[libvirt] PATCH: Use -help arg with QEMU probing
This patch makes the code that probes QEMU args explicitly add the -help argument. This works around a problem with certain KVM builds which refuse to run if executed without -help, and no KVM modules are present. It also removes the set of setenv() since that changes libvirtd's environ and instead uses execle() to set the child's environment Dan Index: src/qemu_conf.c =================================================================== RCS file: /data/cvs/libvirt/src/qemu_conf.c,v retrieving revision 1.64 diff -u -p -r1.64 qemu_conf.c --- src/qemu_conf.c 15 May 2008 20:07:34 -0000 1.64 +++ src/qemu_conf.c 16 May 2008 14:34:42 -0000 @@ -447,6 +447,8 @@ static int qemudExtractVersionInfo(const } if (child == 0) { /* Kid */ + const char *const qemuenv[] = { "LANG=C", NULL }; + if (close(STDIN_FILENO) < 0) goto cleanup1; if (close(STDERR_FILENO) < 0) @@ -457,8 +459,7 @@ static int qemudExtractVersionInfo(const goto cleanup1; /* Just in case QEMU is translated someday.. */ - setenv("LANG", "C", 1); - execl(qemu, qemu, (char*)NULL); + execle(qemu, qemu, "-help", (char*)NULL, qemuenv); cleanup1: _exit(-1); /* Just in case */ -- |: Red Hat, Engineering, Boston -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|
"Daniel P. Berrange" <berrange@redhat.com> wrote:
This patch makes the code that probes QEMU args explicitly add the -help argument. This works around a problem with certain KVM builds which refuse to run if executed without -help, and no KVM modules are present.
Sounds obtuse enough to deserve a comment in the code.
It also removes the set of setenv() since that changes libvirtd's environ and instead uses execle() to set the child's environment
Dan
Index: src/qemu_conf.c =================================================================== RCS file: /data/cvs/libvirt/src/qemu_conf.c,v retrieving revision 1.64 diff -u -p -r1.64 qemu_conf.c --- src/qemu_conf.c 15 May 2008 20:07:34 -0000 1.64 +++ src/qemu_conf.c 16 May 2008 14:34:42 -0000 @@ -447,6 +447,8 @@ static int qemudExtractVersionInfo(const }
if (child == 0) { /* Kid */ + const char *const qemuenv[] = { "LANG=C", NULL }; + if (close(STDIN_FILENO) < 0) goto cleanup1; if (close(STDERR_FILENO) < 0) @@ -457,8 +459,7 @@ static int qemudExtractVersionInfo(const goto cleanup1;
/* Just in case QEMU is translated someday.. */ - setenv("LANG", "C", 1); - execl(qemu, qemu, (char*)NULL); + execle(qemu, qemu, "-help", (char*)NULL, qemuenv);
cleanup1: _exit(-1); /* Just in case */
ACK
Jim Meyering wrote:
"Daniel P. Berrange" <berrange@redhat.com> wrote:
This patch makes the code that probes QEMU args explicitly add the -help argument. This works around a problem with certain KVM builds which refuse to run if executed without -help, and no KVM modules are present.
Sounds obtuse enough to deserve a comment in the code.
In all fairness, it's never been well defined that the help script is outputted when no options are passed. It actually is machine dependent. When the config file support is merged, and we introduce a default config, it will be possible to configure QEMU to default to -net tap and -boot cdn. In this case, a VM will be launched if no arguments are passed. Regards, Anthony Liguori
It also removes the set of setenv() since that changes libvirtd's environ and instead uses execle() to set the child's environment
Dan
Index: src/qemu_conf.c =================================================================== RCS file: /data/cvs/libvirt/src/qemu_conf.c,v retrieving revision 1.64 diff -u -p -r1.64 qemu_conf.c --- src/qemu_conf.c 15 May 2008 20:07:34 -0000 1.64 +++ src/qemu_conf.c 16 May 2008 14:34:42 -0000 @@ -447,6 +447,8 @@ static int qemudExtractVersionInfo(const }
if (child == 0) { /* Kid */ + const char *const qemuenv[] = { "LANG=C", NULL }; + if (close(STDIN_FILENO) < 0) goto cleanup1; if (close(STDERR_FILENO) < 0) @@ -457,8 +459,7 @@ static int qemudExtractVersionInfo(const goto cleanup1;
/* Just in case QEMU is translated someday.. */ - setenv("LANG", "C", 1); - execl(qemu, qemu, (char*)NULL); + execle(qemu, qemu, "-help", (char*)NULL, qemuenv);
cleanup1: _exit(-1); /* Just in case */
ACK
participants (3)
-
Anthony Liguori -
Daniel P. Berrange -
Jim Meyering