From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55095) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejSQ3-00075k-0v for qemu-devel@nongnu.org; Wed, 07 Feb 2018 11:18:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ejSPz-0007MK-RW for qemu-devel@nongnu.org; Wed, 07 Feb 2018 11:17:59 -0500 From: Laurent Vivier Date: Wed, 7 Feb 2018 17:17:30 +0100 Message-Id: <20180207161730.17194-1-lvivier@redhat.com> Subject: [Qemu-devel] [PATCH] spapr: check smp_threads < vsmt List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org, David Gibson We ignore silently the value of smp_threads when we set the VSMT value, and if smp_threads is greater than VSMT kernel is going into trouble later. Fixes: 8904e5a750 ("spapr: Adjust default VSMT value for better migration compatibility") Signed-off-by: Laurent Vivier --- hw/ppc/spapr.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 32a876be56..638b3cafd0 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2294,15 +2294,7 @@ static void spapr_set_vsmt_mode(sPAPRMachineState *spapr, Error **errp) } /* Detemine the VSMT mode to use: */ - if (vsmt_user) { - if (spapr->vsmt < smp_threads) { - error_setg(&local_err, "Cannot support VSMT mode %d" - " because it must be >= threads/core (%d)", - spapr->vsmt, smp_threads); - goto out; - } - /* In this case, spapr->vsmt has been set by the command line */ - } else { + if (!vsmt_user) { /* * Default VSMT value is tricky, because we need it to be as * consistent as possible (for migration), but this requires @@ -2313,6 +2305,13 @@ static void spapr_set_vsmt_mode(sPAPRMachineState *spapr, Error **errp) spapr->vsmt = 8; } + if (spapr->vsmt < smp_threads) { + error_setg(&local_err, "Cannot support VSMT mode %d" + " because it must be >= threads/core (%d)", + spapr->vsmt, smp_threads); + goto out; + } + /* KVM: If necessary, set the SMT mode: */ if (kvm_enabled() && (spapr->vsmt != kvm_smt)) { ret = kvmppc_set_smt_threads(spapr->vsmt); -- 2.14.3