The commit that prevents disk corruption on domain shutdown
(96fc4784177ecb70357518fa863442455e45ad0e) causes regression with QEMU
0.14.* and 0.15.* because of a regression bug in QEMU that was fixed
only recently in QEMU git. With affected QEMU binaries, domains cannot
be shutdown properly and stay in a paused state. This patch tries to
avoid this by sending SIGKILL to 0.1[45].* QEMU processes. Though we
wait a bit more between sending SIGTERM and SIGKILL to reduce the
possibility of virtual disk corruption.
IMO, SIGKILL should only be sent at the explicit direction of the
user, saying in effect, I'm ok with possible data corruption, I want
the VM killed unconditionally. I would rather leave VMs paused than
risk corrupting data. Let's get as much input as we can from the qemu
folks before we go down this path.
Dave
---
src/qemu/qemu_capabilities.c | 7 +++++++
src/qemu/qemu_capabilities.h | 1 +
src/qemu/qemu_process.c | 19 +++++++++++++------
3 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 36f47a9..823c500 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -136,6 +136,7 @@ VIR_ENUM_IMPL(qemuCaps, QEMU_CAPS_LAST,
"pci-ohci",
"usb-redir",
"usb-hub",
+ "no-shutdown-bug",
);
struct qemu_feature_flags {
@@ -1049,6 +1050,12 @@ qemuCapsComputeCmdFlags(const char *help,
if (version >= 13000)
qemuCapsSet(flags, QEMU_CAPS_PCI_MULTIFUNCTION);
+
+ /* QEMU version 0.14.* and 0.15.* are known not to handle SIGTERM
+ * properly when started with -no-shutdown
+ */
+ if (version >= 14000 && version <= 15999)
+ qemuCapsSet(flags, QEMU_CAPS_NO_SHUTDOWN_BUG);
}
/* We parse the output of 'qemu -help' to get the QEMU
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 96b7a3b..53d5ace 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -110,6 +110,7 @@ enum qemuCapsFlags {
QEMU_CAPS_PCI_OHCI = 71, /* -device pci-ohci */
QEMU_CAPS_USB_REDIR = 72, /* -device usb-redir */
QEMU_CAPS_USB_HUB = 73, /* -device usb-hub */
+ QEMU_CAPS_NO_SHUTDOWN_BUG = 74, /* -no-shutdown doesn't exit on SIGTERM */
QEMU_CAPS_LAST, /* this must always be the last item */
};
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 3baaa19..3311699 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -434,6 +434,7 @@ qemuProcessHandleShutdown(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
virDomainObjPtr vm)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
+ bool gracefully = true;
VIR_DEBUG("vm=%p", vm);
virDomainObjLock(vm);
@@ -443,6 +444,12 @@ qemuProcessHandleShutdown(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
goto cleanup;
}
+ if (qemuCapsGet(priv->qemuCaps, QEMU_CAPS_NO_SHUTDOWN_BUG)) {
+ VIR_DEBUG("Emulator is likely affected by -no-shutdown bug;"
+ " we will not avoid sending SIGKILL to it");
+ gracefully = false;
+ }
+
priv->gotShutdown = true;
if (priv->fakeReboot) {
virDomainObjRef(vm);
@@ -452,12 +459,12 @@ qemuProcessHandleShutdown(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
qemuProcessFakeReboot,
vm) < 0) {
VIR_ERROR(_("Failed to create reboot thread, killing domain"));
- qemuProcessKill(vm, true);
+ qemuProcessKill(vm, gracefully);
if (virDomainObjUnref(vm) == 0)
vm = NULL;
}
} else {
- qemuProcessKill(vm, true);
+ qemuProcessKill(vm, gracefully);
}
cleanup:
@@ -3227,15 +3234,15 @@ void qemuProcessKill(virDomainObjPtr vm, bool gracefully)
}
/* This loop sends SIGTERM, then waits a few iterations
- * (1.6 seconds) to see if it dies. If still alive then
+ * (3 seconds) to see if it dies. If still alive then
* it does SIGKILL, and waits a few more iterations (1.6
* seconds more) to confirm that it has really gone.
*/
- for (i = 0 ; i < 15 ; i++) {
+ for (i = 0 ; i < 23 ; i++) {
int signum;
if (i == 0)
signum = SIGTERM;
- else if (i == 8)
+ else if (i == 15)
signum = SIGKILL;
else
signum = 0; /* Just check for existence */
@@ -3249,7 +3256,7 @@ void qemuProcessKill(virDomainObjPtr vm, bool gracefully)
break;
}
- if (i == 0 && gracefully)
+ if (gracefully)
break;
usleep(200 * 1000);
--
1.7.6.1
--
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