From: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> To: gleb@kernel.org, Michael Ellerman <mpe@ellerman.id.au>, agraf@suse.de, KVM-PPC <kvm-ppc@vger.kernel.org>, linuxppc-dev <linuxppc-dev@ozlabs.org>, Paul Mackerras <paulus@samba.org>, pbonzini@redhat.com Cc: Aravinda Prasad <aravinda@linux.vnet.ibm.com>, KVM <kvm@vger.kernel.org>, david@gibson.dropbear.id.au Subject: [PATCH v8 1/3] KVM: PPC: Add new capability to control MCE behaviour Date: Thu, 06 Apr 2017 23:17:20 +0530 [thread overview] Message-ID: <149150084002.9475.10207482951514093041.stgit@jupiter.in.ibm.com> (raw) In-Reply-To: <149150078227.9475.13869552319691573937.stgit@jupiter.in.ibm.com> From: Aravinda Prasad <aravinda@linux.vnet.ibm.com> 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. The new capability 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. Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> --- Documentation/virtual/kvm/api.txt | 11 +++++++++++ arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kvm/powerpc.c | 9 +++++++++ include/uapi/linux/kvm.h | 1 + 5 files changed, 23 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index fd10689..1c9d281 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4164,6 +4164,17 @@ to take care of that. This capability can be enabled dynamically even if VCPUs were already created and are running. +7.9 KVM_CAP_PPC_FWNMI + +Architectures: ppc +Parameters: none + +With this capability a machine check exception in the guest address +space will cause KVM to exit the guest with NMI exit reason. This +enables QEMU to build error log and branch to guest kernel registered +machine check handling routine. Without this capability KVM will +branch to guests' 0x200 interrupt vector. + 8. Other capabilities. ---------------------- diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 7bba8f4..4d02cbc 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -279,6 +279,7 @@ struct kvm_arch { struct dentry *debugfs_dir; struct dentry *htab_dentry; struct kvm_resize_hpt *resize_hpt; /* protected by kvm->lock */ + u8 fwnmi_enabled; #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 4367e7d..0daa47b 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -481,6 +481,7 @@ int main(void) OFFSET(KVM_ENABLED_HCALLS, kvm, arch.enabled_hcalls); OFFSET(KVM_VRMA_SLB_V, kvm, arch.vrma_slb_v); OFFSET(KVM_RADIX, kvm, arch.radix); + OFFSET(KVM_FWNMI, kvm, arch.fwnmi_enabled); OFFSET(VCPU_DSISR, kvm_vcpu, arch.shregs.dsisr); OFFSET(VCPU_DAR, kvm_vcpu, arch.shregs.dar); OFFSET(VCPU_VPA, kvm_vcpu, arch.vpa.pinned_addr); diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 95c91a9..b8e8cd4 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -618,6 +618,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) /* Disable this on POWER9 until code handles new HPTE format */ r = !!hv_enabled && !cpu_has_feature(CPU_FTR_ARCH_300); break; + case KVM_CAP_PPC_FWNMI: + r = 1; + break; #endif case KVM_CAP_PPC_HTM: r = cpu_has_feature(CPU_FTR_TM_COMP) && @@ -1226,6 +1229,12 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, break; } #endif /* CONFIG_KVM_XICS */ +#ifdef CONFIG_PPC_BOOK3S_64 + case KVM_CAP_PPC_FWNMI: + r = 0; + vcpu->kvm->arch.fwnmi_enabled = true; + break; +#endif /* CONFIG_PPC_BOOK3S_64 */ default: r = -EINVAL; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index f51d508..d5428a7 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -883,6 +883,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_MMU_RADIX 134 #define KVM_CAP_PPC_MMU_HASH_V3 135 #define KVM_CAP_IMMEDIATE_EXIT 136 +#define KVM_CAP_PPC_FWNMI 137 #ifdef KVM_CAP_IRQ_ROUTING
WARNING: multiple messages have this Message-ID (diff)
From: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> To: gleb@kernel.org, Michael Ellerman <mpe@ellerman.id.au>, agraf@suse.de, KVM-PPC <kvm-ppc@vger.kernel.org>, linuxppc-dev <linuxppc-dev@ozlabs.org>, Paul Mackerras <paulus@samba.org>, pbonzini@redhat.com Cc: Aravinda Prasad <aravinda@linux.vnet.ibm.com>, KVM <kvm@vger.kernel.org>, david@gibson.dropbear.id.au Subject: [PATCH v8 1/3] KVM: PPC: Add new capability to control MCE behaviour Date: Thu, 06 Apr 2017 17:59:20 +0000 [thread overview] Message-ID: <149150084002.9475.10207482951514093041.stgit@jupiter.in.ibm.com> (raw) In-Reply-To: <149150078227.9475.13869552319691573937.stgit@jupiter.in.ibm.com> From: Aravinda Prasad <aravinda@linux.vnet.ibm.com> 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. The new capability 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. Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> --- Documentation/virtual/kvm/api.txt | 11 +++++++++++ arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kvm/powerpc.c | 9 +++++++++ include/uapi/linux/kvm.h | 1 + 5 files changed, 23 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index fd10689..1c9d281 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4164,6 +4164,17 @@ to take care of that. This capability can be enabled dynamically even if VCPUs were already created and are running. +7.9 KVM_CAP_PPC_FWNMI + +Architectures: ppc +Parameters: none + +With this capability a machine check exception in the guest address +space will cause KVM to exit the guest with NMI exit reason. This +enables QEMU to build error log and branch to guest kernel registered +machine check handling routine. Without this capability KVM will +branch to guests' 0x200 interrupt vector. + 8. Other capabilities. ---------------------- diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 7bba8f4..4d02cbc 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -279,6 +279,7 @@ struct kvm_arch { struct dentry *debugfs_dir; struct dentry *htab_dentry; struct kvm_resize_hpt *resize_hpt; /* protected by kvm->lock */ + u8 fwnmi_enabled; #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 4367e7d..0daa47b 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -481,6 +481,7 @@ int main(void) OFFSET(KVM_ENABLED_HCALLS, kvm, arch.enabled_hcalls); OFFSET(KVM_VRMA_SLB_V, kvm, arch.vrma_slb_v); OFFSET(KVM_RADIX, kvm, arch.radix); + OFFSET(KVM_FWNMI, kvm, arch.fwnmi_enabled); OFFSET(VCPU_DSISR, kvm_vcpu, arch.shregs.dsisr); OFFSET(VCPU_DAR, kvm_vcpu, arch.shregs.dar); OFFSET(VCPU_VPA, kvm_vcpu, arch.vpa.pinned_addr); diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 95c91a9..b8e8cd4 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -618,6 +618,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) /* Disable this on POWER9 until code handles new HPTE format */ r = !!hv_enabled && !cpu_has_feature(CPU_FTR_ARCH_300); break; + case KVM_CAP_PPC_FWNMI: + r = 1; + break; #endif case KVM_CAP_PPC_HTM: r = cpu_has_feature(CPU_FTR_TM_COMP) && @@ -1226,6 +1229,12 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, break; } #endif /* CONFIG_KVM_XICS */ +#ifdef CONFIG_PPC_BOOK3S_64 + case KVM_CAP_PPC_FWNMI: + r = 0; + vcpu->kvm->arch.fwnmi_enabled = true; + break; +#endif /* CONFIG_PPC_BOOK3S_64 */ default: r = -EINVAL; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index f51d508..d5428a7 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -883,6 +883,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_MMU_RADIX 134 #define KVM_CAP_PPC_MMU_HASH_V3 135 #define KVM_CAP_IMMEDIATE_EXIT 136 +#define KVM_CAP_PPC_FWNMI 137 #ifdef KVM_CAP_IRQ_ROUTING
next prev parent reply other threads:[~2017-04-06 17:48 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-04-06 17:46 [PATCH v8 0/3] KVM: PPC: Add FWNMI support for KVM guests on POWER Mahesh J Salgaonkar 2017-04-06 17:58 ` Mahesh J Salgaonkar 2017-04-06 17:47 ` Mahesh J Salgaonkar [this message] 2017-04-06 17:59 ` [PATCH v8 1/3] KVM: PPC: Add new capability to control MCE behaviour Mahesh J Salgaonkar 2017-04-06 17:47 ` [PATCH v8 2/3] powerpc/book3s: EXPORT_SYMBOL machine_check_print_event_info Mahesh J Salgaonkar 2017-04-06 17:59 ` Mahesh J Salgaonkar 2017-04-07 6:30 ` Michael Ellerman 2017-04-07 6:30 ` Michael Ellerman 2017-04-06 17:48 ` [PATCH v8 3/3] KVM: PPC: Exit guest upon MCE when FWNMI capability is enabled Mahesh J Salgaonkar 2017-04-06 17:49 ` Mahesh J Salgaonkar
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