From: Brijesh Singh Date: Thu, 15 Apr 2021 15:53:55 +0000 (+0000) Subject: KVM: SVM: Add KVM_SEND_UPDATE_DATA command X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=d3d1af85e2c7;p=uclinux-h8%2Flinux.git KVM: SVM: Add KVM_SEND_UPDATE_DATA command The command is used for encrypting the guest memory region using the encryption context created with KVM_SEV_SEND_START. 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 --- diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst index db5c3fb2bab5..79da88a14135 100644 --- a/Documentation/virt/kvm/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/amd-memory-encryption.rst @@ -320,6 +320,34 @@ Returns: 0 on success, -negative on error __u32 session_len; }; +12. KVM_SEV_SEND_UPDATE_DATA +---------------------------- + +The KVM_SEV_SEND_UPDATE_DATA command can be used by the hypervisor to encrypt the +outgoing guest memory region with the encryption context creating using +KVM_SEV_SEND_START. + +If hdr_len or trans_len are zero on entry, the length of the packet header and +transport region are written to hdr_len and trans_len respectively, and all +other fields are not used. + +Parameters (in): struct kvm_sev_send_update_data + +Returns: 0 on success, -negative on error + +:: + + struct kvm_sev_launch_send_update_data { + __u64 hdr_uaddr; /* userspace address containing the packet header */ + __u32 hdr_len; + + __u64 guest_uaddr; /* the source memory region to be encrypted */ + __u32 guest_len; + + __u64 trans_uaddr; /* the destination memory region */ + __u32 trans_len; + }; + References ========== diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 9f5312956d5e..a534ec9ae172 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -34,6 +34,7 @@ static DECLARE_RWSEM(sev_deactivate_lock); static DEFINE_MUTEX(sev_bitmap_lock); unsigned int max_sev_asid; static unsigned int min_sev_asid; +static unsigned long sev_me_mask; static unsigned long *sev_asid_bitmap; static unsigned long *sev_reclaim_asid_bitmap; @@ -1236,6 +1237,126 @@ e_free_session: return ret; } +/* Userspace wants to query either header or trans length. */ +static int +__sev_send_update_data_query_lengths(struct kvm *kvm, struct kvm_sev_cmd *argp, + struct kvm_sev_send_update_data *params) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct sev_data_send_update_data *data; + int ret; + + data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT); + if (!data) + return -ENOMEM; + + data->handle = sev->handle; + ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, data, &argp->error); + if (ret < 0) + goto out; + + params->hdr_len = data->hdr_len; + params->trans_len = data->trans_len; + + if (copy_to_user((void __user *)(uintptr_t)argp->data, params, + sizeof(struct kvm_sev_send_update_data))) + ret = -EFAULT; + +out: + kfree(data); + return ret; +} + +static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct sev_data_send_update_data *data; + struct kvm_sev_send_update_data params; + void *hdr, *trans_data; + struct page **guest_page; + unsigned long n; + int ret, offset; + + if (!sev_guest(kvm)) + return -ENOTTY; + + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, + sizeof(struct kvm_sev_send_update_data))) + return -EFAULT; + + /* userspace wants to query either header or trans length */ + if (!params.trans_len || !params.hdr_len) + return __sev_send_update_data_query_lengths(kvm, argp, ¶ms); + + if (!params.trans_uaddr || !params.guest_uaddr || + !params.guest_len || !params.hdr_uaddr) + 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; + + /* Pin guest memory */ + guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK, + PAGE_SIZE, &n, 0); + if (!guest_page) + return -EFAULT; + + /* allocate memory for header and transport buffer */ + ret = -ENOMEM; + hdr = kmalloc(params.hdr_len, GFP_KERNEL_ACCOUNT); + if (!hdr) + goto e_unpin; + + trans_data = kmalloc(params.trans_len, GFP_KERNEL_ACCOUNT); + if (!trans_data) + goto e_free_hdr; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + goto e_free_trans_data; + + data->hdr_address = __psp_pa(hdr); + data->hdr_len = params.hdr_len; + data->trans_address = __psp_pa(trans_data); + data->trans_len = params.trans_len; + + /* The SEND_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_SEND_UPDATE_DATA, data, &argp->error); + + if (ret) + goto e_free; + + /* copy transport buffer to user space */ + if (copy_to_user((void __user *)(uintptr_t)params.trans_uaddr, + trans_data, params.trans_len)) { + ret = -EFAULT; + goto e_free; + } + + /* Copy packet header to userspace. */ + ret = copy_to_user((void __user *)(uintptr_t)params.hdr_uaddr, hdr, + params.hdr_len); + +e_free: + kfree(data); +e_free_trans_data: + kfree(trans_data); +e_free_hdr: + kfree(hdr); +e_unpin: + sev_unpin_memory(kvm, guest_page, n); + + return ret; +} + int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -1301,6 +1422,9 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp) case KVM_SEV_SEND_START: r = sev_send_start(kvm, &sev_cmd); break; + case KVM_SEV_SEND_UPDATE_DATA: + r = sev_send_update_data(kvm, &sev_cmd); + break; default: r = -EINVAL; goto out; @@ -1559,6 +1683,7 @@ void __init sev_hardware_setup(void) /* Minimum ASID value that should be used for SEV guest */ min_sev_asid = edx; + sev_me_mask = 1UL << (ebx & 0x3f); /* Initialize SEV ASID bitmaps */ sev_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL); diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 11b3e528d35d..d07be69f402f 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1744,6 +1744,15 @@ struct kvm_sev_send_start { __u32 session_len; }; +struct kvm_sev_send_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)