On Thu, Jan 14, 2016 at 11:02:39AM +1100, David Gibson wrote: > 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. > > > > 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. > > > > QEMU part can be found at: > > http://lists.nongnu.org/archive/html/qemu-ppc/2015-12/msg00199.html > > > > 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 > > > > Change Log v2: > > - Added KVM capability > > > > Signed-off-by: Aravinda Prasad <aravinda@xxxxxxxxxxxxxxxxxx> > > --- > > 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(+) > > > > diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/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... Sorry, I missed it in the asm, spotted it now. Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> > > > #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, long ext) > > r = 1; > > break; > > #endif > > + case KVM_CAP_PPC_FWNMI: > > + r = 1; > > + break; > > default: > > r = 0; > > break; > > @@ -1132,6 +1135,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, > > break; > > } > > #endif /* CONFIG_KVM_XICS */ > > + case KVM_CAP_PPC_FWNMI: > > + r = 0; > > + vcpu->kvm->arch.fwnmi_enabled = true; > > + break; > > default: > > r = -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 > > > > #ifdef KVM_CAP_IRQ_ROUTING > > > > > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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