Re: [Qemu-devel] [PATCH] isapc: Fix segfault during initialization

[Anthony Liguori]

On 01/14/2012 07:12 AM, Jan Kiszka wrote:

From: Jan Kiszka<jan.kis...@siemens.com>

Linking the RTC device state to the PIIX does not belong into the
common path that is shared with the isapc. QEMU crashes otherwise.

Signed-off-by: Jan Kiszka<jan.kis...@siemens.com>

Here's the command line.  Even a simple 'qemu-system-x86_64 -M isapc' 
reproduces it:



Regards,

Anthony Liguori

Does isapc actually work for you? I tried to write a qemu-test test case (attached below) to help prevent future regressions. I can reproduce your SEGV but with your patch applied, I get no output (not even the BIOS runs). /home/anthony/build/qemu/x86_64-softmmu/qemu-system-x86_64 -kernel bin/vmlinuz-3.0 -initrd .tmp-3510/initramfs-3510.img.gz -append console=ttyS0 seed=24689 -M isapc -pidfile .tmp-3510/pidfile-3510.pid -qmp unix:.tmp-3510/qmpsock-3510.sock,server,nowait

---
  hw/pc_piix.c |   22 +++++++++++-----------
  1 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index b70431f..3aea3cc 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -201,6 +201,17 @@ static void pc_init1(MemoryRegion *system_memory,
          }
          idebus[0] = qdev_get_child_bus(&dev->qdev, "ide.0");
          idebus[1] = qdev_get_child_bus(&dev->qdev, "ide.1");
+
+        /* FIXME there's some major spaghetti here.  Somehow we create the
+         * devices on the PIIX before we actually create it.  We create the
+         * PIIX3 deep in the recess of the i440fx creation too and then lose
+         * the DeviceState.
+         *
+         * For now, let's "fix" this by making judicious use of paths.  This
+         * is not generally the right way to do this.
+         */
+        qdev_property_add_child(qdev_resolve_path("/i440fx/piix3", NULL),
+                                "rtc", (DeviceState *)rtc_state, NULL);
      } else {
          for(i = 0; i<  MAX_IDE_BUS; i++) {
              ISADevice *dev;
@@ -211,17 +222,6 @@ static void pc_init1(MemoryRegion *system_memory,
          }
      }

-    /* FIXME there's some major spaghetti here.  Somehow we create the devices
-     * on the PIIX before we actually create it.  We create the PIIX3 deep in
-     * the recess of the i440fx creation too and then lose the DeviceState.
-     *
-     * For now, let's "fix" this by making judicious use of paths.  This is not
-     * generally the right way to do this.
-     */
-
-    qdev_property_add_child(qdev_resolve_path("/i440fx/piix3", NULL),
-                            "rtc", (DeviceState *)rtc_state, NULL);
-
      audio_init(isa_bus, pci_enabled ? pci_bus : NULL);

      pc_cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device,

isapc.sh
Description: application/shellscript