From 4e68491f8e378163201f1850aed8e6a412315ca4 Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Fri, 29 Mar 2019 11:44:35 -0500 Subject: [PATCH] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command The command is used for encrypting the incoming buffer with memory encryption key created with KVM_SEV_RECEIVE_START command. Signed-off-by: Brijesh Singh --- .../virtual/kvm/amd-memory-encryption.rst | 24 ++++++ arch/x86/kvm/svm.c | 76 +++++++++++++++++++ include/uapi/linux/kvm.h | 9 +++ 3 files changed, 109 insertions(+) diff --git a/Documentation/virtual/kvm/amd-memory-encryption.rst b/Documentation/virtual/kvm/amd-memory-encryption.rst index 69e561bbcc2e..a2af25359318 100644 --- a/Documentation/virtual/kvm/amd-memory-encryption.rst +++ b/Documentation/virtual/kvm/amd-memory-encryption.rst @@ -322,6 +322,30 @@ On success, the 'handle' field contains a new handle and on error, a negative va For more details, see SEV spec Section 6.12. +14. KVM_SEV_RECEIVE_UPDATE_DATA +---------------------------- + +The KVM_SEV_RECEIVE_UPDATE_DATA command can be used by the hypervisor to copy +the incoming buffers into the guest memory region with encryption context +created during the KVM_SEV_RECEIVE_START. + +Parameters (in): struct kvm_sev_receive_update_data + +Returns: 0 on success, -negative on error + +:: + + struct kvm_sev_launch_receive_update_data { + __u64 hdr_uaddr; /* userspace address containing the packet header */ + __u32 hdr_len; + + __u64 guest_uaddr; /* the destination guest memory region */ + __u32 guest_len; + + __u64 trans_uaddr; /* the incoming buffer memory region */ + __u32 trans_len; + }; + References ========== diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 7a3bf89b0b13..f666835246a7 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7235,6 +7235,79 @@ static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp) return ret; } +static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_receive_update_data params; + struct sev_data_receive_update_data *data; + void *hdr = NULL, *trans = NULL; + struct page **guest_page; + unsigned long n; + int ret, offset; + + if (!sev_guest(kvm)) + return -EINVAL; + + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, + sizeof(struct kvm_sev_receive_update_data))) + return -EFAULT; + + if (!params.hdr_uaddr || !params.hdr_len || + !params.guest_uaddr || !params.guest_len || + !params.trans_uaddr || !params.trans_len) + return -EINVAL; + + /* Check if we are crossing the page boundry */ + offset = params.guest_uaddr & (PAGE_SIZE - 1); + if ((params.guest_len + offset > PAGE_SIZE)) + return -EINVAL; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len); + if (IS_ERR(hdr)) { + ret = PTR_ERR(hdr); + goto e_free; + } + + data->hdr_address = __psp_pa(hdr); + data->hdr_len = params.hdr_len; + + trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto e_free; + } + + data->trans_address = __psp_pa(trans); + data->trans_len = params.trans_len; + + /* Pin guest memory */ + ret = -EFAULT; + guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK, + PAGE_SIZE, &n, 0); + if (!guest_page) + goto e_free; + + data->guest_address = __sme_page_pa(guest_page[0]) + offset; + data->guest_len = params.guest_len; + + /* flush the caches to ensure that DRAM has recent contents */ + sev_clflush_pages(guest_page, n); + + data->handle = sev->handle; + ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, data, &argp->error); + + sev_unpin_memory(kvm, guest_page, n); +e_free: + kfree(data); + kfree(hdr); + kfree(trans); + return ret; +} + static int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -7288,6 +7361,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp) case KVM_SEV_RECEIVE_START: r = sev_receive_start(kvm, &sev_cmd); break; + case KVM_SEV_RECEIVE_UPDATE_DATA: + r = sev_receive_update_data(kvm, &sev_cmd); + break; default: r = -EINVAL; goto out; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index fee75bf1fd90..07e058a3ec11 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1550,6 +1550,15 @@ struct kvm_sev_receive_start { __u32 session_len; }; +struct kvm_sev_receive_update_data { + __u64 hdr_uaddr; + __u32 hdr_len; + __u64 guest_uaddr; + __u32 guest_len; + __u64 trans_uaddr; + __u32 trans_len; +}; + #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) #define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1) #define KVM_DEV_ASSIGN_MASK_INTX (1 << 2)