[PATCH v10 16/28] hw: arm: virt: rework MSI-X configuration

[Mohamed Mediouni <mohamed@unpredictable.fr>]

Introduce a -M msi= argument to be able to control MSI-X support independently
from ITS, as part of supporting GICv3 + GICv2m platforms.

Remove vms->its as it's no longer needed after that change.

Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
---
 hw/arm/virt-acpi-build.c |   3 +-
 hw/arm/virt.c            | 110 +++++++++++++++++++++++++++++++--------
 include/hw/arm/virt.h    |   4 +-
 3 files changed, 93 insertions(+), 24 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 8e730731ca..a6a56455a9 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -961,8 +961,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         }
     }
 
-    if (!(vms->gic_version != VIRT_GIC_VERSION_2 && virt_is_its_enabled(vms))
-     && !vms->no_gicv3_with_gicv2m) {
+    if (virt_is_gicv2m_enabled(vms)) {
         const uint16_t spi_base = vms->irqmap[VIRT_GIC_V2M] + ARM_SPI_BASE;
 
         /* 5.2.12.16 GIC MSI Frame Structure */
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index dbf9a28b8d..6978d4e867 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -964,12 +964,12 @@ static void create_gic(VirtMachineState *vms, MemoryRegion *mem)
 
     fdt_add_gic_node(vms);
 
-    if (vms->gic_version != VIRT_GIC_VERSION_2 && virt_is_its_enabled(vms)) {
+    if (virt_is_its_enabled(vms)) {
         create_its(vms);
-    } else if (vms->gic_version != VIRT_GIC_VERSION_2 && !vms->no_gicv3_with_gicv2m) {
-        create_v2m(vms);
-    } else if (vms->gic_version == VIRT_GIC_VERSION_2) {
+    } else if (virt_is_gicv2m_enabled(vms)) {
         create_v2m(vms);
+    } else {
+        vms->msi_controller = VIRT_MSI_CTRL_NONE;
     }
 }
 
@@ -2716,32 +2716,93 @@ static void virt_set_highmem_mmio_size(Object *obj, Visitor *v,
 
 bool virt_is_its_enabled(VirtMachineState *vms)
 {
-    if (vms->its == ON_OFF_AUTO_OFF) {
-        return false;
+    switch (vms->msi_controller) {
+        case VIRT_MSI_CTRL_NONE:
+            return false;
+        case VIRT_MSI_CTRL_ITS:
+            return true;
+        case VIRT_MSI_CTRL_GICV2M:
+            return false;
+        case VIRT_MSI_CTRL_AUTO:
+            if (whpx_enabled() && whpx_irqchip_in_kernel()) {
+                return false;
+            }
+            if (vms->gic_version == VIRT_GIC_VERSION_2) {
+                return false;
+            }
+            return true;
+        default:
+            return false;
     }
-    if (vms->its == ON_OFF_AUTO_AUTO) {
-        if (whpx_enabled()) {
+}
+
+bool virt_is_gicv2m_enabled(VirtMachineState *vms)
+{
+    switch (vms->msi_controller) {
+        case VIRT_MSI_CTRL_NONE:
             return false;
-        }
+        default:
+            return !virt_is_its_enabled(vms);
     }
-    return true;
 }
 
-static void virt_get_its(Object *obj, Visitor *v, const char *name,
-                          void *opaque, Error **errp)
+static char *virt_get_msi(Object *obj, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+    const char *val;
+
+    switch (vms->msi_controller) {
+    case VIRT_MSI_CTRL_NONE:
+        val = "off";
+        break;
+    case VIRT_MSI_CTRL_ITS:
+        val = "its";
+        break;
+    case VIRT_MSI_CTRL_GICV2M:
+        val = "gicv2m";
+    default:
+        val = "auto";
+        break;
+    }
+    return g_strdup(val);
+}
+
+static void virt_set_msi(Object *obj, const char *value, Error **errp)
 {
     VirtMachineState *vms = VIRT_MACHINE(obj);
-    OnOffAuto its = vms->its;
 
-    visit_type_OnOffAuto(v, name, &its, errp);
+    if (!strcmp(value, "auto")) {
+        vms->msi_controller = VIRT_MSI_CTRL_AUTO; /* Will be overriden later */
+    } else if (!strcmp(value, "its")) {
+        vms->msi_controller = VIRT_MSI_CTRL_ITS;
+    } else if (!strcmp(value, "gicv2m")) {
+        vms->msi_controller = VIRT_MSI_CTRL_GICV2M;
+    } else if (!strcmp(value, "none")) {
+        vms->msi_controller = VIRT_MSI_CTRL_NONE;
+    } else {
+        error_setg(errp, "Invalid msi value");
+        error_append_hint(errp, "Valid values are auto, gicv2m, its, off\n");
+    }
 }
 
-static void virt_set_its(Object *obj, Visitor *v, const char *name,
-                          void *opaque, Error **errp)
+static bool virt_get_its(Object *obj, Error **errp)
 {
     VirtMachineState *vms = VIRT_MACHINE(obj);
 
-    visit_type_OnOffAuto(v, name, &vms->its, errp);
+    return virt_is_its_enabled(vms);
+}
+
+static void virt_set_its(Object *obj, bool value, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+
+    if (value) {
+        vms->msi_controller = VIRT_MSI_CTRL_ITS;
+    } else if (vms->no_gicv3_with_gicv2m) {
+        vms->msi_controller = VIRT_MSI_CTRL_NONE;
+    } else {
+        vms->msi_controller = VIRT_MSI_CTRL_GICV2M;
+    }
 }
 
 static bool virt_get_dtb_randomness(Object *obj, Error **errp)
@@ -3068,6 +3129,8 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
             db_start = base_memmap[VIRT_GIC_V2M].base;
             db_end = db_start + base_memmap[VIRT_GIC_V2M].size - 1;
             break;
+        case VIRT_MSI_CTRL_AUTO:
+            g_assert_not_reached();
         }
         resv_prop_str = g_strdup_printf("0x%"PRIx64":0x%"PRIx64":%u",
                                         db_start, db_end,
@@ -3451,13 +3514,18 @@ static void virt_machine_class_init(ObjectClass *oc, const void *data)
                                           "guest CPU which implements the ARM "
                                           "Memory Tagging Extension");
 
-    object_class_property_add(oc, "its", "OnOffAuto",
-        virt_get_its, virt_set_its,
-        NULL, NULL);
+    object_class_property_add_bool(oc, "its", virt_get_its,
+                                   virt_set_its);
     object_class_property_set_description(oc, "its",
                                           "Set on/off to enable/disable "
                                           "ITS instantiation");
 
+    object_class_property_add_str(oc, "msi", virt_get_msi,
+                                  virt_set_msi);
+    object_class_property_set_description(oc, "msi",
+                                          "Set MSI settings. "
+                                          "Valid values are auto/gicv2m/its/off");
+
     object_class_property_add_bool(oc, "dtb-randomness",
                                    virt_get_dtb_randomness,
                                    virt_set_dtb_randomness);
@@ -3514,7 +3582,7 @@ static void virt_instance_init(Object *obj)
     vms->highmem_redists = true;
 
     /* Default allows ITS instantiation if available */
-    vms->its = ON_OFF_AUTO_AUTO;
+    vms->msi_controller = VIRT_MSI_CTRL_AUTO;
     /* Allow ITS emulation if the machine version supports it */
     vms->tcg_its = !vmc->no_tcg_its;
     vms->no_gicv3_with_gicv2m = false;
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 997dd51678..99db8607e7 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -101,6 +101,8 @@ typedef enum VirtIOMMUType {
 
 typedef enum VirtMSIControllerType {
     VIRT_MSI_CTRL_NONE,
+    /* This value is overriden at runtime.*/
+    VIRT_MSI_CTRL_AUTO,
     VIRT_MSI_CTRL_GICV2M,
     VIRT_MSI_CTRL_ITS,
 } VirtMSIControllerType;
@@ -149,7 +151,6 @@ struct VirtMachineState {
     bool highmem_ecam;
     bool highmem_mmio;
     bool highmem_redists;
-    OnOffAuto its;
     bool tcg_its;
     bool virt;
     bool ras;
@@ -219,5 +220,6 @@ static inline int virt_gicv3_redist_region_count(VirtMachineState *vms)
 }
 
 bool virt_is_its_enabled(VirtMachineState *vms);
+bool virt_is_gicv2m_enabled(VirtMachineState *vms);
 
 #endif /* QEMU_ARM_VIRT_H */
-- 
2.50.1 (Apple Git-155)