Message ID | 20190710201244.25195-6-brijesh.singh@amd.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Add AMD SEV guest live migration support | expand |
On Wed, Jul 10, 2019 at 08:13:06PM +0000, Singh, Brijesh wrote: > The command is used for copying the incoming buffer into the > SEV guest memory space. ... > +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 */ WARNING: 'boundry' may be misspelled - perhaps 'boundary'? > + 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; > + > + /* 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); > + kfree(hdr); > + kfree(trans); Pls add separate labels so that you don't have to init function-local vars above to NULL.
> + > + /* Check if we are crossing the page boundry */ > + offset = params.guest_uaddr & (PAGE_SIZE - 1); > + if ((params.guest_len + offset > PAGE_SIZE)) > + return -EINVAL; Just curious spec only says that "System physical of the guest memory region. Must be 16 B aligned with the C-bit set." and "Length of guest memory region. Must be a multiple of 16 B and no more than 16 kB". Why do we want to avoid crossing a page boundary? Also is there an overflow concern in the conditional because params.guest_len is not checked before this? > + > + 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; > + } > +
diff --git a/Documentation/virtual/kvm/amd-memory-encryption.rst b/Documentation/virtual/kvm/amd-memory-encryption.rst index 59a7903f7c4e..f0ec0cbe2aaf 100644 --- a/Documentation/virtual/kvm/amd-memory-encryption.rst +++ b/Documentation/virtual/kvm/amd-memory-encryption.rst @@ -326,6 +326,30 @@ 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 fae6a870b29a..ea084716f966 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7265,6 +7265,78 @@ 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; + + /* 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); + kfree(hdr); + kfree(trans); + return ret; +} + static int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -7318,6 +7390,9 @@ 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 28d240974ea7..e31cdb41519f 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1561,6 +1561,15 @@ 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)
The command is used for copying the incoming buffer into the SEV guest memory space. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Borislav Petkov <bp@suse.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> --- .../virtual/kvm/amd-memory-encryption.rst | 24 ++++++ arch/x86/kvm/svm.c | 75 +++++++++++++++++++ include/uapi/linux/kvm.h | 9 +++ 3 files changed, 108 insertions(+)