| Message ID | b1b4675537fc592a6a78c0ca1888feba0d515557.1581555616.git.ashish.kalra@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | SEV Live Migration Patchset. | expand |
On Wed, Feb 12, 2020 at 5:15 PM Ashish Kalra <Ashish.Kalra@amd.com> wrote: > > From: Brijesh Singh <brijesh.singh@amd.com> > > The command is used for encrypting the guest memory region using the encryption > context created with KVM_SEV_SEND_START. > > 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> > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> > --- > .../virt/kvm/amd-memory-encryption.rst | 24 ++++ > arch/x86/kvm/svm.c | 136 +++++++++++++++++- > include/uapi/linux/kvm.h | 9 ++ > 3 files changed, 165 insertions(+), 4 deletions(-) > > diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst > index 826911f41f3b..0f1c3860360f 100644 > --- a/Documentation/virt/kvm/amd-memory-encryption.rst > +++ b/Documentation/virt/kvm/amd-memory-encryption.rst > @@ -265,6 +265,30 @@ Returns: 0 on success, -negative on error > __u32 session_len; > }; > > +11. 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. > + > +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 destition memory region */ > + __u32 trans_len; > + }; > + > References > ========== > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 3a7e2cac51de..ae97f774e979 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -426,6 +426,7 @@ static DECLARE_RWSEM(sev_deactivate_lock); > static DEFINE_MUTEX(sev_bitmap_lock); > static 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; > #define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT) > @@ -1231,16 +1232,22 @@ static int avic_ga_log_notifier(u32 ga_tag) > static __init int sev_hardware_setup(void) > { > struct sev_user_data_status *status; > + int eax, ebx; > int rc; > > - /* Maximum number of encrypted guests supported simultaneously */ > - max_sev_asid = cpuid_ecx(0x8000001F); > + /* > + * Query the memory encryption information. > + * EBX: Bit 0:5 Pagetable bit position used to indicate encryption > + * (aka Cbit). > + * ECX: Maximum number of encrypted guests supported simultaneously. > + * EDX: Minimum ASID value that should be used for SEV guest. > + */ > + cpuid(0x8000001f, &eax, &ebx, &max_sev_asid, &min_sev_asid); > > if (!max_sev_asid) > return 1; > > - /* Minimum ASID value that should be used for SEV guest */ > - min_sev_asid = cpuid_edx(0x8000001F); > + sev_me_mask = 1UL << (ebx & 0x3f); > > /* Initialize SEV ASID bitmaps */ > sev_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL); > @@ -7262,6 +7269,124 @@ static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp) > 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); > + > + 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; > + > + 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_unpin; > + } > + > + /* 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; > +} > + > static int svm_mem_enc_op(struct kvm *kvm, void __user *argp) > { > struct kvm_sev_cmd sev_cmd; > @@ -7306,6 +7431,9 @@ static 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; > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 17bef4c245e1..d9dc81bb9c55 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1570,6 +1570,15 @@ 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; > +}; Input from others is welcome here, but I'd put the padding in intentionally (explicitly fill in the reserved u8s between *_len and *_uaddr). I had to double check that this pattern was intentional and matched the SEV spec. > + > #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) > -- > 2.17.1 > High level: this looks good. Same comments on documenting the magic parameters for querying as the prior patch, and also the -EFAULT behavior. Thanks, Steve
On Mon, Mar 09, 2020 at 06:04:56PM -0700, Steve Rutherford wrote: > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > > index 17bef4c245e1..d9dc81bb9c55 100644 > > --- a/include/uapi/linux/kvm.h > > +++ b/include/uapi/linux/kvm.h > > @@ -1570,6 +1570,15 @@ 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; > > +}; > Input from others is welcome here, but I'd put the padding in > intentionally (explicitly fill in the reserved u8s between *_len and > *_uaddr). I had to double check that this pattern was intentional and > matched the SEV spec. struct kvm_sev_send_update_data{} is used to get/send the information from/to userspace, while struct sev_data_send_update_data{} has the paddings and is packed as required by the SEV spec. Thanks, Ashish
diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst index 826911f41f3b..0f1c3860360f 100644 --- a/Documentation/virt/kvm/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/amd-memory-encryption.rst @@ -265,6 +265,30 @@ Returns: 0 on success, -negative on error __u32 session_len; }; +11. 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. + +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 destition memory region */ + __u32 trans_len; + }; + References ========== diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 3a7e2cac51de..ae97f774e979 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -426,6 +426,7 @@ static DECLARE_RWSEM(sev_deactivate_lock); static DEFINE_MUTEX(sev_bitmap_lock); static 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; #define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT) @@ -1231,16 +1232,22 @@ static int avic_ga_log_notifier(u32 ga_tag) static __init int sev_hardware_setup(void) { struct sev_user_data_status *status; + int eax, ebx; int rc; - /* Maximum number of encrypted guests supported simultaneously */ - max_sev_asid = cpuid_ecx(0x8000001F); + /* + * Query the memory encryption information. + * EBX: Bit 0:5 Pagetable bit position used to indicate encryption + * (aka Cbit). + * ECX: Maximum number of encrypted guests supported simultaneously. + * EDX: Minimum ASID value that should be used for SEV guest. + */ + cpuid(0x8000001f, &eax, &ebx, &max_sev_asid, &min_sev_asid); if (!max_sev_asid) return 1; - /* Minimum ASID value that should be used for SEV guest */ - min_sev_asid = cpuid_edx(0x8000001F); + sev_me_mask = 1UL << (ebx & 0x3f); /* Initialize SEV ASID bitmaps */ sev_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL); @@ -7262,6 +7269,124 @@ static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp) 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); + + 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; + + 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_unpin; + } + + /* 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; +} + static int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -7306,6 +7431,9 @@ static 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; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 17bef4c245e1..d9dc81bb9c55 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1570,6 +1570,15 @@ 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)