Commit 2667b05e authored by Thomas Huth's avatar Thomas Huth Committed by Radim Krčmář
Browse files

s390x: Interception tests



Certain CPU instructions will cause an exit of the virtual
machine. Run some of these instructions to check whether
they are emulated right by KVM (or QEMU).
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarThomas Huth <thuth@redhat.com>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent 10594e42
......@@ -15,4 +15,24 @@ void handle_pgm_int(void);
void expect_pgm_int(void);
void check_pgm_int_code(uint16_t code);
/* Activate low-address protection */
static inline void low_prot_enable(void)
{
uint64_t cr0;
asm volatile (" stctg %%c0,%%c0,%0 " : : "Q"(cr0) : "memory");
cr0 |= 1ULL << (63-35);
asm volatile (" lctlg %%c0,%%c0,%0 " : : "Q"(cr0));
}
/* Disable low-address protection */
static inline void low_prot_disable(void)
{
uint64_t cr0;
asm volatile (" stctg %%c0,%%c0,%0 " : : "Q"(cr0) : "memory");
cr0 &= ~(1ULL << (63-35));
asm volatile (" lctlg %%c0,%%c0,%0 " : : "Q"(cr0));
}
#endif
tests = $(TEST_DIR)/selftest.elf
tests += $(TEST_DIR)/intercept.elf
all: directories test_cases
......
/*
* Interception tests - for s390x CPU instruction that cause a VM exit
*
* Copyright (c) 2017 Red Hat Inc
*
* Authors:
* Thomas Huth <thuth@redhat.com>
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU Library General Public License version 2.
*/
#include <libcflat.h>
#include <asm/asm-offsets.h>
#include <asm/interrupt.h>
#include <asm/page.h>
static uint8_t pagebuf[PAGE_SIZE * 2] __attribute__((aligned(PAGE_SIZE * 2)));
static unsigned long nr_iterations;
static unsigned long time_to_run;
/* Test the STORE PREFIX instruction */
static void test_stpx(void)
{
uint32_t old_prefix = -1U, tst_prefix = -1U;
uint32_t new_prefix = (uint32_t)(intptr_t)pagebuf;
/* Can we successfully change the prefix? */
asm volatile (
" stpx %0\n"
" spx %2\n"
" stpx %1\n"
" spx %0\n"
: "+Q"(old_prefix), "+Q"(tst_prefix)
: "Q"(new_prefix));
report("store prefix", old_prefix == 0 && tst_prefix == new_prefix);
expect_pgm_int();
low_prot_enable();
asm volatile(" stpx 0(%0) " : : "r"(8));
low_prot_disable();
check_pgm_int_code(PGM_INT_CODE_PROTECTION);
expect_pgm_int();
asm volatile(" stpx 0(%0) " : : "r"(1));
check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
expect_pgm_int();
asm volatile(" stpx 0(%0) " : : "r"(-8));
check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
}
/* Test the SET PREFIX instruction */
static void test_spx(void)
{
uint32_t new_prefix = (uint32_t)(intptr_t)pagebuf;
uint32_t old_prefix;
memset(pagebuf, 0, PAGE_SIZE * 2);
/*
* Temporarily change the prefix page to our buffer, and store
* some facility bits there ... at least some of them should be
* set in our buffer afterwards.
*/
asm volatile (
" stpx %0\n"
" spx %1\n"
" stfl 0\n"
" spx %0\n"
: "+Q"(old_prefix)
: "Q"(new_prefix)
: "memory");
report("stfl to new prefix", pagebuf[GEN_LC_STFL] != 0);
expect_pgm_int();
asm volatile(" spx 0(%0) " : : "r"(1));
check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
expect_pgm_int();
asm volatile(" spx 0(%0) " : : "r"(-8));
check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
}
/* Test the STORE CPU ADDRESS instruction */
static void test_stap(void)
{
uint16_t cpuid = 0xffff;
asm volatile ("stap %0\n" : "+Q"(cpuid));
report("get cpu address", cpuid != 0xffff);
expect_pgm_int();
low_prot_enable();
asm volatile ("stap 0(%0)\n" : : "r"(8));
low_prot_disable();
check_pgm_int_code(PGM_INT_CODE_PROTECTION);
expect_pgm_int();
asm volatile ("stap 0(%0)\n" : : "r"(1));
check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
expect_pgm_int();
asm volatile ("stap 0(%0)\n" : : "r"(-8));
check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
}
/* Test the TEST BLOCK instruction */
static void test_testblock(void)
{
int cc;
memset(pagebuf, 0xaa, PAGE_SIZE);
asm volatile (
" lghi %%r0,0\n"
" tb %1\n"
" ipm %0\n"
" srl %0,28\n"
: "=d" (cc)
: "a"(pagebuf + 0x123)
: "memory", "0", "cc");
report("page cleared",
cc == 0 && pagebuf[0] == 0 && pagebuf[PAGE_SIZE - 1] == 0);
expect_pgm_int();
low_prot_enable();
asm volatile (" tb %0 " : : "r"(4096));
low_prot_disable();
check_pgm_int_code(PGM_INT_CODE_PROTECTION);
expect_pgm_int();
asm volatile (" tb %0 " : : "r"(-4096));
check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
}
static uint64_t get_clock_ms(void)
{
uint64_t clk;
asm volatile(" stck %0 " : : "Q"(clk) : "memory");
/* Bit 51 is incrememented each microsecond */
return (clk >> (63 - 51)) / 1000;
}
struct {
const char *name;
void (*func)(void);
bool run_it;
} tests[] = {
{ "stpx", test_stpx, false },
{ "spx", test_spx, false },
{ "stap", test_stap, false },
{ "testblock", test_testblock, false },
{ NULL, NULL, false }
};
void parse_intercept_test_args(int argc, char **argv)
{
int i, ti;
bool run_all = true;
for (i = 1; i < argc; i++) {
if (!strcmp("-i", argv[i])) {
i++;
if (i >= argc)
report_abort("-i needs a parameter");
nr_iterations = atol(argv[i]);
} else if (!strcmp("-t", argv[i])) {
i++;
if (i >= argc)
report_abort("-t needs a parameter");
time_to_run = atol(argv[i]);
} else for (ti = 0; tests[ti].name != NULL; ti++) {
if (!strcmp(tests[ti].name, argv[i])) {
run_all = false;
tests[ti].run_it = true;
break;
} else if (tests[ti + 1].name == NULL) {
report_abort("Unsupported parameter '%s'",
argv[i]);
}
}
}
if (run_all) {
for (ti = 0; tests[ti].name != NULL; ti++)
tests[ti].run_it = true;
}
}
int main(int argc, char **argv)
{
uint64_t startclk;
int ti;
parse_intercept_test_args(argc, argv);
if (nr_iterations == 0 && time_to_run == 0)
nr_iterations = 1;
report_prefix_push("intercept");
startclk = get_clock_ms();
for (;;) {
for (ti = 0; tests[ti].name != NULL; ti++) {
report_prefix_push(tests[ti].name);
if (tests[ti].run_it)
tests[ti].func();
report_prefix_pop();
}
if (nr_iterations) {
nr_iterations -= 1;
if (nr_iterations == 0)
break;
}
if (time_to_run) {
if (get_clock_ms() - startclk > time_to_run)
break;
}
}
report_prefix_pop();
return report_summary();
}
......@@ -22,3 +22,6 @@
file = selftest.elf
groups = selftest
extra_params = -append 'test 123'
[intercept]
file = intercept.elf
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