test_handler)
+		uffd[TEST] = uffd_setup_demand_paging(
+				UFFDIO_REGISTER_MODE_MISSING, 0,
+				memslot[TEST].hva, memslot[TEST].paging_size,
+				test->uffd_test_handler);
+}
+
 static void check_event_counts(struct test_desc *test)
 {
 	ASSERT_EQ(test->expected_events.aborts,	events.aborts);
+	ASSERT_EQ(test->expected_events.uffd_faults, events.uffd_faults);
+}
+
+static void free_uffd(struct test_desc *test, struct uffd_desc **uffd)
+{
+	int i;
+
+	if (test->uffd_pt_handler)
+		uffd_stop_demand_paging(uffd[PT]);
+	if (test->uffd_test_handler)
+		uffd_stop_demand_paging(uffd[TEST]);
+	for (i = 0; i < NR_MEMSLOTS; i++)
+		free(memslot[i].data_copy);
 }
 
 static void print_test_banner(enum vm_guest_mode mode, struct test_params *p)
@@ -543,6 +652,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	struct test_params *p = (struct test_params *)arg;
 	struct test_desc *test = p->test_desc;
 	struct kvm_vm *vm;
+	struct uffd_desc *uffd[NR_MEMSLOTS];
 	bool skip_test = false;
 
 	print_test_banner(mode, p);
@@ -554,7 +664,14 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	reset_event_counts();
 	setup_memslots(vm, mode, p);
 
+	/*
+	 * Set some code at memslot[TEST].hva for the guest to execute (only
+	 * applicable to the EXEC tests). This has to be done before
+	 * setup_uffd() as that function copies the memslot data for the uffd
+	 * handler.
+	 */
 	load_exec_code_for_test();
+	setup_uffd(mode, p, uffd);
 	setup_abort_handlers(vm, test);
 	vcpu_args_set(vm, 0, 1, test);
 
@@ -565,7 +682,12 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	sync_stats_from_guest(vm);
 	ucall_uninit(vm);
 	kvm_vm_free(vm);
+	free_uffd(test, uffd);
 
+	/*
+	 * Make sure this is called after the uffd threads have exited (and
+	 * updated their respective event counters).
+	 */
 	if (!skip_test)
 		check_event_counts(test);
 }
@@ -616,6 +738,7 @@ int main(int argc, char *argv[])
 #define SNAME(s)			#s
 #define SCAT2(a, b)			SNAME(a ## _ ## b)
 #define SCAT3(a, b, c)			SCAT2(a, SCAT2(b, c))
+#define SCAT4(a, b, c, d)		SCAT2(a, SCAT3(b, c, d))
 
 #define _CHECK(_test)			_CHECK_##_test
 #define _PREPARE(_test)			_PREPARE_##_test
@@ -646,6 +769,20 @@ int main(int argc, char *argv[])
 	.expected_events	= { 0 },					\
 }
 
+#define TEST_UFFD(_access, _with_af, _mark_cmd,					\
+		  _uffd_test_handler, _uffd_pt_handler, _uffd_faults)		\
+{										\
+	.name			= SCAT4(uffd, _access, _with_af, #_mark_cmd),	\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.guest_test		= _access,					\
+	.mem_mark_cmd		= _mark_cmd,					\
+	.guest_test_check	= { _CHECK(_with_af) },				\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= _uffd_pt_handler,				\
+	.expected_events	= { .uffd_faults = _uffd_faults, },		\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -668,6 +805,36 @@ static struct test_desc tests[] = {
 	TEST_ACCESS(guest_at, no_af, CMD_HOLE_TEST),
 	TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_TEST),
 
+	/*
+	 * Punch holes in the test and PT memslots and mark them for
+	 * userfaultfd handling. This should result in 2 faults: the test
+	 * access and its respective S1 page table walk (S1PTW).
+	 */
+	TEST_UFFD(guest_read64, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	/* no_af should also lead to a PT write. */
+	TEST_UFFD(guest_read64, no_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	/* Note how that cas invokes the read handler. */
+	TEST_UFFD(guest_cas, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	/*
+	 * Can't test guest_at with_af as it's IMPDEF whether the AF is set.
+	 * The S1PTW fault should still be marked as a write.
+	 */
+	TEST_UFFD(guest_at, no_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 1),
+	TEST_UFFD(guest_ld_preidx, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_write64, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_write_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_dc_zva, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_write_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_st_preidx, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_write_handler, uffd_pt_write_handler, 2),
+	TEST_UFFD(guest_exec, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
+			uffd_test_read_handler, uffd_pt_write_handler, 2),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v3 11/13] KVM: selftests: aarch64: Add dirty logging tests into page_fault_test

[Ricardo Koller]

Add some dirty logging tests into page_fault_test. Mark the data and/or
page-table memslots for dirty logging, perform some accesses, and check
that the dirty log bits are set or clean when expected.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index bee525625956..342170e207b0 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -43,6 +43,12 @@
 #define CMD_SKIP_TEST				(1ULL << 1)
 #define CMD_HOLE_PT				(1ULL << 2)
 #define CMD_HOLE_TEST				(1ULL << 3)
+#define CMD_RECREATE_PT_MEMSLOT_WR		(1ULL << 4)
+#define CMD_CHECK_WRITE_IN_DIRTY_LOG		(1ULL << 5)
+#define CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG		(1ULL << 6)
+#define CMD_CHECK_NO_WRITE_IN_DIRTY_LOG		(1ULL << 7)
+#define CMD_CHECK_NO_S1PTW_WR_IN_DIRTY_LOG	(1ULL << 8)
+#define CMD_SET_PTE_AF				(1ULL << 9)
 
 #define PREPARE_FN_NR				10
 #define CHECK_FN_NR				10
@@ -269,6 +275,21 @@ static void guest_check_pte_af(void)
 	GUEST_ASSERT_EQ(*((uint64_t *)TEST_PTE_GVA) & PTE_AF, PTE_AF);
 }
 
+static void guest_check_write_in_dirty_log(void)
+{
+	GUEST_SYNC(CMD_CHECK_WRITE_IN_DIRTY_LOG);
+}
+
+static void guest_check_no_write_in_dirty_log(void)
+{
+	GUEST_SYNC(CMD_CHECK_NO_WRITE_IN_DIRTY_LOG);
+}
+
+static void guest_check_s1ptw_wr_in_dirty_log(void)
+{
+	GUEST_SYNC(CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG);
+}
+
 static void guest_exec(void)
 {
 	int (*code)(void) = (int (*)(void))TEST_EXEC_GVA;
@@ -399,6 +420,19 @@ static void punch_hole_in_memslot(struct kvm_vm *vm,
 	}
 }
 
+static bool check_write_in_dirty_log(struct kvm_vm *vm,
+		struct memslot_desc *ms, uint64_t host_pg_nr)
+{
+	unsigned long *bmap;
+	bool first_page_dirty;
+
+	bmap = bitmap_zalloc(ms->size / getpagesize());
+	kvm_vm_get_dirty_log(vm, ms->idx, bmap);
+	first_page_dirty = test_bit(host_pg_nr, bmap);
+	free(bmap);
+	return first_page_dirty;
+}
+
 /* Returns false when the test was skipped. */
 static bool handle_cmd(struct kvm_vm *vm, int cmd)
 {
@@ -409,6 +443,18 @@ static bool handle_cmd(struct kvm_vm *vm, int cmd)
 		punch_hole_in_memslot(vm, &memslot[PT]);
 	if (cmd & CMD_HOLE_TEST)
 		punch_hole_in_memslot(vm, &memslot[TEST]);
+	if (cmd & CMD_CHECK_WRITE_IN_DIRTY_LOG)
+		TEST_ASSERT(check_write_in_dirty_log(vm, &memslot[TEST], 0),
+				"Missing write in dirty log");
+	if (cmd & CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG)
+		TEST_ASSERT(check_write_in_dirty_log(vm, &memslot[PT], 0),
+				"Missing s1ptw write in dirty log");
+	if (cmd & CMD_CHECK_NO_WRITE_IN_DIRTY_LOG)
+		TEST_ASSERT(!check_write_in_dirty_log(vm, &memslot[TEST], 0),
+				"Unexpected write in dirty log");
+	if (cmd & CMD_CHECK_NO_S1PTW_WR_IN_DIRTY_LOG)
+		TEST_ASSERT(!check_write_in_dirty_log(vm, &memslot[PT], 0),
+				"Unexpected s1ptw write in dirty log");
 
 	return true;
 }
@@ -783,6 +829,19 @@ int main(int argc, char *argv[])
 	.expected_events	= { .uffd_faults = _uffd_faults, },		\
 }
 
+#define TEST_DIRTY_LOG(_access, _with_af, _test_check)				\
+{										\
+	.name			= SCAT3(dirty_log, _access, _with_af),		\
+	.test_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.pt_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.guest_test		= _access,					\
+	.guest_test_check	= { _CHECK(_with_af), _test_check,		\
+				    guest_check_s1ptw_wr_in_dirty_log},		\
+	.expected_events	= { 0 },					\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -835,6 +894,21 @@ static struct test_desc tests[] = {
 	TEST_UFFD(guest_exec, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
 			uffd_test_read_handler, uffd_pt_write_handler, 2),
 
+	/*
+	 * Try accesses when the test and PT memslots are both tracked for
+	 * dirty logging.
+	 */
+	TEST_DIRTY_LOG(guest_read64, with_af, guest_check_no_write_in_dirty_log),
+	/* no_af should also lead to a PT write. */
+	TEST_DIRTY_LOG(guest_read64, no_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_ld_preidx, with_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_at, no_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_exec, with_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_write64, with_af, guest_check_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_cas, with_af, guest_check_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_dc_zva, with_af, guest_check_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_st_preidx, with_af, guest_check_write_in_dirty_log),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 11/13] KVM: selftests: aarch64: Add dirty logging tests into page_fault_test

[Ricardo Koller]

Add some dirty logging tests into page_fault_test. Mark the data and/or
page-table memslots for dirty logging, perform some accesses, and check
that the dirty log bits are set or clean when expected.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index bee525625956..342170e207b0 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -43,6 +43,12 @@
 #define CMD_SKIP_TEST				(1ULL << 1)
 #define CMD_HOLE_PT				(1ULL << 2)
 #define CMD_HOLE_TEST				(1ULL << 3)
+#define CMD_RECREATE_PT_MEMSLOT_WR		(1ULL << 4)
+#define CMD_CHECK_WRITE_IN_DIRTY_LOG		(1ULL << 5)
+#define CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG		(1ULL << 6)
+#define CMD_CHECK_NO_WRITE_IN_DIRTY_LOG		(1ULL << 7)
+#define CMD_CHECK_NO_S1PTW_WR_IN_DIRTY_LOG	(1ULL << 8)
+#define CMD_SET_PTE_AF				(1ULL << 9)
 
 #define PREPARE_FN_NR				10
 #define CHECK_FN_NR				10
@@ -269,6 +275,21 @@ static void guest_check_pte_af(void)
 	GUEST_ASSERT_EQ(*((uint64_t *)TEST_PTE_GVA) & PTE_AF, PTE_AF);
 }
 
+static void guest_check_write_in_dirty_log(void)
+{
+	GUEST_SYNC(CMD_CHECK_WRITE_IN_DIRTY_LOG);
+}
+
+static void guest_check_no_write_in_dirty_log(void)
+{
+	GUEST_SYNC(CMD_CHECK_NO_WRITE_IN_DIRTY_LOG);
+}
+
+static void guest_check_s1ptw_wr_in_dirty_log(void)
+{
+	GUEST_SYNC(CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG);
+}
+
 static void guest_exec(void)
 {
 	int (*code)(void) = (int (*)(void))TEST_EXEC_GVA;
@@ -399,6 +420,19 @@ static void punch_hole_in_memslot(struct kvm_vm *vm,
 	}
 }
 
+static bool check_write_in_dirty_log(struct kvm_vm *vm,
+		struct memslot_desc *ms, uint64_t host_pg_nr)
+{
+	unsigned long *bmap;
+	bool first_page_dirty;
+
+	bmap = bitmap_zalloc(ms->size / getpagesize());
+	kvm_vm_get_dirty_log(vm, ms->idx, bmap);
+	first_page_dirty = test_bit(host_pg_nr, bmap);
+	free(bmap);
+	return first_page_dirty;
+}
+
 /* Returns false when the test was skipped. */
 static bool handle_cmd(struct kvm_vm *vm, int cmd)
 {
@@ -409,6 +443,18 @@ static bool handle_cmd(struct kvm_vm *vm, int cmd)
 		punch_hole_in_memslot(vm, &memslot[PT]);
 	if (cmd & CMD_HOLE_TEST)
 		punch_hole_in_memslot(vm, &memslot[TEST]);
+	if (cmd & CMD_CHECK_WRITE_IN_DIRTY_LOG)
+		TEST_ASSERT(check_write_in_dirty_log(vm, &memslot[TEST], 0),
+				"Missing write in dirty log");
+	if (cmd & CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG)
+		TEST_ASSERT(check_write_in_dirty_log(vm, &memslot[PT], 0),
+				"Missing s1ptw write in dirty log");
+	if (cmd & CMD_CHECK_NO_WRITE_IN_DIRTY_LOG)
+		TEST_ASSERT(!check_write_in_dirty_log(vm, &memslot[TEST], 0),
+				"Unexpected write in dirty log");
+	if (cmd & CMD_CHECK_NO_S1PTW_WR_IN_DIRTY_LOG)
+		TEST_ASSERT(!check_write_in_dirty_log(vm, &memslot[PT], 0),
+				"Unexpected s1ptw write in dirty log");
 
 	return true;
 }
@@ -783,6 +829,19 @@ int main(int argc, char *argv[])
 	.expected_events	= { .uffd_faults = _uffd_faults, },		\
 }
 
+#define TEST_DIRTY_LOG(_access, _with_af, _test_check)				\
+{										\
+	.name			= SCAT3(dirty_log, _access, _with_af),		\
+	.test_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.pt_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.guest_test		= _access,					\
+	.guest_test_check	= { _CHECK(_with_af), _test_check,		\
+				    guest_check_s1ptw_wr_in_dirty_log},		\
+	.expected_events	= { 0 },					\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -835,6 +894,21 @@ static struct test_desc tests[] = {
 	TEST_UFFD(guest_exec, with_af, CMD_HOLE_TEST | CMD_HOLE_PT,
 			uffd_test_read_handler, uffd_pt_write_handler, 2),
 
+	/*
+	 * Try accesses when the test and PT memslots are both tracked for
+	 * dirty logging.
+	 */
+	TEST_DIRTY_LOG(guest_read64, with_af, guest_check_no_write_in_dirty_log),
+	/* no_af should also lead to a PT write. */
+	TEST_DIRTY_LOG(guest_read64, no_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_ld_preidx, with_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_at, no_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_exec, with_af, guest_check_no_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_write64, with_af, guest_check_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_cas, with_af, guest_check_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_dc_zva, with_af, guest_check_write_in_dirty_log),
+	TEST_DIRTY_LOG(guest_st_preidx, with_af, guest_check_write_in_dirty_log),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v3 12/13] KVM: selftests: aarch64: Add readonly memslot tests into page_fault_test

[Ricardo Koller]

Add some readonly memslot tests into page_fault_test. Mark the data
and/or page-table memslots as readonly, perform some accesses, and check
that the right fault is triggered when expected (e.g., a store with no
write-back should lead to an mmio exit).

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 151 +++++++++++++++++-
 1 file changed, 148 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index 342170e207b0..70085db873d3 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -80,6 +80,7 @@ struct memslot_desc {
 
 static struct event_cnt {
 	int aborts;
+	int mmio_exits;
 	int fail_vcpu_runs;
 	int uffd_faults;
 	/* uffd_faults is incremented from multiple threads. */
@@ -97,6 +98,8 @@ struct test_desc {
 	int (*uffd_test_handler)(int mode, int uffd, struct uffd_msg *msg);
 	void (*dabt_handler)(struct ex_regs *regs);
 	void (*iabt_handler)(struct ex_regs *regs);
+	void (*mmio_handler)(struct kvm_run *run);
+	void (*fail_vcpu_run_handler)(int ret);
 	uint32_t pt_memslot_flags;
 	uint32_t test_memslot_flags;
 	bool skip;
@@ -342,6 +345,20 @@ static void guest_code(struct test_desc *test)
 	GUEST_DONE();
 }
 
+static void dabt_s1ptw_on_ro_memslot_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_EQ(read_sysreg(far_el1), TEST_GVA);
+	events.aborts += 1;
+	GUEST_SYNC(CMD_RECREATE_PT_MEMSLOT_WR);
+}
+
+static void iabt_s1ptw_on_ro_memslot_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_EQ(regs->pc, TEST_EXEC_GVA);
+	events.aborts += 1;
+	GUEST_SYNC(CMD_RECREATE_PT_MEMSLOT_WR);
+}
+
 static void no_dabt_handler(struct ex_regs *regs)
 {
 	GUEST_ASSERT_1(false, read_sysreg(far_el1));
@@ -420,6 +437,49 @@ static void punch_hole_in_memslot(struct kvm_vm *vm,
 	}
 }
 
+static int __memory_region_add(struct kvm_vm *vm, void *mem, uint32_t slot,
+		uint32_t size, uint64_t guest_addr,
+		uint32_t flags)
+{
+	struct kvm_userspace_memory_region region;
+	int ret;
+
+	region.slot = slot;
+	region.flags = flags;
+	region.guest_phys_addr = guest_addr;
+	region.memory_size = size;
+	region.userspace_addr = (uintptr_t) mem;
+	ret = ioctl(vm_get_fd(vm), KVM_SET_USER_MEMORY_REGION, &region);
+
+	return ret;
+}
+
+static void recreate_memslot(struct kvm_vm *vm, struct memslot_desc *ms,
+		uint32_t flags)
+{
+	__memory_region_add(vm, ms->hva, ms->idx, 0, ms->gpa, 0);
+	__memory_region_add(vm, ms->hva, ms->idx, ms->size, ms->gpa, flags);
+}
+
+static void mmio_on_test_gpa_handler(struct kvm_run *run)
+{
+	ASSERT_EQ(run->mmio.phys_addr, memslot[TEST].gpa);
+
+	memcpy(memslot[TEST].hva, run->mmio.data, run->mmio.len);
+	events.mmio_exits += 1;
+}
+
+static void mmio_no_handler(struct kvm_run *run)
+{
+	uint64_t data;
+
+	memcpy(&data, run->mmio.data, sizeof(data));
+	pr_debug("addr=%lld len=%d w=%d data=%lx\n",
+			run->mmio.phys_addr, run->mmio.len,
+			run->mmio.is_write, data);
+	TEST_FAIL("There was no MMIO exit expected.");
+}
+
 static bool check_write_in_dirty_log(struct kvm_vm *vm,
 		struct memslot_desc *ms, uint64_t host_pg_nr)
 {
@@ -443,6 +503,8 @@ static bool handle_cmd(struct kvm_vm *vm, int cmd)
 		punch_hole_in_memslot(vm, &memslot[PT]);
 	if (cmd & CMD_HOLE_TEST)
 		punch_hole_in_memslot(vm, &memslot[TEST]);
+	if (cmd & CMD_RECREATE_PT_MEMSLOT_WR)
+		recreate_memslot(vm, &memslot[PT], 0);
 	if (cmd & CMD_CHECK_WRITE_IN_DIRTY_LOG)
 		TEST_ASSERT(check_write_in_dirty_log(vm, &memslot[TEST], 0),
 				"Missing write in dirty log");
@@ -471,6 +533,13 @@ void fail_vcpu_run_no_handler(int ret)
 	TEST_FAIL("Unexpected vcpu run failure\n");
 }
 
+void fail_vcpu_run_mmio_no_syndrome_handler(int ret)
+{
+	TEST_ASSERT(errno == ENOSYS, "The mmio handler in the kernel"
+			" should have returned not implemented.");
+	events.fail_vcpu_runs += 1;
+}
+
 static uint64_t get_total_guest_pages(enum vm_guest_mode mode,
 		struct test_params *p)
 {
@@ -626,10 +695,21 @@ static void setup_uffd(enum vm_guest_mode mode, struct test_params *p,
 				test->uffd_test_handler);
 }
 
+static void setup_default_handlers(struct test_desc *test)
+{
+	if (!test->mmio_handler)
+		test->mmio_handler = mmio_no_handler;
+
+	if (!test->fail_vcpu_run_handler)
+		test->fail_vcpu_run_handler = fail_vcpu_run_no_handler;
+}
+
 static void check_event_counts(struct test_desc *test)
 {
 	ASSERT_EQ(test->expected_events.aborts,	events.aborts);
 	ASSERT_EQ(test->expected_events.uffd_faults, events.uffd_faults);
+	ASSERT_EQ(test->expected_events.mmio_exits, events.mmio_exits);
+	ASSERT_EQ(test->expected_events.fail_vcpu_runs, events.fail_vcpu_runs);
 }
 
 static void free_uffd(struct test_desc *test, struct uffd_desc **uffd)
@@ -661,12 +741,20 @@ static void reset_event_counts(void)
 
 static bool vcpu_run_loop(struct kvm_vm *vm, struct test_desc *test)
 {
+	struct kvm_run *run;
 	bool skip_test = false;
 	struct ucall uc;
-	int stage;
+	int stage, ret;
+
+	run = vcpu_state(vm, VCPU_ID);
 
 	for (stage = 0; ; stage++) {
-		vcpu_run(vm, VCPU_ID);
+		ret = _vcpu_run(vm, VCPU_ID);
+		if (ret) {
+			test->fail_vcpu_run_handler(ret);
+			pr_debug("Done.\n");
+			goto done;
+		}
 
 		switch (get_ucall(vm, VCPU_ID, &uc)) {
 		case UCALL_SYNC:
@@ -684,6 +772,10 @@ static bool vcpu_run_loop(struct kvm_vm *vm, struct test_desc *test)
 		case UCALL_DONE:
 			pr_debug("Done.\n");
 			goto done;
+		case UCALL_NONE:
+			if (run->exit_reason == KVM_EXIT_MMIO)
+				test->mmio_handler(run);
+			break;
 		default:
 			TEST_FAIL("Unknown ucall %lu", uc.cmd);
 		}
@@ -708,6 +800,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	ucall_init(vm, NULL);
 
 	reset_event_counts();
+	setup_abort_handlers(vm, test);
 	setup_memslots(vm, mode, p);
 
 	/*
@@ -718,7 +811,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	 */
 	load_exec_code_for_test();
 	setup_uffd(mode, p, uffd);
-	setup_abort_handlers(vm, test);
+	setup_default_handlers(test);
 	vcpu_args_set(vm, 0, 1, test);
 
 	sync_global_to_guest(vm, memslot);
@@ -842,6 +935,32 @@ int main(int argc, char *argv[])
 	.expected_events	= { 0 },					\
 }
 
+#define TEST_RO_MEMSLOT(_access, _mmio_handler, _mmio_exits,			\
+			_iabt_handler, _dabt_handler, _aborts)			\
+{										\
+	.name			= SCAT3(ro_memslot, _access, _with_af),		\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.guest_prepare		= { _PREPARE(_access) },			\
+	.guest_test 		= _access,					\
+	.mmio_handler		= _mmio_handler,				\
+	.iabt_handler		= _iabt_handler,				\
+	.dabt_handler		= _dabt_handler,				\
+	.expected_events	= { .mmio_exits = _mmio_exits,			\
+				    .aborts = _aborts},				\
+}
+
+#define TEST_RO_MEMSLOT_NO_SYNDROME(_access)					\
+{										\
+	.name			= SCAT2(ro_memslot_no_syndrome, _access),	\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.guest_test 		= _access,					\
+	.dabt_handler		= dabt_s1ptw_on_ro_memslot_handler,		\
+	.fail_vcpu_run_handler	= fail_vcpu_run_mmio_no_syndrome_handler,	\
+	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1 },		\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -909,6 +1028,32 @@ static struct test_desc tests[] = {
 	TEST_DIRTY_LOG(guest_dc_zva, with_af, guest_check_write_in_dirty_log),
 	TEST_DIRTY_LOG(guest_st_preidx, with_af, guest_check_write_in_dirty_log),
 
+	/*
+	 * Try accesses when both the test and PT memslots are marked read-only
+	 * (with KVM_MEM_READONLY). The S1PTW results in an guest abort, whose
+	 * handler asks the host to recreate the memslot as writable. Note that
+	 * guests would typically panic as there's no way of asking the VMM to
+	 * perform the write for the guest (or make the memslot writable).  The
+	 * instruction then is executed: writes with a syndrome result in an
+	 * MMIO exit, writes with no syndrome (e.g., CAS) result in a failed
+	 * vcpu run, and reads/execs with and without syndroms do not fault.
+	 * Check that the expected aborts, failed vcpu runs, mmio exits
+	 * actually happen.
+	 */
+	TEST_RO_MEMSLOT(guest_read64, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT(guest_ld_preidx, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT(guest_at, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT(guest_exec, 0, 0, iabt_s1ptw_on_ro_memslot_handler,
+			0, 1),
+	TEST_RO_MEMSLOT(guest_write64, mmio_on_test_gpa_handler, 1, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT_NO_SYNDROME(guest_dc_zva),
+	TEST_RO_MEMSLOT_NO_SYNDROME(guest_cas),
+	TEST_RO_MEMSLOT_NO_SYNDROME(guest_st_preidx),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 12/13] KVM: selftests: aarch64: Add readonly memslot tests into page_fault_test

[Ricardo Koller]

Add some readonly memslot tests into page_fault_test. Mark the data
and/or page-table memslots as readonly, perform some accesses, and check
that the right fault is triggered when expected (e.g., a store with no
write-back should lead to an mmio exit).

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 151 +++++++++++++++++-
 1 file changed, 148 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index 342170e207b0..70085db873d3 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -80,6 +80,7 @@ struct memslot_desc {
 
 static struct event_cnt {
 	int aborts;
+	int mmio_exits;
 	int fail_vcpu_runs;
 	int uffd_faults;
 	/* uffd_faults is incremented from multiple threads. */
@@ -97,6 +98,8 @@ struct test_desc {
 	int (*uffd_test_handler)(int mode, int uffd, struct uffd_msg *msg);
 	void (*dabt_handler)(struct ex_regs *regs);
 	void (*iabt_handler)(struct ex_regs *regs);
+	void (*mmio_handler)(struct kvm_run *run);
+	void (*fail_vcpu_run_handler)(int ret);
 	uint32_t pt_memslot_flags;
 	uint32_t test_memslot_flags;
 	bool skip;
@@ -342,6 +345,20 @@ static void guest_code(struct test_desc *test)
 	GUEST_DONE();
 }
 
+static void dabt_s1ptw_on_ro_memslot_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_EQ(read_sysreg(far_el1), TEST_GVA);
+	events.aborts += 1;
+	GUEST_SYNC(CMD_RECREATE_PT_MEMSLOT_WR);
+}
+
+static void iabt_s1ptw_on_ro_memslot_handler(struct ex_regs *regs)
+{
+	GUEST_ASSERT_EQ(regs->pc, TEST_EXEC_GVA);
+	events.aborts += 1;
+	GUEST_SYNC(CMD_RECREATE_PT_MEMSLOT_WR);
+}
+
 static void no_dabt_handler(struct ex_regs *regs)
 {
 	GUEST_ASSERT_1(false, read_sysreg(far_el1));
@@ -420,6 +437,49 @@ static void punch_hole_in_memslot(struct kvm_vm *vm,
 	}
 }
 
+static int __memory_region_add(struct kvm_vm *vm, void *mem, uint32_t slot,
+		uint32_t size, uint64_t guest_addr,
+		uint32_t flags)
+{
+	struct kvm_userspace_memory_region region;
+	int ret;
+
+	region.slot = slot;
+	region.flags = flags;
+	region.guest_phys_addr = guest_addr;
+	region.memory_size = size;
+	region.userspace_addr = (uintptr_t) mem;
+	ret = ioctl(vm_get_fd(vm), KVM_SET_USER_MEMORY_REGION, &region);
+
+	return ret;
+}
+
+static void recreate_memslot(struct kvm_vm *vm, struct memslot_desc *ms,
+		uint32_t flags)
+{
+	__memory_region_add(vm, ms->hva, ms->idx, 0, ms->gpa, 0);
+	__memory_region_add(vm, ms->hva, ms->idx, ms->size, ms->gpa, flags);
+}
+
+static void mmio_on_test_gpa_handler(struct kvm_run *run)
+{
+	ASSERT_EQ(run->mmio.phys_addr, memslot[TEST].gpa);
+
+	memcpy(memslot[TEST].hva, run->mmio.data, run->mmio.len);
+	events.mmio_exits += 1;
+}
+
+static void mmio_no_handler(struct kvm_run *run)
+{
+	uint64_t data;
+
+	memcpy(&data, run->mmio.data, sizeof(data));
+	pr_debug("addr=%lld len=%d w=%d data=%lx\n",
+			run->mmio.phys_addr, run->mmio.len,
+			run->mmio.is_write, data);
+	TEST_FAIL("There was no MMIO exit expected.");
+}
+
 static bool check_write_in_dirty_log(struct kvm_vm *vm,
 		struct memslot_desc *ms, uint64_t host_pg_nr)
 {
@@ -443,6 +503,8 @@ static bool handle_cmd(struct kvm_vm *vm, int cmd)
 		punch_hole_in_memslot(vm, &memslot[PT]);
 	if (cmd & CMD_HOLE_TEST)
 		punch_hole_in_memslot(vm, &memslot[TEST]);
+	if (cmd & CMD_RECREATE_PT_MEMSLOT_WR)
+		recreate_memslot(vm, &memslot[PT], 0);
 	if (cmd & CMD_CHECK_WRITE_IN_DIRTY_LOG)
 		TEST_ASSERT(check_write_in_dirty_log(vm, &memslot[TEST], 0),
 				"Missing write in dirty log");
@@ -471,6 +533,13 @@ void fail_vcpu_run_no_handler(int ret)
 	TEST_FAIL("Unexpected vcpu run failure\n");
 }
 
+void fail_vcpu_run_mmio_no_syndrome_handler(int ret)
+{
+	TEST_ASSERT(errno == ENOSYS, "The mmio handler in the kernel"
+			" should have returned not implemented.");
+	events.fail_vcpu_runs += 1;
+}
+
 static uint64_t get_total_guest_pages(enum vm_guest_mode mode,
 		struct test_params *p)
 {
@@ -626,10 +695,21 @@ static void setup_uffd(enum vm_guest_mode mode, struct test_params *p,
 				test->uffd_test_handler);
 }
 
+static void setup_default_handlers(struct test_desc *test)
+{
+	if (!test->mmio_handler)
+		test->mmio_handler = mmio_no_handler;
+
+	if (!test->fail_vcpu_run_handler)
+		test->fail_vcpu_run_handler = fail_vcpu_run_no_handler;
+}
+
 static void check_event_counts(struct test_desc *test)
 {
 	ASSERT_EQ(test->expected_events.aborts,	events.aborts);
 	ASSERT_EQ(test->expected_events.uffd_faults, events.uffd_faults);
+	ASSERT_EQ(test->expected_events.mmio_exits, events.mmio_exits);
+	ASSERT_EQ(test->expected_events.fail_vcpu_runs, events.fail_vcpu_runs);
 }
 
 static void free_uffd(struct test_desc *test, struct uffd_desc **uffd)
@@ -661,12 +741,20 @@ static void reset_event_counts(void)
 
 static bool vcpu_run_loop(struct kvm_vm *vm, struct test_desc *test)
 {
+	struct kvm_run *run;
 	bool skip_test = false;
 	struct ucall uc;
-	int stage;
+	int stage, ret;
+
+	run = vcpu_state(vm, VCPU_ID);
 
 	for (stage = 0; ; stage++) {
-		vcpu_run(vm, VCPU_ID);
+		ret = _vcpu_run(vm, VCPU_ID);
+		if (ret) {
+			test->fail_vcpu_run_handler(ret);
+			pr_debug("Done.\n");
+			goto done;
+		}
 
 		switch (get_ucall(vm, VCPU_ID, &uc)) {
 		case UCALL_SYNC:
@@ -684,6 +772,10 @@ static bool vcpu_run_loop(struct kvm_vm *vm, struct test_desc *test)
 		case UCALL_DONE:
 			pr_debug("Done.\n");
 			goto done;
+		case UCALL_NONE:
+			if (run->exit_reason == KVM_EXIT_MMIO)
+				test->mmio_handler(run);
+			break;
 		default:
 			TEST_FAIL("Unknown ucall %lu", uc.cmd);
 		}
@@ -708,6 +800,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	ucall_init(vm, NULL);
 
 	reset_event_counts();
+	setup_abort_handlers(vm, test);
 	setup_memslots(vm, mode, p);
 
 	/*
@@ -718,7 +811,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	 */
 	load_exec_code_for_test();
 	setup_uffd(mode, p, uffd);
-	setup_abort_handlers(vm, test);
+	setup_default_handlers(test);
 	vcpu_args_set(vm, 0, 1, test);
 
 	sync_global_to_guest(vm, memslot);
@@ -842,6 +935,32 @@ int main(int argc, char *argv[])
 	.expected_events	= { 0 },					\
 }
 
+#define TEST_RO_MEMSLOT(_access, _mmio_handler, _mmio_exits,			\
+			_iabt_handler, _dabt_handler, _aborts)			\
+{										\
+	.name			= SCAT3(ro_memslot, _access, _with_af),		\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.guest_prepare		= { _PREPARE(_access) },			\
+	.guest_test 		= _access,					\
+	.mmio_handler		= _mmio_handler,				\
+	.iabt_handler		= _iabt_handler,				\
+	.dabt_handler		= _dabt_handler,				\
+	.expected_events	= { .mmio_exits = _mmio_exits,			\
+				    .aborts = _aborts},				\
+}
+
+#define TEST_RO_MEMSLOT_NO_SYNDROME(_access)					\
+{										\
+	.name			= SCAT2(ro_memslot_no_syndrome, _access),	\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.guest_test 		= _access,					\
+	.dabt_handler		= dabt_s1ptw_on_ro_memslot_handler,		\
+	.fail_vcpu_run_handler	= fail_vcpu_run_mmio_no_syndrome_handler,	\
+	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1 },		\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -909,6 +1028,32 @@ static struct test_desc tests[] = {
 	TEST_DIRTY_LOG(guest_dc_zva, with_af, guest_check_write_in_dirty_log),
 	TEST_DIRTY_LOG(guest_st_preidx, with_af, guest_check_write_in_dirty_log),
 
+	/*
+	 * Try accesses when both the test and PT memslots are marked read-only
+	 * (with KVM_MEM_READONLY). The S1PTW results in an guest abort, whose
+	 * handler asks the host to recreate the memslot as writable. Note that
+	 * guests would typically panic as there's no way of asking the VMM to
+	 * perform the write for the guest (or make the memslot writable).  The
+	 * instruction then is executed: writes with a syndrome result in an
+	 * MMIO exit, writes with no syndrome (e.g., CAS) result in a failed
+	 * vcpu run, and reads/execs with and without syndroms do not fault.
+	 * Check that the expected aborts, failed vcpu runs, mmio exits
+	 * actually happen.
+	 */
+	TEST_RO_MEMSLOT(guest_read64, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT(guest_ld_preidx, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT(guest_at, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT(guest_exec, 0, 0, iabt_s1ptw_on_ro_memslot_handler,
+			0, 1),
+	TEST_RO_MEMSLOT(guest_write64, mmio_on_test_gpa_handler, 1, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1),
+	TEST_RO_MEMSLOT_NO_SYNDROME(guest_dc_zva),
+	TEST_RO_MEMSLOT_NO_SYNDROME(guest_cas),
+	TEST_RO_MEMSLOT_NO_SYNDROME(guest_st_preidx),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v3 13/13] KVM: selftests: aarch64: Add mix of tests into page_fault_test

[Ricardo Koller]

Add some mix of tests into page_fault_test: memslots with all the
pairwise combinations of read-only, userfaultfd, and dirty-logging.  For
example, writing into a read-only memslot which has a hole handled with
userfaultfd.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 178 ++++++++++++++++++
 1 file changed, 178 insertions(+)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index 70085db873d3..fd83f0adc17f 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -419,6 +419,12 @@ static int uffd_test_read_handler(int mode, int uffd, struct uffd_msg *msg)
 	return uffd_generic_handler(mode, uffd, msg, &memslot[TEST], false);
 }
 
+static int uffd_no_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	TEST_FAIL("There was no UFFD fault expected.");
+	return -1;
+}
+
 static void punch_hole_in_memslot(struct kvm_vm *vm,
 		struct memslot_desc *memslot)
 {
@@ -935,6 +941,22 @@ int main(int argc, char *argv[])
 	.expected_events	= { 0 },					\
 }
 
+#define TEST_UFFD_AND_DIRTY_LOG(_access, _with_af, _uffd_test_handler,		\
+		_uffd_faults, _test_check)					\
+{										\
+	.name			= SCAT3(uffd_and_dirty_log, _access, _with_af),	\
+	.test_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.pt_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.guest_test		= _access,					\
+	.mem_mark_cmd		= CMD_HOLE_TEST | CMD_HOLE_PT,			\
+	.guest_test_check	= { _CHECK(_with_af), _test_check },		\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= uffd_pt_write_handler,			\
+	.expected_events	= { .uffd_faults = _uffd_faults, },		\
+}
+
 #define TEST_RO_MEMSLOT(_access, _mmio_handler, _mmio_exits,			\
 			_iabt_handler, _dabt_handler, _aborts)			\
 {										\
@@ -961,6 +983,71 @@ int main(int argc, char *argv[])
 	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1 },		\
 }
 
+#define TEST_RO_MEMSLOT_AND_DIRTY_LOG(_access, _mmio_handler, _mmio_exits,	\
+				      _iabt_handler, _dabt_handler, _aborts,	\
+				      _test_check)				\
+{										\
+	.name			= SCAT3(ro_memslot, _access, _with_af),		\
+	.test_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.pt_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.guest_prepare		= { _PREPARE(_access) },			\
+	.guest_test 		= _access,					\
+	.guest_test_check	= { _test_check },				\
+	.mmio_handler		= _mmio_handler,				\
+	.iabt_handler		= _iabt_handler,				\
+	.dabt_handler		= _dabt_handler,				\
+	.expected_events	= { .mmio_exits = _mmio_exits,			\
+				    .aborts = _aborts},				\
+}
+
+#define TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(_access, _test_check)		\
+{										\
+	.name			= SCAT2(ro_memslot_no_syn_and_dlog, _access),	\
+	.test_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.pt_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.guest_test 		= _access,					\
+	.guest_test_check	= { _test_check },				\
+	.dabt_handler		= dabt_s1ptw_on_ro_memslot_handler,		\
+	.fail_vcpu_run_handler	= fail_vcpu_run_mmio_no_syndrome_handler,	\
+	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1 },		\
+}
+
+#define TEST_RO_MEMSLOT_AND_UFFD(_access, _mmio_handler, _mmio_exits,		\
+				 _iabt_handler, _dabt_handler, _aborts,		\
+				_uffd_test_handler, _uffd_faults)		\
+{										\
+	.name			= SCAT2(ro_memslot_uffd, _access),		\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.mem_mark_cmd		= CMD_HOLE_TEST | CMD_HOLE_PT,			\
+	.guest_prepare		= { _PREPARE(_access) },			\
+	.guest_test 		= _access,					\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= uffd_pt_write_handler,			\
+	.mmio_handler		= _mmio_handler,				\
+	.iabt_handler		= _iabt_handler,				\
+	.dabt_handler		= _dabt_handler,				\
+	.expected_events	= { .mmio_exits = _mmio_exits,			\
+				    .aborts = _aborts,				\
+				    .uffd_faults = _uffd_faults },		\
+}
+
+#define TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(_access, _uffd_test_handler,	\
+					     _uffd_faults)			\
+{										\
+	.name			= SCAT2(ro_memslot_no_syndrome, _access),	\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.mem_mark_cmd		= CMD_HOLE_TEST | CMD_HOLE_PT,			\
+	.guest_test 		= _access,					\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= uffd_pt_write_handler,			\
+	.dabt_handler		= dabt_s1ptw_on_ro_memslot_handler,		\
+	.fail_vcpu_run_handler	= fail_vcpu_run_mmio_no_syndrome_handler,	\
+	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1,		\
+				    .uffd_faults = _uffd_faults },		\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -1028,6 +1115,35 @@ static struct test_desc tests[] = {
 	TEST_DIRTY_LOG(guest_dc_zva, with_af, guest_check_write_in_dirty_log),
 	TEST_DIRTY_LOG(guest_st_preidx, with_af, guest_check_write_in_dirty_log),
 
+	/*
+	 * Access when the test and PT memslots are both marked for dirty
+	 * logging and UFFD at the same time. The expected result is that
+	 * writes should mark the dirty log and trigger a userfaultfd write
+	 * fault.  Reads/execs should result in a read userfaultfd fault, and
+	 * nothing in the dirty log.  The S1PTW in all cases should result in a
+	 * write in the dirty log and a userfaultfd write.
+	 */
+	TEST_UFFD_AND_DIRTY_LOG(guest_read64, with_af, uffd_test_read_handler, 2,
+			guest_check_no_write_in_dirty_log),
+	/* no_af should also lead to a PT write. */
+	TEST_UFFD_AND_DIRTY_LOG(guest_read64, no_af, uffd_test_read_handler, 2,
+			guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_ld_preidx, with_af, uffd_test_read_handler,
+			2, guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_at, with_af, 0, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_exec, with_af, uffd_test_read_handler, 2,
+			guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_write64, with_af, uffd_test_write_handler,
+			2, guest_check_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_cas, with_af, uffd_test_read_handler, 2,
+			guest_check_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_dc_zva, with_af, uffd_test_write_handler,
+			2, guest_check_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_st_preidx, with_af,
+			uffd_test_write_handler, 2,
+			guest_check_write_in_dirty_log),
+
 	/*
 	 * Try accesses when both the test and PT memslots are marked read-only
 	 * (with KVM_MEM_READONLY). The S1PTW results in an guest abort, whose
@@ -1054,6 +1170,68 @@ static struct test_desc tests[] = {
 	TEST_RO_MEMSLOT_NO_SYNDROME(guest_cas),
 	TEST_RO_MEMSLOT_NO_SYNDROME(guest_st_preidx),
 
+	/*
+	 * Access when both the test and PT memslots are read-only and marked
+	 * for dirty logging at the same time. The expected result is that
+	 * there should be no write in the dirty log. The S1PTW results in an
+	 * abort which is handled by asking the host to recreate the memslot as
+	 * writable. The readonly handling are the same as if the memslots were
+	 * not marked for dirty logging: writes with a syndrome result in an
+	 * MMIO exit, and writes with no syndrome result in a failed vcpu run.
+	 */
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_read64, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_ld_preidx, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_at, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_exec, 0, 0,
+			iabt_s1ptw_on_ro_memslot_handler, 0, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_write64, mmio_on_test_gpa_handler,
+			1, 0, dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(guest_dc_zva,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(guest_cas,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(guest_st_preidx,
+			guest_check_no_write_in_dirty_log),
+
+	/*
+	 * Access when both the test and PT memslots are read-only, and punched
+	 * with holes tracked with userfaultfd.  The expected result is the
+	 * union of both userfaultfd and read-only behaviors. For example,
+	 * write accesses result in a userfaultfd write fault and an MMIO exit.
+	 * Writes with no syndrome result in a failed vcpu run and no
+	 * userfaultfd write fault. Reads only result in userfaultfd getting
+	 * triggered.
+	 */
+	TEST_RO_MEMSLOT_AND_UFFD(guest_read64, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_ld_preidx, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_at, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_no_handler, 1),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_exec, 0, 0,
+			iabt_s1ptw_on_ro_memslot_handler, 0, 1,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_write64, mmio_on_test_gpa_handler, 1, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_test_write_handler, 2),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(guest_cas,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(guest_dc_zva,
+			uffd_no_handler, 1),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(guest_st_preidx,
+			uffd_no_handler, 1),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 13/13] KVM: selftests: aarch64: Add mix of tests into page_fault_test

[Ricardo Koller]

Add some mix of tests into page_fault_test: memslots with all the
pairwise combinations of read-only, userfaultfd, and dirty-logging.  For
example, writing into a read-only memslot which has a hole handled with
userfaultfd.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
 .../selftests/kvm/aarch64/page_fault_test.c   | 178 ++++++++++++++++++
 1 file changed, 178 insertions(+)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index 70085db873d3..fd83f0adc17f 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -419,6 +419,12 @@ static int uffd_test_read_handler(int mode, int uffd, struct uffd_msg *msg)
 	return uffd_generic_handler(mode, uffd, msg, &memslot[TEST], false);
 }
 
+static int uffd_no_handler(int mode, int uffd, struct uffd_msg *msg)
+{
+	TEST_FAIL("There was no UFFD fault expected.");
+	return -1;
+}
+
 static void punch_hole_in_memslot(struct kvm_vm *vm,
 		struct memslot_desc *memslot)
 {
@@ -935,6 +941,22 @@ int main(int argc, char *argv[])
 	.expected_events	= { 0 },					\
 }
 
+#define TEST_UFFD_AND_DIRTY_LOG(_access, _with_af, _uffd_test_handler,		\
+		_uffd_faults, _test_check)					\
+{										\
+	.name			= SCAT3(uffd_and_dirty_log, _access, _with_af),	\
+	.test_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.pt_memslot_flags	= KVM_MEM_LOG_DIRTY_PAGES,			\
+	.guest_prepare		= { _PREPARE(_with_af),				\
+				    _PREPARE(_access) },			\
+	.guest_test		= _access,					\
+	.mem_mark_cmd		= CMD_HOLE_TEST | CMD_HOLE_PT,			\
+	.guest_test_check	= { _CHECK(_with_af), _test_check },		\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= uffd_pt_write_handler,			\
+	.expected_events	= { .uffd_faults = _uffd_faults, },		\
+}
+
 #define TEST_RO_MEMSLOT(_access, _mmio_handler, _mmio_exits,			\
 			_iabt_handler, _dabt_handler, _aborts)			\
 {										\
@@ -961,6 +983,71 @@ int main(int argc, char *argv[])
 	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1 },		\
 }
 
+#define TEST_RO_MEMSLOT_AND_DIRTY_LOG(_access, _mmio_handler, _mmio_exits,	\
+				      _iabt_handler, _dabt_handler, _aborts,	\
+				      _test_check)				\
+{										\
+	.name			= SCAT3(ro_memslot, _access, _with_af),		\
+	.test_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.pt_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.guest_prepare		= { _PREPARE(_access) },			\
+	.guest_test 		= _access,					\
+	.guest_test_check	= { _test_check },				\
+	.mmio_handler		= _mmio_handler,				\
+	.iabt_handler		= _iabt_handler,				\
+	.dabt_handler		= _dabt_handler,				\
+	.expected_events	= { .mmio_exits = _mmio_exits,			\
+				    .aborts = _aborts},				\
+}
+
+#define TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(_access, _test_check)		\
+{										\
+	.name			= SCAT2(ro_memslot_no_syn_and_dlog, _access),	\
+	.test_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.pt_memslot_flags	= KVM_MEM_READONLY | KVM_MEM_LOG_DIRTY_PAGES,	\
+	.guest_test 		= _access,					\
+	.guest_test_check	= { _test_check },				\
+	.dabt_handler		= dabt_s1ptw_on_ro_memslot_handler,		\
+	.fail_vcpu_run_handler	= fail_vcpu_run_mmio_no_syndrome_handler,	\
+	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1 },		\
+}
+
+#define TEST_RO_MEMSLOT_AND_UFFD(_access, _mmio_handler, _mmio_exits,		\
+				 _iabt_handler, _dabt_handler, _aborts,		\
+				_uffd_test_handler, _uffd_faults)		\
+{										\
+	.name			= SCAT2(ro_memslot_uffd, _access),		\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.mem_mark_cmd		= CMD_HOLE_TEST | CMD_HOLE_PT,			\
+	.guest_prepare		= { _PREPARE(_access) },			\
+	.guest_test 		= _access,					\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= uffd_pt_write_handler,			\
+	.mmio_handler		= _mmio_handler,				\
+	.iabt_handler		= _iabt_handler,				\
+	.dabt_handler		= _dabt_handler,				\
+	.expected_events	= { .mmio_exits = _mmio_exits,			\
+				    .aborts = _aborts,				\
+				    .uffd_faults = _uffd_faults },		\
+}
+
+#define TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(_access, _uffd_test_handler,	\
+					     _uffd_faults)			\
+{										\
+	.name			= SCAT2(ro_memslot_no_syndrome, _access),	\
+	.test_memslot_flags	= KVM_MEM_READONLY,				\
+	.pt_memslot_flags	= KVM_MEM_READONLY,				\
+	.mem_mark_cmd		= CMD_HOLE_TEST | CMD_HOLE_PT,			\
+	.guest_test 		= _access,					\
+	.uffd_test_handler	= _uffd_test_handler,				\
+	.uffd_pt_handler	= uffd_pt_write_handler,			\
+	.dabt_handler		= dabt_s1ptw_on_ro_memslot_handler,		\
+	.fail_vcpu_run_handler	= fail_vcpu_run_mmio_no_syndrome_handler,	\
+	.expected_events	= { .aborts = 1, .fail_vcpu_runs = 1,		\
+				    .uffd_faults = _uffd_faults },		\
+}
+
 static struct test_desc tests[] = {
 	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
 	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
@@ -1028,6 +1115,35 @@ static struct test_desc tests[] = {
 	TEST_DIRTY_LOG(guest_dc_zva, with_af, guest_check_write_in_dirty_log),
 	TEST_DIRTY_LOG(guest_st_preidx, with_af, guest_check_write_in_dirty_log),
 
+	/*
+	 * Access when the test and PT memslots are both marked for dirty
+	 * logging and UFFD at the same time. The expected result is that
+	 * writes should mark the dirty log and trigger a userfaultfd write
+	 * fault.  Reads/execs should result in a read userfaultfd fault, and
+	 * nothing in the dirty log.  The S1PTW in all cases should result in a
+	 * write in the dirty log and a userfaultfd write.
+	 */
+	TEST_UFFD_AND_DIRTY_LOG(guest_read64, with_af, uffd_test_read_handler, 2,
+			guest_check_no_write_in_dirty_log),
+	/* no_af should also lead to a PT write. */
+	TEST_UFFD_AND_DIRTY_LOG(guest_read64, no_af, uffd_test_read_handler, 2,
+			guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_ld_preidx, with_af, uffd_test_read_handler,
+			2, guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_at, with_af, 0, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_exec, with_af, uffd_test_read_handler, 2,
+			guest_check_no_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_write64, with_af, uffd_test_write_handler,
+			2, guest_check_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_cas, with_af, uffd_test_read_handler, 2,
+			guest_check_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_dc_zva, with_af, uffd_test_write_handler,
+			2, guest_check_write_in_dirty_log),
+	TEST_UFFD_AND_DIRTY_LOG(guest_st_preidx, with_af,
+			uffd_test_write_handler, 2,
+			guest_check_write_in_dirty_log),
+
 	/*
 	 * Try accesses when both the test and PT memslots are marked read-only
 	 * (with KVM_MEM_READONLY). The S1PTW results in an guest abort, whose
@@ -1054,6 +1170,68 @@ static struct test_desc tests[] = {
 	TEST_RO_MEMSLOT_NO_SYNDROME(guest_cas),
 	TEST_RO_MEMSLOT_NO_SYNDROME(guest_st_preidx),
 
+	/*
+	 * Access when both the test and PT memslots are read-only and marked
+	 * for dirty logging at the same time. The expected result is that
+	 * there should be no write in the dirty log. The S1PTW results in an
+	 * abort which is handled by asking the host to recreate the memslot as
+	 * writable. The readonly handling are the same as if the memslots were
+	 * not marked for dirty logging: writes with a syndrome result in an
+	 * MMIO exit, and writes with no syndrome result in a failed vcpu run.
+	 */
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_read64, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_ld_preidx, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_at, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_exec, 0, 0,
+			iabt_s1ptw_on_ro_memslot_handler, 0, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_AND_DIRTY_LOG(guest_write64, mmio_on_test_gpa_handler,
+			1, 0, dabt_s1ptw_on_ro_memslot_handler, 1,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(guest_dc_zva,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(guest_cas,
+			guest_check_no_write_in_dirty_log),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_DIRTY_LOG(guest_st_preidx,
+			guest_check_no_write_in_dirty_log),
+
+	/*
+	 * Access when both the test and PT memslots are read-only, and punched
+	 * with holes tracked with userfaultfd.  The expected result is the
+	 * union of both userfaultfd and read-only behaviors. For example,
+	 * write accesses result in a userfaultfd write fault and an MMIO exit.
+	 * Writes with no syndrome result in a failed vcpu run and no
+	 * userfaultfd write fault. Reads only result in userfaultfd getting
+	 * triggered.
+	 */
+	TEST_RO_MEMSLOT_AND_UFFD(guest_read64, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_ld_preidx, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_at, 0, 0, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_no_handler, 1),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_exec, 0, 0,
+			iabt_s1ptw_on_ro_memslot_handler, 0, 1,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_AND_UFFD(guest_write64, mmio_on_test_gpa_handler, 1, 0,
+			dabt_s1ptw_on_ro_memslot_handler, 1,
+			uffd_test_write_handler, 2),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(guest_cas,
+			uffd_test_read_handler, 2),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(guest_dc_zva,
+			uffd_no_handler, 1),
+	TEST_RO_MEMSLOT_NO_SYNDROME_AND_UFFD(guest_st_preidx,
+			uffd_no_handler, 1),
+
 	{ 0 },
 };
 
-- 
2.35.1.1178.g4f1659d476-goog

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Re: [PATCH v3 02/13] KVM: selftests: aarch64: Add vm_get_pte_gpa library function

[Oliver Upton]

Hey Ricardo,

Sorry about my last email hitting your v2. I fudged my inbox filtering
so v3 missed my explicit-cc inbox. Oops!

On Thu, Apr 07, 2022 at 05:41:09PM -0700, Ricardo Koller wrote:
> Add a library function (in-guest)

This function is called from host userspace, no?

> to get the GPA of the PTE of a
> particular GVA.  This will be used in a future commit by a test to clear
> and check the AF (access flag) of a particular page.
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>
> ---
>  .../selftests/kvm/include/aarch64/processor.h |  2 ++
>  .../selftests/kvm/lib/aarch64/processor.c     | 24 +++++++++++++++++--
>  2 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 8f9f46979a00..caa572d83062 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -125,6 +125,8 @@ void vm_install_exception_handler(struct kvm_vm *vm,
>  void vm_install_sync_handler(struct kvm_vm *vm,
>  		int vector, int ec, handler_fn handler);
>  
> +vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva);
> +
>  static inline void cpu_relax(void)
>  {
>  	asm volatile("yield" ::: "memory");
> diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
> index 9343d82519b4..ee006d354b79 100644
> --- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
> @@ -139,7 +139,7 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
>  	_virt_pg_map(vm, vaddr, paddr, attr_idx);
>  }
>  
> -vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
> +vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva)
>  {
>  	uint64_t *ptep;
>  
> @@ -162,7 +162,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
>  			goto unmapped_gva;
>  		/* fall through */
>  	case 2:
> -		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, gva) * 8;
> +		ptep = (uint64_t *)(pte_addr(vm, *ptep) + pte_index(vm, gva) * 8);

this seems a bit odd. ptep is an HVA in the above cases, but really a
GPA here.

Also -- not your code but the baked-in assumption that the stage-1 MMU
always maps at leaf page granularity might be a bit of a mess if we ever
do anything more interesting inside of the guest.

>  		if (!ptep)
>  			goto unmapped_gva;
>  		break;
> @@ -170,6 +170,26 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
>  		TEST_FAIL("Page table levels must be 2, 3, or 4");
>  	}
>  
> +	return (vm_paddr_t)ptep;
> +
> +unmapped_gva:
> +	TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
> +	exit(1);

Isn't this just a workaround for the fact that TEST_FAIL() doesn't have
the noreturn attribute specified somewhere?

> +}
> +
> +vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
> +{
> +	uint64_t *ptep;
> +	vm_paddr_t ptep_gpa;
> +
> +	ptep_gpa = vm_get_pte_gpa(vm, gva);
> +	if (!ptep_gpa)
> +		goto unmapped_gva;

This branch will never be taken since vm_get_pte_gpa() will explode on
its own, right?

--
Thanks,
Oliver

Re: [PATCH v3 02/13] KVM: selftests: aarch64: Add vm_get_pte_gpa library function

[Oliver Upton]

Hey Ricardo,

Sorry about my last email hitting your v2. I fudged my inbox filtering
so v3 missed my explicit-cc inbox. Oops!

On Thu, Apr 07, 2022 at 05:41:09PM -0700, Ricardo Koller wrote:
> Add a library function (in-guest)

This function is called from host userspace, no?

> to get the GPA of the PTE of a
> particular GVA.  This will be used in a future commit by a test to clear
> and check the AF (access flag) of a particular page.
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>
> ---
>  .../selftests/kvm/include/aarch64/processor.h |  2 ++
>  .../selftests/kvm/lib/aarch64/processor.c     | 24 +++++++++++++++++--
>  2 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 8f9f46979a00..caa572d83062 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -125,6 +125,8 @@ void vm_install_exception_handler(struct kvm_vm *vm,
>  void vm_install_sync_handler(struct kvm_vm *vm,
>  		int vector, int ec, handler_fn handler);
>  
> +vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva);
> +
>  static inline void cpu_relax(void)
>  {
>  	asm volatile("yield" ::: "memory");
> diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
> index 9343d82519b4..ee006d354b79 100644
> --- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
> @@ -139,7 +139,7 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
>  	_virt_pg_map(vm, vaddr, paddr, attr_idx);
>  }
>  
> -vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
> +vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva)
>  {
>  	uint64_t *ptep;
>  
> @@ -162,7 +162,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
>  			goto unmapped_gva;
>  		/* fall through */
>  	case 2:
> -		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, gva) * 8;
> +		ptep = (uint64_t *)(pte_addr(vm, *ptep) + pte_index(vm, gva) * 8);

this seems a bit odd. ptep is an HVA in the above cases, but really a
GPA here.

Also -- not your code but the baked-in assumption that the stage-1 MMU
always maps at leaf page granularity might be a bit of a mess if we ever
do anything more interesting inside of the guest.

>  		if (!ptep)
>  			goto unmapped_gva;
>  		break;
> @@ -170,6 +170,26 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
>  		TEST_FAIL("Page table levels must be 2, 3, or 4");
>  	}
>  
> +	return (vm_paddr_t)ptep;
> +
> +unmapped_gva:
> +	TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
> +	exit(1);

Isn't this just a workaround for the fact that TEST_FAIL() doesn't have
the noreturn attribute specified somewhere?

> +}
> +
> +vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
> +{
> +	uint64_t *ptep;
> +	vm_paddr_t ptep_gpa;
> +
> +	ptep_gpa = vm_get_pte_gpa(vm, gva);
> +	if (!ptep_gpa)
> +		goto unmapped_gva;

This branch will never be taken since vm_get_pte_gpa() will explode on
its own, right?

--
Thanks,
Oliver
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Re: [PATCH v3 03/13] KVM: selftests: Add vm_alloc_page_table_in_memslot library function

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:10PM -0700, Ricardo Koller wrote:
> Add a library function to allocate a page-table physical page in a
> particular memslot.  The default behavior is to create new page-table
> pages in memslot 0.
> 
> Reviewed-by: Ben Gardon <bgardon@google.com>
> Signed-off-by: Ricardo Koller <ricarkol@google.com>
> ---
>  tools/testing/selftests/kvm/include/kvm_util_base.h | 1 +
>  tools/testing/selftests/kvm/lib/kvm_util.c          | 8 +++++++-
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index 4ed6aa049a91..3a69b35e37cc 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -306,6 +306,7 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
>  vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
>  			      vm_paddr_t paddr_min, uint32_t memslot);
>  vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm);
> +vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot);
>  
>  /*
>   * Create a VM with reasonable defaults
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index d8cf851ab119..e18f1c93e4b4 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -2386,9 +2386,15 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
>  /* Arbitrary minimum physical address used for virtual translation tables. */
>  #define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000
>  
> +vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot)
> +{
> +	return vm_phy_page_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR,

Test code needs to plop the memslot with some space above
PAGE_TABLE_MIN_PADDR then, right?

Reviewed-by: Oliver Upton <oupton@google.com>

Re: [PATCH v3 03/13] KVM: selftests: Add vm_alloc_page_table_in_memslot library function

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:10PM -0700, Ricardo Koller wrote:
> Add a library function to allocate a page-table physical page in a
> particular memslot.  The default behavior is to create new page-table
> pages in memslot 0.
> 
> Reviewed-by: Ben Gardon <bgardon@google.com>
> Signed-off-by: Ricardo Koller <ricarkol@google.com>
> ---
>  tools/testing/selftests/kvm/include/kvm_util_base.h | 1 +
>  tools/testing/selftests/kvm/lib/kvm_util.c          | 8 +++++++-
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index 4ed6aa049a91..3a69b35e37cc 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -306,6 +306,7 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
>  vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
>  			      vm_paddr_t paddr_min, uint32_t memslot);
>  vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm);
> +vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot);
>  
>  /*
>   * Create a VM with reasonable defaults
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index d8cf851ab119..e18f1c93e4b4 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -2386,9 +2386,15 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
>  /* Arbitrary minimum physical address used for virtual translation tables. */
>  #define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000
>  
> +vm_paddr_t vm_alloc_page_table_in_memslot(struct kvm_vm *vm, uint32_t pt_memslot)
> +{
> +	return vm_phy_page_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR,

Test code needs to plop the memslot with some space above
PAGE_TABLE_MIN_PADDR then, right?

Reviewed-by: Oliver Upton <oupton@google.com>
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Re: [PATCH v3 04/13] KVM: selftests: aarch64: Export _virt_pg_map with a pt_memslot arg

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:11PM -0700, Ricardo Koller wrote:
> Add an argument, pt_memslot, into _virt_pg_map in order to use a
> specific memslot for the page-table allocations performed when creating
> a new map. This will be used in a future commit to test having PTEs
> stored on memslots with different setups (e.g., hugetlb with a hole).
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>

Reviewed-by: Oliver Upton <oupton@google.com>

I wonder if we should pay off the churn now to make _all_ arches have a
deeper call to map using memory from a particular memslot...

--
Thanks,
Oliver

Re: [PATCH v3 04/13] KVM: selftests: aarch64: Export _virt_pg_map with a pt_memslot arg

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:11PM -0700, Ricardo Koller wrote:
> Add an argument, pt_memslot, into _virt_pg_map in order to use a
> specific memslot for the page-table allocations performed when creating
> a new map. This will be used in a future commit to test having PTEs
> stored on memslots with different setups (e.g., hugetlb with a hole).
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>

Reviewed-by: Oliver Upton <oupton@google.com>

I wonder if we should pay off the churn now to make _all_ arches have a
deeper call to map using memory from a particular memslot...

--
Thanks,
Oliver
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Re: [PATCH v3 05/13] KVM: selftests: Add missing close and munmap in __vm_mem_region_delete

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:12PM -0700, Ricardo Koller wrote:
> Deleting a memslot (when freeing a VM) is not closing the backing fd,
> nor it's unmapping the alias mapping. Fix by adding the missing close
> and munmap.
> 
> Reviewed-by: Ben Gardon <bgardon@google.com>
> Signed-off-by: Ricardo Koller <ricarkol@google.com>

Reviewed-by: Oliver Upton <oupton@google.com>

Re: [PATCH v3 05/13] KVM: selftests: Add missing close and munmap in __vm_mem_region_delete

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:12PM -0700, Ricardo Koller wrote:
> Deleting a memslot (when freeing a VM) is not closing the backing fd,
> nor it's unmapping the alias mapping. Fix by adding the missing close
> and munmap.
> 
> Reviewed-by: Ben Gardon <bgardon@google.com>
> Signed-off-by: Ricardo Koller <ricarkol@google.com>

Reviewed-by: Oliver Upton <oupton@google.com>
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Re: [PATCH v3 06/13] KVM: selftests: Add vm_mem_region_get_src_fd library function

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:13PM -0700, Ricardo Koller wrote:
> Add a library function to get the backing source FD of a memslot.
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>

Reviewed-by: Oliver Upton <oupton@google.com>

> ---
>  .../selftests/kvm/include/kvm_util_base.h     |  1 +
>  tools/testing/selftests/kvm/lib/kvm_util.c    | 23 +++++++++++++++++++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index 3a69b35e37cc..c8dce12a9a52 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -163,6 +163,7 @@ int _kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
>  void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
>  void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa);
>  void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
> +int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot);
>  void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
>  vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
>  vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 268ad3d75fe2..a0a9cd575fac 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -580,6 +580,29 @@ kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start,
>  	return &region->region;
>  }
>  
> +/*
> + * KVM Userspace Memory Get Backing Source FD
> + *
> + * Input Args:
> + *   vm - Virtual Machine
> + *   memslot - KVM memory slot ID
> + *
> + * Output Args: None
> + *
> + * Return:
> + *   Backing source file descriptor, -1 if the memslot is an anonymous region.
> + *
> + * Returns the backing source fd of a memslot, so tests can use it to punch
> + * holes, or to setup permissions.
> + */
> +int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot)
> +{
> +	struct userspace_mem_region *region;
> +
> +	region = memslot2region(vm, memslot);
> +	return region->fd;
> +}
> +
>  /*
>   * VCPU Find
>   *
> -- 
> 2.35.1.1178.g4f1659d476-goog
> 

Re: [PATCH v3 06/13] KVM: selftests: Add vm_mem_region_get_src_fd library function

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:13PM -0700, Ricardo Koller wrote:
> Add a library function to get the backing source FD of a memslot.
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>

Reviewed-by: Oliver Upton <oupton@google.com>

> ---
>  .../selftests/kvm/include/kvm_util_base.h     |  1 +
>  tools/testing/selftests/kvm/lib/kvm_util.c    | 23 +++++++++++++++++++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index 3a69b35e37cc..c8dce12a9a52 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -163,6 +163,7 @@ int _kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
>  void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
>  void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa);
>  void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
> +int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot);
>  void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
>  vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
>  vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 268ad3d75fe2..a0a9cd575fac 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -580,6 +580,29 @@ kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start,
>  	return &region->region;
>  }
>  
> +/*
> + * KVM Userspace Memory Get Backing Source FD
> + *
> + * Input Args:
> + *   vm - Virtual Machine
> + *   memslot - KVM memory slot ID
> + *
> + * Output Args: None
> + *
> + * Return:
> + *   Backing source file descriptor, -1 if the memslot is an anonymous region.
> + *
> + * Returns the backing source fd of a memslot, so tests can use it to punch
> + * holes, or to setup permissions.
> + */
> +int vm_mem_region_get_src_fd(struct kvm_vm *vm, uint32_t memslot)
> +{
> +	struct userspace_mem_region *region;
> +
> +	region = memslot2region(vm, memslot);
> +	return region->fd;
> +}
> +
>  /*
>   * VCPU Find
>   *
> -- 
> 2.35.1.1178.g4f1659d476-goog
> 
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Re: [PATCH v3 07/13] KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macros

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:14PM -0700, Ricardo Koller wrote:
> Define macros for memory type indexes and construct DEFAULT_MAIR_EL1
> with macros from asm/sysreg.h.  The index macros can then be used when
> constructing PTEs (instead of using raw numbers).
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>
> ---
>  .../selftests/kvm/include/aarch64/processor.h | 24 ++++++++++++++-----
>  .../selftests/kvm/lib/aarch64/processor.c     |  2 +-
>  2 files changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 3965a5ac778e..16753a1f28e3 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -38,12 +38,24 @@
>   * NORMAL             4     1111:1111
>   * NORMAL_WT          5     1011:1011
>   */
> -#define DEFAULT_MAIR_EL1 ((0x00ul << (0 * 8)) | \
> -			  (0x04ul << (1 * 8)) | \
> -			  (0x0cul << (2 * 8)) | \
> -			  (0x44ul << (3 * 8)) | \
> -			  (0xfful << (4 * 8)) | \
> -			  (0xbbul << (5 * 8)))
> +
> +/* Linux doesn't use these memory types, so let's define them. */
> +#define MAIR_ATTR_DEVICE_GRE	UL(0x0c)
> +#define MAIR_NORMAL_WT		UL(0xbb)

nit: MAIR_ATTR_NORMAL_WT

Might be annoying if these are actually defined at a later date and
someone tries to refresh the tools/ header copy. A bit more work, but
how about adding these to the real asm/sysreg.h then catching tools/ up
in a subsequent commit?

Modulo the nit, fine with this as is:

Reviewed-by: Oliver Upton <oupton@google.com>

Re: [PATCH v3 07/13] KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macros

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:14PM -0700, Ricardo Koller wrote:
> Define macros for memory type indexes and construct DEFAULT_MAIR_EL1
> with macros from asm/sysreg.h.  The index macros can then be used when
> constructing PTEs (instead of using raw numbers).
> 
> Signed-off-by: Ricardo Koller <ricarkol@google.com>
> ---
>  .../selftests/kvm/include/aarch64/processor.h | 24 ++++++++++++++-----
>  .../selftests/kvm/lib/aarch64/processor.c     |  2 +-
>  2 files changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 3965a5ac778e..16753a1f28e3 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -38,12 +38,24 @@
>   * NORMAL             4     1111:1111
>   * NORMAL_WT          5     1011:1011
>   */
> -#define DEFAULT_MAIR_EL1 ((0x00ul << (0 * 8)) | \
> -			  (0x04ul << (1 * 8)) | \
> -			  (0x0cul << (2 * 8)) | \
> -			  (0x44ul << (3 * 8)) | \
> -			  (0xfful << (4 * 8)) | \
> -			  (0xbbul << (5 * 8)))
> +
> +/* Linux doesn't use these memory types, so let's define them. */
> +#define MAIR_ATTR_DEVICE_GRE	UL(0x0c)
> +#define MAIR_NORMAL_WT		UL(0xbb)

nit: MAIR_ATTR_NORMAL_WT

Might be annoying if these are actually defined at a later date and
someone tries to refresh the tools/ header copy. A bit more work, but
how about adding these to the real asm/sysreg.h then catching tools/ up
in a subsequent commit?

Modulo the nit, fine with this as is:

Reviewed-by: Oliver Upton <oupton@google.com>
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Re: [PATCH v3 08/13] tools: Copy bitfield.h from the kernel sources

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:15PM -0700, Ricardo Koller wrote:
> Copy bitfield.h from include/linux/bitfield.h. It defines some
> FIELD_{GET,PREP} macros that will be needed in the next patch in the
> series. The header was copied as-is, no changes needed.

nit: this commit could be the parent of several other descendants.
Perhaps ambigiously state "A subsequent change will make use ..."

Reviewed-by: Oliver Upton <oupton@google.com>

Re: [PATCH v3 08/13] tools: Copy bitfield.h from the kernel sources

[Oliver Upton]

On Thu, Apr 07, 2022 at 05:41:15PM -0700, Ricardo Koller wrote:
> Copy bitfield.h from include/linux/bitfield.h. It defines some
> FIELD_{GET,PREP} macros that will be needed in the next patch in the
> series. The header was copied as-is, no changes needed.

nit: this commit could be the parent of several other descendants.
Perhaps ambigiously state "A subsequent change will make use ..."

Reviewed-by: Oliver Upton <oupton@google.com>
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Re: [PATCH v3 09/13] KVM: selftests: aarch64: Add aarch64/page_fault_test

[Oliver Upton]

Hi Ricardo,

On Thu, Apr 07, 2022 at 05:41:16PM -0700, Ricardo Koller wrote:
> diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
> new file mode 100644
> index 000000000000..04fc6007f630
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c

[...]

> +/* Guest virtual addresses that point to the test page and its PTE. */
> +#define TEST_GVA				0xc0000000
> +#define TEST_EXEC_GVA				0xc0000008
> +#define TEST_PTE_GVA				0xd0000000
> +#define TEST_DATA				0x0123456789ABCDEF
> +
> +#define CMD_NONE				(0)
> +#define CMD_SKIP_TEST				(1ULL << 1)
> +#define CMD_HOLE_PT				(1ULL << 2)
> +#define CMD_HOLE_TEST				(1ULL << 3)
> +
> +#define PREPARE_FN_NR				10
> +#define CHECK_FN_NR				10
> +
> +uint64_t pte_gpa;
> +
> +enum { PT, TEST, NR_MEMSLOTS};

nit: fix formatting (just use newlines for each value).

> +struct memslot_desc {
> +	void *hva;
> +	uint64_t gpa;
> +	uint64_t size;
> +	uint64_t guest_pages;
> +	uint64_t backing_pages;
> +	enum vm_mem_backing_src_type src_type;
> +	uint32_t idx;
> +} memslot[NR_MEMSLOTS] = {
> +	{
> +		.idx = TEST_PT_SLOT_INDEX,
> +		.backing_pages = PT_MEMSLOT_BACKING_SRC_NPAGES,
> +	},
> +	{
> +		.idx = TEST_MEM_SLOT_INDEX,
> +		.backing_pages = TEST_MEMSLOT_BACKING_SRC_NPAGES,

nit: initialize fields in the order they appear in the struct.

[...]

> +static void guest_write64(void)
> +{
> +	uint64_t val;
> +
> +	WRITE_ONCE(*((uint64_t *)TEST_GVA), TEST_DATA);
> +	val = READ_ONCE(*(uint64_t *)TEST_GVA);

nit: you could proabably avoid casting with a global pointer.

  static uint64_t *guest_test_memory = (uint64_t *)TEST_GVA;

[...]

> +static void guest_test_check(struct test_desc *test)
> +{
> +	void (*check_fn)(void);
> +	int i;
> +
> +	for (i = 0; i < CHECK_FN_NR; i++) {
> +		check_fn = test->guest_test_check[i];
> +		if (!check_fn)
> +			continue;
> +		check_fn();

nit:

  if (check_fn)
          check_fn();

One less line :)

> +	}
> +}
> +
> +static void guest_code(struct test_desc *test)
> +{
> +	if (!test->guest_test)
> +		test->guest_test = guest_nop;

In other cases you've chosen to skip function calls if NULL. Is there a
need to call something here that I've missed or could you just do:

  if (test->guest_test)
          test->guest_test();

below?

> +	if (!guest_prepare(test))
> +		GUEST_SYNC(CMD_SKIP_TEST);
> +
> +	GUEST_SYNC(test->mem_mark_cmd);
> +	test->guest_test();
> +
> +	guest_test_check(test);
> +	GUEST_DONE();
> +}

[...]

> +
> +#define SNAME(s)			#s
> +#define SCAT2(a, b)			SNAME(a ## _ ## b)
> +#define SCAT3(a, b, c)			SCAT2(a, SCAT2(b, c))
> +
> +#define _CHECK(_test)			_CHECK_##_test
> +#define _PREPARE(_test)			_PREPARE_##_test
> +#define _PREPARE_guest_read64		guest_prepare_nop
> +#define _PREPARE_guest_ld_preidx	guest_prepare_nop
> +#define _PREPARE_guest_write64		guest_prepare_nop
> +#define _PREPARE_guest_st_preidx	guest_prepare_nop
> +#define _PREPARE_guest_exec		guest_prepare_nop
> +#define _PREPARE_guest_at		guest_prepare_nop

Since you check for NULL in guest_prepare(), could you just use NULL for
these and drop guest_prepare_nop()?

> +#define _PREPARE_guest_dc_zva		guest_check_dc_zva
> +#define _PREPARE_guest_cas		guest_check_lse
> +
> +/* With or without access flag checks */
> +#define _PREPARE_with_af		guest_set_ha, guest_clear_pte_af
> +#define _PREPARE_no_af			guest_prepare_nop
> +#define _CHECK_with_af			guest_check_pte_af
> +#define _CHECK_no_af			guest_check_nop
> +
> +/* Performs an access and checks that no faults (no events) were triggered. */
> +#define TEST_ACCESS(_access, _with_af, _mark_cmd)				\
> +{										\
> +	.name			= SCAT3(_access, _with_af, #_mark_cmd),		\
> +	.guest_prepare		= { _PREPARE(_with_af),				\
> +				    _PREPARE(_access) },			\
> +	.mem_mark_cmd		= _mark_cmd,					\
> +	.guest_test		= _access,					\
> +	.guest_test_check	= { _CHECK(_with_af) },				\
> +	.expected_events	= { 0 },					\
> +}
> +
> +static struct test_desc tests[] = {
> +	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
> +	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_ld_preidx, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_cas, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_write64, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_st_preidx, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_dc_zva, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_exec, with_af, CMD_NONE),
> +
> +	/*
> +	 * Accessing a hole in the test memslot (punched with fallocate or
> +	 * madvise) shouldn't fault (more sanity checks).
> +	 */
> +	TEST_ACCESS(guest_read64, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_cas, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_ld_preidx, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_write64, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_st_preidx, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_at, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_TEST),
> +
> +	{ 0 },

nit: no comma, we don't want to ever add anything after the sentinel I
presume.

> +};
> +
> +static void for_each_test_and_guest_mode(
> +		void (*func)(enum vm_guest_mode m, void *a),
> +		enum vm_mem_backing_src_type src_type)
> +{

Could you avoid the forward declaration and instead move definitions
around to satisfy the compiler?

> +	struct test_desc *t;
> +
> +	for (t = &tests[0]; t->name; t++) {
> +		if (t->skip)
> +			continue;
> +
> +		struct test_params p = {
> +			.src_type = src_type,
> +			.test_desc = t,
> +		};
> +
> +		for_each_guest_mode(run_test, &p);
> +	}
> +}
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 16753a1f28e3..cb5849fd8fd1 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -125,6 +125,12 @@ enum {
>  #define ESR_EC_WP_CURRENT	0x35
>  #define ESR_EC_BRK_INS		0x3c
>  
> +/* Access flag */
> +#define PTE_AF			(1ULL << 10)
> +
> +/* Acces flag update enable/disable */

typo: Access

--
Thanks,
Oliver

Re: [PATCH v3 09/13] KVM: selftests: aarch64: Add aarch64/page_fault_test

[Oliver Upton]

Hi Ricardo,

On Thu, Apr 07, 2022 at 05:41:16PM -0700, Ricardo Koller wrote:
> diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
> new file mode 100644
> index 000000000000..04fc6007f630
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c

[...]

> +/* Guest virtual addresses that point to the test page and its PTE. */
> +#define TEST_GVA				0xc0000000
> +#define TEST_EXEC_GVA				0xc0000008
> +#define TEST_PTE_GVA				0xd0000000
> +#define TEST_DATA				0x0123456789ABCDEF
> +
> +#define CMD_NONE				(0)
> +#define CMD_SKIP_TEST				(1ULL << 1)
> +#define CMD_HOLE_PT				(1ULL << 2)
> +#define CMD_HOLE_TEST				(1ULL << 3)
> +
> +#define PREPARE_FN_NR				10
> +#define CHECK_FN_NR				10
> +
> +uint64_t pte_gpa;
> +
> +enum { PT, TEST, NR_MEMSLOTS};

nit: fix formatting (just use newlines for each value).

> +struct memslot_desc {
> +	void *hva;
> +	uint64_t gpa;
> +	uint64_t size;
> +	uint64_t guest_pages;
> +	uint64_t backing_pages;
> +	enum vm_mem_backing_src_type src_type;
> +	uint32_t idx;
> +} memslot[NR_MEMSLOTS] = {
> +	{
> +		.idx = TEST_PT_SLOT_INDEX,
> +		.backing_pages = PT_MEMSLOT_BACKING_SRC_NPAGES,
> +	},
> +	{
> +		.idx = TEST_MEM_SLOT_INDEX,
> +		.backing_pages = TEST_MEMSLOT_BACKING_SRC_NPAGES,

nit: initialize fields in the order they appear in the struct.

[...]

> +static void guest_write64(void)
> +{
> +	uint64_t val;
> +
> +	WRITE_ONCE(*((uint64_t *)TEST_GVA), TEST_DATA);
> +	val = READ_ONCE(*(uint64_t *)TEST_GVA);

nit: you could proabably avoid casting with a global pointer.

  static uint64_t *guest_test_memory = (uint64_t *)TEST_GVA;

[...]

> +static void guest_test_check(struct test_desc *test)
> +{
> +	void (*check_fn)(void);
> +	int i;
> +
> +	for (i = 0; i < CHECK_FN_NR; i++) {
> +		check_fn = test->guest_test_check[i];
> +		if (!check_fn)
> +			continue;
> +		check_fn();

nit:

  if (check_fn)
          check_fn();

One less line :)

> +	}
> +}
> +
> +static void guest_code(struct test_desc *test)
> +{
> +	if (!test->guest_test)
> +		test->guest_test = guest_nop;

In other cases you've chosen to skip function calls if NULL. Is there a
need to call something here that I've missed or could you just do:

  if (test->guest_test)
          test->guest_test();

below?

> +	if (!guest_prepare(test))
> +		GUEST_SYNC(CMD_SKIP_TEST);
> +
> +	GUEST_SYNC(test->mem_mark_cmd);
> +	test->guest_test();
> +
> +	guest_test_check(test);
> +	GUEST_DONE();
> +}

[...]

> +
> +#define SNAME(s)			#s
> +#define SCAT2(a, b)			SNAME(a ## _ ## b)
> +#define SCAT3(a, b, c)			SCAT2(a, SCAT2(b, c))
> +
> +#define _CHECK(_test)			_CHECK_##_test
> +#define _PREPARE(_test)			_PREPARE_##_test
> +#define _PREPARE_guest_read64		guest_prepare_nop
> +#define _PREPARE_guest_ld_preidx	guest_prepare_nop
> +#define _PREPARE_guest_write64		guest_prepare_nop
> +#define _PREPARE_guest_st_preidx	guest_prepare_nop
> +#define _PREPARE_guest_exec		guest_prepare_nop
> +#define _PREPARE_guest_at		guest_prepare_nop

Since you check for NULL in guest_prepare(), could you just use NULL for
these and drop guest_prepare_nop()?

> +#define _PREPARE_guest_dc_zva		guest_check_dc_zva
> +#define _PREPARE_guest_cas		guest_check_lse
> +
> +/* With or without access flag checks */
> +#define _PREPARE_with_af		guest_set_ha, guest_clear_pte_af
> +#define _PREPARE_no_af			guest_prepare_nop
> +#define _CHECK_with_af			guest_check_pte_af
> +#define _CHECK_no_af			guest_check_nop
> +
> +/* Performs an access and checks that no faults (no events) were triggered. */
> +#define TEST_ACCESS(_access, _with_af, _mark_cmd)				\
> +{										\
> +	.name			= SCAT3(_access, _with_af, #_mark_cmd),		\
> +	.guest_prepare		= { _PREPARE(_with_af),				\
> +				    _PREPARE(_access) },			\
> +	.mem_mark_cmd		= _mark_cmd,					\
> +	.guest_test		= _access,					\
> +	.guest_test_check	= { _CHECK(_with_af) },				\
> +	.expected_events	= { 0 },					\
> +}
> +
> +static struct test_desc tests[] = {
> +	/* Check that HW is setting the Access Flag (AF) (sanity checks). */
> +	TEST_ACCESS(guest_read64, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_ld_preidx, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_cas, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_write64, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_st_preidx, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_dc_zva, with_af, CMD_NONE),
> +	TEST_ACCESS(guest_exec, with_af, CMD_NONE),
> +
> +	/*
> +	 * Accessing a hole in the test memslot (punched with fallocate or
> +	 * madvise) shouldn't fault (more sanity checks).
> +	 */
> +	TEST_ACCESS(guest_read64, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_cas, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_ld_preidx, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_write64, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_st_preidx, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_at, no_af, CMD_HOLE_TEST),
> +	TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_TEST),
> +
> +	{ 0 },

nit: no comma, we don't want to ever add anything after the sentinel I
presume.

> +};
> +
> +static void for_each_test_and_guest_mode(
> +		void (*func)(enum vm_guest_mode m, void *a),
> +		enum vm_mem_backing_src_type src_type)
> +{

Could you avoid the forward declaration and instead move definitions
around to satisfy the compiler?

> +	struct test_desc *t;
> +
> +	for (t = &tests[0]; t->name; t++) {
> +		if (t->skip)
> +			continue;
> +
> +		struct test_params p = {
> +			.src_type = src_type,
> +			.test_desc = t,
> +		};
> +
> +		for_each_guest_mode(run_test, &p);
> +	}
> +}
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 16753a1f28e3..cb5849fd8fd1 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -125,6 +125,12 @@ enum {
>  #define ESR_EC_WP_CURRENT	0x35
>  #define ESR_EC_BRK_INS		0x3c
>  
> +/* Access flag */
> +#define PTE_AF			(1ULL << 10)
> +
> +/* Acces flag update enable/disable */

typo: Access

--
Thanks,
Oliver
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