[Xen-devel] [PATCH][QEMU] Fix HVM guest hang in save/restore with the network load

[SUZUKI Kazuhiro <kaz@xxxxxxxxxxxxxx>]

Hi all,

When we repeat migration(save/restore) of the HVM guest with the
network load, the guest hangs. The attached patch fixes it.

We need to save PCIDevice.irq_state[] and PCIBus.irq_count[] in QEMU.
Otherwise, xc_hvm_set_pci_intx_level() in
tools/ioemu/target-i386-dm/piix_pci-dm.c:59 could not be called with 
level = 0 which calls hvm_pci_intx_deassert() in
xen/arch/x86/hvm/irq.c:83 by hypercall.
If gsi_assert_count[] could not be decreased because this function is
not called, then vioapic_deliver() in xen/arch/x86/hvm/vioapic.c:473
is called every time.
So the guest enters endless IRQ loop and hangs.

Thanks,
KAZ

Signed-off-by: Kazuhiro Suzuki <kaz@xxxxxxxxxxxxxx>

diff -r a464af87c9db tools/ioemu/hw/pci.c
--- a/tools/ioemu/hw/pci.c      Fri Apr 11 17:29:26 2008 +0100
+++ b/tools/ioemu/hw/pci.c      Mon Apr 14 16:15:33 2008 +0900
@@ -81,6 +81,7 @@ void pci_device_save(PCIDevice *s, QEMUF
 {
     qemu_put_be32(f, 1); /* PCI device version */
     qemu_put_buffer(f, s->config, 256);
+    qemu_put_buffer(f, (uint8_t*)s->irq_state, sizeof(s->irq_state));
 }
 
 int pci_device_load(PCIDevice *s, QEMUFile *f)
@@ -91,6 +92,18 @@ int pci_device_load(PCIDevice *s, QEMUFi
         return -EINVAL;
     qemu_get_buffer(f, s->config, 256);
     pci_update_mappings(s);
+    qemu_get_buffer(f, (uint8_t*)s->irq_state, sizeof(s->irq_state));
+    return 0;
+}
+
+void pci_bus_save(PCIBus *bus, QEMUFile *f, int nirq)
+{
+    qemu_put_buffer(f, (uint8_t*)bus->irq_count, nirq * sizeof(int));
+}
+
+int pci_bus_load(PCIBus *bus, QEMUFile *f, int nirq)
+{
+    qemu_get_buffer(f, (uint8_t*)bus->irq_count, nirq * sizeof(int));
     return 0;
 }
 
diff -r a464af87c9db tools/ioemu/target-i386-dm/piix_pci-dm.c
--- a/tools/ioemu/target-i386-dm/piix_pci-dm.c  Fri Apr 11 17:29:26 2008 +0100
+++ b/tools/ioemu/target-i386-dm/piix_pci-dm.c  Mon Apr 14 16:15:33 2008 +0900
@@ -64,6 +64,7 @@ static void i440fx_save(QEMUFile* f, voi
 {
     PCIDevice *d = opaque;
     pci_device_save(d, f);
+    pci_bus_save(d->bus, f, 128);
 #ifndef CONFIG_DM
     qemu_put_8s(f, &smm_enabled);
 #endif /* !CONFIG_DM */
@@ -79,6 +80,7 @@ static int i440fx_load(QEMUFile* f, void
     ret = pci_device_load(d, f);
     if (ret < 0)
         return ret;
+    pci_bus_load(d->bus, f, 128);
 #ifndef CONFIG_DM
     i440fx_update_memory_mappings(d);
     qemu_get_8s(f, &smm_enabled);
diff -r a464af87c9db tools/ioemu/vl.h
--- a/tools/ioemu/vl.h  Fri Apr 11 17:29:26 2008 +0100
+++ b/tools/ioemu/vl.h  Mon Apr 14 16:15:33 2008 +0900
@@ -843,6 +843,9 @@ void pci_device_save(PCIDevice *s, QEMUF
 void pci_device_save(PCIDevice *s, QEMUFile *f);
 int pci_device_load(PCIDevice *s, QEMUFile *f);
 
+void pci_bus_save(PCIBus *bus, QEMUFile *f, int nirq);
+int pci_bus_load(PCIBus *bus, QEMUFile *f, int nirq);
+
 typedef void (*pci_set_irq_fn)(void *pic, int irq_num, int level);
 typedef int (*pci_map_irq_fn)(PCIDevice *pci_dev, int irq_num);
 PCIBus *pci_register_bus(pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel