[Qemu-devel] [PATCH v2 1/2] pvpanic: initialization cleanup

[Qemu-devel] [PATCH v2 1/2] pvpanic: initialization cleanup

[Michael S. Tsirkin]

Avoid use of static variables: PC systems
initialize pvpanic device through pvpanic_init,
so we can simply create the fw_cfg file at that point.
This also makes it possible to assert if fw_cfg is not there
rather than skipping the device silently.

Reviewed-by:  Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

Changes from v1:
    don't assert if !fw_cfg, simply skip fwcfg

 hw/misc/pvpanic.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/hw/misc/pvpanic.c b/hw/misc/pvpanic.c
index 060099b..8329a0a 100644
--- a/hw/misc/pvpanic.c
+++ b/hw/misc/pvpanic.c
@@ -97,25 +97,27 @@ static void pvpanic_isa_realizefn(DeviceState *dev, Error **errp)
 {
     ISADevice *d = ISA_DEVICE(dev);
     PVPanicState *s = ISA_PVPANIC_DEVICE(dev);
-    static bool port_configured;
-    FWCfgState *fw_cfg;
 
     isa_register_ioport(d, &s->io, s->ioport);
+}
 
-    if (!port_configured) {
-        fw_cfg = fw_cfg_find();
-        if (fw_cfg) {
-            fw_cfg_add_file(fw_cfg, "etc/pvpanic-port",
-                            g_memdup(&s->ioport, sizeof(s->ioport)),
-                            sizeof(s->ioport));
-            port_configured = true;
-        }
-    }
+static void pvpanic_fw_cfg(ISADevice *dev, FWCfgState *fw_cfg)
+{
+    PVPanicState *s = ISA_PVPANIC_DEVICE(dev);
+
+    fw_cfg_add_file(fw_cfg, "etc/pvpanic-port",
+                    g_memdup(&s->ioport, sizeof(s->ioport)),
+                    sizeof(s->ioport));
 }
 
 int pvpanic_init(ISABus *bus)
 {
-    isa_create_simple(bus, TYPE_ISA_PVPANIC_DEVICE);
+    ISADevice *dev = isa_create_simple(bus, TYPE_ISA_PVPANIC_DEVICE);
+    FWCfgState *fw_cfg = fw_cfg_find();
+    if (fw_cfg) {
+        pvpanic_fw_cfg(dev, fw_cfg)
+    }
+
     return 0;
 }
 
-- 
MST

[Qemu-devel] [PATCH v2 2/2] pvpanic: fix fwcfg for big endian hosts

[Michael S. Tsirkin]

Convert port number to little endian when
exposing it in fw cfg.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/misc/pvpanic.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/hw/misc/pvpanic.c b/hw/misc/pvpanic.c
index 8329a0a..7fd82cb 100644
--- a/hw/misc/pvpanic.c
+++ b/hw/misc/pvpanic.c
@@ -104,10 +104,11 @@ static void pvpanic_isa_realizefn(DeviceState *dev, Error **errp)
 static void pvpanic_fw_cfg(ISADevice *dev, FWCfgState *fw_cfg)
 {
     PVPanicState *s = ISA_PVPANIC_DEVICE(dev);
+    uint16_t *pvpanic_port = g_malloc(sizeof(*pvpanic_port));
+    *pvpanic_port = cpu_to_le16(s->ioport);
 
-    fw_cfg_add_file(fw_cfg, "etc/pvpanic-port",
-                    g_memdup(&s->ioport, sizeof(s->ioport)),
-                    sizeof(s->ioport));
+    fw_cfg_add_file(fw_cfg, "etc/pvpanic-port", pvpanic_port,
+                    sizeof(*pvpanic_port));
 }
 
 int pvpanic_init(ISABus *bus)
-- 
MST

Re: [Qemu-devel] [PATCH v2 1/2] pvpanic: initialization cleanup

[Laszlo Ersek]

On 06/18/13 15:01, Michael S. Tsirkin wrote:
> Avoid use of static variables: PC systems
> initialize pvpanic device through pvpanic_init,
> so we can simply create the fw_cfg file at that point.
> This also makes it possible to assert if fw_cfg is not there
> rather than skipping the device silently.
> 
> Reviewed-by:  Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> 
> Changes from v1:
>     don't assert if !fw_cfg, simply skip fwcfg
> 
>  hw/misc/pvpanic.c | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)

Patches look good, however I think you missed to update the 1/2 commit
message completely. You removed the sentence

  Others don't use fw_cfg at all.

but

  This also makes it possible to assert if fw_cfg is not there rather
  than skipping the device silently.

remains, although it's exactly the assert() that's been erased.

Laszlo

Re: [Qemu-devel] [PATCH v2 1/2] pvpanic: initialization cleanup

[Michael S. Tsirkin]

On Wed, Jun 19, 2013 at 04:07:27PM +0200, Laszlo Ersek wrote:
> On 06/18/13 15:01, Michael S. Tsirkin wrote:
> > Avoid use of static variables: PC systems
> > initialize pvpanic device through pvpanic_init,
> > so we can simply create the fw_cfg file at that point.
> > This also makes it possible to assert if fw_cfg is not there
> > rather than skipping the device silently.
> > 
> > Reviewed-by:  Laszlo Ersek <lersek@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> > 
> > Changes from v1:
> >     don't assert if !fw_cfg, simply skip fwcfg
> > 
> >  hw/misc/pvpanic.c | 26 ++++++++++++++------------
> >  1 file changed, 14 insertions(+), 12 deletions(-)
> 
> Patches look good, however I think you missed to update the 1/2 commit
> message completely. You removed the sentence
> 
>   Others don't use fw_cfg at all.
> 
> but
> 
>   This also makes it possible to assert if fw_cfg is not there rather
>   than skipping the device silently.
> 
> remains, although it's exactly the assert() that's been erased.
> 
> Laszlo

Good point. It's going in through my tree so I'll tweak the
commit log but won't repost.
Thanks a lot for the thorough review!