Re: [kvm-unit-tests PATCH v9 27/31] powerpc: add pmu tests

[Thomas Huth <thuth@xxxxxxxxxx>]

On 04/05/2024 14.28, Nicholas Piggin wrote:
> Add some initial PMU testing.
>
> - PMC5/6 tests
> - PMAE / PMI test
> - BHRB basic tests
>
> Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
> ---
...
> diff --git a/lib/powerpc/setup.c b/lib/powerpc/setup.c
> index a4ff678ce..8ff4939e2 100644
> --- a/lib/powerpc/setup.c
> +++ b/lib/powerpc/setup.c
> @@ -33,6 +33,7 @@ u32 initrd_size;
>   u32 cpu_to_hwid[NR_CPUS] = { [0 ... NR_CPUS-1] = (~0U) };
>   int nr_cpus_present;
>   uint64_t tb_hz;
> +uint64_t cpu_hz;
>   
>   struct mem_region mem_regions[NR_MEM_REGIONS];
>   phys_addr_t __physical_start, __physical_end;
> @@ -42,6 +43,7 @@ struct cpu_set_params {
>   	unsigned icache_bytes;
>   	unsigned dcache_bytes;
>   	uint64_t tb_hz;
> +	uint64_t cpu_hz;
>   };
>   
>   static void cpu_set(int fdtnode, u64 regval, void *info)
> @@ -95,6 +97,22 @@ static void cpu_set(int fdtnode, u64 regval, void *info)
>   		data = (u32 *)prop->data;
>   		params->tb_hz = fdt32_to_cpu(*data);
>   
> +		prop = fdt_get_property(dt_fdt(), fdtnode,
> +					"ibm,extended-clock-frequency", NULL);
> +		if (prop) {
> +			data = (u32 *)prop->data;
> +			params->cpu_hz = fdt32_to_cpu(*data);
> +			params->cpu_hz <<= 32;
> +			data = (u32 *)prop->data + 1;
> +			params->cpu_hz |= fdt32_to_cpu(*data);

Why don't you simply cast to (u64 *) and use fdt64_to_cpu() here instead?

...
> diff --git a/powerpc/pmu.c b/powerpc/pmu.c
> new file mode 100644
> index 000000000..8b13ee4cd
> --- /dev/null
> +++ b/powerpc/pmu.c
> @@ -0,0 +1,403 @@
...
> +static void test_pmc5_with_fault(void)
> +{
> +	unsigned long pmc5_1, pmc5_2;
> +
> +	handle_exception(0x700, &illegal_handler, NULL);
> +	handle_exception(0xe40, &illegal_handler, NULL);
> +
> +	reset_mmcr0();
> +	mtspr(SPR_PMC5, 0);
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) & ~(MMCR0_FC | MMCR0_FC56));
> +	asm volatile(".long 0x0" ::: "memory");
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) | (MMCR0_FC | MMCR0_FC56));
> +	assert(got_interrupt);
> +	got_interrupt = false;
> +	pmc5_1 = mfspr(SPR_PMC5);
> +
> +	reset_mmcr0();
> +	mtspr(SPR_PMC5, 0);
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) & ~(MMCR0_FC | MMCR0_FC56));
> +	asm volatile(".rep 20 ; nop ; .endr ; .long 0x0" ::: "memory");
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) | (MMCR0_FC | MMCR0_FC56));
> +	assert(got_interrupt);
> +	got_interrupt = false;
> +	pmc5_2 = mfspr(SPR_PMC5);
> +
> +	/* TCG and POWER9 do not count instructions around faults correctly */
> +	report_kfail(true, pmc5_1 + 20 == pmc5_2, "PMC5 counts instructions with fault");

It would be nice to have the TCG detection patch before this patch, so you 
could use the right condition here right from the start.

> +	handle_exception(0x700, NULL, NULL);
> +	handle_exception(0xe40, NULL, NULL);
> +}
> +
> +static void test_pmc5_with_sc(void)
> +{
> +	unsigned long pmc5_1, pmc5_2;
> +
> +	handle_exception(0xc00, &sc_handler, NULL);
> +
> +	reset_mmcr0();
> +	mtspr(SPR_PMC5, 0);
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) & ~(MMCR0_FC | MMCR0_FC56));
> +	asm volatile("sc 0" ::: "memory");
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) | (MMCR0_FC | MMCR0_FC56));
> +	assert(got_interrupt);
> +	got_interrupt = false;
> +	pmc5_1 = mfspr(SPR_PMC5);
> +
> +	reset_mmcr0();
> +	mtspr(SPR_PMC5, 0);
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) & ~(MMCR0_FC | MMCR0_FC56));
> +	asm volatile(".rep 20 ; nop ; .endr ; sc 0" ::: "memory");
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) | (MMCR0_FC | MMCR0_FC56));
> +	assert(got_interrupt);
> +	got_interrupt = false;
> +	pmc5_2 = mfspr(SPR_PMC5);
> +
> +	/* TCG does not count instructions around syscalls correctly */
> +	report_kfail(true, pmc5_1 + 20 == pmc5_2, "PMC5 counts instructions with syscall");

dito

> +	handle_exception(0xc00, NULL, NULL);
> +}
> +
> +static void test_pmc56(void)
> +{
> +	unsigned long tmp;
> +
> +	report_prefix_push("pmc56");
> +
> +	reset_mmcr0();
> +	mtspr(SPR_PMC5, 0);
> +	mtspr(SPR_PMC6, 0);
> +	report(mfspr(SPR_PMC5) == 0, "PMC5 zeroed");
> +	report(mfspr(SPR_PMC6) == 0, "PMC6 zeroed");
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) & ~MMCR0_FC);
> +	msleep(100);
> +	report(mfspr(SPR_PMC5) == 0, "PMC5 frozen");
> +	report(mfspr(SPR_PMC6) == 0, "PMC6 frozen");
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) & ~MMCR0_FC56);
> +	mdelay(100);
> +	mtspr(SPR_MMCR0, mfspr(SPR_MMCR0) | (MMCR0_FC | MMCR0_FC56));
> +	report(mfspr(SPR_PMC5) != 0, "PMC5 counting");
> +	report(mfspr(SPR_PMC6) != 0, "PMC6 counting");
> +
> +	/* Dynamic frequency scaling could cause to be out, so don't fail. */
> +	tmp = mfspr(SPR_PMC6);
> +	report(true, "PMC6 ratio to reported clock frequency is %ld%%", tmp * 1000 / cpu_hz);

report(true, ...) looks weird. Use report_info() instead?

 Thomas