From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 64FF31A08F5 for ; Thu, 14 Jan 2016 11:02:15 +1100 (AEDT) Date: Thu, 14 Jan 2016 11:02:39 +1100 From: David Gibson To: Aravinda Prasad Cc: gleb@kernel.org, agraf@suse.de, kvm-ppc@vger.kernel.org, paulus@ozlabs.org, linuxppc-dev@ozlabs.org, pbonzini@redhat.com, mahesh@linux.vnet.ibm.com, kvm@vger.kernel.org, mpe@ellerman.id.au Subject: Re: [PATCH v3 1/2] KVM: PPC: New capability to control MCE behaviour Message-ID: <20160114000239.GB22925@voom.redhat.com> References: <20160113070759.20248.86252.stgit@aravindap> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="iluUylAmeNVF81ZM" In-Reply-To: <20160113070759.20248.86252.stgit@aravindap> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --iluUylAmeNVF81ZM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jan 13, 2016 at 12:37:59PM +0530, Aravinda Prasad wrote: > This patch introduces a new KVM capability to control > how KVM behaves on machine check exception (MCE). > Without this capability, KVM redirects machine check > exceptions to guest's 0x200 vector if the address in > error belongs to the guest. With this capability KVM > causes a guest exit with NMI exit reason. >=20 > This is required to avoid problems if a new kernel/KVM > is used with an old QEMU for guests that don't issue > "ibm,nmi-register". As old QEMU does not understand the > NMI exit type, it treats it as a fatal error. However, > the guest could have handled the machine check error > if the exception was delivered to guest's 0x200 interrupt > vector instead of NMI exit in case of old QEMU. >=20 > QEMU part can be found at: > http://lists.nongnu.org/archive/html/qemu-ppc/2015-12/msg00199.html >=20 > Change Log v3: > - Split the patch into 2. First patch introduces the > new capability while the second one enhances KVM to > redirect MCE. > - Fix access width bug > - Rebased to v4.4-rc7 >=20 > Change Log v2: > - Added KVM capability >=20 > Signed-off-by: Aravinda Prasad > --- > arch/powerpc/include/asm/kvm_host.h | 1 + > arch/powerpc/kernel/asm-offsets.c | 1 + > arch/powerpc/kvm/powerpc.c | 7 +++++++ > include/uapi/linux/kvm.h | 1 + > 4 files changed, 10 insertions(+) >=20 > diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/a= sm/kvm_host.h > index cfa758c..9ac2b84 100644 > --- a/arch/powerpc/include/asm/kvm_host.h > +++ b/arch/powerpc/include/asm/kvm_host.h > @@ -243,6 +243,7 @@ struct kvm_arch { > int hpt_cma_alloc; > struct dentry *debugfs_dir; > struct dentry *htab_dentry; > + u8 fwnmi_enabled; Um.. I don't see anything in this patch or 2/2 which actually tests this flag... > #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */ > #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE > struct mutex hpt_mutex; > diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-= offsets.c > index 221d584..6a4e81a 100644 > --- a/arch/powerpc/kernel/asm-offsets.c > +++ b/arch/powerpc/kernel/asm-offsets.c > @@ -506,6 +506,7 @@ int main(void) > DEFINE(KVM_ENABLED_HCALLS, offsetof(struct kvm, arch.enabled_hcalls)); > DEFINE(KVM_LPCR, offsetof(struct kvm, arch.lpcr)); > DEFINE(KVM_VRMA_SLB_V, offsetof(struct kvm, arch.vrma_slb_v)); > + DEFINE(KVM_FWNMI, offsetof(struct kvm, arch.fwnmi_enabled)); > DEFINE(VCPU_DSISR, offsetof(struct kvm_vcpu, arch.shregs.dsisr)); > DEFINE(VCPU_DAR, offsetof(struct kvm_vcpu, arch.shregs.dar)); > DEFINE(VCPU_VPA, offsetof(struct kvm_vcpu, arch.vpa.pinned_addr)); > diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c > index 6fd2405..a8399b5 100644 > --- a/arch/powerpc/kvm/powerpc.c > +++ b/arch/powerpc/kvm/powerpc.c > @@ -570,6 +570,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, lon= g ext) > r =3D 1; > break; > #endif > + case KVM_CAP_PPC_FWNMI: > + r =3D 1; > + break; > default: > r =3D 0; > break; > @@ -1132,6 +1135,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vc= pu *vcpu, > break; > } > #endif /* CONFIG_KVM_XICS */ > + case KVM_CAP_PPC_FWNMI: > + r =3D 0; > + vcpu->kvm->arch.fwnmi_enabled =3D true; > + break; > default: > r =3D -EINVAL; > break; > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 03f3618..d8a07b5 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -831,6 +831,7 @@ struct kvm_ppc_smmu_info { > #define KVM_CAP_GUEST_DEBUG_HW_WPS 120 > #define KVM_CAP_SPLIT_IRQCHIP 121 > #define KVM_CAP_IOEVENTFD_ANY_LENGTH 122 > +#define KVM_CAP_PPC_FWNMI 123 > =20 > #ifdef KVM_CAP_IRQ_ROUTING > =20 >=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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