From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52599) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1afkFh-0003yH-QO for qemu-devel@nongnu.org; Tue, 15 Mar 2016 04:22:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1afkFf-0004rL-MQ for qemu-devel@nongnu.org; Tue, 15 Mar 2016 04:22:53 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:38955) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1afkFf-0004qj-4y for qemu-devel@nongnu.org; Tue, 15 Mar 2016 04:22:51 -0400 Received: from localhost by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 15 Mar 2016 18:22:47 +1000 Date: Tue, 15 Mar 2016 13:51:40 +0530 From: Bharata B Rao Message-ID: <20160315082140.GA13176@in.ibm.com> References: <1457974600-13828-1-git-send-email-clg@fr.ibm.com> <1457974600-13828-5-git-send-email-clg@fr.ibm.com> <56E70F14.2020406@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <56E70F14.2020406@redhat.com> Subject: Re: [Qemu-devel] [PATCH 04/17] ppc: Add number of threads per core to the processor definition Reply-To: bharata@linux.vnet.ibm.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: =?iso-8859-1?Q?C=E9dric?= Le Goater , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, David Gibson On Mon, Mar 14, 2016 at 08:20:52PM +0100, Thomas Huth wrote: > On 14.03.2016 17:56, Cédric Le Goater wrote: > > From: Benjamin Herrenschmidt > > > > Also use it to clamp the max SMT mode and ensure that the cpu_dt_id > > are offset by that value in order to preserve consistency with the > > HW implementations. > > > > Signed-off-by: Benjamin Herrenschmidt > > --- > > target-ppc/cpu-qom.h | 1 + > > target-ppc/translate_init.c | 11 ++++++++++- > > 2 files changed, 11 insertions(+), 1 deletion(-) > > > > diff --git a/target-ppc/cpu-qom.h b/target-ppc/cpu-qom.h > > index 7d5e2b36a997..735981309c5b 100644 > > --- a/target-ppc/cpu-qom.h > > +++ b/target-ppc/cpu-qom.h > > @@ -68,6 +68,7 @@ typedef struct PowerPCCPUClass { > > uint32_t flags; > > int bfd_mach; > > uint32_t l1_dcache_size, l1_icache_size; > > + uint32_t threads_per_core; > > #if defined(TARGET_PPC64) > > const struct ppc_segment_page_sizes *sps; > > #endif > > diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c > > index 43c6e524a6bc..46dabe58783a 100644 > > --- a/target-ppc/translate_init.c > > +++ b/target-ppc/translate_init.c > > @@ -8231,6 +8231,7 @@ POWERPC_FAMILY(POWER5P)(ObjectClass *oc, void *data) > > POWERPC_FLAG_BUS_CLK; > > pcc->l1_dcache_size = 0x8000; > > pcc->l1_icache_size = 0x10000; > > + pcc->threads_per_core = 2; > > } > > > > static void powerpc_get_compat(Object *obj, Visitor *v, const char *name, > > @@ -8408,6 +8409,7 @@ POWERPC_FAMILY(POWER7)(ObjectClass *oc, void *data) > > pcc->l1_dcache_size = 0x8000; > > pcc->l1_icache_size = 0x8000; > > pcc->interrupts_big_endian = ppc_cpu_interrupts_big_endian_lpcr; > > + pcc->threads_per_core = 4; > > } > > > > static void init_proc_POWER8(CPUPPCState *env) > > @@ -8492,6 +8494,7 @@ POWERPC_FAMILY(POWER8)(ObjectClass *oc, void *data) > > pcc->l1_dcache_size = 0x8000; > > pcc->l1_icache_size = 0x8000; > > pcc->interrupts_big_endian = ppc_cpu_interrupts_big_endian_lpcr; > > + pcc->threads_per_core = 8; > > } > > #endif /* defined (TARGET_PPC64) */ > > > > @@ -9195,6 +9198,12 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp) > > #endif > > > > #if !defined(CONFIG_USER_ONLY) > > + if (pcc->threads_per_core == 0) { > > + pcc->threads_per_core = 1; > > + } > > + if (max_smt > pcc->threads_per_core) { I wonder when can the above condition be true. max_smt is kvmppc_smt_threads() which returns threads_per_subcore via KVM_CAP_PPC_SMT capability call. > > + max_smt = pcc->threads_per_core; > > + } > > if (smp_threads > max_smt) { > > error_setg(errp, "Cannot support more than %d threads on PPC with %s", > > max_smt, kvm_enabled() ? "KVM" : "TCG"); > > @@ -9215,7 +9224,7 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp) > > } > > > > #if !defined(CONFIG_USER_ONLY) > > - cpu->cpu_dt_id = (cs->cpu_index / smp_threads) * max_smt > > + cpu->cpu_dt_id = (cs->cpu_index / smp_threads) * pcc->threads_per_core > > + (cs->cpu_index % smp_threads); > > #endif > > That looks like it could collide with Bharata's CPU hotplug series ... > Bharata, > what do you think? In my last patchset, I was following the existing logic of DT id generation to assign DT ids for spapr-cpu-core devices. Guess I will have to change that when this patch is accepted. Regards, Bharata.