From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Vivier Subject: Re: [kvm-unit-tests PATCH v2] powerpc: Check whether TM is available before running other tests Date: Fri, 30 Sep 2016 12:01:59 +0200 Message-ID: References: <1475229293-11605-1-git-send-email-thuth@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , kvm-ppc@vger.kernel.org, Drew Jones , Suraj Jitindar Singh To: Thomas Huth , kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43226 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933241AbcI3KCD (ORCPT ); Fri, 30 Sep 2016 06:02:03 -0400 In-Reply-To: <1475229293-11605-1-git-send-email-thuth@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 30/09/2016 11:54, Thomas Huth wrote: > Transactional memory is currently only supported on KVM-HV, and > not yet on KVM-PR. So it's better to check the device tree first > and fail gracefully if it is not available. > > Signed-off-by: Thomas Huth > --- > v2: > - Reworked the check for the "ibm,pa-features" and added a comment > - Use a dedicated variable "has_tm" instead of "i" in main() > > Laurent, Suraj, Andrew, I did not add your Reviewed-by (thanks for > that!) from v1 here since I changed the code a little bit. So it > would be great if you could have another quick look at this v2. Reviewed-by: Laurent Vivier > > powerpc/tm.c | 43 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 42 insertions(+), 1 deletion(-) > > diff --git a/powerpc/tm.c b/powerpc/tm.c > index 6ce750a..8344318 100644 > --- a/powerpc/tm.c > +++ b/powerpc/tm.c > @@ -10,6 +10,41 @@ > #include > #include > #include > +#include > +#include > + > +/* Check "ibm,pa-features" property of a CPU node for the TM flag */ > +static void cpu_has_tm(int fdtnode, u32 regval __unused, void *ptr) > +{ > + const struct fdt_property *prop; > + int plen; > + > + prop = fdt_get_property(dt_fdt(), fdtnode, "ibm,pa-features", &plen); > + if (!prop) /* No features means TM is also not available */ > + return; > + /* Sanity check for the property layout (first two bytes are header) */ > + assert(plen >= 8 && prop->data[1] == 0 && prop->data[0] <= plen - 2); > + > + /* > + * The "Transactional Memory Category Support" flags are at byte > + * offset 22 and 23 of the attribute type 0, so when adding the > + * two bytes for the header, we've got to look at offset 24 for > + * the TM support bit. > + */ > + if (plen >= 26 && prop->data[0] >= 24 && (prop->data[24] & 0x80) != 0) > + *(int *)ptr += 1; > +} > + > +/* Check whether all CPU nodes have the TM flag */ > +static bool all_cpus_have_tm(void) > +{ > + int ret; > + int available = 0; > + > + ret = dt_for_each_cpu_node(cpu_has_tm, &available); > + > + return ret == 0 && available == nr_cpus; > +} > > static int h_cede(void) > { > @@ -101,11 +136,17 @@ struct { > > int main(int argc, char **argv) > { > - bool all; > + bool all, has_tm; > int i; > > report_prefix_push("tm"); > > + has_tm = all_cpus_have_tm(); > + report_xfail("TM available in 'ibm,pa-features' property", > + !has_tm, has_tm); > + if (!has_tm) > + return report_summary(); > + > all = argc == 1 || !strcmp(argv[1], "all"); > > for (i = 0; hctests[i].name != NULL; i++) { >