[PATCH 0/2] kselftest/arm64: Minor SME signals test additions

[PATCH 0/2] kselftest/arm64: Minor SME signals test additions

[Mark Brown]

While discussing the SME signal handling support I realised that
we were not verifying that SVE_SIG_FLAG_SM is set for streaming
SVE, and not explicitly covering the case where we are both in
streaming mode and have ZA enabled.  Add coverage of these cases,
I didn't find any problems running these new tests.

To: Catalin Marinas <catalin.marinas@arm.com>
To: Will Deacon <will@kernel.org>
To: Shuah Khan <shuah@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kselftest@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

---
Mark Brown (2):
      kselftest/arm64: Verify that SSVE signal context has SVE_SIG_FLAG_SM set
      kselftest/arm64: Verify simultaneous SSVE and ZA context generation

 .../selftests/arm64/signal/testcases/ssve_regs.c   |   5 +
 .../arm64/signal/testcases/ssve_za_regs.c          | 162 +++++++++++++++++++++
 2 files changed, 167 insertions(+)
---
base-commit: b7bfaa761d760e72a969d116517eaa12e404c262
change-id: 20230117-arm64-test-ssve-za-7128c0ce8dc9

Best regards,
-- 
Mark Brown <broonie@kernel.org>

[PATCH 1/2] kselftest/arm64: Verify that SSVE signal context has SVE_SIG_FLAG_SM set

[Mark Brown]

Streaming mode SVE signal context should have SVE_SIG_FLAG_SM set but we
were not actually validating this. Add a check.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/testcases/ssve_regs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
index d0a178945b1a..cd738265cdcd 100644
--- a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
@@ -92,6 +92,11 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 		return 1;
 	}
 
+	if (!(ssve->flags & SVE_SIG_FLAG_SM)) {
+		fprintf(stderr, "SVE_SIG_FLAG_SM not set in SVE record\n");
+		return 1;
+	}
+
 	/* The actual size validation is done in get_current_context() */
 	fprintf(stderr, "Got expected size %u and VL %d\n",
 		head->size, ssve->vl);

-- 
2.34.1

[PATCH 2/2] kselftest/arm64: Verify simultaneous SSVE and ZA context generation

[Mark Brown]

Add a test that generates SSVE and ZA context in a single signal frame to
ensure that nothing is going wrong in that case for any reason.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 .../arm64/signal/testcases/ssve_za_regs.c          | 162 +++++++++++++++++++++
 1 file changed, 162 insertions(+)

diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c
new file mode 100644
index 000000000000..954a21f6121a
--- /dev/null
+++ b/tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Limited
+ *
+ * Verify that both the streaming SVE and ZA register context in
+ * signal frames is set up as expected when enabled simultaneously.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/prctl.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
+static unsigned int vls[SVE_VQ_MAX];
+unsigned int nvls = 0;
+
+static bool sme_get_vls(struct tdescr *td)
+{
+	int vq, vl;
+
+	/*
+	 * Enumerate up to SVE_VQ_MAX vector lengths
+	 */
+	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
+		vl = prctl(PR_SME_SET_VL, vq * 16);
+		if (vl == -1)
+			return false;
+
+		vl &= PR_SME_VL_LEN_MASK;
+
+		/* Skip missing VLs */
+		vq = sve_vq_from_vl(vl);
+
+		vls[nvls++] = vl;
+	}
+
+	/* We need at least one VL */
+	if (nvls < 1) {
+		fprintf(stderr, "Only %d VL supported\n", nvls);
+		return false;
+	}
+
+	return true;
+}
+
+static void setup_regs(void)
+{
+	/* smstart sm; real data is TODO */
+	asm volatile(".inst 0xd503437f" : : : );
+
+	/* smstart za; real data is TODO */
+	asm volatile(".inst 0xd503457f" : : : );
+}
+
+static char zeros[ZA_SIG_REGS_SIZE(SVE_VQ_MAX)];
+
+static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
+			 unsigned int vl)
+{
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+	struct _aarch64_ctx *regs;
+	struct sve_context *ssve;
+	struct za_context *za;
+	int ret;
+
+	fprintf(stderr, "Testing VL %d\n", vl);
+
+	ret = prctl(PR_SME_SET_VL, vl);
+	if (ret != vl) {
+		fprintf(stderr, "Failed to set VL, got %d\n", ret);
+		return 1;
+	}
+
+	/*
+	 * Get a signal context which should have the SVE and ZA
+	 * frames in it.
+	 */
+	setup_regs();
+	if (!get_current_context(td, &context.uc, sizeof(context)))
+		return 1;
+
+	regs = get_header(head, SVE_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
+	if (!regs) {
+		fprintf(stderr, "No SVE context\n");
+		return 1;
+	}
+
+	ssve = (struct sve_context *)regs;
+	if (ssve->vl != vl) {
+		fprintf(stderr, "Got SSVE VL %d, expected %d\n", ssve->vl, vl);
+		return 1;
+	}
+
+	if (!(ssve->flags & SVE_SIG_FLAG_SM)) {
+		fprintf(stderr, "SVE_SIG_FLAG_SM not set in SVE record\n");
+		return 1;
+	}
+
+	fprintf(stderr, "Got expected SSVE size %u and VL %d\n",
+		regs->size, ssve->vl);
+
+	regs = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
+	if (!regs) {
+		fprintf(stderr, "No ZA context\n");
+		return 1;
+	}
+
+	za = (struct za_context *)regs;
+	if (za->vl != vl) {
+		fprintf(stderr, "Got ZA VL %d, expected %d\n", za->vl, vl);
+		return 1;
+	}
+
+	fprintf(stderr, "Got expected ZA size %u and VL %d\n",
+		regs->size, za->vl);
+
+	/* We didn't load any data into ZA so it should be all zeros */
+	if (memcmp(zeros, (char *)za + ZA_SIG_REGS_OFFSET,
+		   ZA_SIG_REGS_SIZE(sve_vq_from_vl(za->vl))) != 0) {
+		fprintf(stderr, "ZA data invalid\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+	int i;
+
+	for (i = 0; i < nvls; i++) {
+		if (do_one_sme_vl(td, si, uc, vls[i]))
+			return 1;
+	}
+
+	td->pass = 1;
+
+	return 0;
+}
+
+struct tdescr tde = {
+	.name = "Streaming SVE registers",
+	.descr = "Check that we get the right Streaming SVE registers reported",
+	/*
+	 * We shouldn't require FA64 but things like memset() used in the
+	 * helpers might use unsupported instructions so for now disable
+	 * the test unless we've got the full instruction set.
+	 */
+	.feats_required = FEAT_SME | FEAT_SME_FA64,
+	.timeout = 3,
+	.init = sme_get_vls,
+	.run = sme_regs,
+};

-- 
2.34.1

Re: [PATCH 0/2] kselftest/arm64: Minor SME signals test additions

[Catalin Marinas]

On Fri, 20 Jan 2023 12:04:08 +0000, Mark Brown wrote:
> While discussing the SME signal handling support I realised that
> we were not verifying that SVE_SIG_FLAG_SM is set for streaming
> SVE, and not explicitly covering the case where we are both in
> streaming mode and have ZA enabled.  Add coverage of these cases,
> I didn't find any problems running these new tests.
> 
> 
> [...]

Applied to arm64 (for-next/kselftest), thanks!

[1/2] kselftest/arm64: Verify that SSVE signal context has SVE_SIG_FLAG_SM set
      https://git.kernel.org/arm64/c/f76cb73a2d7c
[2/2] kselftest/arm64: Verify simultaneous SSVE and ZA context generation
      https://git.kernel.org/arm64/c/bc69da5ff087

-- 
Catalin