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=-8.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 382D1C432C1 for ; Wed, 25 Sep 2019 01:42:14 +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 F2FC720874 for ; Wed, 25 Sep 2019 01:42:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="ZPdttV6z" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2FC720874 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44616 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iCwJo-0007NF-L3 for qemu-devel@archiver.kernel.org; Tue, 24 Sep 2019 21:42:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37129) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iCwHb-0005TY-MO for qemu-devel@nongnu.org; Tue, 24 Sep 2019 21:39:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iCwHZ-0003I3-Sf for qemu-devel@nongnu.org; Tue, 24 Sep 2019 21:39:55 -0400 Received: from bilbo.ozlabs.org ([2401:3900:2:1::2]:34579 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iCwHY-0003HC-Vk; Tue, 24 Sep 2019 21:39:53 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 46dLMm5V4Fz9sP3; Wed, 25 Sep 2019 11:39:48 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1569375588; bh=vLIdMJoa28jg7ayQKBwl2iYEf8kLES4gg4S0wfVpObo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZPdttV6ziF0GISKp7Rt9d7d2mpl92F5757A3IWb+2Oy3YPmcd5n/XSs2qu4ST9BD7 pkf/4/lqTGEmRg6UQuYxJVVX8xUw3J6IF/jK9zRr+pruZN13EHwWPh58HQoNplJrqk T+/1Ge9ip4MmhGs3tfSJQUSU3maz7eVTb0t3oBuw= Date: Wed, 25 Sep 2019 11:12:00 +1000 From: David Gibson To: Aravinda Prasad Subject: Re: [PATCH v14 2/7] ppc: spapr: Introduce FWNMI capability Message-ID: <20190925011200.GF17405@umbus> References: <156879398718.18368.17640174821710157715.stgit@aravinda> <156879433743.18368.1281417894007921022.stgit@aravinda> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="HCdXmnRlPgeNBad2" Content-Disposition: inline In-Reply-To: <156879433743.18368.1281417894007921022.stgit@aravinda> User-Agent: Mutt/1.12.1 (2019-06-15) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2401:3900:2:1::2 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: aik@ozlabs.ru, qemu-devel@nongnu.org, groug@kaod.org, paulus@ozlabs.org, qemu-ppc@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --HCdXmnRlPgeNBad2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 18, 2019 at 01:42:17PM +0530, Aravinda Prasad wrote: > Introduce the KVM capability KVM_CAP_PPC_FWNMI so that > the KVM causes guest exit with NMI as exit reason > when it encounters a machine check exception on the > address belonging to a guest. Without this capability > enabled, KVM redirects machine check exceptions to > guest's 0x200 vector. >=20 > This patch also introduces fwnmi-mce capability to > deal with the case when a guest with the > KVM_CAP_PPC_FWNMI capability enabled is attempted > to migrate to a host that does not support this > capability. >=20 > Signed-off-by: Aravinda Prasad Mostly ok, but there's one ugly problem. > --- > hw/ppc/spapr.c | 1 + > hw/ppc/spapr_caps.c | 29 +++++++++++++++++++++++++++++ > include/hw/ppc/spapr.h | 4 +++- > target/ppc/kvm.c | 26 ++++++++++++++++++++++++++ > target/ppc/kvm_ppc.h | 12 ++++++++++++ > 5 files changed, 71 insertions(+), 1 deletion(-) >=20 > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index ea56499..8288e8b 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -4487,6 +4487,7 @@ static void spapr_machine_class_init(ObjectClass *o= c, void *data) > smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] =3D SPAPR_CAP_OFF; > smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] =3D SPAPR_CAP_ON; > smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] =3D SPAPR_CAP_OFF; > + smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] =3D SPAPR_CAP_OFF; > spapr_caps_add_properties(smc, &error_abort); > smc->irq =3D &spapr_irq_dual; > smc->dr_phb_enabled =3D true; > diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c > index 481dfd2..c11ff87 100644 > --- a/hw/ppc/spapr_caps.c > +++ b/hw/ppc/spapr_caps.c > @@ -496,6 +496,25 @@ static void cap_ccf_assist_apply(SpaprMachineState *= spapr, uint8_t val, > } > } > =20 > +static void cap_fwnmi_mce_apply(SpaprMachineState *spapr, uint8_t val, > + Error **errp) > +{ > + if (!val) { > + return; /* Disabled by default */ > + } > + > + if (tcg_enabled()) { > + /* > + * TCG support may not be correct in some conditions (e.g., in c= ase > + * of software injected faults like duplicate SLBs). > + */ > + warn_report("Firmware Assisted Non-Maskable Interrupts not suppo= rted in TCG"); > + } else if (kvm_enabled() && !kvmppc_has_cap_ppc_fwnmi()) { > + error_setg(errp, > +"Firmware Assisted Non-Maskable Interrupts not supported by KVM, try cap= -fwnmi-mce=3Doff"); > + } > +} > + > SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] =3D { > [SPAPR_CAP_HTM] =3D { > .name =3D "htm", > @@ -595,6 +614,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = =3D { > .type =3D "bool", > .apply =3D cap_ccf_assist_apply, > }, > + [SPAPR_CAP_FWNMI_MCE] =3D { > + .name =3D "fwnmi-mce", > + .description =3D "Handle fwnmi machine check exceptions", > + .index =3D SPAPR_CAP_FWNMI_MCE, > + .get =3D spapr_cap_get_bool, > + .set =3D spapr_cap_set_bool, > + .type =3D "bool", > + .apply =3D cap_fwnmi_mce_apply, > + }, > }; > =20 > static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr, > @@ -734,6 +762,7 @@ SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MA= XPAGESIZE); > 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_MCE); > =20 > void spapr_caps_init(SpaprMachineState *spapr) > { > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > index 03111fd..66049ac 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -79,8 +79,10 @@ typedef enum { > #define SPAPR_CAP_LARGE_DECREMENTER 0x08 > /* Count Cache Flush Assist HW Instruction */ > #define SPAPR_CAP_CCF_ASSIST 0x09 > +/* FWNMI machine check handling */ > +#define SPAPR_CAP_FWNMI_MCE 0x0A > /* Num Caps */ > -#define SPAPR_CAP_NUM (SPAPR_CAP_CCF_ASSIST + 1) > +#define SPAPR_CAP_NUM (SPAPR_CAP_FWNMI_MCE + 1) > =20 > /* > * Capability Values > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > index 8c5b1f2..8b1ab78 100644 > --- a/target/ppc/kvm.c > +++ b/target/ppc/kvm.c > @@ -85,6 +85,7 @@ static int cap_ppc_safe_indirect_branch; > static int cap_ppc_count_cache_flush_assist; > static int cap_ppc_nested_kvm_hv; > static int cap_large_decr; > +static int cap_ppc_fwnmi; > =20 > static uint32_t debug_inst_opcode; > =20 > @@ -2055,6 +2056,26 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mp= ic_proxy) > } > } > =20 > +int kvmppc_set_fwnmi(void) > +{ > + PowerPCCPU *cpu =3D POWERPC_CPU(first_cpu); > + CPUState *cs =3D CPU(cpu); > + int ret; > + > + ret =3D kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0); > + if (ret) { > + error_report("This KVM version does not support FWNMI"); > + return ret; > + } > + > + /* > + * cap_ppc_fwnmi is set when FWNMI is available and enabled in KVM > + * and not just when FWNMI is available in KVM > + */ > + cap_ppc_fwnmi =3D 1; Using these cap globals is only slighly ugly when they can be initialized very early and thereafter remain constant. However, since you're only setting this later (in fact *never* until several patches down the series, since kvmppc_set_fwnmi() isn't called), this makes it very ugly with this global set at an indeterminite time having effects on things the relative order of which is not at all obvious. I think it would make much more sense to eliminate the cap_ppc_fwnmi global, and instead attempt the enable_cap in cap_fwnmi_mce_apply, failing the apply if the enable_cap fails. > + return ret; > +} > + > int kvmppc_smt_threads(void) > { > return cap_ppc_smt ? cap_ppc_smt : 1; > @@ -2355,6 +2376,11 @@ bool kvmppc_has_cap_mmu_hash_v3(void) > return cap_mmu_hash_v3; > } > =20 > +bool kvmppc_has_cap_ppc_fwnmi(void) > +{ > + return cap_ppc_fwnmi; > +} > + > static bool kvmppc_power8_host(void) > { > bool ret =3D false; > diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h > index 98bd7d5..ce5c1f9 100644 > --- a/target/ppc/kvm_ppc.h > +++ b/target/ppc/kvm_ppc.h > @@ -27,6 +27,8 @@ void kvmppc_enable_h_page_init(void); > void kvmppc_set_papr(PowerPCCPU *cpu); > int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr); > void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy); > +int kvmppc_set_fwnmi(void); > +bool kvmppc_has_cap_ppc_fwnmi(void); > int kvmppc_smt_threads(void); > void kvmppc_hint_smt_possible(Error **errp); > int kvmppc_set_smt_threads(int smt); > @@ -159,6 +161,16 @@ static inline void kvmppc_set_mpic_proxy(PowerPCCPU = *cpu, int mpic_proxy) > { > } > =20 > +static inline int kvmppc_set_fwnmi(void) > +{ > + return -1; > +} > + > +static inline bool kvmppc_has_cap_ppc_fwnmi(void) > +{ > + return false; > +} > + > static inline int kvmppc_smt_threads(void) > { > return 1; >=20 --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. 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