<tt>Cole Robinson <crobinso@redhat.com> wrote on 11/17/2015 04:37:56 PM: > From: Cole Robinson <crobinso@redhat.com></tt> <tt>> To: Stefan Berger/Watson/IBM@IBMUS, libvir-list@redhat.com, > berrange@redhat.com</tt> <tt>> Cc: Stefan Berger <stefanb@linux.vnet.ibm.com></tt> <tt>> Date: 11/17/2015 04:38 PM</tt> <tt>> Subject: Re: [PATCH v2] tpm: adapt sysfs cancel path for new TPM driver</tt> <tt>> > On 11/17/2015 10:46 AM, Stefan Berger wrote: > > Adapt the sysfs TPM command cancel path for the TPM driver that > > does not use a miscdevice anymore since Linux 4.0. Support old > > and new paths and check their availability. > > > > Add a mockup for the test cases to avoid the testing for > > availability of the cancel path. > > > > Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com> > > --- > > src/util/virtpm.c | 22 ++++++++++++++++++++-- > > tests/qemuxml2argvmock.c | 15 +++++++++++++++ > > 2 files changed, 35 insertions(+), 2 deletions(-) > > > > diff --git a/src/util/virtpm.c b/src/util/virtpm.c > > index 88f8361..3872a31 100644 > > --- a/src/util/virtpm.c > > +++ b/src/util/virtpm.c > > @@ -23,9 +23,12 @@ > > #include <config.h> > > > > #include <sys/stat.h> > > +#include <fcntl.h> > > > > #include "virstring.h" > > #include "virerror.h" > > +#include "viralloc.h" > > +#include "virfile.h" > > #include "virtpm.h" > > > > #define VIR_FROM_THIS VIR_FROM_NONE > > @@ -41,13 +44,28 @@ virTPMCreateCancelPath(const char *devpath) > > { > > char *path = NULL; > > const char *dev; > > + const char *prefix[] = {"misc/", "tpm/"}; > > + size_t i; > > + int fd; > > > > if (devpath) { > > dev = strrchr(devpath, '/'); > > if (dev) { > > dev++; > > - if (virAsprintf(&path, "/sys/class/misc/%s/device/cancel", > > - dev) < 0) > > + for (i = 0; i < ARRAY_CARDINALITY(prefix); i++) { > > + if (virAsprintf(&path, "/sys/class/%s%s/device/cancel", > > + prefix[i], dev) < 0) > > + goto cleanup; > > + > > + fd = open(path, O_WRONLY); > > + if (fd >= 0) { > > + VIR_FORCE_CLOSE(fd); > > + break; > > + } > > + VIR_FREE(path); > > + } > > You can use virFileExists(path) to simplify this</tt> <tt>Right.</tt> <tt> > > > + /* /dev/null does not allow to cancel cmds but it canbe used */ > > + if (!path && virAsprintf(&path, "/dev/null") < 0) > > goto cleanup; > > } else { > > Hmm, does this mean we might selinux relabel /dev/null? Maybe just fall back > to no cancel-path if we want this to be non-fatal</tt> <tt>We have to pass something on the command line otherwise QEMU will try to find a path and SELinux will not allow it to open the file. Basically either one of these sysfs files has to be there.</tt> <tt>I'll resort to displaying an error instead.</tt> <tt>Regards,</tt> <tt> Stefan</tt>