We ignore silently the value of smp_threads when we set the default 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 <lviv...@redhat.com> --- Notes: v3: use MAX(8, smp_threads) and let KVM to return an error if nb_threads is too big update subject to reflect the change v2: display a specific error message when the default VSMT is used fix subject hw/ppc/spapr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 32a876be56..c8a1eefa17 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2310,7 +2310,7 @@ static void spapr_set_vsmt_mode(sPAPRMachineState *spapr, Error **errp) * the value that we'd get with KVM on POWER8, the * overwhelmingly common case in production systems. */ - spapr->vsmt = 8; + spapr->vsmt = MAX(8, smp_threads); } /* KVM: If necessary, set the SMT mode: */ -- 2.14.3