1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * EPSW Interception Tests
4 *
5 * Copyright IBM Corp. 2022
6 *
7 * Authors:
8 * Nico Boehr <nrb@linux.ibm.com>
9 */
10 #include <libcflat.h>
11 #include <css.h>
12 #include <hardware.h>
13
zero_out_cc_from_epsw_op1(uint32_t epsw_op1)14 static uint32_t zero_out_cc_from_epsw_op1(uint32_t epsw_op1)
15 {
16 return epsw_op1 & ~GENMASK(31 - 18, 31 - 20);
17 }
18
generate_crw(void)19 static void generate_crw(void)
20 {
21 int test_device_sid = css_enumerate();
22 int cc, ret;
23
24 if (!(test_device_sid & SCHID_ONE)) {
25 report_fail("No I/O device found");
26 return;
27 }
28
29 cc = css_enable(test_device_sid, IO_SCH_ISC);
30 report(cc == 0, "Enable subchannel %08x", test_device_sid);
31
32 ret = css_generate_crw(test_device_sid);
33 if (ret)
34 report_fail("Couldn't generate CRW");
35 }
36
test_epsw(void)37 static void test_epsw(void)
38 {
39 const uint64_t MAGIC1 = 0x1234567890abcdefUL;
40 const uint64_t MAGIC2 = 0xcafedeadbeeffaceUL;
41
42 uint64_t op1 = MAGIC1;
43 uint64_t op2 = MAGIC2;
44 uint32_t prev_epsw_op1;
45
46 /*
47 * having machine check interrupts masked and pending CRW ensures
48 * EPSW is intercepted under KVM
49 */
50 generate_crw();
51
52 report_prefix_push("both operands given");
53 asm volatile(
54 "epsw %0, %1\n"
55 : "+&d" (op1), "+&a" (op2));
56 report(upper_32_bits(op1) == upper_32_bits(MAGIC1) &&
57 upper_32_bits(op2) == upper_32_bits(MAGIC2),
58 "upper 32 bits unmodified");
59 report(lower_32_bits(op1) != lower_32_bits(MAGIC1) &&
60 lower_32_bits(op2) != lower_32_bits(MAGIC2),
61 "lower 32 bits modified");
62 prev_epsw_op1 = zero_out_cc_from_epsw_op1(lower_32_bits(op1));
63 report_prefix_pop();
64
65 report_prefix_push("second operand 0");
66 op1 = MAGIC1;
67 op2 = MAGIC2;
68 asm volatile(
69 " lgr 0,%[op2]\n"
70 " epsw %[op1], 0\n"
71 " lgr %[op2],0\n"
72 : [op2] "+&d" (op2), [op1] "+&a" (op1)
73 :
74 : "0");
75 report(upper_32_bits(op1) == upper_32_bits(MAGIC1),
76 "upper 32 bits of first operand unmodified");
77 report(zero_out_cc_from_epsw_op1(lower_32_bits(op1)) == prev_epsw_op1,
78 "first operand matches previous reading");
79 report(op2 == MAGIC2, "r0 unmodified");
80 report_prefix_pop();
81
82 report_prefix_push("both operands 0");
83 op1 = MAGIC1;
84 asm volatile(
85 " lgr 0,%[op1]\n"
86 " epsw 0, 0\n"
87 " lgr %[op1],0\n"
88 : [op1] "+&d" (op1)
89 :
90 : "0");
91 report(upper_32_bits(op1) == upper_32_bits(MAGIC1),
92 "upper 32 bits of first operand unmodified");
93 report(zero_out_cc_from_epsw_op1(lower_32_bits(op1)) == prev_epsw_op1,
94 "first operand matches previous reading");
95 report_prefix_pop();
96 }
97
main(int argc,char ** argv)98 int main(int argc, char **argv)
99 {
100 report_prefix_push("epsw");
101
102 if (!host_is_kvm() && !host_is_tcg()) {
103 report_skip("Not running under QEMU");
104 goto done;
105 }
106
107 test_epsw();
108
109 done:
110 report_prefix_pop();
111
112 return report_summary();
113 }
114