From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60340) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WlIpq-0001wp-5u for qemu-devel@nongnu.org; Fri, 16 May 2014 10:10:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WlIpj-0001HW-U1 for qemu-devel@nongnu.org; Fri, 16 May 2014 10:10:06 -0400 Message-ID: <53761C32.3050300@suse.de> Date: Fri, 16 May 2014 16:09:54 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1400153291-20759-1-git-send-email-aik@ozlabs.ru> <1400153291-20759-8-git-send-email-aik@ozlabs.ru> In-Reply-To: <1400153291-20759-8-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 7/9] spapr: Limit threads per core according to current compatibility mode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org On 15.05.14 13:28, Alexey Kardashevskiy wrote: > This puts a limit to the number of threads per core based on the current > compatibility mode. Although PowerISA specs do not specify the maximum > threads per core number, the linux guest still expects that > PowerISA2.05-compatible CPU supports only 2 threads per core as this > is what POWER6 (2.05 compliant CPU) implements, same is true for > POWER7 (2.06, 4 threads) and POWER8 (2.07, 8 threads). > > Signed-off-by: Alexey Kardashevskiy > --- > hw/ppc/spapr.c | 31 ++++++++++++++++++++++++++++--- > 1 file changed, 28 insertions(+), 3 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index cf53a7a..a2c9106 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -34,6 +34,7 @@ > #include "sysemu/kvm.h" > #include "kvm_ppc.h" > #include "mmu-hash64.h" > +#include "cpu-models.h" > > #include "hw/boards.h" > #include "hw/ppc/ppc.h" > @@ -203,6 +204,29 @@ static XICSState *xics_system_init(int nr_servers, int nr_irqs) > return icp; > } > > +static int spapr_get_compat_smp_threads(PowerPCCPU *cpu) > +{ > + int ret = -1; > + > + switch (cpu->cpu_version) { > + case CPU_POWERPC_LOGICAL_2_05: > + ret = 2; > + break; > + case CPU_POWERPC_LOGICAL_2_06: > + ret = 4; > + break; > + case CPU_POWERPC_LOGICAL_2_07: > + ret = 8; > + break; > + default: > + ret = smp_threads; > + break; > + } > + ret = MIN(ret, smp_threads); Just call this in the function where you set the compat property and error out if threads > supported_threads. We always default to 1 thread anyway, so the only thing that could get us a broken configuration is the user. Alex