From 934676c7b726fe9cccac02a7a4fa23c1e6a4c91e Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Wed, 5 Jul 2023 22:06:30 +1000 Subject: [PATCH] ppc/pnv: SMT support for powernv MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Set the TIR default value with the SMT thread index, and place some standard limits on SMT configurations. Now powernv is able to boot skiboot and Linux with a SMT topology, including booting a KVM guest. There are several SPRs and other features (e.g., broadcast msgsnd) that are not implemented, but not used by OPAL or Linux and can be added incrementally. Reviewed-by: Cédric Le Goater Tested-by: Cédric Le Goater Signed-off-by: Nicholas Piggin Message-ID: <20230705120631.27670-4-npiggin@gmail.com> Signed-off-by: Daniel Henrique Barboza --- docs/system/ppc/powernv.rst | 5 ----- hw/ppc/pnv.c | 12 ++++++++++++ hw/ppc/pnv_core.c | 13 +++++-------- 3 files changed, 17 insertions(+), 13 deletions(-) diff --git a/docs/system/ppc/powernv.rst b/docs/system/ppc/powernv.rst index c8f9762342..09f3965858 100644 --- a/docs/system/ppc/powernv.rst +++ b/docs/system/ppc/powernv.rst @@ -195,11 +195,6 @@ Use a MTD drive to add a PNOR to the machine, and get a NVRAM : -drive file=./witherspoon.pnor,format=raw,if=mtd -CAVEATS -------- - - * No support for multiple HW threads (SMT=1). Same as pseries. - Maintainer contact information ------------------------------ diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c index 5f25fe985a..23740f9d07 100644 --- a/hw/ppc/pnv.c +++ b/hw/ppc/pnv.c @@ -887,6 +887,18 @@ static void pnv_init(MachineState *machine) pnv->num_chips = machine->smp.max_cpus / (machine->smp.cores * machine->smp.threads); + + if (machine->smp.threads > 8) { + error_report("Cannot support more than 8 threads/core " + "on a powernv machine"); + exit(1); + } + if (!is_power_of_2(machine->smp.threads)) { + error_report("Cannot support %d threads/core on a powernv" + "machine because it must be a power of 2", + machine->smp.threads); + exit(1); + } /* * TODO: should we decide on how many chips we can create based * on #cores and Venice vs. Murano vs. Naples chip type etc..., diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c index b7223bb445..8a72171ce0 100644 --- a/hw/ppc/pnv_core.c +++ b/hw/ppc/pnv_core.c @@ -218,12 +218,13 @@ static const MemoryRegionOps pnv_core_power10_xscom_ops = { .endianness = DEVICE_BIG_ENDIAN, }; -static void pnv_core_cpu_realize(PnvCore *pc, PowerPCCPU *cpu, Error **errp) +static void pnv_core_cpu_realize(PnvCore *pc, PowerPCCPU *cpu, Error **errp, + int thread_index) { CPUPPCState *env = &cpu->env; int core_pir; - int thread_index = 0; /* TODO: TCG supports only one thread */ ppc_spr_t *pir = &env->spr_cb[SPR_PIR]; + ppc_spr_t *tir = &env->spr_cb[SPR_TIR]; Error *local_err = NULL; PnvChipClass *pcc = PNV_CHIP_GET_CLASS(pc->chip); @@ -239,11 +240,7 @@ static void pnv_core_cpu_realize(PnvCore *pc, PowerPCCPU *cpu, Error **errp) core_pir = object_property_get_uint(OBJECT(pc), "pir", &error_abort); - /* - * The PIR of a thread is the core PIR + the thread index. We will - * need to find a way to get the thread index when TCG supports - * more than 1. We could use the object name ? - */ + tir->default_value = thread_index; pir->default_value = core_pir + thread_index; /* Set time-base frequency to 512 MHz */ @@ -292,7 +289,7 @@ static void pnv_core_realize(DeviceState *dev, Error **errp) } for (j = 0; j < cc->nr_threads; j++) { - pnv_core_cpu_realize(pc, pc->threads[j], &local_err); + pnv_core_cpu_realize(pc, pc->threads[j], &local_err, j); if (local_err) { goto err; } -- 2.30.2