KVM: remove support for kernel-irqchip=off

-machine kernel-irqchip=off is broken for many guest OSes; kernel-irqchip=split
is the replacement that works, so remove the deprecated support for the former.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

docs/about/deprecated.rst

@@ -58,13 +58,6 @@ and will cause a warning.
 The replacement for the ``nodelay`` short-form boolean option is ``nodelay=on``
 rather than ``delay=off``.
 
-Userspace local APIC with KVM (x86, since 6.0)
-''''''''''''''''''''''''''''''''''''''''''''''
-
-Using ``-M kernel-irqchip=off`` with x86 machine types that include a local
-APIC is deprecated.  The ``split`` setting is supported, as is using
-``-M kernel-irqchip=off`` with the ISA PC machine type.
-
 hexadecimal sizes with scaling multipliers (since 6.0)
 ''''''''''''''''''''''''''''''''''''''''''''''''''''''
 

docs/about/removed-features.rst

@@ -616,6 +616,16 @@ x86 ``Icelake-Client`` CPU (removed in 7.1)
 There isn't ever Icelake Client CPU, it is some wrong and imaginary one.
 Use ``Icelake-Server`` instead.
 
+System accelerators
+-------------------
+
+Userspace local APIC with KVM (x86, removed 8.0)
+''''''''''''''''''''''''''''''''''''''''''''''''
+
+``-M kernel-irqchip=off`` cannot be used on KVM if the CPU model includes
+a local APIC.  The ``split`` setting is supported, as is using ``-M
+kernel-irqchip=off`` when the CPU does not have a local APIC.
+
 System emulator machines
 ------------------------
 

hw/i386/amd_iommu.c

@@ -1368,7 +1368,7 @@ static MemTxResult amdvi_mem_ir_write(void *opaque, hwaddr addr,
         return MEMTX_ERROR;
     }
 
-    apic_get_class()->send_msi(&to);
+    apic_get_class(NULL)->send_msi(&to);
 
     trace_amdvi_mem_ir_write(to.address, to.data);
     return MEMTX_OK;

hw/i386/intel_iommu.c

@@ -396,7 +396,7 @@ static void vtd_generate_interrupt(IntelIOMMUState *s, hwaddr mesg_addr_reg,
 
     trace_vtd_irq_generate(msi.address, msi.data);
 
-    apic_get_class()->send_msi(&msi);
+    apic_get_class(NULL)->send_msi(&msi);
 }
 
 /* Generate a fault event to software via MSI if conditions are met.
@@ -3529,7 +3529,7 @@ static MemTxResult vtd_mem_ir_write(void *opaque, hwaddr addr,
         return MEMTX_ERROR;
     }
 
-    apic_get_class()->send_msi(&to);
+    apic_get_class(NULL)->send_msi(&to);
 
     return MEMTX_OK;
 }

include/hw/i386/apic_internal.h

@@ -226,6 +226,6 @@ static inline int apic_get_bit(uint32_t *tab, int index)
     return !!(tab[i] & mask);
 }
 
-APICCommonClass *apic_get_class(void);
+APICCommonClass *apic_get_class(Error **errp);
 
 #endif /* QEMU_APIC_INTERNAL_H */

target/i386/cpu-sysemu.c

@@ -247,12 +247,16 @@ void x86_cpu_machine_reset_cb(void *opaque)
     cpu_reset(CPU(cpu));
 }
 
-APICCommonClass *apic_get_class(void)
+APICCommonClass *apic_get_class(Error **errp)
 {
     const char *apic_type = "apic";
 
     /* TODO: in-kernel irqchip for hvf */
-    if (kvm_apic_in_kernel()) {
+    if (kvm_enabled()) {
+        if (!kvm_apic_in_kernel()) {
+            error_setg(errp, "KVM does not support userspace APIC");
+            return NULL;
+        }
         apic_type = "kvm-apic";
     } else if (xen_enabled()) {
         apic_type = "xen-apic";
@@ -266,10 +270,13 @@ APICCommonClass *apic_get_class(void)
 void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
 {
     APICCommonState *apic;
-    ObjectClass *apic_class = OBJECT_CLASS(apic_get_class());
+    APICCommonClass *apic_class = apic_get_class(errp);
 
-    cpu->apic_state = DEVICE(object_new_with_class(apic_class));
+    if (!apic_class) {
+        return;
+    }
 
+    cpu->apic_state = DEVICE(object_new_with_class(OBJECT_CLASS(apic_class)));
     object_property_add_child(OBJECT(cpu), "lapic",
                               OBJECT(cpu->apic_state));
     object_unref(OBJECT(cpu->apic_state));