Re: [libvirt] [PATCH v2] qemuOpenVhostNet: Decrease vhostfdSize on open failure

On 05/27/2013 02:44 AM, Michal Privoznik wrote: > Currently, if there's an error opening /dev/vhost-net (e.g. because > it doesn't exist) but it's not required we proceed with vhostfd array > filled with -1 and vhostfdSize unchanged. Later, when constructing > the qemu command line only non-negative items within vhostfd array > are taken into account. This means, vhostfdSize may be greater than > the actual count of non-negative items in vhostfd array. This results > in improper command line arguments being generated, e.g.: > > -netdev tap,fd=21,id=hostnet0,vhost=on,vhostfd=(null) > --- > src/qemu/qemu_command.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index 0373626..c4a162a 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -486,6 +486,10 @@ qemuOpenVhostNet(virDomainDefPtr def, > "but is unavailable")); > goto error; > } > + VIR_WARN("Unable to open vhost-net. Opened so far %d, requested %d", > + i, *vhostfdSize); > + *vhostfdSize = i; > + break; > } > } > virDomainAuditNetDevice(def, net, "/dev/vhost-net", *vhostfdSize); > @@ -6560,12 +6564,10 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd, > } > > for (i = 0; i < vhostfdSize; i++) { > - if (vhostfd[i] >= 0) { > - virCommandTransferFD(cmd, vhostfd[i]); > - if (virAsprintf(&vhostfdName[i], "%d", vhostfd[i]) < 0) { > - virReportOOMError(); > - goto cleanup; > - } > + virCommandTransferFD(cmd, vhostfd[i]); > + if (virAsprintf(&vhostfdName[i], "%d", vhostfd[i]) < 0) { > + virReportOOMError(); > + goto cleanup; > } > } > ACK.