
On Sat, May 05, 2018 at 12:48:45 -0500, Chris Venteicher wrote:
Start and connect to QEMU so QMP commands can be performed.
Isolates code for starting QEMU and establishing Monitor connections from code for obtaining capabilities so that arbitrary QMP commands can be exchanged with QEMU. --- src/qemu/qemu_capabilities.c | 59 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index afce3eb2b7..097985cbe7 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -4303,6 +4303,65 @@ virQEMUCapsInitQMPCommandRun(virQEMUCapsInitQMPCommandPtr cmd, }
+/* Start and connect to QEMU so QMP commands can be performed. + */ +static virQEMUCapsInitQMPCommandPtr +virQEMUCapsSpinUpQemu(const char *exec, + const char *libDir, uid_t runUid, gid_t runGid, + bool forceTCG)
This wrapper should have a different signature (accepting qemuCaps), and probably a different name which would suggest it's for onetime QMP commands. I'm not sure what the right name would be, though :-)
+{ + virQEMUCapsInitQMPCommandPtr cmd = NULL; + virQEMUCapsInitQMPCommandPtr rtn_cmd = NULL; + char *binary = NULL; + + if (exec) { + if (VIR_STRDUP(binary, exec) < 0) + goto cleanup; + } else { + /* Check for existence of base emulator, or alternate base + * which can be used with magic cpu choice + */ + virArch arch = virArchFromHost(); + binary = virQEMUCapsFindBinaryForArch(arch, arch); + } + + VIR_DEBUG("binary=%s", binary);
We have a cache of QEMU capabilities for all binaries we found so there's no need to try to look for them again.
+ + /* Make sure the binary we are about to try exec'ing exists. + * Technically we could catch the exec() failure, but that's + * in a sub-process so it's hard to feed back a useful error. + */ + if (!virFileIsExecutable(binary)) { + virReportSystemError(errno, _("QEMU binary %s is not executable"), + binary); + goto cleanup; + }
Getting qemuCaps from the cache will also make sure the binary is executable.
+ + if (!(cmd = virQEMUCapsInitQMPCommandNew(binary, libDir, + runUid, runGid, NULL))) + goto cleanup;
This will use capabilities.monitor.sock and capabilities.pidfile for all processes. We either need to serialize this code with caps probing and also serialize all threads running baseline/compare QMP commands, or we need to refactor virQEMUCapsInitQMPCommandNew a bit so that it can be used simultaneously by several threads.
+ + if ((virQEMUCapsInitQMPCommandRun(cmd, forceTCG)) < 0) {
No need for extra () since there's no assignment here.
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("Error starting QEMU"));
This would override any useful error already set by virQEMUCapsInitQMPCommandRun.
+ goto cleanup; + } + + if (!(cmd->mon)) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Error connecting to QEMU")); + goto cleanup; + }
We should just check virQEMUCapsInitQMPCommandRun returned 0 and fail otherwise.
+ + VIR_STEAL_PTR(rtn_cmd, cmd); + + cleanup: + virQEMUCapsInitQMPCommandFree(cmd); + VIR_FREE(binary); + + return rtn_cmd; +} + + static int virQEMUCapsInitQMP(virQEMUCapsPtr qemuCaps, const char *libDir, -- 2.14.1
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