Re: [libvirt] [PATCH] Report original error when QMP probing fails with new QEMU

If probing capabilities via QMP fails, we now have a check that prevents us falling back to -help parsing. Unfortunately the error message "Failed to probe capabilities for /usr/bin/qemu-kvm: unsupported configuration: QEMU 2.1.2 is too new for help parsing" is proving rather unhelpful to the user. We need to be telling them why QMP failed (the root cause), rather than they can't use -help (the side effect). To do this we should capture stderr during QMP probing, and if -help parsing then sees a new QEMU version, we know that QMP should have worked, and so we can show the messages from stderr. The message thus becomes "Failed to probe capabilities for /usr/bin/qemu-kvm: internal error: QEMU / QMP failed: Could not access KVM kernel module: No such file or directory failed to initialize KVM: No such file or directory" --- src/qemu/qemu_capabilities.c | 37 +++++++++++++++++++++++++++---------- src/qemu/qemu_capabilities.h | 3 ++- src/qemu/qemu_process.c | 4 ++-- tests/qemuhelptest.c | 2 +- 4 files changed, 32 insertions(+), 14 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index d2c046d..f777484 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -1331,7 +1331,8 @@ int virQEMUCapsParseHelpStr(const char *qemu, unsigned int *version, bool *is_kvm, unsigned int *kvm_version, - bool check_yajl) + bool check_yajl, + const char *qemuerr)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index a14b6f7..68777e8 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -3554,12 +3554,12 @@ qemuProcessReconnect(void *opaque) struct qemuProcessReconnectData *data = opaque; virQEMUDriverPtr driver = data->driver; virDomainObjPtr obj = data->obj; - qemuDomainObjPrivatePtr priv; + qemuDomainObjPrivatePtr priv = NULL; virConnectPtr conn = data->conn; struct qemuDomainJobObj oldjob; int state; int reason; - virQEMUDriverConfigPtr cfg; + virQEMUDriverConfigPtr cfg = NULL; size_t i; int ret;

diff --git a/tests/qemuhelptest.c b/tests/qemuhelptest.c index 0c68367..6d9525c 100644 --- a/tests/qemuhelptest.c +++ b/tests/qemuhelptest.c @@ -59,7 +59,7 @@ static int testHelpStrParsing(const void *data) goto cleanup; if (virQEMUCapsParseHelpStr("QEMU", help, flags, - &version, &is_kvm, &kvm_version, false) == -1) { + &version, &is_kvm, &kvm_version, false, NULL) == -1) { if (info->error && virGetLastError()->code == info->error) ret = 0; goto cleanup;