[PULL 31/37] pc-bios/s390-ccw: Handle true secure IPL mode

[Eric Farman <farman@linux.ibm.com>]

From: Zhuoying Cai <zycai@linux.ibm.com>

When secure boot is enabled (-secure-boot on) and certificate(s) are
provided, the boot operates in True Secure IPL mode.

Any verification error during True Secure IPL mode will cause the
entire boot process to terminate.

Secure IPL in audit mode requires at least one certificate provided in
the key store along with necessary facilities. If secure boot is enabled
but no certificate is provided, the boot process will also terminate, as
this is not a valid secure boot configuration.

Note: True Secure IPL mode is implemented for the SCSI scheme of
virtio-blk/virtio-scsi devices.

Signed-off-by: Zhuoying Cai <zycai@linux.ibm.com>
Reviewed-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20260730214624.2328883-30-zycai@linux.ibm.com
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 docs/system/s390x/secure-ipl.rst | 13 +++++++++++++
 hw/s390x/ipl.c                   |  3 ++-
 pc-bios/s390-ccw/bootmap.c       |  6 +++++-
 pc-bios/s390-ccw/main.c          |  7 ++++++-
 pc-bios/s390-ccw/s390-ccw.h      |  1 +
 pc-bios/s390-ccw/secure-ipl.h    |  3 +++
 6 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/docs/system/s390x/secure-ipl.rst b/docs/system/s390x/secure-ipl.rst
index 9e3955f8fc..c8fb887ac0 100644
--- a/docs/system/s390x/secure-ipl.rst
+++ b/docs/system/s390x/secure-ipl.rst
@@ -66,3 +66,16 @@ Configuration:
 .. code-block:: shell
 
     qemu-system-s390x -machine s390-ccw-virtio,boot-certs.0.path=/.../qemu/certs,boot-certs.1.path=/another/path/cert.pem ...
+
+Secure Mode
+^^^^^^^^^^^
+
+When the ``secure-boot=on`` option is set and certificates are provided,
+a secure boot is performed with error reporting enabled. The boot process aborts
+if any error occurs.
+
+Configuration:
+
+.. code-block:: shell
+
+    qemu-system-s390x -machine s390-ccw-virtio,secure-boot=on,boot-certs.0.path=/.../qemu/certs,boot-certs.1.path=/another/path/cert.pem ...
diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index 08294af4d0..35bdfe03d8 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -851,7 +851,8 @@ void s390_ipl_prepare_cpu(S390CPU *cpu)
              * Secure IPL without specifying a boot device.
              * IPLB is not generated if no boot device is defined.
              */
-            if (s390_has_certificate() && !ipl->iplb_valid) {
+            if ((s390_has_certificate() || s390_secure_boot_enabled()) &&
+                !ipl->iplb_valid) {
                 error_report("No boot device defined for Secure IPL");
                 exit(1);
             }
diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index 16c20313c8..9e0890f38d 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -743,6 +743,7 @@ static int zipl_run(ScsiBlockPtr *pte)
     case ZIPL_BOOT_MODE_NORMAL:
         rc = zipl_run_normal(&entry, tmp_sec);
         break;
+    case ZIPL_BOOT_MODE_SECURE:
     case ZIPL_BOOT_MODE_SECURE_AUDIT:
         rc = zipl_run_secure(&entry, tmp_sec, &comp_list, &cert_list, &tmp_cert_buf);
         break;
@@ -762,7 +763,8 @@ static int zipl_run(ScsiBlockPtr *pte)
 
     write_reset_psw(entry->compdat.load_psw);
 
-    if (boot_mode == ZIPL_BOOT_MODE_SECURE_AUDIT) {
+    if (boot_mode == ZIPL_BOOT_MODE_SECURE ||
+        boot_mode == ZIPL_BOOT_MODE_SECURE_AUDIT) {
         update_cert_list(&cert_list);
         update_iirb(&comp_list, &cert_list);
         free(tmp_cert_buf);
@@ -1130,6 +1132,8 @@ ZiplBootMode get_boot_mode(uint8_t hdr_flags)
 
     if (!sipl_set && iplir_set) {
         return ZIPL_BOOT_MODE_SECURE_AUDIT;
+    } else if (sipl_set && iplir_set) {
+        return ZIPL_BOOT_MODE_SECURE;
     }
 
     return ZIPL_BOOT_MODE_NORMAL;
diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index 520c448c2c..c5c093534c 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -402,15 +402,20 @@ void main(void)
 
     boot_mode = get_boot_mode(iplb->hdr_flags);
     switch (boot_mode) {
+    case ZIPL_BOOT_MODE_SECURE:
     case ZIPL_BOOT_MODE_SECURE_AUDIT:
         if (!secure_ipl_supported()) {
-            panic("Unable to boot in audit mode");
+            panic("Unable to boot in secure/audit mode");
         }
 
         vcssb_len = zipl_secure_get_vcssb();
         if (vcssb_len == 0) {
             panic("Failed to query certificate storage information!");
         }
+
+        if (vcssb_len == VCSSB_NO_VC) {
+            panic("Need at least one certificate for secure boot!");
+        }
         break;
     default:
         break;
diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
index 64584dc8a7..b2afc155d2 100644
--- a/pc-bios/s390-ccw/s390-ccw.h
+++ b/pc-bios/s390-ccw/s390-ccw.h
@@ -90,6 +90,7 @@ void zipl_load(void);
 typedef enum ZiplBootMode {
     ZIPL_BOOT_MODE_NORMAL = 0,
     ZIPL_BOOT_MODE_SECURE_AUDIT = 1,
+    ZIPL_BOOT_MODE_SECURE = 2,
 } ZiplBootMode;
 
 extern ZiplBootMode boot_mode;
diff --git a/pc-bios/s390-ccw/secure-ipl.h b/pc-bios/s390-ccw/secure-ipl.h
index ce354b4d6a..4908245b9b 100644
--- a/pc-bios/s390-ccw/secure-ipl.h
+++ b/pc-bios/s390-ccw/secure-ipl.h
@@ -59,6 +59,9 @@ static inline void zipl_secure_error(const char *message)
     case ZIPL_BOOT_MODE_SECURE_AUDIT:
         printf("AUDIT MODE WARNING: %s\n", message);
         break;
+    case ZIPL_BOOT_MODE_SECURE:
+        panic(message);
+        break;
     default:
         /*
          * Errors are intentionally ignored in non-secure boot modes.
-- 
2.55.0