Re: [PATCH] kvm powerpc/book3s-apiv2: Add suite initialization to skip GSB tests without APIv2 support
From: Amit Machhiwal <hidden>
Date: 2026-06-04 17:10:14
Also in:
kvm
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Hi Vaibhav, Thanks for the patch. Please find my comments inline. On 2026/06/04 02:59 PM, Vaibhav Jain wrote:
quoted hunk ↗ jump to hunk
The guest state buffer (GSB) test suite currently fails on systems that do not support the PAPR APIv2 nested virtualization. This happens because the tests attempt to use APIv2-specific functionality without first checking if the host supports it. This was recently reported [1] when test-guest-state-buffer kunit tests were being run on Qemu without enabling Qemu capability 'cap-nested-papr' which enabled APIv2 nested virtualization for PPC64 Pseries Qemu machine. Add a suite_init callback that checks for APIv2 support by calling plpar_guest_get_capabilities(). If the host does not support APIv2 (indicated by H_SUCCESS not being returned), mark all test cases in the suite as KUNIT_SKIPPED. This prevents test failures on systems without APIv2 support while still allowing the tests to run on capable systems. [1] https://lore.kernel.org/all/20260603064225.GC18149@sol/ (local) Reported-by: Eric Biggers <ebiggers@kernel.org> Closes: https://lore.kernel.org/all/20260603064225.GC18149@sol (local) Signed-off-by: Vaibhav Jain <redacted> Assisted-by: Bob:Claude-3.7-Sonnet Bob-Shell --- arch/powerpc/kvm/test-guest-state-buffer.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)diff --git a/arch/powerpc/kvm/test-guest-state-buffer.c b/arch/powerpc/kvm/test-guest-state-buffer.c index 5ccca306997a..f84b40fa55db 100644 --- a/arch/powerpc/kvm/test-guest-state-buffer.c +++ b/arch/powerpc/kvm/test-guest-state-buffer.c@@ -521,6 +521,24 @@ static void test_gs_hostwide_counters(struct kunit *test) kvmppc_gsb_free(gsb); } +static int init_gs_test_suite(struct kunit_suite *suite) +{ + long rc; + unsigned long host_capabilities; + struct kunit_case *test_case; + + /* Enable test suite only if APIv2 is supported */ + rc = plpar_guest_get_capabilities(0, &host_capabilities);
I believe we don't really need an hcall overhead to check the availability of APIv2. We could simply check:
diff --git a/arch/powerpc/kvm/test-guest-state-buffer.c b/arch/powerpc/kvm/test-guest-state-buffer.c
index 5ccca306997a..a263e7f31e15 100644
--- a/arch/powerpc/kvm/test-guest-state-buffer.c
+++ b/arch/powerpc/kvm/test-guest-state-buffer.c@@ -521,6 +521,18 @@ static void test_gs_hostwide_counters(struct kunit *test) kvmppc_gsb_free(gsb); } +static int init_gs_test_suite(struct kunit_suite *suite) +{ + struct kunit_case *test_case; + + if (!kvmhv_is_nestedv2()) { + kunit_suite_for_each_test_case(suite, test_case) + WRITE_ONCE(test_case->status, KUNIT_SKIPPED); + } + + return 0; +} +
Also, I understand that these tests exercise gsb related tests specific to APIv2 but I see that only 'test_gs_hostwide_counters' relies on an APIv2 specific 'H_GUEST_GET_STATE' hcall but rest of the tests just operate on in-memory gsb. So, do we really want to skip all the tests when APIv2 is not available? If not, we could simply skip this one test as:
diff --git a/arch/powerpc/kvm/test-guest-state-buffer.c b/arch/powerpc/kvm/test-guest-state-buffer.c
index 5ccca306997a..89999b80fdfc 100644
--- a/arch/powerpc/kvm/test-guest-state-buffer.c
+++ b/arch/powerpc/kvm/test-guest-state-buffer.c@@ -462,7 +462,10 @@ static void test_gs_hostwide_counters(struct kunit *test) int rc; if (!kvmhv_on_pseries()) - kunit_skip(test, "This test need a kmv-hv guest"); + kunit_skip(test, "This test need a kvm-hv guest"); + + if (!kvmhv_is_nestedv2()) + kunit_skip(test, "This test needs an spapr nested APIv2 support"); gsm = kvmppc_gsm_new(&gs_msg_test_hostwide_ops, &test_data, GSM_SEND, GFP_KERNEL);
Please let me know your views. Thanks, Amit
quoted hunk ↗ jump to hunk
+ + if (rc != H_SUCCESS) { + /* Skip all testcases if no APIv2 support */ + kunit_suite_for_each_test_case(suite, test_case) + WRITE_ONCE(test_case->status, KUNIT_SKIPPED); + } + + return 0; +} + static struct kunit_case guest_state_buffer_testcases[] = { KUNIT_CASE(test_creating_buffer), KUNIT_CASE(test_adding_element),@@ -535,6 +553,7 @@ static struct kunit_case guest_state_buffer_testcases[] = { static struct kunit_suite guest_state_buffer_test_suite = { .name = "guest_state_buffer_test", .test_cases = guest_state_buffer_testcases, + .suite_init = init_gs_test_suite, }; kunit_test_suites(&guest_state_buffer_test_suite);-- 2.54.0