Jim MacArthur <[email protected]> writes:
> Tests ASID2 is present and FNG1, FNG0, and A2 are writable, and read
> value shows the update.
>
> Signed-off-by: Jim MacArthur <[email protected]>
> ---
> tests/tcg/aarch64/system/asid2.c | 53 ++++++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
> create mode 100644 tests/tcg/aarch64/system/asid2.c
>
> diff --git a/tests/tcg/aarch64/system/asid2.c
> b/tests/tcg/aarch64/system/asid2.c
> new file mode 100644
> index 0000000000..cfe69db2ae
> --- /dev/null
> +++ b/tests/tcg/aarch64/system/asid2.c
> @@ -0,0 +1,53 @@
> +/*
> + * ASID2 Feature presence and enabled TCR2_EL1 bits test
> + *
> + * Copyright (c) 2025 Linaro Ltd
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#include <stdint.h>
> +#include <minilib.h>
> +
> +#define ID_AA64MMFR4_EL1 "S3_0_C0_C7_4"
> +#define TCR2_EL1 "S3_0_C2_C0_3"
> +
> +int main()
> +{
> + /*
> + * Test for presence of ASID2 and three feature bits enabled by it:
> + *
> https://developer.arm.com/documentation/109697/2025_09/Feature-descriptions/The-Armv9-5-architecture-extension
> + * Bits added are FNG1, FNG0, and A2. These should be RES0 if A2 is
> + * not enabled and read as the written value if A2 is enabled.
> + */
> +
> + uint64_t out;
> + uint64_t idreg;
> +
> + /* Mask is FNG1, FNG0, and A2 */
> + const uint64_t feature_mask = (1ULL << 18 | 1ULL << 17 | 1ULL << 16);
> + const uint64_t in = feature_mask;
> +
> + asm("mrs %[x1], " ID_AA64MMFR4_EL1 "\n\t"
> + : [x1] "=r" (idreg));
> + if ((idreg & 0xF00) != 0) {
> + /* ASID2 is enabled */
> + } else {
> + ml_printf("FAIL: ASID2 not present in ID_AA64MMFR4 (%lx)\n", idreg);
> + return 1;
> + }
If we instead use this to test for the presence of the feature and then...
> +
> + asm("msr " TCR2_EL1 ", %[x0]\n\t"
> + "mrs %[x1], " TCR2_EL1 "\n\t"
> + : [x1] "=r" (out)
> + : [x0] "r" (in));
> +
> + if ((out & feature_mask) == in) {
> + ml_printf("OK\n");
> + return 0;
> + } else {
> + ml_printf("FAIL: read value %lx != written value %lx\n",
> + out & feature_mask, in);
> + return 1;
> + }
extend this part to check the bits are behaving as the feature dictates
then we can add a second test like this (Makefile.softmmu-target):
run-asid2-oldcpu: asid2
$(call run-test, $<, \
$(QEMU) -monitor none -display none \
-chardev file$(COMMA)path=$<.out$(COMMA)id=output \
$(QEMU_OPTS) $<)
run-asid2-oldcpu: QEMU_OPTS=-M virt -cpu cortex-a72 -display none
$(QEMU_BASE_ARGS) -kernel
EXTRA_RUNS += run-asid2-oldcpu
Although its a bit clunky - one day I'll get around to converting this
lot to meson.
> +}
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
