xref: /kvm-unit-tests/powerpc/sprs.c (revision 851ef5165069857e56e35b01c8ed43b115c2737e)

/*
 * Test Special Purpose Registers
 *
 * Copyright 2017  Thomas Huth, Red Hat Inc.
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.
 *
 * The basic idea of this test is to check whether the contents of the Special
 * Purpose Registers (SPRs) are preserved correctly during migration. So we
 * fill in the SPRs with a well-known value, read the values back (since not
 * all bits might be retained in the SPRs), then wait for migration to complete
 * (if the '-w' option has been specified) so that the user has a chance to
 * migrate the VM. Alternatively, the test can also simply sleep a little bit
 * with the H_CEDE hypercall, in the hope that we'll get scheduled to another
 * host CPU and thus register contents might have changed, too (in case of
 * bugs). Finally, we read back the values from the SPRs and compare them with
 * the values before the migration. Mismatches are reported as test failures.
 * Note that we do not test all SPRs since some of the registers change their
 * content automatically, and some are only accessible with hypervisor privi-
 * leges or have bad side effects, so we have to omit those registers.
 */
#include <libcflat.h>
#include <util.h>
#include <migrate.h>
#include <alloc.h>
#include <asm/ppc_asm.h>
#include <asm/handlers.h>
#include <asm/hcall.h>
#include <asm/processor.h>
#include <asm/time.h>
#include <asm/barrier.h>

/* "Indirect" mfspr/mtspr which accept a non-constant spr number */
static uint64_t __mfspr(unsigned spr)
{
	uint64_t tmp;
	uint64_t ret;

	asm volatile(
"	bcl	20, 31, 1f		\n"
"1:	mflr	%0			\n"
"	addi	%0, %0, (2f-1b)		\n"
"	add	%0, %0, %2		\n"
"	mtctr	%0			\n"
"	bctr				\n"
"2:					\n"
".LSPR=0				\n"
".rept 1024				\n"
"	mfspr	%1, .LSPR		\n"
"	b	3f			\n"
"	.LSPR=.LSPR+1			\n"
".endr					\n"
"3:					\n"
	: "=&r"(tmp),
	  "=r"(ret)
	: "r"(spr*8) /* 8 bytes per 'mfspr ; b' block */
	: "lr", "ctr");

	return ret;
}

static void __mtspr(unsigned spr, uint64_t val)
{
	uint64_t tmp;

	asm volatile(
"	bcl	20, 31, 1f		\n"
"1:	mflr	%0			\n"
"	addi	%0, %0, (2f-1b)		\n"
"	add	%0, %0, %2		\n"
"	mtctr	%0			\n"
"	bctr				\n"
"2:					\n"
".LSPR=0				\n"
".rept 1024				\n"
"	mtspr	.LSPR, %1		\n"
"	b	3f			\n"
"	.LSPR=.LSPR+1			\n"
".endr					\n"
"3:					\n"
	: "=&r"(tmp)
	: "r"(val),
	  "r"(spr*8) /* 8 bytes per 'mfspr ; b' block */
	: "lr", "ctr", "xer");
}

static uint64_t before[1024], after[1024];

#define SPR_PR_READ	0x0001
#define SPR_PR_WRITE	0x0002
#define SPR_OS_READ	0x0010
#define SPR_OS_WRITE	0x0020
#define SPR_HV_READ	0x0100
#define SPR_HV_WRITE	0x0200

#define RW		0x333
#define RO		0x111
#define WO		0x222
#define OS_RW		0x330
#define OS_RO		0x110
#define OS_WO		0x220
#define HV_RW		0x300
#define HV_RO		0x100
#define HV_WO		0x200

#define SPR_ASYNC	0x1000	/* May be updated asynchronously */
#define SPR_INT		0x2000	/* May be updated by synchronous interrupt */
#define SPR_HARNESS	0x4000	/* Test harness uses the register */

struct spr {
	const char	*name;
	uint8_t		width;
	uint16_t	access;
	uint16_t	type;
};

/* SPRs common denominator back to PowerPC Operating Environment Architecture */
static const struct spr sprs_common[1024] = {
  [1] = { "XER",	64,	RW,		SPR_HARNESS, }, /* Used by compiler */
  [8] = { "LR", 	64,	RW,		SPR_HARNESS, }, /* Compiler, mfspr/mtspr */
  [9] = { "CTR",	64,	RW,		SPR_HARNESS, }, /* Compiler, mfspr/mtspr */
 [18] = { "DSISR",	32,	OS_RW,		SPR_INT, },
 [19] = { "DAR",	64,	OS_RW,		SPR_INT, },
 [26] = { "SRR0",	64,	OS_RW,		SPR_INT, },
 [27] = { "SRR1",	64,	OS_RW,		SPR_INT, },
[268] = { "TB",		64,	RO	,	SPR_ASYNC, },
[269] = { "TBU",	32,	RO,		SPR_ASYNC, },
[272] = { "SPRG0",	64,	OS_RW,		SPR_HARNESS, }, /* Interrupt stacr */
[273] = { "SPRG1",	64,	OS_RW,		SPR_HARNESS, }, /* Interrupt Scratch */
[274] = { "SPRG2",	64,	OS_RW, },
[275] = { "SPRG3",	64,	OS_RW, },
[287] = { "PVR",	32,	OS_RO, },
};

/* SPRs from PowerPC Operating Environment Architecture, Book III, Vers. 2.01 */
static const struct spr sprs_201[1024] = {
 [22] = { "DEC",	32,	OS_RW,		SPR_ASYNC, },
 [25] = { "SDR1",	64,	HV_RW | OS_RO, },
 [29] = { "ACCR",	64,	OS_RW, },
[136] = { "CTRL",	32,	RO, },
[152] = { "CTRL",	32,	OS_WO, },
[259] = { "SPRG3",	64,	RO, },
/* ASR, EAR omitted */
[284] = { "TBL",	32,	HV_WO, },
[285] = { "TBU",	32,	HV_WO, },
[310] = { "HDEC",	32,	HV_RW,		SPR_ASYNC, },
[1013]= { "DABR",	64,	HV_RW | OS_RO, },
[1023]= { "PIR",	32,	OS_RO,		SPR_ASYNC, }, /* Can't be virtualised, appears to be async */
};

static const struct spr sprs_970_pmu[1024] = {
/* POWER4+ PMU, should confirm with PPC970 */
[770] = { "MMCRA",	64,	RO, },
[771] = { "PMC1",	32,	RO, },
[772] = { "PMC2",	32,	RO, },
[773] = { "PMC3",	32,	RO, },
[774] = { "PMC4",	32,	RO, },
[775] = { "PMC5",	32,	RO, },
[776] = { "PMC6",	32,	RO, },
[777] = { "PMC7",	32,	RO, },
[778] = { "PMC8",	32,	RO, },
[779] = { "MMCR0",	64,	RO, },
[780] = { "SIAR",	64,	RO, },
[781] = { "SDAR",	64,	RO, },
[782] = { "MMCR1",	64,	RO, },
[786] = { "MMCRA",	64,	OS_RW, },
[787] = { "PMC1",	32,	OS_RW, },
[788] = { "PMC2",	32,	OS_RW, },
[789] = { "PMC3",	32,	OS_RW, },
[790] = { "PMC4",	32,	OS_RW, },
[791] = { "PMC5",	32,	OS_RW, },
[792] = { "PMC6",	32,	OS_RW, },
[793] = { "PMC7",	32,	OS_RW, },
[794] = { "PMC8",	32,	OS_RW, },
[795] = { "MMCR0",	64,	OS_RW, },
[796] = { "SIAR",	64,	OS_RW, },
[797] = { "SDAR",	64,	OS_RW, },
[798] = { "MMCR1",	64,	OS_RW, },
};

/* These are common SPRs from 2.07S onward (POWER CPUs that support KVM HV) */
static const struct spr sprs_power_common[1024] = {
  [3] = { "DSCR",	64,	RW, },
 [13] = { "AMR",	64,	RW, },
 [17] = { "DSCR",	64,	OS_RW, },
 [28] = { "CFAR",	64,	OS_RW,		SPR_ASYNC, }, /* Effectively async */
 [29] = { "AMR",	64,	OS_RW, },
 [61] = { "IAMR",	64,	OS_RW, },
[136] = { "CTRL",	32,	RO, },
[152] = { "CTRL",	32,	OS_WO, },
[153] = { "FSCR",	64,	OS_RW, },
[157] = { "UAMOR",	64,	OS_RW, },
[159] = { "PSPB",	32,	OS_RW, },
[176] = { "DPDES",	64,	HV_RW | OS_RO, },
[180] = { "DAWR0",	64,	HV_RW, },
[186] = { "RPR",	64,	HV_RW, },
[187] = { "CIABR",	64,	HV_RW, },
[188] = { "DAWRX0",	32,	HV_RW, },
[190] = { "HFSCR",	64,	HV_RW, },
[256] = { "VRSAVE",	32,	RW, },
[259] = { "SPRG3",	64,	RO, },
[284] = { "TBL",	32,	HV_WO, }, /* Things can go a bit wonky with */
[285] = { "TBU",	32,	HV_WO, }, /* Timebase changing. Should save */
[286] = { "TBU40",	64,	HV_WO, }, /* and restore it. */
[304] = { "HSPRG0",	64,	HV_RW, },
[305] = { "HSPRG1",	64,	HV_RW, },
[306] = { "HDSISR",	32,	HV_RW,		SPR_INT, },
[307] = { "HDAR",	64,	HV_RW,		SPR_INT, },
[308] = { "SPURR",	64,	HV_RW | OS_RO,	SPR_ASYNC, },
[309] = { "PURR",	64,	HV_RW | OS_RO,	SPR_ASYNC, },
[313] = { "HRMOR",	64,	HV_RW,		SPR_HARNESS, }, /* Harness can't cope with HRMOR changing */
[314] = { "HSRR0",	64,	HV_RW,		SPR_INT, },
[315] = { "HSRR1",	64,	HV_RW,		SPR_INT, },
[318] = { "LPCR",	64,	HV_RW, },
[319] = { "LPIDR",	32,	HV_RW, },
[336] = { "HMER",	64,	HV_RW, },
[337] = { "HMEER",	64,	HV_RW, },
[338] = { "PCR",	64,	HV_RW, },
[349] = { "AMOR",	64,	HV_RW, },
[446] = { "TIR",	64,	OS_RO, },
[800] = { "BESCRS",	64,	RW, },
[801] = { "BESCRSU",	32,	RW, },
[802] = { "BESCRR",	64,	RW, },
[803] = { "BESCRRU",	32,	RW, },
[804] = { "EBBHR",	64,	RW, },
[805] = { "EBBRR",	64,	RW, },
[806] = { "BESCR",	64,	RW, },
[815] = { "TAR",	64,	RW, },
[848] = { "IC",		64,	HV_RW | OS_RO,	SPR_ASYNC, },
[849] = { "VTB",	64,	HV_RW | OS_RO,	SPR_ASYNC, },
[896] = { "PPR",	64,	RW,		SPR_ASYNC, }, /* PPR(32) is changed by cpu_relax(), appears to be async */
[898] = { "PPR32",	32,	RW,		SPR_ASYNC, },
[1023]= { "PIR",	32,	OS_RO,		SPR_ASYNC, }, /* Can't be virtualised, appears to be async */
};

static const struct spr sprs_tm[1024] = {
#if 0
	/* XXX: leave these out until enabling TM facility (and more testing) */
[128] = { "TFHAR",	64,	RW, },
[129] = { "TFIAR",	64,	RW, },
[130] = { "TEXASR",	64,	RW, },
[131] = { "TEXASRU",	32,	RW, },
#endif
};

/* SPRs from PowerISA 2.07 Book III-S */
static const struct spr sprs_207[1024] = {
 [22] = { "DEC",	32,	OS_RW,		SPR_ASYNC, },
 [25] = { "SDR1",	64,	HV_RW, },
[177] = { "DHDES",	64,	HV_RW, },
[283] = { "CIR",	32,	OS_RO, },
[310] = { "HDEC",	32,	HV_RW,		SPR_ASYNC, },
[312] = { "RMOR",	64,	HV_RW, },
[339] = { "HEIR",	32,	HV_RW,		SPR_INT, },
};

/* SPRs from PowerISA 3.00 Book III */
static const struct spr sprs_300[1024] = {
 [22] = { "DEC",	64,	OS_RW,		SPR_ASYNC, },
 [48] = { "PIDR",	32,	OS_RW, },
[144] = { "TIDR",	64,	OS_RW, },
[283] = { "CIR",	32,	OS_RO, },
[310] = { "HDEC",	64,	HV_RW,		SPR_ASYNC, },
[339] = { "HEIR",	32,	HV_RW,		SPR_INT, },
[464] = { "PTCR",	64,	HV_RW, },
[816] = { "ASDR",	64,	HV_RW,		SPR_INT, },
[823] = { "PSSCR",	64,	OS_RW, },
[855] = { "PSSCR",	64,	HV_RW, },
};

/* SPRs from PowerISA 3.1B Book III */
static const struct spr sprs_31[1024] = {
 [22] = { "DEC",	64,	OS_RW,		SPR_ASYNC, },
 [48] = { "PIDR",	32,	OS_RW, },
[181] = { "DAWR1",	64,	HV_RW, },
[189] = { "DAWRX1",	32,	HV_RW, },
[310] = { "HDEC",	64,	HV_RW,		SPR_ASYNC, },
[339] = { "HEIR",	64,	HV_RW,		SPR_INT, },
[455] = { "HDEXCR",	32,	RO, },
[464] = { "PTCR",	64,	HV_RW, },
[468] = { "HASHKEYR",	64,	OS_RW, },
[469] = { "HASHPKEYR",	64,	HV_RW, },
[471] = { "HDEXCR",	64,	HV_RW, },
[812] = { "DEXCR",	32,	RO, },
[816] = { "ASDR",	64,	HV_RW,		SPR_INT, },
[823] = { "PSSCR",	64,	OS_RW, },
[828] = { "DEXCR",	64,	OS_RW, },
[855] = { "PSSCR",	64,	HV_RW, },
};

/* SPRs POWER9, POWER10 User Manual */
static const struct spr sprs_power9_10[1024] = {
[276] = { "SPRC",	64,	HV_RW, },
[277] = { "SPRD",	64,	HV_RW, },
[317] = { "TFMR",	64,	HV_RW, },
[799] = { "IMC",	64,	HV_RW, },
[850] = { "LDBAR",	64,	HV_RO, },
[851] = { "MMCRC",	32,	HV_RW, },
[853] = { "PMSR",	32,	HV_RO, },
[861] = { "L2QOSR",	64,	HV_WO, },
[881] = { "TRIG1",	64,	OS_WO, },
[882] = { "TRIG2",	64,	OS_WO, },
[884] = { "PMCR",	64,	HV_RW, },
[885] = { "RWMR",	64,	HV_RW, },
[895] = { "WORT",	64,	OS_RW, }, /* UM says 18-bits! */
[921] = { "TSCR",	32,	HV_RW, },
[922] = { "TTR",	64,	HV_RW, },
[1006]= { "TRACE",	64,	WO, },
[1008]= { "HID",	64,	HV_RW,		SPR_HARNESS, }, /* HILE would be unhelpful to change */
};

/* This covers POWER8 and POWER9 PMUs */
static const struct spr sprs_power_common_pmu[1024] = {
[768] = { "SIER",	64,	RO, },
[769] = { "MMCR2",	64,	RW, },
[770] = { "MMCRA",	64,	RW, },
[771] = { "PMC1",	32,	RW, },
[772] = { "PMC2",	32,	RW, },
[773] = { "PMC3",	32,	RW, },
[774] = { "PMC4",	32,	RW, },
[775] = { "PMC5",	32,	RW, },
[776] = { "PMC6",	32,	RW, },
[779] = { "MMCR0",	64,	RW, },
[780] = { "SIAR",	64,	RO, },
[781] = { "SDAR",	64,	RO, },
[782] = { "MMCR1",	64,	RO, },
[784] = { "SIER",	64,	OS_RW, },
[785] = { "MMCR2",	64,	OS_RW, },
[786] = { "MMCRA",	64,	OS_RW, },
[787] = { "PMC1",	32,	OS_RW, },
[788] = { "PMC2",	32,	OS_RW, },
[789] = { "PMC3",	32,	OS_RW, },
[790] = { "PMC4",	32,	OS_RW, },
[791] = { "PMC5",	32,	OS_RW, },
[792] = { "PMC6",	32,	OS_RW, },
[795] = { "MMCR0",	64,	OS_RW, },
[796] = { "SIAR",	64,	OS_RW, },
[797] = { "SDAR",	64,	OS_RW, },
[798] = { "MMCR1",	64,	OS_RW, },
};

static const struct spr sprs_power10_pmu[1024] = {
[736] = { "SIER2",	64,	RO, },
[737] = { "SIER3",	64,	RO, },
[738] = { "MMCR3",	64,	RO, },
[752] = { "SIER2",	64,	OS_RW, },
[753] = { "SIER3",	64,	OS_RW, },
[754] = { "MMCR3",	64,	OS_RW, },
};

static struct spr sprs[1024];

static bool spr_read_perms(int spr)
{
	if (cpu_has_hv)
		return !!(sprs[spr].access & SPR_HV_READ);
	else
		return !!(sprs[spr].access & SPR_OS_READ);
}

static bool spr_write_perms(int spr)
{
	if (cpu_has_hv)
		return !!(sprs[spr].access & SPR_HV_WRITE);
	else
		return !!(sprs[spr].access & SPR_OS_WRITE);
}

static void setup_sprs(void)
{
	int i;

	for (i = 0; i < 1024; i++) {
		if (sprs_common[i].name) {
			memcpy(&sprs[i], &sprs_common[i], sizeof(struct spr));
		}
	}

	switch (mfspr(SPR_PVR) & PVR_VERSION_MASK) {
	case PVR_VER_970:
	case PVR_VER_970FX:
	case PVR_VER_970MP:
		for (i = 0; i < 1024; i++) {
			if (sprs_201[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_201[i], sizeof(struct spr));
			}
			if (sprs_970_pmu[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power_common_pmu[i], sizeof(struct spr));
			}
		}
		break;

	case PVR_VER_POWER8E:
	case PVR_VER_POWER8NVL:
	case PVR_VER_POWER8:
		for (i = 0; i < 1024; i++) {
			if (sprs_power_common[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power_common[i], sizeof(struct spr));
			}
			if (sprs_207[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_207[i], sizeof(struct spr));
			}
			if (sprs_tm[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_tm[i], sizeof(struct spr));
			}
			if (sprs_power_common_pmu[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power_common_pmu[i], sizeof(struct spr));
			}
		}
		break;

	case PVR_VER_POWER9:
		for (i = 0; i < 1024; i++) {
			if (sprs_power_common[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power_common[i], sizeof(struct spr));
			}
			if (sprs_300[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_300[i], sizeof(struct spr));
			}
			if (sprs_tm[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_tm[i], sizeof(struct spr));
			}
			if (sprs_power9_10[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power9_10[i], sizeof(struct spr));
			}
			if (sprs_power_common_pmu[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power_common_pmu[i], sizeof(struct spr));
			}
		}
		break;

	case PVR_VER_POWER10:
		for (i = 0; i < 1024; i++) {
			if (sprs_power_common[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power_common[i], sizeof(struct spr));
			}
			if (sprs_31[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_31[i], sizeof(struct spr));
			}
			if (sprs_power9_10[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power9_10[i], sizeof(struct spr));
			}
			if (sprs_power_common_pmu[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power_common_pmu[i], sizeof(struct spr));
			}
			if (sprs_power10_pmu[i].name) {
				assert(!sprs[i].name);
				memcpy(&sprs[i], &sprs_power10_pmu[i], sizeof(struct spr));
			}
		}
		break;

	default:
		memcpy(sprs, sprs_common, sizeof(sprs));
		puts("Warning: Unknown processor version, falling back to common SPRs!\n");
		break;
	}
}

static void get_sprs(uint64_t *v)
{
	int i;

	for (i = 0; i < 1024; i++) {
		if (!spr_read_perms(i))
			continue;
		v[i] = __mfspr(i);
	}
}

static void set_sprs(uint64_t val)
{
	int i;

	for (i = 0; i < 1024; i++) {
		if (!spr_write_perms(i))
			continue;

		if (sprs[i].type & SPR_HARNESS)
			continue;
		__mtspr(i, val);
	}
}

int main(int argc, char **argv)
{
	int i;
	bool pause = false;
	uint64_t pat = 0xcafefacec0debabeULL;
	const uint64_t patterns[] = {
		0xcafefacec0debabeULL, ~0xcafefacec0debabeULL,
		0xAAAA5555AAAA5555ULL, 0x5555AAAA5555AAAAULL,
		0x1234567890ABCDEFULL, 0xFEDCBA0987654321ULL,
		-1ULL,
	};

	for (i = 1; i < argc; i++) {
		if (!strcmp(argv[i], "-w")) {
			pause = true;
		} else if (!strcmp(argv[i], "-p")) {
			i += 1;
			if (i >= argc || *argv[i] < '0'
			    || *argv[i] >= '0' + ARRAY_SIZE(patterns))
				report_abort("Error: bad value for -p");
			pat ^= patterns[*argv[i] - '0'];
		} else if (!strcmp(argv[i], "-t")) {
			/* Randomize with timebase register */
			asm volatile("mftb %0" : "=r"(i));
			pat ^= i;
			asm volatile("mftb %0" : "=r"(i));
			pat ^= ~(uint64_t)i << 32;
		} else {
			report_abort("Warning: Unsupported argument: %s",
			             argv[i]);
		}
	}

	setup_sprs();

	printf("Setting SPRs to 0x%lx...\n", pat);
	set_sprs(pat);

	memset(before, 0, sizeof(before));
	memset(after, 0, sizeof(after));

	get_sprs(before);

	if (pause) {
		migrate_once();
		/* Reload regs changed by getchar/putchar hcalls */
		before[SPR_SRR0] = mfspr(SPR_SRR0);
		before[SPR_SRR1] = mfspr(SPR_SRR1);

		/* WORT seems to go to 0 after KVM switch, perhaps CPU idle */
		if (sprs[895].name)
			before[895] = mfspr(895);
	} else {
		/*
		 * msleep will enable MSR[EE] and take a decrementer
		 * interrupt. Must account for changed registers and
		 * prevent taking unhandled interrupts.
		 */
		/* Prevent PMU interrupt */
		mtspr(SPR_MMCR0, (mfspr(SPR_MMCR0) | MMCR0_FC) &
					~(MMCR0_PMAO | MMCR0_PMAE));
		before[SPR_MMCR0] = mfspr(SPR_MMCR0);
		before[779] = mfspr(SPR_MMCR0);
		msleep(2000);

		/* Reload regs changed by dec interrupt */
		before[SPR_SRR0] = mfspr(SPR_SRR0);
		before[SPR_SRR1] = mfspr(SPR_SRR1);
		before[SPR_SPRG1] = mfspr(SPR_SPRG1);

		/* WORT seems to go to 0 after KVM switch, perhaps CPU idle */
		if (sprs[895].name)
			before[895] = mfspr(895);
	}

	get_sprs(after);

	puts("Checking SPRs...\n");
	for (i = 0; i < 1024; i++) {
		bool pass = true;

		if (!spr_read_perms(i))
			continue;

		if (sprs[i].width == 32) {
			if (before[i] >> 32)
				pass = false;
		}
		if (!(sprs[i].type & (SPR_HARNESS|SPR_ASYNC)) && (before[i] != after[i]))
			pass = false;

		if (sprs[i].width == 32 && !(before[i] >> 32) && !(after[i] >> 32)) {
			/* known failure KVM migration of CTRL */
			report_kfail(host_is_kvm && i == 136, pass,
				"%-10s(%4d):\t        0x%08lx <==>         0x%08lx",
				sprs[i].name, i,
				before[i], after[i]);
		} else {
			report(pass, "%-10s(%4d):\t0x%016lx <==> 0x%016lx",
				sprs[i].name, i,
				before[i], after[i]);
		}
	}

	return report_summary();
}