[PATCH v1 5/9] selftests: kvm: s390: Add debug print functions

[Christoph Schlameuss <schlameuss@xxxxxxxxxxxxx>]

Add functions to simply print some basic state information in selftests.

The output can be enabled by setting:

    #define TH_LOG_ENABLED 1
    #define DEBUG 1

* print_psw: current SIE state description and VM run state
* print_hex_bytes: print memory with some counting markers
* print_hex: PRINT_HEX with 512 bytes
* print_run: use print_psw and print_hex to print contents of VM run
  state and SIE state description
* print_regs: print content of general and control registers

All prints use pr_debug for the output and can be configured using
DEBUG.

Signed-off-by: Christoph Schlameuss <schlameuss@xxxxxxxxxxxxx>
---
 .../selftests/kvm/include/s390x/debug_print.h | 78 +++++++++++++++++++
 .../selftests/kvm/s390x/ucontrol_test.c       |  1 +
 2 files changed, 79 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/include/s390x/debug_print.h

diff --git a/tools/testing/selftests/kvm/include/s390x/debug_print.h b/tools/testing/selftests/kvm/include/s390x/debug_print.h
new file mode 100644
index 000000000000..7cc21596398e
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/s390x/debug_print.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Definition for kernel virtual machines on s390x
+ *
+ * Copyright IBM Corp. 2024
+ *
+ * Authors:
+ *  Christoph Schlameuss <schlameuss@xxxxxxxxxxxxx>
+ */
+
+#ifndef SELFTEST_KVM_DEBUG_PRINT_H
+#define SELFTEST_KVM_DEBUG_PRINT_H
+
+#include "kvm_util.h"
+#include "sie.h"
+
+static inline void print_hex_bytes(const char *name, u64 page, size_t len)
+{
+	pr_debug("%s (%p)\t\t8-0x08  12-0x0c  16-0x10  20-0x14  24-0x18  28-0x1c",
+		 name, (void *)page);
+	for (u8 pp_row = 0; pp_row < (len / 32); pp_row++) {
+		pr_debug("\n %3d 0x%.3x ", pp_row * 32, pp_row * 32);
+		for (u8 pp_block = 0; pp_block < 8; pp_block++)
+			pr_debug(" %8x", *(((u32 *)page) + 8 * pp_row + pp_block));
+	}
+	pr_debug("\n");
+}
+
+static inline void print_hex(const char *name, u64 page)
+{
+	print_hex_bytes(name, page, 512);
+}
+
+static inline void print_psw(struct kvm_run *run, struct kvm_s390_sie_block *sie_block)
+{
+	pr_debug("flags:0x%x psw:0x%.16llx:0x%.16llx exit:%u %s\n",
+		 run->flags,
+		 run->psw_mask, run->psw_addr,
+		 run->exit_reason, exit_reason_str(run->exit_reason));
+	pr_debug("sie_block psw:0x%.16llx:0x%.16llx\n",
+		 sie_block->psw_mask, sie_block->psw_addr);
+}
+
+static inline void print_run(struct kvm_run *run, struct kvm_s390_sie_block *sie_block)
+{
+	print_hex("run", (u64)run);
+	print_hex("sie_block", (u64)sie_block);
+	print_psw(run, sie_block);
+}
+
+static inline void print_regs(int vcpu_fd)
+{
+	struct kvm_sregs sregs = {};
+	struct kvm_regs regs = {};
+	int i;
+
+	if (ioctl(vcpu_fd, KVM_GET_REGS, &regs) != 0)
+		TEST_FAIL("get regs failed, %s", strerror(errno));
+	pr_debug("gprs:\n");
+	for (i = 0; i < 16; i += 4)
+		pr_debug("0x%.16llx 0x%.16llx 0x%.16llx 0x%.16llx\n",
+			 regs.gprs[i], regs.gprs[i + 1],
+			 regs.gprs[i + 2], regs.gprs[i + 3]);
+	if (ioctl(vcpu_fd, KVM_GET_SREGS, &sregs) != 0)
+		TEST_FAIL("get sregs failed, %s", strerror(errno));
+	pr_debug("acrs:\n");
+	for (i = 0; i < 16; i += 4)
+		pr_debug("0x%.8x 0x%.8x 0x%.8x 0x%.8x\n",
+			 sregs.acrs[i], sregs.acrs[i + 1],
+			 sregs.acrs[i + 2], sregs.acrs[i + 3]);
+	pr_debug("crs:\n");
+	for (i = 0; i < 16; i += 4)
+		pr_debug("0x%.16llx 0x%.16llx 0x%.16llx 0x%.16llx\n",
+			 sregs.crs[i], sregs.crs[i + 1],
+			 sregs.crs[i + 2], sregs.crs[i + 3]);
+}
+
+#endif /* SELFTEST_KVM_DEBUG_PRINT_H */
diff --git a/tools/testing/selftests/kvm/s390x/ucontrol_test.c b/tools/testing/selftests/kvm/s390x/ucontrol_test.c
index 44945af6d47d..5c009ee27fd2 100644
--- a/tools/testing/selftests/kvm/s390x/ucontrol_test.c
+++ b/tools/testing/selftests/kvm/s390x/ucontrol_test.c
@@ -7,6 +7,7 @@
  * Authors:
  *  Christoph Schlameuss <schlameuss@xxxxxxxxxxxxx>
  */
+#include "debug_print.h"
 #include "kselftest_harness.h"
 #include "kvm_util.h"
 #include "processor.h"
-- 
2.45.2