From 15fb7de1a7f5af0d5910ca4352b26f887543e26e Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Thu, 15 Apr 2021 15:55:17 +0000 Subject: [PATCH] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command The command is used for copying the incoming buffer into the SEV guest memory space. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Paolo Bonzini Cc: Joerg Roedel Cc: Borislav Petkov Cc: Tom Lendacky Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Steve Rutherford Signed-off-by: Brijesh Singh Signed-off-by: Ashish Kalra Message-Id: Signed-off-by: Paolo Bonzini --- .../virt/kvm/amd-memory-encryption.rst | 24 ++++++ arch/x86/kvm/svm/sev.c | 79 +++++++++++++++++++ include/uapi/linux/kvm.h | 9 +++ 3 files changed, 112 insertions(+) diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst index 86c9b36f4a57..bb94c6e3615f 100644 --- a/Documentation/virt/kvm/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/amd-memory-encryption.rst @@ -394,6 +394,30 @@ On success, the 'handle' field contains a new handle and on error, a negative va For more details, see SEV spec Section 6.12. +16. 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/sev.c b/arch/x86/kvm/svm/sev.c index 3e5064c69124..ff6435527a67 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1475,6 +1475,82 @@ e_free_pdh: 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 boundary */ + offset = params.guest_uaddr & (PAGE_SIZE - 1); + if ((params.guest_len + offset > PAGE_SIZE)) + return -EINVAL; + + hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len); + if (IS_ERR(hdr)) + return PTR_ERR(hdr); + + trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto e_free_hdr; + } + + ret = -ENOMEM; + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + goto e_free_trans; + + data->hdr_address = __psp_pa(hdr); + data->hdr_len = params.hdr_len; + 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; + + /* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */ + data->guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + + offset; + data->guest_address |= sev_me_mask; + data->guest_len = params.guest_len; + 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); +e_free_trans: + kfree(trans); +e_free_hdr: + kfree(hdr); + + return ret; +} + int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -1552,6 +1628,9 @@ 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 248d1d266bc3..d76533498543 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1764,6 +1764,15 @@ 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)