[PATCH v3 00/11] qdev: Make array properties user accessible again

[PATCH v3 00/11] qdev: Make array properties user accessible again

[Kevin Wolf]

Array properties have been inaccessible since commit f3558b1b both on
the command line and in QMP. This series reworks them so that they are
made accessible again in these external interfaces, this time as JSON
lists. See patch 11 for details.

v3:
- Rebased, patch 1 was already merged in the context of another series
- malloc() the elements for the temporary list in set_prop_array().
  Having the value directly in GenericList.padding resulted in bad
  alignment for some property types on 32 bit platforms.

v2:
- Patch 1: Use unsigned instead of uint32_t
- Patch 9: Fixed build error
- Patch 11: Split into a separate patch to clarify the intention
- Patch 12:
  * Improved the commit message
  * Document and statically assert alignment requirements for array
    elements (the static assertion turned out to be much uglier than I
    had hoped, but it is what it is)
  * Replace UB in pointer arithmetics with uintptr_t calculations
  * Fix properties without a .release callback
  * Check array size for integer overflow
  * Call visit_check_list() even for output visitors
- Coding style changes

Kevin Wolf (11):
  hw/i386/pc: Use qdev_prop_set_array()
  hw/arm/mps2-tz: Use qdev_prop_set_array()
  hw/arm/mps2: Use qdev_prop_set_array()
  hw/arm/sbsa-ref: Use qdev_prop_set_array()
  hw/arm/vexpress: Use qdev_prop_set_array()
  hw/arm/virt: Use qdev_prop_set_array()
  hw/arm/xlnx-versal: Use qdev_prop_set_array()
  hw/rx/rx62n: Use qdev_prop_set_array()
  qom: Add object_property_set_default_list()
  qdev: Make netdev properties work as list elements
  qdev: Rework array properties based on list visitor

 include/hw/qdev-properties.h     |  35 ++---
 include/qom/object.h             |   8 ++
 hw/arm/mps2-tz.c                 |  10 +-
 hw/arm/mps2.c                    |  12 +-
 hw/arm/sbsa-ref.c                |   7 +-
 hw/arm/vexpress.c                |  21 +--
 hw/arm/virt.c                    |  31 ++--
 hw/arm/xlnx-versal.c             |   9 +-
 hw/core/qdev-properties-system.c |   2 +-
 hw/core/qdev-properties.c        | 237 ++++++++++++++++++++-----------
 hw/i386/pc.c                     |   8 +-
 hw/rx/rx62n.c                    |  19 +--
 qom/object.c                     |   6 +
 13 files changed, 257 insertions(+), 148 deletions(-)

-- 
2.41.0

[PATCH v3 01/11] hw/i386/pc: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/i386/pc.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 188bc9d0f8..29b9964733 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -44,6 +44,7 @@
 #include "sysemu/reset.h"
 #include "kvm/kvm_i386.h"
 #include "hw/xen/xen.h"
+#include "qapi/qmp/qlist.h"
 #include "qemu/error-report.h"
 #include "hw/acpi/cpu_hotplug.h"
 #include "acpi-build.h"
@@ -1457,10 +1458,11 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
         /* Declare the APIC range as the reserved MSI region */
         char *resv_prop_str = g_strdup_printf("0xfee00000:0xfeefffff:%d",
                                               VIRTIO_IOMMU_RESV_MEM_T_MSI);
+        QList *reserved_regions = qlist_new();
+
+        qlist_append_str(reserved_regions, resv_prop_str);
+        qdev_prop_set_array(dev, "reserved-regions", reserved_regions);
 
-        object_property_set_uint(OBJECT(dev), "len-reserved-regions", 1, errp);
-        object_property_set_str(OBJECT(dev), "reserved-regions[0]",
-                                resv_prop_str, errp);
         g_free(resv_prop_str);
     }
 
-- 
2.41.0

[PATCH v3 02/11] hw/arm/mps2-tz: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/mps2-tz.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/hw/arm/mps2-tz.c b/hw/arm/mps2-tz.c
index eae3639da2..668db5ed61 100644
--- a/hw/arm/mps2-tz.c
+++ b/hw/arm/mps2-tz.c
@@ -48,6 +48,7 @@
 #include "qemu/units.h"
 #include "qemu/cutils.h"
 #include "qapi/error.h"
+#include "qapi/qmp/qlist.h"
 #include "qemu/error-report.h"
 #include "hw/arm/boot.h"
 #include "hw/arm/armv7m.h"
@@ -461,6 +462,7 @@ static MemoryRegion *make_scc(MPS2TZMachineState *mms, void *opaque,
     MPS2SCC *scc = opaque;
     DeviceState *sccdev;
     MPS2TZMachineClass *mmc = MPS2TZ_MACHINE_GET_CLASS(mms);
+    QList *oscclk;
     uint32_t i;
 
     object_initialize_child(OBJECT(mms), "scc", scc, TYPE_MPS2_SCC);
@@ -469,11 +471,13 @@ static MemoryRegion *make_scc(MPS2TZMachineState *mms, void *opaque,
     qdev_prop_set_uint32(sccdev, "scc-cfg4", 0x2);
     qdev_prop_set_uint32(sccdev, "scc-aid", 0x00200008);
     qdev_prop_set_uint32(sccdev, "scc-id", mmc->scc_id);
-    qdev_prop_set_uint32(sccdev, "len-oscclk", mmc->len_oscclk);
+
+    oscclk = qlist_new();
     for (i = 0; i < mmc->len_oscclk; i++) {
-        g_autofree char *propname = g_strdup_printf("oscclk[%u]", i);
-        qdev_prop_set_uint32(sccdev, propname, mmc->oscclk[i]);
+        qlist_append_int(oscclk, mmc->oscclk[i]);
     }
+    qdev_prop_set_array(sccdev, "oscclk", oscclk);
+
     sysbus_realize(SYS_BUS_DEVICE(scc), &error_fatal);
     return sysbus_mmio_get_region(SYS_BUS_DEVICE(sccdev), 0);
 }
-- 
2.41.0

[PATCH v3 03/11] hw/arm/mps2: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/mps2.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/hw/arm/mps2.c b/hw/arm/mps2.c
index d92fd60684..292a180ad2 100644
--- a/hw/arm/mps2.c
+++ b/hw/arm/mps2.c
@@ -48,6 +48,7 @@
 #include "net/net.h"
 #include "hw/watchdog/cmsdk-apb-watchdog.h"
 #include "hw/qdev-clock.h"
+#include "qapi/qmp/qlist.h"
 #include "qom/object.h"
 
 typedef enum MPS2FPGAType {
@@ -138,6 +139,7 @@ static void mps2_common_init(MachineState *machine)
     MemoryRegion *system_memory = get_system_memory();
     MachineClass *mc = MACHINE_GET_CLASS(machine);
     DeviceState *armv7m, *sccdev;
+    QList *oscclk;
     int i;
 
     if (strcmp(machine->cpu_type, mc->default_cpu_type) != 0) {
@@ -402,10 +404,12 @@ static void mps2_common_init(MachineState *machine)
     qdev_prop_set_uint32(sccdev, "scc-aid", 0x00200008);
     qdev_prop_set_uint32(sccdev, "scc-id", mmc->scc_id);
     /* All these FPGA images have the same OSCCLK configuration */
-    qdev_prop_set_uint32(sccdev, "len-oscclk", 3);
-    qdev_prop_set_uint32(sccdev, "oscclk[0]", 50000000);
-    qdev_prop_set_uint32(sccdev, "oscclk[1]", 24576000);
-    qdev_prop_set_uint32(sccdev, "oscclk[2]", 25000000);
+    oscclk = qlist_new();
+    qlist_append_int(oscclk, 50000000);
+    qlist_append_int(oscclk, 24576000);
+    qlist_append_int(oscclk, 25000000);
+    qdev_prop_set_array(sccdev, "oscclk", oscclk);
+
     sysbus_realize(SYS_BUS_DEVICE(&mms->scc), &error_fatal);
     sysbus_mmio_map(SYS_BUS_DEVICE(sccdev), 0, 0x4002f000);
     object_initialize_child(OBJECT(mms), "fpgaio",
-- 
2.41.0

[PATCH v3 04/11] hw/arm/sbsa-ref: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/sbsa-ref.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/hw/arm/sbsa-ref.c b/hw/arm/sbsa-ref.c
index bce44690e5..f3c9704693 100644
--- a/hw/arm/sbsa-ref.c
+++ b/hw/arm/sbsa-ref.c
@@ -48,6 +48,7 @@
 #include "hw/char/pl011.h"
 #include "hw/watchdog/sbsa_gwdt.h"
 #include "net/net.h"
+#include "qapi/qmp/qlist.h"
 #include "qom/object.h"
 
 #define RAMLIMIT_GB 8192
@@ -437,6 +438,7 @@ static void create_gic(SBSAMachineState *sms, MemoryRegion *mem)
     SysBusDevice *gicbusdev;
     const char *gictype;
     uint32_t redist0_capacity, redist0_count;
+    QList *redist_region_count;
     int i;
 
     gictype = gicv3_class_name();
@@ -455,8 +457,9 @@ static void create_gic(SBSAMachineState *sms, MemoryRegion *mem)
                 sbsa_ref_memmap[SBSA_GIC_REDIST].size / GICV3_REDIST_SIZE;
     redist0_count = MIN(smp_cpus, redist0_capacity);
 
-    qdev_prop_set_uint32(sms->gic, "len-redist-region-count", 1);
-    qdev_prop_set_uint32(sms->gic, "redist-region-count[0]", redist0_count);
+    redist_region_count = qlist_new();
+    qlist_append_int(redist_region_count, redist0_count);
+    qdev_prop_set_array(sms->gic, "redist-region-count", redist_region_count);
 
     object_property_set_link(OBJECT(sms->gic), "sysmem",
                              OBJECT(mem), &error_fatal);
-- 
2.41.0

[PATCH v3 05/11] hw/arm/vexpress: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/vexpress.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/hw/arm/vexpress.c b/hw/arm/vexpress.c
index c08ea34e92..fd981f4c33 100644
--- a/hw/arm/vexpress.c
+++ b/hw/arm/vexpress.c
@@ -43,6 +43,7 @@
 #include "hw/cpu/a15mpcore.h"
 #include "hw/i2c/arm_sbcon_i2c.h"
 #include "hw/sd/sd.h"
+#include "qapi/qmp/qlist.h"
 #include "qom/object.h"
 #include "audio/audio.h"
 
@@ -544,6 +545,7 @@ static void vexpress_common_init(MachineState *machine)
     ram_addr_t vram_size, sram_size;
     MemoryRegion *sysmem = get_system_memory();
     const hwaddr *map = daughterboard->motherboard_map;
+    QList *db_voltage, *db_clock;
     int i;
 
     daughterboard->init(vms, machine->ram_size, machine->cpu_type, pic);
@@ -584,20 +586,19 @@ static void vexpress_common_init(MachineState *machine)
     sysctl = qdev_new("realview_sysctl");
     qdev_prop_set_uint32(sysctl, "sys_id", sys_id);
     qdev_prop_set_uint32(sysctl, "proc_id", daughterboard->proc_id);
-    qdev_prop_set_uint32(sysctl, "len-db-voltage",
-                         daughterboard->num_voltage_sensors);
+
+    db_voltage = qlist_new();
     for (i = 0; i < daughterboard->num_voltage_sensors; i++) {
-        char *propname = g_strdup_printf("db-voltage[%d]", i);
-        qdev_prop_set_uint32(sysctl, propname, daughterboard->voltages[i]);
-        g_free(propname);
+        qlist_append_int(db_voltage, daughterboard->voltages[i]);
     }
-    qdev_prop_set_uint32(sysctl, "len-db-clock",
-                         daughterboard->num_clocks);
+    qdev_prop_set_array(sysctl, "db-voltage", db_voltage);
+
+    db_clock = qlist_new();
     for (i = 0; i < daughterboard->num_clocks; i++) {
-        char *propname = g_strdup_printf("db-clock[%d]", i);
-        qdev_prop_set_uint32(sysctl, propname, daughterboard->clocks[i]);
-        g_free(propname);
+        qlist_append_int(db_clock, daughterboard->clocks[i]);
     }
+    qdev_prop_set_array(sysctl, "db-clock", db_clock);
+
     sysbus_realize_and_unref(SYS_BUS_DEVICE(sysctl), &error_fatal);
     sysbus_mmio_map(SYS_BUS_DEVICE(sysctl), 0, map[VE_SYSREGS]);
 
-- 
2.41.0

[PATCH v3 06/11] hw/arm/virt: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/virt.c | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 0a16ab3095..85e3c5ba9d 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -69,6 +69,7 @@
 #include "hw/firmware/smbios.h"
 #include "qapi/visitor.h"
 #include "qapi/qapi-visit-common.h"
+#include "qapi/qmp/qlist.h"
 #include "standard-headers/linux/input.h"
 #include "hw/arm/smmuv3.h"
 #include "hw/acpi/acpi.h"
@@ -752,14 +753,23 @@ static void create_gic(VirtMachineState *vms, MemoryRegion *mem)
     }
 
     if (vms->gic_version != VIRT_GIC_VERSION_2) {
+        QList *redist_region_count;
         uint32_t redist0_capacity = virt_redist_capacity(vms, VIRT_GIC_REDIST);
         uint32_t redist0_count = MIN(smp_cpus, redist0_capacity);
 
         nb_redist_regions = virt_gicv3_redist_region_count(vms);
 
-        qdev_prop_set_uint32(vms->gic, "len-redist-region-count",
-                             nb_redist_regions);
-        qdev_prop_set_uint32(vms->gic, "redist-region-count[0]", redist0_count);
+        redist_region_count = qlist_new();
+        qlist_append_int(redist_region_count, redist0_count);
+        if (nb_redist_regions == 2) {
+            uint32_t redist1_capacity =
+                virt_redist_capacity(vms, VIRT_HIGH_GIC_REDIST2);
+
+            qlist_append_int(redist_region_count,
+                MIN(smp_cpus - redist0_count, redist1_capacity));
+        }
+        qdev_prop_set_array(vms->gic, "redist-region-count",
+                            redist_region_count);
 
         if (!kvm_irqchip_in_kernel()) {
             if (vms->tcg_its) {
@@ -768,14 +778,6 @@ static void create_gic(VirtMachineState *vms, MemoryRegion *mem)
                 qdev_prop_set_bit(vms->gic, "has-lpi", true);
             }
         }
-
-        if (nb_redist_regions == 2) {
-            uint32_t redist1_capacity =
-                virt_redist_capacity(vms, VIRT_HIGH_GIC_REDIST2);
-
-            qdev_prop_set_uint32(vms->gic, "redist-region-count[1]",
-                MIN(smp_cpus - redist0_count, redist1_capacity));
-        }
     } else {
         if (!kvm_irqchip_in_kernel()) {
             qdev_prop_set_bit(vms->gic, "has-virtualization-extensions",
@@ -2748,6 +2750,7 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
         virtio_md_pci_pre_plug(VIRTIO_MD_PCI(dev), MACHINE(hotplug_dev), errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
         hwaddr db_start = 0, db_end = 0;
+        QList *reserved_regions;
         char *resv_prop_str;
 
         if (vms->iommu != VIRT_IOMMU_NONE) {
@@ -2774,9 +2777,9 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
                                         db_start, db_end,
                                         VIRTIO_IOMMU_RESV_MEM_T_MSI);
 
-        object_property_set_uint(OBJECT(dev), "len-reserved-regions", 1, errp);
-        object_property_set_str(OBJECT(dev), "reserved-regions[0]",
-                                resv_prop_str, errp);
+        reserved_regions = qlist_new();
+        qlist_append_str(reserved_regions, resv_prop_str);
+        qdev_prop_set_array(dev, "reserved-regions", reserved_regions);
         g_free(resv_prop_str);
     }
 }
-- 
2.41.0

[PATCH v3 07/11] hw/arm/xlnx-versal: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/xlnx-versal.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/arm/xlnx-versal.c b/hw/arm/xlnx-versal.c
index 4f74a64a0d..9600551c44 100644
--- a/hw/arm/xlnx-versal.c
+++ b/hw/arm/xlnx-versal.c
@@ -12,6 +12,7 @@
 #include "qemu/osdep.h"
 #include "qemu/units.h"
 #include "qapi/error.h"
+#include "qapi/qmp/qlist.h"
 #include "qemu/module.h"
 #include "hw/sysbus.h"
 #include "net/net.h"
@@ -69,6 +70,7 @@ static void versal_create_apu_gic(Versal *s, qemu_irq *pic)
     };
     SysBusDevice *gicbusdev;
     DeviceState *gicdev;
+    QList *redist_region_count;
     int nr_apu_cpus = ARRAY_SIZE(s->fpd.apu.cpu);
     int i;
 
@@ -79,8 +81,11 @@ static void versal_create_apu_gic(Versal *s, qemu_irq *pic)
     qdev_prop_set_uint32(gicdev, "revision", 3);
     qdev_prop_set_uint32(gicdev, "num-cpu", nr_apu_cpus);
     qdev_prop_set_uint32(gicdev, "num-irq", XLNX_VERSAL_NR_IRQS + 32);
-    qdev_prop_set_uint32(gicdev, "len-redist-region-count", 1);
-    qdev_prop_set_uint32(gicdev, "redist-region-count[0]", nr_apu_cpus);
+
+    redist_region_count = qlist_new();
+    qlist_append_int(redist_region_count, nr_apu_cpus);
+    qdev_prop_set_array(gicdev, "redist-region-count", redist_region_count);
+
     qdev_prop_set_bit(gicdev, "has-security-extensions", true);
 
     sysbus_realize(SYS_BUS_DEVICE(&s->fpd.apu.gic), &error_fatal);
-- 
2.41.0

[PATCH v3 08/11] hw/rx/rx62n: Use qdev_prop_set_array()

[Kevin Wolf]

Instead of manually setting "foo-len" and "foo[i]" properties, build a
QList and use the new qdev_prop_set_array() helper to set the whole
array property with a single call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/rx/rx62n.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/hw/rx/rx62n.c b/hw/rx/rx62n.c
index d00fcb0ef0..4dc44afd9d 100644
--- a/hw/rx/rx62n.c
+++ b/hw/rx/rx62n.c
@@ -28,6 +28,7 @@
 #include "hw/sysbus.h"
 #include "hw/qdev-properties.h"
 #include "sysemu/sysemu.h"
+#include "qapi/qmp/qlist.h"
 #include "qom/object.h"
 
 /*
@@ -130,22 +131,22 @@ static void register_icu(RX62NState *s)
 {
     int i;
     SysBusDevice *icu;
+    QList *ipr_map, *trigger_level;
 
     object_initialize_child(OBJECT(s), "icu", &s->icu, TYPE_RX_ICU);
     icu = SYS_BUS_DEVICE(&s->icu);
-    qdev_prop_set_uint32(DEVICE(icu), "len-ipr-map", NR_IRQS);
+
+    ipr_map = qlist_new();
     for (i = 0; i < NR_IRQS; i++) {
-        char propname[32];
-        snprintf(propname, sizeof(propname), "ipr-map[%d]", i);
-        qdev_prop_set_uint32(DEVICE(icu), propname, ipr_table[i]);
+        qlist_append_int(ipr_map, ipr_table[i]);
     }
-    qdev_prop_set_uint32(DEVICE(icu), "len-trigger-level",
-                         ARRAY_SIZE(levelirq));
+    qdev_prop_set_array(DEVICE(icu), "ipr-map", ipr_map);
+
+    trigger_level = qlist_new();
     for (i = 0; i < ARRAY_SIZE(levelirq); i++) {
-        char propname[32];
-        snprintf(propname, sizeof(propname), "trigger-level[%d]", i);
-        qdev_prop_set_uint32(DEVICE(icu), propname, levelirq[i]);
+        qlist_append_int(trigger_level, levelirq[i]);
     }
+    qdev_prop_set_array(DEVICE(icu), "trigger-level", trigger_level);
 
     for (i = 0; i < NR_IRQS; i++) {
         s->irq[i] = qdev_get_gpio_in(DEVICE(icu), i);
-- 
2.41.0

[PATCH v3 09/11] qom: Add object_property_set_default_list()

[Kevin Wolf]

This function provides a default for properties that are accessed using
the list visitor interface. The default is always an empty list.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/qom/object.h | 8 ++++++++
 qom/object.c         | 6 ++++++
 2 files changed, 14 insertions(+)

diff --git a/include/qom/object.h b/include/qom/object.h
index ef7258a5e1..afccd24ca7 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -1093,6 +1093,14 @@ void object_property_set_default_bool(ObjectProperty *prop, bool value);
  */
 void object_property_set_default_str(ObjectProperty *prop, const char *value);
 
+/**
+ * object_property_set_default_list:
+ * @prop: the property to set
+ *
+ * Set the property default value to be an empty list.
+ */
+void object_property_set_default_list(ObjectProperty *prop);
+
 /**
  * object_property_set_default_int:
  * @prop: the property to set
diff --git a/qom/object.c b/qom/object.c
index 8557fe8e4e..95c0dc8285 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -31,6 +31,7 @@
  * of the QOM core on QObject?  */
 #include "qom/qom-qobject.h"
 #include "qapi/qmp/qbool.h"
+#include "qapi/qmp/qlist.h"
 #include "qapi/qmp/qnum.h"
 #include "qapi/qmp/qstring.h"
 #include "qemu/error-report.h"
@@ -1588,6 +1589,11 @@ void object_property_set_default_str(ObjectProperty *prop, const char *value)
     object_property_set_default(prop, QOBJECT(qstring_from_str(value)));
 }
 
+void object_property_set_default_list(ObjectProperty *prop)
+{
+    object_property_set_default(prop, QOBJECT(qlist_new()));
+}
+
 void object_property_set_default_int(ObjectProperty *prop, int64_t value)
 {
     object_property_set_default(prop, QOBJECT(qnum_from_int(value)));
-- 
2.41.0

[PATCH v3 10/11] qdev: Make netdev properties work as list elements

[Kevin Wolf]

The 'name' parameter of QOM setters is primarily used to specify the name
of the currently parsed input element in the visitor interface. For
top-level qdev properties, this is always set and matches 'prop->name'.

However, for list elements it is NULL, because each element of a list
doesn't have a separate name. Passing a non-NULL value runs into
assertion failures in the visitor code.

Therefore, using 'name' in error messages is not right for property
types that are used in lists, because "(null)" (or even a segfault)
isn't very helpful to identify what QEMU is complaining about.

Change netdev properties to use 'prop->name' instead, which will contain
the name of the array property after switching array properties to lists
in the external interface. (This is still not perfect, as it doesn't
identify which element in the list caused the error, but strictly better
than before.)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/core/qdev-properties-system.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index b46d16cd2c..1473ab3d5e 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -450,7 +450,7 @@ static void set_netdev(Object *obj, Visitor *v, const char *name,
     peers_ptr->queues = queues;
 
 out:
-    error_set_from_qdev_prop_error(errp, err, obj, name, str);
+    error_set_from_qdev_prop_error(errp, err, obj, prop->name, str);
     g_free(str);
 }
 
-- 
2.41.0

[PATCH v3 11/11] qdev: Rework array properties based on list visitor

[Kevin Wolf]

Until now, array properties are actually implemented with a hack that
uses multiple properties on the QOM level: a static "foo-len" property
and after it is set, dynamically created "foo[i]" properties.

In external interfaces (-device on the command line and device_add in
QMP), this interface was broken by commit f3558b1b ('qdev: Base object
creation on QDict rather than QemuOpts') because QDicts are unordered
and therefore it could happen that QEMU tried to set the indexed
properties before setting the length, which fails and effectively makes
array properties inaccessible. In particular, this affects the 'ports'
property of the 'rocker' device, which used to be configured like this:

-device rocker,len-ports=2,ports[0]=dev0,ports[1]=dev1

This patch reworks the external interface so that instead of using a
separate top-level property for the length and for each element, we use
a single true array property that accepts a list value. In the external
interfaces, this is naturally expressed as a JSON list and makes array
properties accessible again. The new syntax looks like this:

-device '{"driver":"rocker","ports":["dev0","dev1"]}'

Creating an array property on the command line without using JSON format
is currently not possible. This could be fixed by switching from
QemuOpts to a keyval parser, which however requires consideration of the
compatibility implications.

All internal users of devices with array properties go through
qdev_prop_set_array() at this point, so updating it takes care of all of
them.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1090
Fixes: f3558b1b763683bb877f7dd5b282469cdadc65c3
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/hw/qdev-properties.h |  35 +++---
 hw/core/qdev-properties.c    | 237 +++++++++++++++++++++++------------
 2 files changed, 172 insertions(+), 100 deletions(-)

diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
index 7fa2fdb7c9..25743a29a0 100644
--- a/include/hw/qdev-properties.h
+++ b/include/hw/qdev-properties.h
@@ -61,7 +61,7 @@ extern const PropertyInfo qdev_prop_size;
 extern const PropertyInfo qdev_prop_string;
 extern const PropertyInfo qdev_prop_on_off_auto;
 extern const PropertyInfo qdev_prop_size32;
-extern const PropertyInfo qdev_prop_arraylen;
+extern const PropertyInfo qdev_prop_array;
 extern const PropertyInfo qdev_prop_link;
 
 #define DEFINE_PROP(_name, _state, _field, _prop, _type, ...) {  \
@@ -115,8 +115,6 @@ extern const PropertyInfo qdev_prop_link;
                 .bitmask    = (_bitmask),                     \
                 .set_default = false)
 
-#define PROP_ARRAY_LEN_PREFIX "len-"
-
 /**
  * DEFINE_PROP_ARRAY:
  * @_name: name of the array
@@ -127,28 +125,25 @@ extern const PropertyInfo qdev_prop_link;
  * @_arrayprop: PropertyInfo defining what property the array elements have
  * @_arraytype: C type of the array elements
  *
- * Define device properties for a variable-length array _name.  A
- * static property "len-arrayname" is defined. When the device creator
- * sets this property to the desired length of array, further dynamic
- * properties "arrayname[0]", "arrayname[1]", ...  are defined so the
- * device creator can set the array element values. Setting the
- * "len-arrayname" property more than once is an error.
+ * Define device properties for a variable-length array _name.  The array is
+ * represented as a list in the visitor interface.
+ *
+ * @_arraytype is required to be movable with memcpy().
  *
- * When the array length is set, the @_field member of the device
+ * When the array property is set, the @_field member of the device
  * struct is set to the array length, and @_arrayfield is set to point
- * to (zero-initialised) memory allocated for the array.  For a zero
- * length array, @_field will be set to 0 and @_arrayfield to NULL.
+ * to the memory allocated for the array.
+ *
  * It is the responsibility of the device deinit code to free the
  * @_arrayfield memory.
  */
-#define DEFINE_PROP_ARRAY(_name, _state, _field,               \
-                          _arrayfield, _arrayprop, _arraytype) \
-    DEFINE_PROP((PROP_ARRAY_LEN_PREFIX _name),                 \
-                _state, _field, qdev_prop_arraylen, uint32_t,  \
-                .set_default = true,                           \
-                .defval.u = 0,                                 \
-                .arrayinfo = &(_arrayprop),                    \
-                .arrayfieldsize = sizeof(_arraytype),          \
+#define DEFINE_PROP_ARRAY(_name, _state, _field,                        \
+                          _arrayfield, _arrayprop, _arraytype)          \
+    DEFINE_PROP(_name, _state, _field, qdev_prop_array, uint32_t,       \
+                .set_default = true,                                    \
+                .defval.u = 0,                                          \
+                .arrayinfo = &(_arrayprop),                             \
+                .arrayfieldsize = sizeof(_arraytype),                   \
                 .arrayoffset = offsetof(_state, _arrayfield))
 
 #define DEFINE_PROP_LINK(_name, _state, _field, _type, _ptr_type)     \
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 950ef48e01..91632f7be9 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -546,98 +546,187 @@ const PropertyInfo qdev_prop_size32 = {
 
 /* --- support for array properties --- */
 
-/* Used as an opaque for the object properties we add for each
- * array element. Note that the struct Property must be first
- * in the struct so that a pointer to this works as the opaque
- * for the underlying element's property hooks as well as for
- * our own release callback.
+typedef struct ArrayElementList ArrayElementList;
+
+struct ArrayElementList {
+    ArrayElementList *next;
+    void *value;
+};
+
+/*
+ * Given an array property @parent_prop in @obj, return a Property for a
+ * specific element of the array. Arrays are backed by an uint32_t length field
+ * and an element array. @elem points at an element in this element array.
  */
-typedef struct {
-    struct Property prop;
-    char *propname;
-    ObjectPropertyRelease *release;
-} ArrayElementProperty;
-
-/* object property release callback for array element properties:
- * we call the underlying element's property release hook, and
- * then free the memory we allocated when we added the property.
+static Property array_elem_prop(Object *obj, Property *parent_prop,
+                                const char *name, char *elem)
+{
+    return (Property) {
+        .info = parent_prop->arrayinfo,
+        .name = name,
+        /*
+         * This ugly piece of pointer arithmetic sets up the offset so
+         * that when the underlying release hook calls qdev_get_prop_ptr
+         * they get the right answer despite the array element not actually
+         * being inside the device struct.
+         */
+        .offset = (uintptr_t)elem - (uintptr_t)obj,
+    };
+}
+
+/*
+ * Object property release callback for array properties: We call the
+ * underlying element's property release hook for each element.
+ *
+ * Note that it is the responsibility of the individual device's deinit
+ * to free the array proper.
  */
-static void array_element_release(Object *obj, const char *name, void *opaque)
+static void release_prop_array(Object *obj, const char *name, void *opaque)
 {
-    ArrayElementProperty *p = opaque;
-    if (p->release) {
-        p->release(obj, name, opaque);
+    Property *prop = opaque;
+    uint32_t *alenptr = object_field_prop_ptr(obj, prop);
+    void **arrayptr = (void *)obj + prop->arrayoffset;
+    char *elem = *arrayptr;
+    int i;
+
+    if (!prop->arrayinfo->release) {
+        return;
+    }
+
+    for (i = 0; i < *alenptr; i++) {
+        Property elem_prop = array_elem_prop(obj, prop, name, elem);
+        prop->arrayinfo->release(obj, NULL, &elem_prop);
+        elem += prop->arrayfieldsize;
     }
-    g_free(p->propname);
-    g_free(p);
 }
 
-static void set_prop_arraylen(Object *obj, Visitor *v, const char *name,
-                              void *opaque, Error **errp)
+/*
+ * Setter for an array property. This sets both the array length (which
+ * is technically the property field in the object) and the array itself
+ * (a pointer to which is stored in the additional field described by
+ * prop->arrayoffset).
+ */
+static void set_prop_array(Object *obj, Visitor *v, const char *name,
+                           void *opaque, Error **errp)
 {
-    /* Setter for the property which defines the length of a
-     * variable-sized property array. As well as actually setting the
-     * array-length field in the device struct, we have to create the
-     * array itself and dynamically add the corresponding properties.
-     */
+    ERRP_GUARD();
     Property *prop = opaque;
     uint32_t *alenptr = object_field_prop_ptr(obj, prop);
     void **arrayptr = (void *)obj + prop->arrayoffset;
-    void *eltptr;
-    const char *arrayname;
-    int i;
+    ArrayElementList *list, *elem, *next;
+    const size_t size = sizeof(*list);
+    char *elemptr;
+    bool ok = true;
 
     if (*alenptr) {
         error_setg(errp, "array size property %s may not be set more than once",
                    name);
         return;
     }
-    if (!visit_type_uint32(v, name, alenptr, errp)) {
+
+    if (!visit_start_list(v, name, (GenericList **) &list, size, errp)) {
         return;
     }
-    if (!*alenptr) {
+
+    /* Read the whole input into a temporary list */
+    elem = list;
+    while (elem) {
+        Property elem_prop;
+
+        elem->value = g_malloc0(prop->arrayfieldsize);
+        elem_prop = array_elem_prop(obj, prop, name, elem->value);
+        prop->arrayinfo->set(obj, v, NULL, &elem_prop, errp);
+        if (*errp) {
+            ok = false;
+            goto out_obj;
+        }
+        if (*alenptr == INT_MAX) {
+            error_setg(errp, "array is too big");
+            return;
+        }
+        (*alenptr)++;
+        elem = (ArrayElementList *) visit_next_list(v, (GenericList*) elem,
+                                                    size);
+    }
+
+    ok = visit_check_list(v, errp);
+out_obj:
+    visit_end_list(v, (void**) &list);
+
+    if (!ok) {
+        for (elem = list; elem; elem = next) {
+            Property elem_prop = array_elem_prop(obj, prop, name,
+                                                 elem->value);
+            if (prop->arrayinfo->release) {
+                prop->arrayinfo->release(obj, NULL, &elem_prop);
+            }
+            next = elem->next;
+            g_free(elem->value);
+            g_free(elem);
+        }
         return;
     }
 
-    /* DEFINE_PROP_ARRAY guarantees that name should start with this prefix;
-     * strip it off so we can get the name of the array itself.
+    /*
+     * Now that we know how big the array has to be, move the data over to a
+     * linear array and free the temporary list.
      */
-    assert(strncmp(name, PROP_ARRAY_LEN_PREFIX,
-                   strlen(PROP_ARRAY_LEN_PREFIX)) == 0);
-    arrayname = name + strlen(PROP_ARRAY_LEN_PREFIX);
+    *arrayptr = g_malloc_n(*alenptr, prop->arrayfieldsize);
+    elemptr = *arrayptr;
+    for (elem = list; elem; elem = next) {
+        memcpy(elemptr, elem->value, prop->arrayfieldsize);
+        elemptr += prop->arrayfieldsize;
+        next = elem->next;
+        g_free(elem->value);
+        g_free(elem);
+    }
+}
 
-    /* Note that it is the responsibility of the individual device's deinit
-     * to free the array proper.
-     */
-    *arrayptr = eltptr = g_malloc0(*alenptr * prop->arrayfieldsize);
-    for (i = 0; i < *alenptr; i++, eltptr += prop->arrayfieldsize) {
-        char *propname = g_strdup_printf("%s[%d]", arrayname, i);
-        ArrayElementProperty *arrayprop = g_new0(ArrayElementProperty, 1);
-        arrayprop->release = prop->arrayinfo->release;
-        arrayprop->propname = propname;
-        arrayprop->prop.info = prop->arrayinfo;
-        arrayprop->prop.name = propname;
-        /* This ugly piece of pointer arithmetic sets up the offset so
-         * that when the underlying get/set hooks call qdev_get_prop_ptr
-         * they get the right answer despite the array element not actually
-         * being inside the device struct.
-         */
-        arrayprop->prop.offset = eltptr - (void *)obj;
-        assert(object_field_prop_ptr(obj, &arrayprop->prop) == eltptr);
-        object_property_add(obj, propname,
-                            arrayprop->prop.info->name,
-                            field_prop_getter(arrayprop->prop.info),
-                            field_prop_setter(arrayprop->prop.info),
-                            array_element_release,
-                            arrayprop);
+static void get_prop_array(Object *obj, Visitor *v, const char *name,
+                           void *opaque, Error **errp)
+{
+    ERRP_GUARD();
+    Property *prop = opaque;
+    uint32_t *alenptr = object_field_prop_ptr(obj, prop);
+    void **arrayptr = (void *)obj + prop->arrayoffset;
+    char *elem = *arrayptr;
+    GenericList *list;
+    const size_t list_elem_size = sizeof(*list) + prop->arrayfieldsize;
+    int i;
+    bool ok;
+
+    if (!visit_start_list(v, name, &list, list_elem_size, errp)) {
+        return;
     }
+
+    for (i = 0; i < *alenptr; i++) {
+        Property elem_prop = array_elem_prop(obj, prop, name, elem);
+        prop->arrayinfo->get(obj, v, NULL, &elem_prop, errp);
+        if (*errp) {
+            goto out_obj;
+        }
+        elem += prop->arrayfieldsize;
+    }
+
+    /* visit_check_list() can only fail for input visitors */
+    ok = visit_check_list(v, errp);
+    assert(ok);
+
+out_obj:
+    visit_end_list(v, (void**) &list);
 }
 
-const PropertyInfo qdev_prop_arraylen = {
-    .name = "uint32",
-    .get = get_uint32,
-    .set = set_prop_arraylen,
-    .set_default_value = qdev_propinfo_set_default_value_uint,
+static void default_prop_array(ObjectProperty *op, const Property *prop)
+{
+    object_property_set_default_list(op);
+}
+
+const PropertyInfo qdev_prop_array = {
+    .name = "list",
+    .get = get_prop_array,
+    .set = set_prop_array,
+    .release = release_prop_array,
+    .set_default_value = default_prop_array,
 };
 
 /* --- public helpers --- */
@@ -743,20 +832,8 @@ void qdev_prop_set_enum(DeviceState *dev, const char *name, int value)
 
 void qdev_prop_set_array(DeviceState *dev, const char *name, QList *values)
 {
-    const QListEntry *entry;
-    g_autofree char *prop_len = g_strdup_printf("len-%s", name);
-    uint32_t i = 0;
-
-    object_property_set_int(OBJECT(dev), prop_len, qlist_size(values),
-                            &error_abort);
-
-    QLIST_FOREACH_ENTRY(values, entry) {
-        g_autofree char *prop_idx = g_strdup_printf("%s[%u]", name, i);
-        object_property_set_qobject(OBJECT(dev), prop_idx, entry->value,
-                                    &error_abort);
-        i++;
-    }
-
+    object_property_set_qobject(OBJECT(dev), name, QOBJECT(values),
+                                &error_abort);
     qobject_unref(values);
 }
 
-- 
2.41.0

Re: [PATCH v3 01/11] hw/i386/pc: Use qdev_prop_set_array()

[Philippe Mathieu-Daudé]

On 9/11/23 18:42, Kevin Wolf wrote:
> Instead of manually setting "foo-len" and "foo[i]" properties, build a
> QList and use the new qdev_prop_set_array() helper to set the whole
> array property with a single call.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   hw/i386/pc.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v3 09/11] qom: Add object_property_set_default_list()

[Philippe Mathieu-Daudé]

On 9/11/23 18:42, Kevin Wolf wrote:
> This function provides a default for properties that are accessed using
> the list visitor interface. The default is always an empty list.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   include/qom/object.h | 8 ++++++++
>   qom/object.c         | 6 ++++++
>   2 files changed, 14 insertions(+)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v3 10/11] qdev: Make netdev properties work as list elements

[Philippe Mathieu-Daudé]

On 9/11/23 18:42, Kevin Wolf wrote:
> The 'name' parameter of QOM setters is primarily used to specify the name
> of the currently parsed input element in the visitor interface. For
> top-level qdev properties, this is always set and matches 'prop->name'.
> 
> However, for list elements it is NULL, because each element of a list
> doesn't have a separate name. Passing a non-NULL value runs into
> assertion failures in the visitor code.
> 
> Therefore, using 'name' in error messages is not right for property
> types that are used in lists, because "(null)" (or even a segfault)
> isn't very helpful to identify what QEMU is complaining about.
> 
> Change netdev properties to use 'prop->name' instead, which will contain
> the name of the array property after switching array properties to lists
> in the external interface. (This is still not perfect, as it doesn't
> identify which element in the list caused the error, but strictly better
> than before.)
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   hw/core/qdev-properties-system.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v3 00/11] qdev: Make array properties user accessible again

[Philippe Mathieu-Daudé]

Hi Kevin,

On 9/11/23 18:42, Kevin Wolf wrote:
> Array properties have been inaccessible since commit f3558b1b both on
> the command line and in QMP. This series reworks them so that they are
> made accessible again in these external interfaces, this time as JSON
> lists. See patch 11 for details.

This justifies getting this merged for v8.2, right?