[PATCH 09/10] hw: Add "loadparm" property to PCI devices for booting on s390x

[jrossi@linux.ibm.com]

From: Jared Rossi <jrossi@linux.ibm.com>

The loadparm is required on s390x to pass the information to the boot loader
such as which kernel should be started or whether the boot menu should be shown.

Because PCI devices do not naturally allocate space for this, the property is
added on an architecture specific basis.

Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
---
 include/hw/pci/pci_device.h |  3 +++
 hw/pci/pci.c                | 39 +++++++++++++++++++++++++++++++++++++
 hw/s390x/ipl.c              | 11 +++++++++--
 3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/include/hw/pci/pci_device.h b/include/hw/pci/pci_device.h
index 88ccea5011..5cac6e1688 100644
--- a/include/hw/pci/pci_device.h
+++ b/include/hw/pci/pci_device.h
@@ -62,6 +62,9 @@ struct PCIDevice {
     bool partially_hotplugged;
     bool enabled;
 
+    /* only for s390x */
+    char *loadparm;
+
     /* PCI config space */
     uint8_t *config;
 
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index b1eba348e0..1ea0d7c54c 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -36,6 +36,7 @@
 #include "migration/qemu-file-types.h"
 #include "migration/vmstate.h"
 #include "net/net.h"
+#include "system/arch_init.h"
 #include "system/numa.h"
 #include "system/runstate.h"
 #include "system/system.h"
@@ -2825,6 +2826,43 @@ int pci_qdev_find_device(const char *id, PCIDevice **pdev)
     return rc;
 }
 
+static char *pci_qdev_property_get_loadparm(Object *obj, Error **errp)
+{
+    return g_strdup(PCI_DEVICE(obj)->loadparm);
+}
+
+static void pci_qdev_property_set_loadparm(Object *obj, const char *value,
+                                       Error **errp)
+{
+    void *lp_str;
+
+    if (object_property_get_int(obj, "bootindex", NULL) < 0) {
+        error_setg(errp, "'loadparm' is only valid for boot devices");
+        return;
+    }
+
+    lp_str = g_malloc0(strlen(value) + 1);
+    if (!qdev_prop_sanitize_s390x_loadparm(lp_str, value, errp)) {
+        g_free(lp_str);
+        return;
+    }
+    PCI_DEVICE(obj)->loadparm = lp_str;
+}
+
+static void pci_qdev_property_add_specifics(DeviceClass *dc)
+{
+    ObjectClass *oc = OBJECT_CLASS(dc);
+
+    /* The loadparm property is only supported on s390x */
+    if (qemu_arch_available(QEMU_ARCH_S390X)) {
+        object_class_property_add_str(oc, "loadparm",
+                                      pci_qdev_property_get_loadparm,
+                                      pci_qdev_property_set_loadparm);
+        object_class_property_set_description(oc, "loadparm",
+                                              "load parameter (s390x only)");
+    }
+}
+
 MemoryRegion *pci_address_space(PCIDevice *dev)
 {
     return pci_get_bus(dev)->address_space_mem;
@@ -2843,6 +2881,7 @@ static void pci_device_class_init(ObjectClass *klass, const void *data)
     k->unrealize = pci_qdev_unrealize;
     k->bus_type = TYPE_PCI_BUS;
     device_class_set_props(k, pci_props);
+    pci_qdev_property_add_specifics(k);
     object_class_property_set_description(
         klass, "x-max-bounce-buffer-size",
         "Maximum buffer size allocated for bounce buffers used for mapped "
diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index cf423ac764..57f5a7a204 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -460,6 +460,7 @@ static bool s390_build_iplb(DeviceState *dev_st, IplParameterBlock *iplb)
     int devtype;
     uint8_t *lp;
     g_autofree void *scsi_lp = NULL;
+    g_autofree void *pci_lp = NULL;
 
     ccw_dev = s390_get_ccw_device(dev_st, &devtype);
     if (ccw_dev) {
@@ -512,6 +513,14 @@ static bool s390_build_iplb(DeviceState *dev_st, IplParameterBlock *iplb)
 
     pbdev = s390_get_pci_device(dev_st, &devtype);
     if (pbdev) {
+        pci_lp = object_property_get_str(OBJECT(pbdev->pdev), "loadparm", NULL);
+        if (pci_lp && strlen(pci_lp) > 0) {
+            lp = pci_lp;
+        } else {
+            /* Use machine loadparm as a place holder if PCI LP is unset */
+            lp = S390_CCW_MACHINE(qdev_get_machine())->loadparm;
+        }
+
         switch (devtype) {
         case PCI_DEVTYPE_VIRTIO:
             iplb->len = S390_IPLB_MIN_PCI_LEN;
@@ -522,8 +531,6 @@ static bool s390_build_iplb(DeviceState *dev_st, IplParameterBlock *iplb)
             return false;
         }
 
-        /* Per-device loadparm not yet supported for non-ccw IPL */
-        lp = S390_CCW_MACHINE(qdev_get_machine())->loadparm;
         s390_ipl_convert_loadparm((char *)lp, iplb->loadparm);
         iplb->flags |= DIAG308_FLAGS_LP_VALID;
 
-- 
2.49.0