diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2023-06-22 19:33:55 +1000 |
|---|---|---|
| committer | Cédric Le Goater <clg@kaod.org> | 2023-06-25 22:41:30 +0200 |
| commit | dc5e072188ea622071bab47c4f899817d6ef1295 (patch) | |
| tree | 134ba5eddeae653d47c5057817695d08a1f2c2e3 /hw/ppc/spapr.c | |
| parent | 516cd737330a9b4d90a66136ebf738c4653b4e78 (diff) | |
spapr: TCG allow up to 8-thread SMT on POWER8 and newer CPUs
PPC TCG supports SMT CPU configurations for non-hypervisor state, so
permit POWER8-10 pseries machines to enable SMT.
This requires PIR and TIR be set, because that's how sibling thread
matching is done by TCG.
spapr's nested-HV capability does not currently coexist with SMT, so
that combination is prohibited (interestingly somewhat analogous to
LPAR-per-core mode on real hardware which also does not support KVM).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[ clg: Also test smp_threads when checking for POWER8 CPU and above ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Diffstat (limited to 'hw/ppc/spapr.c')
| -rw-r--r-- | hw/ppc/spapr.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 8e7d497f25..54dbfd7fe9 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2525,10 +2525,19 @@ static void spapr_set_vsmt_mode(SpaprMachineState *spapr, Error **errp) int ret; unsigned int smp_threads = ms->smp.threads; - if (tcg_enabled() && (smp_threads > 1)) { - error_setg(errp, "TCG cannot support more than 1 thread/core " - "on a pseries machine"); - return; + if (tcg_enabled()) { + if (smp_threads > 1 && + !ppc_type_check_compat(ms->cpu_type, CPU_POWERPC_LOGICAL_2_07, 0, + spapr->max_compat_pvr)) { + error_setg(errp, "TCG only supports SMT on POWER8 or newer CPUs"); + return; + } + + if (smp_threads > 8) { + error_setg(errp, "TCG cannot support more than 8 threads/core " + "on a pseries machine"); + return; + } } if (!is_power_of_2(smp_threads)) { error_setg(errp, "Cannot support %d threads/core on a pseries " |