From 22945688acd4d0ec2620b0670a53110401ed9c59 Mon Sep 17 00:00:00 2001 From: Bharata B Rao Date: Mon, 25 Nov 2019 08:36:30 +0530 Subject: [PATCH] KVM: PPC: Book3S HV: Support reset of secure guest Add support for reset of secure guest via a new ioctl KVM_PPC_SVM_OFF. This ioctl will be issued by QEMU during reset and includes the the following steps: - Release all device pages of the secure guest. - Ask UV to terminate the guest via UV_SVM_TERMINATE ucall - Unpin the VPA pages so that they can be migrated back to secure side when guest becomes secure again. This is required because pinned pages can't be migrated. - Reinit the partition scoped page tables After these steps, guest is ready to issue UV_ESM call once again to switch to secure mode. Signed-off-by: Bharata B Rao Signed-off-by: Sukadev Bhattiprolu [Implementation of uv_svm_terminate() and its call from guest shutdown path] Signed-off-by: Ram Pai [Unpinning of VPA pages] Signed-off-by: Paul Mackerras --- Documentation/virt/kvm/api.txt | 18 +++++ arch/powerpc/include/asm/kvm_ppc.h | 1 + arch/powerpc/include/asm/ultravisor-api.h | 1 + arch/powerpc/include/asm/ultravisor.h | 5 ++ arch/powerpc/kvm/book3s_hv.c | 90 +++++++++++++++++++++++ arch/powerpc/kvm/powerpc.c | 12 +++ include/uapi/linux/kvm.h | 1 + 7 files changed, 128 insertions(+) diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt index 49183add44e7..9fecec6b4e86 100644 --- a/Documentation/virt/kvm/api.txt +++ b/Documentation/virt/kvm/api.txt @@ -4149,6 +4149,24 @@ Valid values for 'action': #define KVM_PMU_EVENT_ALLOW 0 #define KVM_PMU_EVENT_DENY 1 +4.121 KVM_PPC_SVM_OFF + +Capability: basic +Architectures: powerpc +Type: vm ioctl +Parameters: none +Returns: 0 on successful completion, +Errors: + EINVAL: if ultravisor failed to terminate the secure guest + ENOMEM: if hypervisor failed to allocate new radix page tables for guest + +This ioctl is used to turn off the secure mode of the guest or transition +the guest from secure mode to normal mode. This is invoked when the guest +is reset. This has no effect if called for a normal guest. + +This ioctl issues an ultravisor call to terminate the secure guest, +unpins the VPA pages and releases all the device pages that are used to +track the secure pages by hypervisor. 5. The kvm_run structure ------------------------ diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index d63f649fe713..3d2f871241a8 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -322,6 +322,7 @@ struct kvmppc_ops { int size); int (*store_to_eaddr)(struct kvm_vcpu *vcpu, ulong *eaddr, void *ptr, int size); + int (*svm_off)(struct kvm *kvm); }; extern struct kvmppc_ops *kvmppc_hv_ops; diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h index 4b0d044caa2a..b66f6db7be6c 100644 --- a/arch/powerpc/include/asm/ultravisor-api.h +++ b/arch/powerpc/include/asm/ultravisor-api.h @@ -34,5 +34,6 @@ #define UV_UNSHARE_PAGE 0xF134 #define UV_UNSHARE_ALL_PAGES 0xF140 #define UV_PAGE_INVAL 0xF138 +#define UV_SVM_TERMINATE 0xF13C #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */ diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h index b8e59b7b4ac8..790b0e63681f 100644 --- a/arch/powerpc/include/asm/ultravisor.h +++ b/arch/powerpc/include/asm/ultravisor.h @@ -77,4 +77,9 @@ static inline int uv_page_inval(u64 lpid, u64 gpa, u64 page_shift) return ucall_norets(UV_PAGE_INVAL, lpid, gpa, page_shift); } +static inline int uv_svm_terminate(u64 lpid) +{ + return ucall_norets(UV_SVM_TERMINATE, lpid); +} + #endif /* _ASM_POWERPC_ULTRAVISOR_H */ diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index a8e815648b0a..dc53578193ee 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4983,6 +4983,7 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm) if (nesting_enabled(kvm)) kvmhv_release_all_nested(kvm); kvm->arch.process_table = 0; + uv_svm_terminate(kvm->arch.lpid); kvmhv_set_ptbl_entry(kvm->arch.lpid, 0, 0); } @@ -5425,6 +5426,94 @@ static int kvmhv_store_to_eaddr(struct kvm_vcpu *vcpu, ulong *eaddr, void *ptr, return rc; } +static void unpin_vpa_reset(struct kvm *kvm, struct kvmppc_vpa *vpa) +{ + unpin_vpa(kvm, vpa); + vpa->gpa = 0; + vpa->pinned_addr = NULL; + vpa->dirty = false; + vpa->update_pending = 0; +} + +/* + * IOCTL handler to turn off secure mode of guest + * + * - Release all device pages + * - Issue ucall to terminate the guest on the UV side + * - Unpin the VPA pages. + * - Reinit the partition scoped page tables + */ +static int kvmhv_svm_off(struct kvm *kvm) +{ + struct kvm_vcpu *vcpu; + int mmu_was_ready; + int srcu_idx; + int ret = 0; + int i; + + if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)) + return ret; + + mutex_lock(&kvm->arch.mmu_setup_lock); + mmu_was_ready = kvm->arch.mmu_ready; + if (kvm->arch.mmu_ready) { + kvm->arch.mmu_ready = 0; + /* order mmu_ready vs. vcpus_running */ + smp_mb(); + if (atomic_read(&kvm->arch.vcpus_running)) { + kvm->arch.mmu_ready = 1; + ret = -EBUSY; + goto out; + } + } + + srcu_idx = srcu_read_lock(&kvm->srcu); + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { + struct kvm_memory_slot *memslot; + struct kvm_memslots *slots = __kvm_memslots(kvm, i); + + if (!slots) + continue; + + kvm_for_each_memslot(memslot, slots) { + kvmppc_uvmem_drop_pages(memslot, kvm); + uv_unregister_mem_slot(kvm->arch.lpid, memslot->id); + } + } + srcu_read_unlock(&kvm->srcu, srcu_idx); + + ret = uv_svm_terminate(kvm->arch.lpid); + if (ret != U_SUCCESS) { + ret = -EINVAL; + goto out; + } + + /* + * When secure guest is reset, all the guest pages are sent + * to UV via UV_PAGE_IN before the non-boot vcpus get a + * chance to run and unpin their VPA pages. Unpinning of all + * VPA pages is done here explicitly so that VPA pages + * can be migrated to the secure side. + * + * This is required to for the secure SMP guest to reboot + * correctly. + */ + kvm_for_each_vcpu(i, vcpu, kvm) { + spin_lock(&vcpu->arch.vpa_update_lock); + unpin_vpa_reset(kvm, &vcpu->arch.dtl); + unpin_vpa_reset(kvm, &vcpu->arch.slb_shadow); + unpin_vpa_reset(kvm, &vcpu->arch.vpa); + spin_unlock(&vcpu->arch.vpa_update_lock); + } + + kvmppc_setup_partition_table(kvm); + kvm->arch.secure_guest = 0; + kvm->arch.mmu_ready = mmu_was_ready; +out: + mutex_unlock(&kvm->arch.mmu_setup_lock); + return ret; +} + static struct kvmppc_ops kvm_ops_hv = { .get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv, .set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv, @@ -5468,6 +5557,7 @@ static struct kvmppc_ops kvm_ops_hv = { .enable_nested = kvmhv_enable_nested, .load_from_eaddr = kvmhv_load_from_eaddr, .store_to_eaddr = kvmhv_store_to_eaddr, + .svm_off = kvmhv_svm_off, }; static int kvm_init_subcore_bitmap(void) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 9e085e931d74..416fb3d2a1d0 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -31,6 +31,8 @@ #include #include #endif +#include +#include #include "timing.h" #include "irq.h" @@ -2413,6 +2415,16 @@ long kvm_arch_vm_ioctl(struct file *filp, r = -EFAULT; break; } + case KVM_PPC_SVM_OFF: { + struct kvm *kvm = filp->private_data; + + r = 0; + if (!kvm->arch.kvm_ops->svm_off) + goto out; + + r = kvm->arch.kvm_ops->svm_off(kvm); + break; + } default: { struct kvm *kvm = filp->private_data; r = kvm->arch.kvm_ops->arch_vm_ioctl(filp, ioctl, arg); diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index e6f17c8e2dba..f0a16b4adbbd 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1348,6 +1348,7 @@ struct kvm_s390_ucas_mapping { #define KVM_PPC_GET_CPU_CHAR _IOR(KVMIO, 0xb1, struct kvm_ppc_cpu_char) /* Available with KVM_CAP_PMU_EVENT_FILTER */ #define KVM_SET_PMU_EVENT_FILTER _IOW(KVMIO, 0xb2, struct kvm_pmu_event_filter) +#define KVM_PPC_SVM_OFF _IO(KVMIO, 0xb3) /* ioctl for vm fd */ #define KVM_CREATE_DEVICE _IOWR(KVMIO, 0xe0, struct kvm_create_device) -- 2.45.2