Use KVM_SET_USER_MEMORY_REGION2 throughout KVM's selftests library so that
support for guest private memory can be added without needing an entirely
separate set of helpers.

Note, this obviously makes selftests backwards-incompatible with older KVM
versions from this point forward.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../selftests/kvm/include/kvm_util_base.h     |  2 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    | 19 ++++++++++---------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 967eaaeacd75..9f144841c2ee 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -44,7 +44,7 @@ typedef uint64_t vm_paddr_t; /* Virtual Machine (Guest) physical address */
 typedef uint64_t vm_vaddr_t; /* Virtual Machine (Guest) virtual address */
 
 struct userspace_mem_region {
-	struct kvm_userspace_memory_region region;
+	struct kvm_userspace_memory_region2 region;
 	struct sparsebit *unused_phy_pages;
 	int fd;
 	off_t offset;
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index f09295d56c23..3676b37bea38 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -453,8 +453,9 @@ void kvm_vm_restart(struct kvm_vm *vmp)
 		vm_create_irqchip(vmp);
 
 	hash_for_each(vmp->regions.slot_hash, ctr, region, slot_node) {
-		int ret = ioctl(vmp->fd, KVM_SET_USER_MEMORY_REGION, &region->region);
-		TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed,\n"
+		int ret = ioctl(vmp->fd, KVM_SET_USER_MEMORY_REGION2, &region->region);
+
+		TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION2 IOCTL failed,\n"
 			    "  rc: %i errno: %i\n"
 			    "  slot: %u flags: 0x%x\n"
 			    "  guest_phys_addr: 0x%llx size: 0x%llx",
@@ -657,7 +658,7 @@ static void __vm_mem_region_delete(struct kvm_vm *vm,
 	}
 
 	region->region.memory_size = 0;
-	vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION, &region->region);
+	vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION2, &region->region);
 
 	sparsebit_free(&region->unused_phy_pages);
 	ret = munmap(region->mmap_start, region->mmap_size);
@@ -1014,8 +1015,8 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
 	region->region.guest_phys_addr = guest_paddr;
 	region->region.memory_size = npages * vm->page_size;
 	region->region.userspace_addr = (uintptr_t) region->host_mem;
-	ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION, &region->region);
-	TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed,\n"
+	ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION2, &region->region);
+	TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION2 IOCTL failed,\n"
 		"  rc: %i errno: %i\n"
 		"  slot: %u flags: 0x%x\n"
 		"  guest_phys_addr: 0x%lx size: 0x%lx",
@@ -1097,9 +1098,9 @@ void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags)
 
 	region->region.flags = flags;
 
-	ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION, &region->region);
+	ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION2, &region->region);
 
-	TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed,\n"
+	TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION2 IOCTL failed,\n"
 		"  rc: %i errno: %i slot: %u flags: 0x%x",
 		ret, errno, slot, flags);
 }
@@ -1127,9 +1128,9 @@ void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa)
 
 	region->region.guest_phys_addr = new_gpa;
 
-	ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION, &region->region);
+	ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION2, &region->region);
 
-	TEST_ASSERT(!ret, "KVM_SET_USER_MEMORY_REGION failed\n"
+	TEST_ASSERT(!ret, "KVM_SET_USER_MEMORY_REGION2 failed\n"
 		    "ret: %i errno: %i slot: %u new_gpa: 0x%lx",
 		    ret, errno, slot, new_gpa);
 }
-- 
2.42.0.820.g83a721a137-goog

On Fri, Oct 27, 2023 at 11:22:07AM -0700, Sean Christopherson wrote:
> Use KVM_SET_USER_MEMORY_REGION2 throughout KVM's selftests library so that
> support for guest private memory can be added without needing an entirely
> separate set of helpers.
> 
> Note, this obviously makes selftests backwards-incompatible with older KVM
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> versions from this point forward.
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Is there a way we could disable the tests on older kernels instead of
making them fail?  Check uname or something?  There is probably a
standard way to do this...  It's these tests which fail.

 kvm_aarch32_id_regs
 kvm_access_tracking_perf_test
 kvm_arch_timer
 kvm_debug-exceptions
 kvm_demand_paging_test
 kvm_dirty_log_perf_test
 kvm_dirty_log_test
 kvm_guest_print_test
 kvm_hypercalls
 kvm_kvm_page_table_test
 kvm_memslot_modification_stress_test
 kvm_memslot_perf_test
 kvm_page_fault_test
 kvm_psci_test
 kvm_rseq_test
 kvm_smccc_filter
 kvm_steal_time
 kvm_vgic_init
 kvm_vgic_irq
 kvm_vpmu_counter_access

regards,
dan carpenter

On 4/25/24 08:12, Dan Carpenter wrote:
> On Fri, Oct 27, 2023 at 11:22:07AM -0700, Sean Christopherson wrote:
>> Use KVM_SET_USER_MEMORY_REGION2 throughout KVM's selftests library so that
>> support for guest private memory can be added without needing an entirely
>> separate set of helpers.
>>
>> Note, this obviously makes selftests backwards-incompatible with older KVM
>    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> versions from this point forward.
>    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> Is there a way we could disable the tests on older kernels instead of
> making them fail?  Check uname or something?  There is probably a
> standard way to do this...  It's these tests which fail.

They shouldn't fail - the tests should be skipped on older kernels.
If it is absolutely necessary to dd uname to check kernel version,
refer to zram/zram_lib.sh for an example.

thanks,
-- Shuah

On Thu, Apr 25, 2024, Shuah Khan wrote:
> On 4/25/24 08:12, Dan Carpenter wrote:
> > On Fri, Oct 27, 2023 at 11:22:07AM -0700, Sean Christopherson wrote:
> > > Use KVM_SET_USER_MEMORY_REGION2 throughout KVM's selftests library so that
> > > support for guest private memory can be added without needing an entirely
> > > separate set of helpers.
> > > 
> > > Note, this obviously makes selftests backwards-incompatible with older KVM
> >    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > versions from this point forward.
> >    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > 
> > Is there a way we could disable the tests on older kernels instead of
> > making them fail?  Check uname or something?  There is probably a
> > standard way to do this...  It's these tests which fail.
> 
> They shouldn't fail - the tests should be skipped on older kernels.

Ah, that makes sense.  Except for a few outliers that aren't all that interesting,
all KVM selftests create memslots, so I'm tempted to just make it a hard requirement
to spare us headache, e.g.

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index b2262b5fad9e..4b2038b1f11f 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2306,6 +2306,9 @@ void __attribute((constructor)) kvm_selftest_init(void)
        /* Tell stdout not to buffer its content. */
        setbuf(stdout, NULL);
 
+       __TEST_REQUIRE(kvm_has_cap(KVM_CAP_USER_MEMORY2),
+                      "KVM selftests from v6.8+ require KVM_SET_USER_MEMORY_REGION2");
+
        kvm_selftest_arch_init();
 }

--

but it's also easy enough to be more precise and skip only those that actually
create memslots.

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index b2262b5fad9e..b21152adf448 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -944,6 +944,9 @@ int __vm_set_user_memory_region2(struct kvm_vm *vm, uint32_t slot, uint32_t flag
                .guest_memfd_offset = guest_memfd_offset,
        };
 
+       __TEST_REQUIRE(kvm_has_cap(KVM_CAP_USER_MEMORY2),
+                      "KVM selftests from v6.8+ require KVM_SET_USER_MEMORY_REGION2");
+
        return ioctl(vm->fd, KVM_SET_USER_MEMORY_REGION2, &region);
 }
 
@@ -970,6 +973,9 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type,
        size_t mem_size = npages * vm->page_size;
        size_t alignment;
 
+       __TEST_REQUIRE(kvm_has_cap(KVM_CAP_USER_MEMORY2),
+                      "KVM selftests from v6.8+ require KVM_SET_USER_MEMORY_REGION2");
+
        TEST_ASSERT(vm_adjust_num_guest_pages(vm->mode, npages) == npages,
                "Number of guest pages is not compatible with the host. "
                "Try npages=%d", vm_adjust_num_guest_pages(vm->mode, npages));
--

On Thu Apr 25, 2024 at 6:09 PM EEST, Sean Christopherson wrote:
> +       __TEST_REQUIRE(kvm_has_cap(KVM_CAP_USER_MEMORY2),
> +                      "KVM selftests from v6.8+ require KVM_SET_USER_MEMORY_REGION2");

This would work also for casual (but not seasoned) visitor in KVM code
as additionl documentation.

BR, Jarkko

On 4/25/24 09:09, Sean Christopherson wrote:
> On Thu, Apr 25, 2024, Shuah Khan wrote:
>> On 4/25/24 08:12, Dan Carpenter wrote:
>>> On Fri, Oct 27, 2023 at 11:22:07AM -0700, Sean Christopherson wrote:
>>>> Use KVM_SET_USER_MEMORY_REGION2 throughout KVM's selftests library so that
>>>> support for guest private memory can be added without needing an entirely
>>>> separate set of helpers.
>>>>
>>>> Note, this obviously makes selftests backwards-incompatible with older KVM
>>>     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>>> versions from this point forward.
>>>     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>>
>>> Is there a way we could disable the tests on older kernels instead of
>>> making them fail?  Check uname or something?  There is probably a
>>> standard way to do this...  It's these tests which fail.
>>
>> They shouldn't fail - the tests should be skipped on older kernels.
> 
> Ah, that makes sense.  Except for a few outliers that aren't all that interesting,
> all KVM selftests create memslots, so I'm tempted to just make it a hard requirement
> to spare us headache, e.g.
> 
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index b2262b5fad9e..4b2038b1f11f 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -2306,6 +2306,9 @@ void __attribute((constructor)) kvm_selftest_init(void)
>          /* Tell stdout not to buffer its content. */
>          setbuf(stdout, NULL);
>   
> +       __TEST_REQUIRE(kvm_has_cap(KVM_CAP_USER_MEMORY2),
> +                      "KVM selftests from v6.8+ require KVM_SET_USER_MEMORY_REGION2");
> +
>          kvm_selftest_arch_init();
>   }
> 
> --
> 
> but it's also easy enough to be more precise and skip only those that actually
> create memslots.

This is approach is what is recommended in kselfest document. Rubn as many tests
as possible and skip the ones that can't be run due to unmet dependencies.

> 
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index b2262b5fad9e..b21152adf448 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -944,6 +944,9 @@ int __vm_set_user_memory_region2(struct kvm_vm *vm, uint32_t slot, uint32_t flag
>                  .guest_memfd_offset = guest_memfd_offset,
>          };
>   
> +       __TEST_REQUIRE(kvm_has_cap(KVM_CAP_USER_MEMORY2),
> +                      "KVM selftests from v6.8+ require KVM_SET_USER_MEMORY_REGION2");
> +
>          return ioctl(vm->fd, KVM_SET_USER_MEMORY_REGION2, &region);
>   }
>   
> @@ -970,6 +973,9 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type,
>          size_t mem_size = npages * vm->page_size;
>          size_t alignment;
>   
> +       __TEST_REQUIRE(kvm_has_cap(KVM_CAP_USER_MEMORY2),
> +                      "KVM selftests from v6.8+ require KVM_SET_USER_MEMORY_REGION2");
> +
>          TEST_ASSERT(vm_adjust_num_guest_pages(vm->mode, npages) == npages,
>                  "Number of guest pages is not compatible with the host. "
>                  "Try npages=%d", vm_adjust_num_guest_pages(vm->mode, npages));
> --

thanks,
-- Shuah