Commit 9c4866b2 authored by Benjamin Gray's avatar Benjamin Gray Committed by Michael Ellerman
Browse files

selftests/powerpc/dexcr: Add DEXCR config details to lsdexcr 



Now that the DEXCR can be configured with prctl, add a section in
lsdexcr that explains why each aspect is set the way it is.

Signed-off-by: default avatarBenjamin Gray <bgray@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-8-bgray@linux.ibm.com
parent 9930fba0

tools/testing/selftests/powerpc/dexcr/lsdexcr.c

+111 −2
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+



#include <errno.h>

#include <stddef.h>

#include <stdio.h>

#include <string.h>

#include <sys/prctl.h>



#include "dexcr.h"

#include "utils.h"
@@ -16,6 +16,8 @@ struct dexcr_aspect { 
	const char *name;

	const char *desc;

	unsigned int index;

	unsigned long prctl;

	const char *sysctl;

};



static const struct dexcr_aspect aspects[] = {
@@ -23,26 +25,36 @@ static const struct dexcr_aspect aspects[] = { 
		.name = "SBHE",

		.desc = "Speculative branch hint enable",

		.index = 0,

		.prctl = PR_PPC_DEXCR_SBHE,

		.sysctl = "speculative_branch_hint_enable",

	},

	{

		.name = "IBRTPD",

		.desc = "Indirect branch recurrent target prediction disable",

		.index = 3,

		.prctl = PR_PPC_DEXCR_IBRTPD,

		.sysctl = "indirect_branch_recurrent_target_prediction_disable",

	},

	{

		.name = "SRAPD",

		.desc = "Subroutine return address prediction disable",

		.index = 4,

		.prctl = PR_PPC_DEXCR_SRAPD,

		.sysctl = "subroutine_return_address_prediction_disable",

	},

	{

		.name = "NPHIE",

		.desc = "Non-privileged hash instruction enable",

		.index = 5,

		.prctl = PR_PPC_DEXCR_NPHIE,

		.sysctl = "nonprivileged_hash_instruction_enable",

	},

	{

		.name = "PHIE",

		.desc = "Privileged hash instruction enable",

		.index = 6,

		.prctl = -1,

		.sysctl = NULL,

	},

};
@@ -60,7 +72,7 @@ static void print_dexcr(char *name, unsigned int bits) 
	const char *enabled_aspects[ARRAY_SIZE(aspects) + 1] = {NULL};

	size_t j = 0;



	printf("%s: %08x", name, bits);

	printf("%s: 0x%08x", name, bits);



	if (bits == 0) {

		printf("\n");
@@ -103,6 +115,95 @@ static void print_aspect(const struct dexcr_aspect *aspect) 
	printf("  \t(%s)\n", aspect->desc);

}



static void print_aspect_config(const struct dexcr_aspect *aspect)

{

	char sysctl_path[128] = "/proc/sys/kernel/dexcr/";

	const char *reason = "unknown";

	const char *reason_hyp = NULL;

	const char *reason_sysctl = "no sysctl";

	const char *reason_prctl = "no prctl";

	bool actual = effective & DEXCR_PR_BIT(aspect->index);

	bool expected = false;



	long sysctl_ctrl = 0;

	int prctl_ctrl = 0;

	int err;



	if (aspect->prctl >= 0) {

		prctl_ctrl = pr_get_dexcr(aspect->prctl);

		if (prctl_ctrl < 0)

			reason_prctl = "(failed to read prctl)";

		else {

			if (prctl_ctrl & PR_PPC_DEXCR_CTRL_SET) {

				reason_prctl = "set by prctl";

				expected = true;

			} else if (prctl_ctrl & PR_PPC_DEXCR_CTRL_CLEAR) {

				reason_prctl = "cleared by prctl";

				expected = false;

			} else

				reason_prctl = "unknown prctl";



			reason = reason_prctl;

		}

	}



	if (aspect->sysctl) {

		strcat(sysctl_path, aspect->sysctl);

		err = read_long(sysctl_path, &sysctl_ctrl, 10);

		if (err)

			reason_sysctl = "(failed to read sysctl)";

		else {

			switch (sysctl_ctrl) {

			case 0:

				reason_sysctl = "cleared by sysctl";

				reason = reason_sysctl;

				expected = false;

				break;

			case 1:

				reason_sysctl = "set by sysctl";

				reason = reason_sysctl;

				expected = true;

				break;

			case 2:

				reason_sysctl = "not modified by sysctl";

				break;

			case 3:

				reason_sysctl = "cleared by sysctl (permanent)";

				reason = reason_sysctl;

				expected = false;

				break;

			case 4:

				reason_sysctl = "set by sysctl (permanent)";

				reason = reason_sysctl;

				expected = true;

				break;

			default:

				reason_sysctl = "unknown sysctl";

				break;

			}

		}

	}





	if (hdexcr & DEXCR_PR_BIT(aspect->index)) {

		reason_hyp = "set by hypervisor";

		reason = reason_hyp;

		expected = true;

	} else

		reason_hyp = "not modified by hypervisor";



	printf("%12s (%d): %-28s (%s, %s, %s)\n",

	       aspect->name,

	       aspect->index,

	       reason,

	       reason_hyp,

	       reason_sysctl,

	       reason_prctl);



	if (actual != expected)

		printf("                : ! actual %s does not match config\n", aspect->name);

}



int main(int argc, char *argv[])

{

	if (!dexcr_exists()) {
@@ -114,6 +215,8 @@ int main(int argc, char *argv[]) 
	hdexcr = get_dexcr(HDEXCR);

	effective = dexcr | hdexcr;



	printf("current status:\n");



	print_dexcr("    DEXCR", dexcr);

	print_dexcr("   HDEXCR", hdexcr);

	print_dexcr("Effective", effective);
@@ -136,6 +239,12 @@ int main(int argc, char *argv[]) 
		else

			printf("ignored\n");

	}

	printf("\n");



	printf("configuration:\n");

	for (size_t i = 0; i < ARRAY_SIZE(aspects); i++)

		print_aspect_config(&aspects[i]);

	printf("\n");



	return 0;

}