Re: [libvirt] [PATCH] Enable support for nested SVM

On 10/12/2010 04:46 AM, Daniel P. Berrange wrote: >This enables support for nested SVM using the regular CPU >model/features block. If the CPU model or features include >'svm', then the '-enable-nesting' flag will be added to the >QEMU command line. Latest out of tree patches for nested >'vmx', no longer require the '-enable-nesting' flag. They >instead just look at the cpu features. Several of the models >already include svm support, but QEMU was just masking out >the svm bit silently. So this will enable SVM on such >models > >+ >+bool >+cpuHasFeature(const char *arch, >+ const union cpuData *data, >+ const char *feature) >+{ >+ struct cpuArchDriver *driver; >+ >+ VIR_DEBUG("arch=%s, data=%p, feature=%s", >+ arch, data, feature); >+ >+ if ((driver = cpuGetSubDriver(arch)) == NULL) >+ return -1; Ouch. -1 promotes to true. >+ >+ if (driver->hasFeature == NULL) { >+ virCPUReportError(VIR_ERR_NO_SUPPORT, >+ _("cannot check guest CPU data for %s architecture"), >+ arch); >+ return -1; Likewise. >+ } >+ >+ return driver->hasFeature(data, feature); >+} You either need to change the return type to int and take a bool* parameter (return -1 on failure, 0 on success when *param was written to), or return an int value rather than a bool; since the caller needs to distinguish between feature-not-present and error-message-reported.