[RFC PATCH 2/2] hw/s390x: modularize virtio-gpu-ccw

[Halil Pasic]

Since the virtio-gpu-ccw device depends on the hw-display-virtio-gpu
module, which provides the type virtio-gpu-device, packaging the
hw-display-virtio-gpu module as a separate package that may or may not
be installed along with the qemu package leads to problems. Namely if
the hw-display-virtio-gpu is absent, qemu continues to advertise
virtio-gpu-ccw, but it aborts not only when one attempts using
virtio-gpu-ccw, but also when libvirtd's capability probing tries
to instantiate the type to introspect it.

Let us thus introduce a module named hw-s390x-virtio-gpu-ccw that
is going to provide the virtio-gpu-ccw device. The hw-s390x prefix
was chosen because it is not a portable device.

With virtio-gpu-ccw built as a module, the correct way to package a
modularized qemu is to require that hw-display-virtio-gpu must be
installed whenever the module hw-s390x-virtio-gpu-ccw.

The definition S390_ADAPTER_SUPPRESSIBLE was moved to "cpu.h", per
suggestion of Thomas Huth. From interface design perspective, IMHO, not
a good thing as it belongs to the public interface of
css_register_io_adapters(). We did this because CONFIG_KVM requeires
NEED_CPU_H and Thomas, and other commenters did not like the
consequences of that.

Moving the interrupt related declarations to s390_flic.h was suggested
by Cornelia Huck.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
---
 hw/s390x/meson.build         | 7 +++++++
 include/hw/s390x/css.h       | 7 -------
 include/hw/s390x/s390_flic.h | 3 +++
 target/s390x/cpu.h           | 9 ++++++---
 util/module.c                | 1 +
 5 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/hw/s390x/meson.build b/hw/s390x/meson.build
index 0cee605f0a..ad2941f7ca 100644
--- a/hw/s390x/meson.build
+++ b/hw/s390x/meson.build
@@ -47,3 +47,10 @@ virtio_ss.add(when: 'CONFIG_VHOST_USER_FS', if_true: 
files('vhost-user-fs-ccw.c'
 s390x_ss.add_all(when: 'CONFIG_VIRTIO_CCW', if_true: virtio_ss)
 
 hw_arch += {'s390x': s390x_ss}
+
+hw_s390x_modules = {}
+virtio_gpu_ccw_ss = ss.source_set()
+virtio_gpu_ccw_ss.add(when: 'CONFIG_VIRTIO_GPU', if_true: 
[files('virtio-ccw-gpu.c'), pixman])
+hw_s390x_modules += {'virtio-gpu-ccw': virtio_gpu_ccw_ss}
+modules += {'hw-s390x': hw_s390x_modules}
+modules_restricted += {'hw-s390x-virtio-gpu-ccw': ['s390x-softmmu']}
diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
index 7901ab276c..bba7593d2e 100644
--- a/include/hw/s390x/css.h
+++ b/include/hw/s390x/css.h
@@ -12,7 +12,6 @@
 #ifndef CSS_H
 #define CSS_H
 
-#include "cpu.h"
 #include "hw/s390x/adapter.h"
 #include "hw/s390x/s390_flic.h"
 #include "hw/s390x/ioinst.h"
@@ -233,12 +232,6 @@ uint32_t css_get_adapter_id(CssIoAdapterType type, uint8_t 
isc);
 void css_register_io_adapters(CssIoAdapterType type, bool swap, bool maskable,
                               uint8_t flags, Error **errp);
 
-#ifndef CONFIG_KVM
-#define S390_ADAPTER_SUPPRESSIBLE 0x01
-#else
-#define S390_ADAPTER_SUPPRESSIBLE KVM_S390_ADAPTER_SUPPRESSIBLE
-#endif
-
 #ifndef CONFIG_USER_ONLY
 SubchDev *css_find_subch(uint8_t m, uint8_t cssid, uint8_t ssid,
                          uint16_t schid);
diff --git a/include/hw/s390x/s390_flic.h b/include/hw/s390x/s390_flic.h
index e91b15d2d6..3907a13d07 100644
--- a/include/hw/s390x/s390_flic.h
+++ b/include/hw/s390x/s390_flic.h
@@ -134,6 +134,9 @@ void s390_flic_init(void);
 S390FLICState *s390_get_flic(void);
 QEMUS390FLICState *s390_get_qemu_flic(S390FLICState *fs);
 S390FLICStateClass *s390_get_flic_class(S390FLICState *fs);
+void s390_crw_mchk(void);
+void s390_io_interrupt(uint16_t subchannel_id, uint16_t subchannel_nr,
+                       uint32_t io_int_parm, uint32_t io_int_word);
 bool ais_needed(void *opaque);
 
 #endif /* HW_S390_FLIC_H */
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 60d434d5ed..b434b905c0 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -40,6 +40,12 @@
 
 #define S390_MAX_CPUS 248
 
+#ifndef CONFIG_KVM
+#define S390_ADAPTER_SUPPRESSIBLE 0x01
+#else
+#define S390_ADAPTER_SUPPRESSIBLE KVM_S390_ADAPTER_SUPPRESSIBLE
+#endif
+
 typedef struct PSW {
     uint64_t mask;
     uint64_t addr;
@@ -806,9 +812,6 @@ int cpu_s390x_signal_handler(int host_signum, void *pinfo, 
void *puc);
 
 
 /* interrupt.c */
-void s390_crw_mchk(void);
-void s390_io_interrupt(uint16_t subchannel_id, uint16_t subchannel_nr,
-                       uint32_t io_int_parm, uint32_t io_int_word);
 #define RA_IGNORED                  0
 void s390_program_interrupt(CPUS390XState *env, uint32_t code, uintptr_t ra);
 /* service interrupts are floating therefore we must not pass an cpustate */
diff --git a/util/module.c b/util/module.c
index 26fc893d98..5638202357 100644
--- a/util/module.c
+++ b/util/module.c
@@ -313,6 +313,7 @@ static struct {
     { "virtio-gpu-pci-base",   "hw-", "display-virtio-gpu-pci" },
     { "virtio-gpu-pci",        "hw-", "display-virtio-gpu-pci" },
     { "vhost-user-gpu-pci",    "hw-", "display-virtio-gpu-pci" },
+    { "virtio-gpu-ccw",        "hw-", "s390x-virtio-gpu-ccw"   },
     { "virtio-vga-base",       "hw-", "display-virtio-vga"    },
     { "virtio-vga",            "hw-", "display-virtio-vga"    },
     { "vhost-user-vga",        "hw-", "display-virtio-vga"    },
-- 
2.25.1