[PATCH] qemu: use a fixed directory for saving qmp capabilities process

From c7ee36417b88df7dcfe5e18d1eb72b6d7c175268 Mon Sep 17 00:00:00 2001 From: Bihong Yu <yubihong@huawei.com> Date: Tue, 14 Jul 2020 11:17:46 +0800 Subject: [PATCH] qemu: use a fixed directory for saving qmp capabilities process
In some case, the qmp capabilities process possible residues. So we need to cleanup the residual process during start libvirt. For this reason, we should use a fixed directory for saving qmp capabilities process. Change-Id: I6a74a046e192eee169a0e2677ce3aed9ded5e0ed Signed-off-by:Bihong Yu <yubihong@huawei.com> --- src/qemu/qemu_process.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 70fc24b..eba14ed 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -8450,21 +8450,24 @@ static int qemuProcessQMPInit(qemuProcessQMPPtr proc) { g_autofree char *template = NULL; + virErrorPtr orig_err; VIR_DEBUG("proc=%p, emulator=%s", proc, proc->binary); - template = g_strdup_printf("%s/qmp-XXXXXX", proc->libDir); + template = g_strdup_printf("%s/qmp-capabilities", proc->libDir); - if (!(proc->uniqDir = g_mkdtemp(template))) { + if (g_mkdir_with_parents(template, 0700) < 0) { virReportSystemError(errno, _("Failed to create unique directory with " "template '%s' for probing QEMU"), template); return -1; } - /* if g_mkdtemp succeeds, proc->uniqDir is now the owner of - * the string. Set template to NULL to avoid freeing - * the memory in this case */ + /* + * if g_mkdir_with_parents succeeds, assign the template to proc->uniqDir. + * Then set template to NULL to avoid freeing the memory in this case. + */ + proc->uniqDir = template; template = NULL; if (qemuProcessQEMULabelUniqPath(proc) < 0) @@ -8481,6 +8484,10 @@ qemuProcessQMPInit(qemuProcessQMPPtr proc) */ proc->pidfile = g_strdup_printf("%s/%s", proc->uniqDir, "qmp.pid"); + virErrorPreserveLast(&orig_err); + if (virPidFileForceCleanupPath(proc->pidfile) < 0) + VIR_WARN("Unable to kill qemu QMP process"); + virErrorRestore(&orig_err); return 0; } -- 1.8.3.1

On Tue, Jul 14, 2020 at 11:20:00 +0800, Bihong Yu wrote:
From c7ee36417b88df7dcfe5e18d1eb72b6d7c175268 Mon Sep 17 00:00:00 2001 From: Bihong Yu <yubihong@huawei.com> Date: Tue, 14 Jul 2020 11:17:46 +0800 Subject: [PATCH] qemu: use a fixed directory for saving qmp capabilities process
In some case, the qmp capabilities process possible residues. So we need to cleanup the residual process during start libvirt. For this reason, we should use a fixed directory for saving qmp capabilities process.
Change-Id: I6a74a046e192eee169a0e2677ce3aed9ded5e0ed Signed-off-by:Bihong Yu <yubihong@huawei.com> --- src/qemu/qemu_process.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
We can't do this because this code is used in more places than just QMP capabilities probing. Specifically, APIs for CPU comparison and baseline on s390x are passed to QEMU using this code. Which means we can have multiple QEMU processes running at the same time. We should rather make sure such temporary directories are not left behind and possible cleanup them when QEMU driver starts to remove those which were left behind when libvirtd gets restarted. NACK
participants (2)
-
Bihong Yu
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Jiri Denemark