The VMM needs to populate the realm with some data before starting (e.g. a kernel and initrd). This is measured by the RMM and used as part of the attestation later on. Signed-off-by: Steven Price --- Changes since v12: * The ioctl now updates the structure with the amount populated rather than returning this through the ioctl return code. * Use the new RMM v2.0 range based RMI calls. * Adapt to upstream changes in kvm_gmem_populate(). Changes since v11: * The multiplex CAP is gone and there's a new ioctl which makes use of the generic kvm_gmem_populate() functionality. Changes since v7: * Improve the error codes. * Other minor changes from review. Changes since v6: * Handle host potentially having a larger page size than the RMM granule. * Drop historic "par" (protected address range) from populate_par_region() - it doesn't exist within the current architecture. * Add a cond_resched() call in kvm_populate_realm(). Changes since v5: * Refactor to use PFNs rather than tracking struct page in realm_create_protected_data_page(). * Pull changes from a later patch (in the v5 series) for accessing pages from a guest memfd. * Do the populate in chunks to avoid holding locks for too long and triggering RCU stall warnings. --- arch/arm64/include/asm/kvm_rmi.h | 4 ++ arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/arm.c | 13 ++++ arch/arm64/kvm/rmi.c | 111 +++++++++++++++++++++++++++++++ 4 files changed, 129 insertions(+) diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h index 46b0cbe6c202..bf663bb240c4 100644 --- a/arch/arm64/include/asm/kvm_rmi.h +++ b/arch/arm64/include/asm/kvm_rmi.h @@ -96,6 +96,10 @@ int kvm_rec_enter(struct kvm_vcpu *vcpu); int kvm_rec_pre_enter(struct kvm_vcpu *vcpu); int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status); +struct kvm_arm_rmi_populate; + +int kvm_arm_rmi_populate(struct kvm *kvm, + struct kvm_arm_rmi_populate *arg); void kvm_realm_unmap_range(struct kvm *kvm, unsigned long ipa, unsigned long size, diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 1cac6dfc0972..b495dfd3a8b4 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -39,6 +39,7 @@ menuconfig KVM select GUEST_PERF_EVENTS if PERF_EVENTS select KVM_GUEST_MEMFD select KVM_GENERIC_MEMORY_ATTRIBUTES + select HAVE_KVM_ARCH_GMEM_POPULATE help Support hosting virtualized guest machines. diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index badb94b398bc..43d05da7e694 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2089,6 +2089,19 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) return -EFAULT; return kvm_vm_ioctl_get_reg_writable_masks(kvm, &range); } + case KVM_ARM_RMI_POPULATE: { + struct kvm_arm_rmi_populate req; + int ret; + + if (!kvm_is_realm(kvm)) + return -ENXIO; + if (copy_from_user(&req, argp, sizeof(req))) + return -EFAULT; + ret = kvm_arm_rmi_populate(kvm, &req); + if (copy_to_user(argp, &req, sizeof(req))) + return -EFAULT; + return ret; + } default: return -EINVAL; } diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index 13eed6f0b9eb..b48f4e12e4e0 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -718,6 +718,80 @@ void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start, realm_unmap_private_range(kvm, start, end, may_block); } +static int realm_create_protected_data_page(struct kvm *kvm, + unsigned long ipa, + kvm_pfn_t dst_pfn, + kvm_pfn_t src_pfn, + unsigned long flags) +{ + struct realm *realm = &kvm->arch.realm; + phys_addr_t rd = virt_to_phys(realm->rd); + phys_addr_t dst_phys, src_phys; + int ret; + + dst_phys = __pfn_to_phys(dst_pfn); + src_phys = __pfn_to_phys(src_pfn); + + if (delegate_page(dst_phys)) + return -ENXIO; + + ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys, flags); + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) { + /* Create missing RTTs and retry */ + int level = RMI_RETURN_INDEX(ret); + + KVM_BUG_ON(level == RMM_RTT_MAX_LEVEL, kvm); + + ret = realm_create_rtt_levels(realm, ipa, level, + RMM_RTT_MAX_LEVEL, NULL); + if (!ret) { + ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys, + flags); + } + } + + if (ret) { + if (WARN_ON(undelegate_page(dst_phys))) { + /* Undelegate failed, so we leak the page */ + get_page(pfn_to_page(dst_pfn)); + } + } + + return ret; +} + +static int populate_region_cb(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, + struct page *src_page, void *opaque) +{ + unsigned long data_flags = *(unsigned long *)opaque; + phys_addr_t ipa = gfn_to_gpa(gfn); + + if (!src_page) + return -EOPNOTSUPP; + + return realm_create_protected_data_page(kvm, ipa, pfn, + page_to_pfn(src_page), + data_flags); +} + +static long populate_region(struct kvm *kvm, + gfn_t base_gfn, + unsigned long pages, + u64 uaddr, + unsigned long data_flags) +{ + long ret = 0; + + mutex_lock(&kvm->slots_lock); + mmap_read_lock(current->mm); + ret = kvm_gmem_populate(kvm, base_gfn, u64_to_user_ptr(uaddr), pages, + populate_region_cb, &data_flags); + mmap_read_unlock(current->mm); + mutex_unlock(&kvm->slots_lock); + + return ret; +} + enum ripas_action { RIPAS_INIT, RIPAS_SET, @@ -815,6 +889,43 @@ static int realm_ensure_created(struct kvm *kvm) return -ENXIO; } +int kvm_arm_rmi_populate(struct kvm *kvm, + struct kvm_arm_rmi_populate *args) +{ + unsigned long data_flags = 0; + unsigned long ipa_start = args->base; + unsigned long ipa_end = ipa_start + args->size; + long pages_populated; + int ret; + + if (args->reserved || + (args->flags & ~KVM_ARM_RMI_POPULATE_FLAGS_MEASURE) || + !IS_ALIGNED(ipa_start, PAGE_SIZE) || + !IS_ALIGNED(ipa_end, PAGE_SIZE) || + !IS_ALIGNED(args->source_uaddr, PAGE_SIZE)) + return -EINVAL; + + ret = realm_ensure_created(kvm); + if (ret) + return ret; + + if (args->flags & KVM_ARM_RMI_POPULATE_FLAGS_MEASURE) + data_flags |= RMI_MEASURE_CONTENT; + + pages_populated = populate_region(kvm, gpa_to_gfn(ipa_start), + args->size >> PAGE_SHIFT, + args->source_uaddr, data_flags); + + if (pages_populated < 0) + return pages_populated; + + args->size -= pages_populated << PAGE_SHIFT; + args->source_uaddr += pages_populated << PAGE_SHIFT; + args->base += pages_populated << PAGE_SHIFT; + + return 0; +} + static void kvm_complete_ripas_change(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; -- 2.43.0