Test the newly introduced KVM_MEM_ALLONES memslots:
- Reads from all pages return '0xff'
- Writes to all pages cause KVM_EXIT_MMIO

Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../testing/selftests/kvm/include/kvm_util.h  |   1 +
 tools/testing/selftests/kvm/lib/kvm_util.c    |  81 +++++++------
 .../kvm/x86_64/memory_region_allones.c        | 112 ++++++++++++++++++
 4 files changed, 162 insertions(+), 33 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/x86_64/memory_region_allones.c

diff --git a/tools/testing/selftests/kvm/Makefile 
b/tools/testing/selftests/kvm/Makefile
index 7af62030c12f..0c9aff445755 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -15,6 +15,7 @@ LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c
 TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
 TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
 TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
+TEST_GEN_PROGS_x86_64 += x86_64/memory_region_allones
 TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
 TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
 TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
b/tools/testing/selftests/kvm/include/kvm_util.h
index 53b11d725d81..8f5ebc8520b8 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -59,6 +59,7 @@ enum vm_mem_backing_src_type {
        VM_MEM_SRC_ANONYMOUS,
        VM_MEM_SRC_ANONYMOUS_THP,
        VM_MEM_SRC_ANONYMOUS_HUGETLB,
+       VM_MEM_SRC_NONE,
 };
 
 int kvm_check_cap(long cap);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c 
b/tools/testing/selftests/kvm/lib/kvm_util.c
index 33ab0a36d230..232b63ba0b4b 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -446,8 +446,11 @@ static void __vm_mem_region_delete(struct kvm_vm *vm,
                    "rc: %i errno: %i", ret, errno);
 
        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->mmap_start) {
+               ret = munmap(region->mmap_start, region->mmap_size);
+               TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i", ret,
+                           errno);
+       }
 
        free(region);
 }
@@ -636,34 +639,42 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
        alignment = 1;
 #endif
 
-       if (src_type == VM_MEM_SRC_ANONYMOUS_THP)
-               alignment = max(huge_page_size, alignment);
-
-       /* Add enough memory to align up if necessary */
-       if (alignment > 1)
-               region->mmap_size += alignment;
-
-       region->mmap_start = mmap(NULL, region->mmap_size,
-                                 PROT_READ | PROT_WRITE,
-                                 MAP_PRIVATE | MAP_ANONYMOUS
-                                 | (src_type == VM_MEM_SRC_ANONYMOUS_HUGETLB ? 
MAP_HUGETLB : 0),
-                                 -1, 0);
-       TEST_ASSERT(region->mmap_start != MAP_FAILED,
-                   "test_malloc failed, mmap_start: %p errno: %i",
-                   region->mmap_start, errno);
-
-       /* Align host address */
-       region->host_mem = align(region->mmap_start, alignment);
-
-       /* As needed perform madvise */
-       if (src_type == VM_MEM_SRC_ANONYMOUS || src_type == 
VM_MEM_SRC_ANONYMOUS_THP) {
-               ret = madvise(region->host_mem, npages * vm->page_size,
-                            src_type == VM_MEM_SRC_ANONYMOUS ? MADV_NOHUGEPAGE 
: MADV_HUGEPAGE);
-               TEST_ASSERT(ret == 0, "madvise failed,\n"
-                           "  addr: %p\n"
-                           "  length: 0x%lx\n"
-                           "  src_type: %x",
-                           region->host_mem, npages * vm->page_size, src_type);
+       if (src_type != VM_MEM_SRC_NONE) {
+               if (src_type == VM_MEM_SRC_ANONYMOUS_THP)
+                       alignment = max(huge_page_size, alignment);
+
+               /* Add enough memory to align up if necessary */
+               if (alignment > 1)
+                       region->mmap_size += alignment;
+
+               region->mmap_start = mmap(NULL, region->mmap_size,
+                         PROT_READ | PROT_WRITE,
+                         MAP_PRIVATE | MAP_ANONYMOUS
+                         | (src_type == VM_MEM_SRC_ANONYMOUS_HUGETLB ?
+                            MAP_HUGETLB : 0), -1, 0);
+               TEST_ASSERT(region->mmap_start != MAP_FAILED,
+                           "test_malloc failed, mmap_start: %p errno: %i",
+                           region->mmap_start, errno);
+
+               /* Align host address */
+               region->host_mem = align(region->mmap_start, alignment);
+
+               /* As needed perform madvise */
+               if (src_type == VM_MEM_SRC_ANONYMOUS ||
+                   src_type == VM_MEM_SRC_ANONYMOUS_THP) {
+                       ret = madvise(region->host_mem, npages * vm->page_size,
+                                     src_type == VM_MEM_SRC_ANONYMOUS ?
+                                     MADV_NOHUGEPAGE : MADV_HUGEPAGE);
+                       TEST_ASSERT(ret == 0, "madvise failed,\n"
+                                   "  addr: %p\n"
+                                   "  length: 0x%lx\n"
+                                   "  src_type: %x",
+                                   region->host_mem, npages * vm->page_size,
+                                   src_type);
+               }
+       } else {
+               region->mmap_start = NULL;
+               region->host_mem = NULL;
        }
 
        region->unused_phy_pages = sparsebit_alloc();
@@ -1069,9 +1080,13 @@ void *addr_gpa2hva(struct kvm_vm *vm, vm_paddr_t gpa)
        list_for_each_entry(region, &vm->userspace_mem_regions, list) {
                if ((gpa >= region->region.guest_phys_addr)
                        && (gpa <= (region->region.guest_phys_addr
-                               + region->region.memory_size - 1)))
-                       return (void *) ((uintptr_t) region->host_mem
-                               + (gpa - region->region.guest_phys_addr));
+                               + region->region.memory_size - 1))) {
+                       if (region->host_mem)
+                               return (void *) ((uintptr_t) region->host_mem
+                                + (gpa - region->region.guest_phys_addr));
+                       else
+                               return NULL;
+               }
        }
 
        TEST_FAIL("No vm physical memory at 0x%lx", gpa);
diff --git a/tools/testing/selftests/kvm/x86_64/memory_region_allones.c 
b/tools/testing/selftests/kvm/x86_64/memory_region_allones.c
new file mode 100644
index 000000000000..23fec4873422
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/memory_region_allones.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include <linux/compiler.h>
+
+#include <test_util.h>
+#include <kvm_util.h>
+#include <processor.h>
+
+#define VCPU_ID 0
+
+#define MEM_REGION_GPA         0xc0000000
+#define MEM_REGION_SIZE                0x4000
+#define MEM_REGION_SLOT                10
+
+static void guest_code(void)
+{
+       uint8_t val;
+
+       /* First byte in the first page */
+       val = READ_ONCE(*((uint8_t *)MEM_REGION_GPA));
+       GUEST_ASSERT(val == 0xff);
+
+       GUEST_SYNC(1);
+
+       /* Random byte in the second page */
+       val = READ_ONCE(*((uint8_t *)MEM_REGION_GPA + 5000));
+       GUEST_ASSERT(val == 0xff);
+
+       GUEST_SYNC(2);
+
+       /* Write to the first page */
+       WRITE_ONCE(*((uint64_t *)MEM_REGION_GPA + 1024/8), 0xdeafbeef);
+
+       GUEST_SYNC(3);
+
+       /* Write to the second page */
+       WRITE_ONCE(*((uint64_t *)MEM_REGION_GPA + 8000/8), 0xdeafbeef);
+
+       GUEST_SYNC(4);
+
+       GUEST_DONE();
+}
+
+int main(int argc, char *argv[])
+{
+       struct kvm_vm *vm;
+       struct kvm_run *run;
+       struct ucall uc;
+       int stage, rv;
+
+       rv = kvm_check_cap(KVM_CAP_ALLONES_MEM);
+       if (!rv) {
+               print_skip("KVM_CAP_ALLONES_MEM not supported");
+               exit(KSFT_SKIP);
+       }
+
+       vm = vm_create_default(VCPU_ID, 0, guest_code);
+
+       run = vcpu_state(vm, VCPU_ID);
+
+       vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+       vm_userspace_mem_region_add(vm, VM_MEM_SRC_NONE,
+                                   MEM_REGION_GPA, MEM_REGION_SLOT,
+                                   MEM_REGION_SIZE / getpagesize(),
+                                   KVM_MEM_ALLONES);
+
+       virt_map(vm, MEM_REGION_GPA, MEM_REGION_GPA,
+                MEM_REGION_SIZE / getpagesize(), 0);
+
+       for (stage = 1;; stage++) {
+               _vcpu_run(vm, VCPU_ID);
+
+               if (stage == 3 || stage == 5) {
+                       TEST_ASSERT(run->exit_reason == KVM_EXIT_MMIO,
+                           "Write to ALLONES page should cause KVM_EXIT_MMIO");
+                       continue;
+               }
+
+               TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+                           "Stage %d: unexpected exit reason: %u (%s),\n",
+                           stage, run->exit_reason,
+                           exit_reason_str(run->exit_reason));
+
+               switch (get_ucall(vm, VCPU_ID, &uc)) {
+               case UCALL_ABORT:
+                       TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
+                                 __FILE__, uc.args[1]);
+                       /* NOT REACHED */
+               case UCALL_SYNC:
+                       break;
+               case UCALL_DONE:
+                       goto done;
+               default:
+                       TEST_FAIL("Unknown ucall %lu", uc.cmd);
+               }
+       }
+
+done:
+       kvm_vm_free(vm);
+
+       return 0;
+}
-- 
2.25.4

Reply via email to