From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLACK,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9300C47258 for ; Mon, 4 May 2020 11:32:51 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 908CF2073E for ; Mon, 4 May 2020 11:32:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 908CF2073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59066 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jVZL8-0006NZ-QU for qemu-devel@archiver.kernel.org; Mon, 04 May 2020 07:32:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48982) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jVZJ7-0004fq-Ta for qemu-devel@nongnu.org; Mon, 04 May 2020 07:30:46 -0400 Received: from 5.mo69.mail-out.ovh.net ([46.105.43.105]:54153) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jVZJ4-0000nC-VO for qemu-devel@nongnu.org; Mon, 04 May 2020 07:30:45 -0400 Received: from player761.ha.ovh.net (unknown [10.108.35.124]) by mo69.mail-out.ovh.net (Postfix) with ESMTP id 325C58D931 for ; Mon, 4 May 2020 13:30:40 +0200 (CEST) Received: from kaod.org (lns-bzn-46-82-253-208-248.adsl.proxad.net [82.253.208.248]) (Authenticated sender: groug@kaod.org) by player761.ha.ovh.net (Postfix) with ESMTPSA id E3C4D1201243F; Mon, 4 May 2020 11:30:29 +0000 (UTC) Date: Mon, 4 May 2020 13:30:27 +0200 From: Greg Kurz To: Alexey Kardashevskiy Subject: Re: [PATCH qemu] spapr: Add PVR setting capability Message-ID: <20200504133027.4f5a18f8@bahia.lan> In-Reply-To: <20200417041105.63563-1-aik@ozlabs.ru> References: <20200417041105.63563-1-aik@ozlabs.ru> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Ovh-Tracer-Id: 18221282617894738421 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduhedrjeeggdefkecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpefirhgvghcumfhurhiiuceoghhrohhugheskhgrohgurdhorhhgqeenucggtffrrghtthgvrhhnpeehkefhtdehgeehheejledufeekhfdvleefvdeihefhkefhudffhfeuuedvffdthfenucfkpheptddrtddrtddrtddpkedvrddvheefrddvtdekrddvgeeknecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepphhlrgihvghrjeeiuddrhhgrrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpehgrhhouhhgsehkrghougdrohhrghdprhgtphhtthhopehqvghmuhdquggvvhgvlhesnhhonhhgnhhurdhorhhg Received-SPF: pass client-ip=46.105.43.105; envelope-from=groug@kaod.org; helo=5.mo69.mail-out.ovh.net X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/04 07:30:41 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 17 Apr 2020 14:11:05 +1000 Alexey Kardashevskiy wrote: > At the moment the VCPU init sequence includes setting PVR which in case of > KVM-HV only checks if it matches the hardware PVR mask as PVR cannot be > virtualized by the hardware. In order to cope with various CPU revisions > only top 16bit of PVR are checked which works for minor revision updates. > > However in every CPU generation starting POWER7 (at least) there were CPUs > supporting the (almost) same POWER ISA level but having different top > 16bits of PVR - POWER7+, POWER8E, POWER8NVL; this time we got POWER9+ > with a new PVR family. We would normally add the PVR mask for the new one > too, the problem with it is that although the physical machines exist, > P9+ is not going to be released as a product, and this situation is likely > to repeat in the future. > > Instead of adding every new CPU family in QEMU, this adds a new sPAPR > machine capability to force PVR setting/checking. It is "on" by default > to preserve the existing behavior. When "off", it is the user's > responsibility to specify the correct CPU. > I don't quite understand the motivation for this... what does this buy us ? > Signed-off-by: Alexey Kardashevskiy > --- > include/hw/ppc/spapr.h | 5 ++++- > hw/ppc/spapr.c | 1 + > hw/ppc/spapr_caps.c | 18 ++++++++++++++++++ > target/ppc/kvm.c | 16 ++++++++++++++-- > 4 files changed, 37 insertions(+), 3 deletions(-) > > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > index e579eaf28c05..5ccac4d56871 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -81,8 +81,10 @@ typedef enum { > #define SPAPR_CAP_CCF_ASSIST 0x09 > /* Implements PAPR FWNMI option */ > #define SPAPR_CAP_FWNMI 0x0A > +/* Implements PAPR PVR option */ > +#define SPAPR_CAP_PVR 0x0B > /* Num Caps */ > -#define SPAPR_CAP_NUM (SPAPR_CAP_FWNMI + 1) > +#define SPAPR_CAP_NUM (SPAPR_CAP_PVR + 1) > > /* > * Capability Values > @@ -912,6 +914,7 @@ extern const VMStateDescription vmstate_spapr_cap_nested_kvm_hv; > extern const VMStateDescription vmstate_spapr_cap_large_decr; > extern const VMStateDescription vmstate_spapr_cap_ccf_assist; > extern const VMStateDescription vmstate_spapr_cap_fwnmi; > +extern const VMStateDescription vmstate_spapr_cap_pvr; > > static inline uint8_t spapr_get_cap(SpaprMachineState *spapr, int cap) > { > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 841b5ec59b12..ecc74c182b9f 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -4535,6 +4535,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data) > smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON; > smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_ON; > smc->default_caps.caps[SPAPR_CAP_FWNMI] = SPAPR_CAP_ON; > + smc->default_caps.caps[SPAPR_CAP_PVR] = SPAPR_CAP_ON; > spapr_caps_add_properties(smc, &error_abort); > smc->irq = &spapr_irq_dual; > smc->dr_phb_enabled = true; > diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c > index eb54f9422722..398b72b77f9f 100644 > --- a/hw/ppc/spapr_caps.c > +++ b/hw/ppc/spapr_caps.c > @@ -525,6 +525,14 @@ static void cap_fwnmi_apply(SpaprMachineState *spapr, uint8_t val, > } > } > > +static void cap_pvr_apply(SpaprMachineState *spapr, uint8_t val, Error **errp) > +{ > + if (val) { > + return; > + } > + warn_report("If you're uing kvm-hv.ko, only \"-cpu host\" is supported"); > +} > + > SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = { > [SPAPR_CAP_HTM] = { > .name = "htm", > @@ -633,6 +641,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = { > .type = "bool", > .apply = cap_fwnmi_apply, > }, > + [SPAPR_CAP_PVR] = { > + .name = "pvr", > + .description = "Enforce PVR in KVM", > + .index = SPAPR_CAP_PVR, > + .get = spapr_cap_get_bool, > + .set = spapr_cap_set_bool, > + .type = "bool", > + .apply = cap_pvr_apply, > + }, > }; > > static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr, > @@ -773,6 +790,7 @@ SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV); > SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER); > SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST); > SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI); > +SPAPR_CAP_MIG_STATE(pvr, SPAPR_CAP_PVR); > > void spapr_caps_init(SpaprMachineState *spapr) > { > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > index 03d0667e8f94..a4adc29b6522 100644 > --- a/target/ppc/kvm.c > +++ b/target/ppc/kvm.c > @@ -466,15 +466,27 @@ int kvm_arch_init_vcpu(CPUState *cs) > PowerPCCPU *cpu = POWERPC_CPU(cs); > CPUPPCState *cenv = &cpu->env; > int ret; > + SpaprMachineState *spapr; > We generally try to avoid adding such explicit dependencies to the machine code within the target directory... A virtual hypervisor hook could possibly do the trick but this would require to set PowerPCCPU::vhyp before kvm_arch_init_vcpu() gets called, eg. when the vCPU is created in spapr_create_vcpu() rather than when it gets realized. > /* Synchronize sregs with kvm */ > ret = kvm_arch_sync_sregs(cpu); > if (ret) { > if (ret == -EINVAL) { > error_report("Register sync failed... If you're using kvm-hv.ko," > - " only \"-cpu host\" is possible"); > + " only \"-cpu host\" is supported"); > + } > + /* > + * The user chose not to set PVR which makes sense if we are running > + * on a CPU with known ISA level but unknown PVR. > + */ > + spapr = (SpaprMachineState *) > + object_dynamic_cast(OBJECT(qdev_get_machine()), TYPE_SPAPR_MACHINE); > + > + if (spapr && spapr->eff.caps[SPAPR_CAP_PVR] == SPAPR_CAP_OFF) { > + ret = 0; > + } else { > + return ret; > } > - return ret; > } > > switch (cenv->mmu_model) {