| Message ID | 20221214194056.161492-41-michael.roth@amd.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support | expand |
On 12/14/22 13:40, Michael Roth wrote: > From: Brijesh Singh <brijesh.singh@amd.com> > > The KVM_SEV_SNP_LAUNCH_FINISH finalize the cryptographic digest and stores > it as the measurement of the guest at launch. > > While finalizing the launch flow, it also issues the LAUNCH_UPDATE command > to encrypt the VMSA pages. > > If its an SNP guest, then VMSA was added in the RMP entry as > a guest owned page and also removed from the kernel direct map > so flush it later after it is transitioned back to hypervisor > state and restored in the direct map. > > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > Signed-off-by: Harald Hoyer <harald@profian.com> > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> > Signed-off-by: Michael Roth <michael.roth@amd.com> > --- > .../virt/kvm/x86/amd-memory-encryption.rst | 22 ++++ > arch/x86/kvm/svm/sev.c | 119 ++++++++++++++++++ > include/uapi/linux/kvm.h | 14 +++ > 3 files changed, 155 insertions(+) > > diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst b/Documentation/virt/kvm/x86/amd-memory-encryption.rst > index c94be8e6d657..e4b42aaab1de 100644 > --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst > +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst > @@ -513,6 +513,28 @@ Returns: 0 on success, -negative on error > See the SEV-SNP spec for further details on how to build the VMPL permission > mask and page type. > > +21. KVM_SNP_LAUNCH_FINISH > +------------------------- > + > +After completion of the SNP guest launch flow, the KVM_SNP_LAUNCH_FINISH command can be > +issued to make the guest ready for the execution. > + > +Parameters (in): struct kvm_sev_snp_launch_finish > + > +Returns: 0 on success, -negative on error > + > +:: > + > + struct kvm_sev_snp_launch_finish { > + __u64 id_block_uaddr; > + __u64 id_auth_uaddr; > + __u8 id_block_en; > + __u8 auth_key_en; > + __u8 host_data[32]; This is missing the 6 bytes of padding at the end of the struct. > + }; > + > + > +See SEV-SNP specification for further details on launch finish input parameters. > > References > ========== > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index 379e61a9226a..6f901545bed9 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -2243,6 +2243,106 @@ static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp) > snp_launch_update_gfn_handler, argp); > } > > +static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) > +{ > + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; > + struct sev_data_snp_launch_update data = {}; > + int i, ret; > + > + data.gctx_paddr = __psp_pa(sev->snp_context); > + data.page_type = SNP_PAGE_TYPE_VMSA; > + > + for (i = 0; i < kvm->created_vcpus; i++) { > + struct vcpu_svm *svm = to_svm(xa_load(&kvm->vcpu_array, i)); > + u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT; > + > + /* Perform some pre-encryption checks against the VMSA */ > + ret = sev_es_sync_vmsa(svm); > + if (ret) > + return ret; > + > + /* Transition the VMSA page to a firmware state. */ > + ret = rmp_make_private(pfn, -1, PG_LEVEL_4K, sev->asid, true); > + if (ret) > + return ret; > + > + /* Issue the SNP command to encrypt the VMSA */ > + data.address = __sme_pa(svm->sev_es.vmsa); > + ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_UPDATE, > + &data, &argp->error); > + if (ret) { > + snp_page_reclaim(pfn); > + return ret; > + } > + > + svm->vcpu.arch.guest_state_protected = true; > + } > + > + return 0; > +} > + > +static int snp_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) > +{ > + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; > + struct kvm_sev_snp_launch_finish params; > + struct sev_data_snp_launch_finish *data; > + void *id_block = NULL, *id_auth = NULL; > + int ret; > + > + if (!sev_snp_guest(kvm)) > + return -ENOTTY; > + > + if (!sev->snp_context) > + return -EINVAL; > + > + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, sizeof(params))) > + return -EFAULT; > + > + /* Measure all vCPUs using LAUNCH_UPDATE before finalizing the launch flow. */ > + ret = snp_launch_update_vmsa(kvm, argp); > + if (ret) > + return ret; > + > + data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT); > + if (!data) > + return -ENOMEM; > + > + if (params.id_block_en) { > + id_block = psp_copy_user_blob(params.id_block_uaddr, KVM_SEV_SNP_ID_BLOCK_SIZE); > + if (IS_ERR(id_block)) { > + ret = PTR_ERR(id_block); > + goto e_free; > + } > + > + data->id_block_en = 1; > + data->id_block_paddr = __sme_pa(id_block); > + > + id_auth = psp_copy_user_blob(params.id_auth_uaddr, KVM_SEV_SNP_ID_AUTH_SIZE); > + if (IS_ERR(id_auth)) { > + ret = PTR_ERR(id_auth); > + goto e_free_id_block; > + } > + > + data->id_auth_paddr = __sme_pa(id_auth); > + > + if (params.auth_key_en) > + data->auth_key_en = 1; > + } > + > + data->gctx_paddr = __psp_pa(sev->snp_context); This is missing the copying of the params.host_data field into the data->host_data field. This is needed so that the host_data shows up in the attestation report. Thanks, Tom > + ret = sev_issue_cmd(kvm, SEV_CMD_SNP_LAUNCH_FINISH, data, &argp->error); > + > + kfree(id_auth); > + > +e_free_id_block: > + kfree(id_block); > + > +e_free: > + kfree(data); > + > + return ret; > +} > + > int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp) > { > struct kvm_sev_cmd sev_cmd; > @@ -2339,6 +2439,9 @@ int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp) > case KVM_SEV_SNP_LAUNCH_UPDATE: > r = snp_launch_update(kvm, &sev_cmd); > break; > + case KVM_SEV_SNP_LAUNCH_FINISH: > + r = snp_launch_finish(kvm, &sev_cmd); > + break; > default: > r = -EINVAL; > goto out; > @@ -2794,11 +2897,27 @@ void sev_free_vcpu(struct kvm_vcpu *vcpu) > > svm = to_svm(vcpu); > > + /* > + * If its an SNP guest, then VMSA was added in the RMP entry as > + * a guest owned page. Transition the page to hypervisor state > + * before releasing it back to the system. > + * Also the page is removed from the kernel direct map, so flush it > + * later after it is transitioned back to hypervisor state and > + * restored in the direct map. > + */ > + if (sev_snp_guest(vcpu->kvm)) { > + u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT; > + > + if (host_rmp_make_shared(pfn, PG_LEVEL_4K, true)) > + goto skip_vmsa_free; > + } > + > if (vcpu->arch.guest_state_protected) > sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa); > > __free_page(virt_to_page(svm->sev_es.vmsa)); > > +skip_vmsa_free: > if (svm->sev_es.ghcb_sa_free) > kvfree(svm->sev_es.ghcb_sa); > } > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 9b6c95cc62a8..c468adc1f147 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1942,6 +1942,7 @@ enum sev_cmd_id { > KVM_SEV_SNP_INIT, > KVM_SEV_SNP_LAUNCH_START, > KVM_SEV_SNP_LAUNCH_UPDATE, > + KVM_SEV_SNP_LAUNCH_FINISH, > > KVM_SEV_NR_MAX, > }; > @@ -2076,6 +2077,19 @@ struct kvm_sev_snp_launch_update { > __u8 vmpl1_perms; > }; > > +#define KVM_SEV_SNP_ID_BLOCK_SIZE 96 > +#define KVM_SEV_SNP_ID_AUTH_SIZE 4096 > +#define KVM_SEV_SNP_FINISH_DATA_SIZE 32 > + > +struct kvm_sev_snp_launch_finish { > + __u64 id_block_uaddr; > + __u64 id_auth_uaddr; > + __u8 id_block_en; > + __u8 auth_key_en; > + __u8 host_data[KVM_SEV_SNP_FINISH_DATA_SIZE]; > + __u8 pad[6]; > +}; > + > #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)
Hello Tom, On 12/19/2022 12:04 PM, Tom Lendacky wrote: > On 12/14/22 13:40, Michael Roth wrote: >> From: Brijesh Singh <brijesh.singh@amd.com> >> >> The KVM_SEV_SNP_LAUNCH_FINISH finalize the cryptographic digest and >> stores >> it as the measurement of the guest at launch. >> >> While finalizing the launch flow, it also issues the LAUNCH_UPDATE >> command >> to encrypt the VMSA pages. >> >> If its an SNP guest, then VMSA was added in the RMP entry as >> a guest owned page and also removed from the kernel direct map >> so flush it later after it is transitioned back to hypervisor >> state and restored in the direct map. >> >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >> Signed-off-by: Harald Hoyer <harald@profian.com> >> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> >> Signed-off-by: Michael Roth <michael.roth@amd.com> >> --- >> .../virt/kvm/x86/amd-memory-encryption.rst | 22 ++++ >> arch/x86/kvm/svm/sev.c | 119 ++++++++++++++++++ >> include/uapi/linux/kvm.h | 14 +++ >> 3 files changed, 155 insertions(+) >> >> diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst >> b/Documentation/virt/kvm/x86/amd-memory-encryption.rst >> index c94be8e6d657..e4b42aaab1de 100644 >> --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst >> +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst >> @@ -513,6 +513,28 @@ Returns: 0 on success, -negative on error >> See the SEV-SNP spec for further details on how to build the VMPL >> permission >> mask and page type. >> +21. KVM_SNP_LAUNCH_FINISH >> +------------------------- >> + >> +After completion of the SNP guest launch flow, the >> KVM_SNP_LAUNCH_FINISH command can be >> +issued to make the guest ready for the execution. >> + >> +Parameters (in): struct kvm_sev_snp_launch_finish >> + >> +Returns: 0 on success, -negative on error >> + >> +:: >> + >> + struct kvm_sev_snp_launch_finish { >> + __u64 id_block_uaddr; >> + __u64 id_auth_uaddr; >> + __u8 id_block_en; >> + __u8 auth_key_en; >> + __u8 host_data[32]; > > This is missing the 6 bytes of padding at the end of the struct. > Yes will fix this, the documentation is missing that, the structure defination in include/uapi/linux/kvm.h includes it. But why do we need this padding ? >> + }; >> + >> + >> +See SEV-SNP specification for further details on launch finish input >> parameters. >> References >> ========== >> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c >> index 379e61a9226a..6f901545bed9 100644 >> --- a/arch/x86/kvm/svm/sev.c >> +++ b/arch/x86/kvm/svm/sev.c >> @@ -2243,6 +2243,106 @@ static int snp_launch_update(struct kvm *kvm, >> struct kvm_sev_cmd *argp) >> snp_launch_update_gfn_handler, argp); >> } >> +static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd >> *argp) >> +{ >> + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; >> + struct sev_data_snp_launch_update data = {}; >> + int i, ret; >> + >> + data.gctx_paddr = __psp_pa(sev->snp_context); >> + data.page_type = SNP_PAGE_TYPE_VMSA; >> + >> + for (i = 0; i < kvm->created_vcpus; i++) { >> + struct vcpu_svm *svm = to_svm(xa_load(&kvm->vcpu_array, i)); >> + u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT; >> + >> + /* Perform some pre-encryption checks against the VMSA */ >> + ret = sev_es_sync_vmsa(svm); >> + if (ret) >> + return ret; >> + >> + /* Transition the VMSA page to a firmware state. */ >> + ret = rmp_make_private(pfn, -1, PG_LEVEL_4K, sev->asid, true); >> + if (ret) >> + return ret; >> + >> + /* Issue the SNP command to encrypt the VMSA */ >> + data.address = __sme_pa(svm->sev_es.vmsa); >> + ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_UPDATE, >> + &data, &argp->error); >> + if (ret) { >> + snp_page_reclaim(pfn); >> + return ret; >> + } >> + >> + svm->vcpu.arch.guest_state_protected = true; >> + } >> + >> + return 0; >> +} >> + >> +static int snp_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) >> +{ >> + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; >> + struct kvm_sev_snp_launch_finish params; >> + struct sev_data_snp_launch_finish *data; >> + void *id_block = NULL, *id_auth = NULL; >> + int ret; >> + >> + if (!sev_snp_guest(kvm)) >> + return -ENOTTY; >> + >> + if (!sev->snp_context) >> + return -EINVAL; >> + >> + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, >> sizeof(params))) >> + return -EFAULT; >> + >> + /* Measure all vCPUs using LAUNCH_UPDATE before finalizing the >> launch flow. */ >> + ret = snp_launch_update_vmsa(kvm, argp); >> + if (ret) >> + return ret; >> + >> + data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT); >> + if (!data) >> + return -ENOMEM; >> + >> + if (params.id_block_en) { >> + id_block = psp_copy_user_blob(params.id_block_uaddr, >> KVM_SEV_SNP_ID_BLOCK_SIZE); >> + if (IS_ERR(id_block)) { >> + ret = PTR_ERR(id_block); >> + goto e_free; >> + } >> + >> + data->id_block_en = 1; >> + data->id_block_paddr = __sme_pa(id_block); >> + >> + id_auth = psp_copy_user_blob(params.id_auth_uaddr, >> KVM_SEV_SNP_ID_AUTH_SIZE); >> + if (IS_ERR(id_auth)) { >> + ret = PTR_ERR(id_auth); >> + goto e_free_id_block; >> + } >> + >> + data->id_auth_paddr = __sme_pa(id_auth); >> + >> + if (params.auth_key_en) >> + data->auth_key_en = 1; >> + } >> + >> + data->gctx_paddr = __psp_pa(sev->snp_context); > > This is missing the copying of the params.host_data field into the > data->host_data field. This is needed so that the host_data shows up in > the attestation report. > Yes will fix this. Thanks, Ashish > Thanks, > Tom > >> + ret = sev_issue_cmd(kvm, SEV_CMD_SNP_LAUNCH_FINISH, data, >> &argp->error); >> + >> + kfree(id_auth); >> + >> +e_free_id_block: >> + kfree(id_block); >> + >> +e_free: >> + kfree(data); >> + >> + return ret; >> +} >> + >> int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp) >> { >> struct kvm_sev_cmd sev_cmd; >> @@ -2339,6 +2439,9 @@ int sev_mem_enc_ioctl(struct kvm *kvm, void >> __user *argp) >> case KVM_SEV_SNP_LAUNCH_UPDATE: >> r = snp_launch_update(kvm, &sev_cmd); >> break; >> + case KVM_SEV_SNP_LAUNCH_FINISH: >> + r = snp_launch_finish(kvm, &sev_cmd); >> + break; >> default: >> r = -EINVAL; >> goto out; >> @@ -2794,11 +2897,27 @@ void sev_free_vcpu(struct kvm_vcpu *vcpu) >> svm = to_svm(vcpu); >> + /* >> + * If its an SNP guest, then VMSA was added in the RMP entry as >> + * a guest owned page. Transition the page to hypervisor state >> + * before releasing it back to the system. >> + * Also the page is removed from the kernel direct map, so flush it >> + * later after it is transitioned back to hypervisor state and >> + * restored in the direct map. >> + */ >> + if (sev_snp_guest(vcpu->kvm)) { >> + u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT; >> + >> + if (host_rmp_make_shared(pfn, PG_LEVEL_4K, true)) >> + goto skip_vmsa_free; >> + } >> + >> if (vcpu->arch.guest_state_protected) >> sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa); >> __free_page(virt_to_page(svm->sev_es.vmsa)); >> +skip_vmsa_free: >> if (svm->sev_es.ghcb_sa_free) >> kvfree(svm->sev_es.ghcb_sa); >> } >> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h >> index 9b6c95cc62a8..c468adc1f147 100644 >> --- a/include/uapi/linux/kvm.h >> +++ b/include/uapi/linux/kvm.h >> @@ -1942,6 +1942,7 @@ enum sev_cmd_id { >> KVM_SEV_SNP_INIT, >> KVM_SEV_SNP_LAUNCH_START, >> KVM_SEV_SNP_LAUNCH_UPDATE, >> + KVM_SEV_SNP_LAUNCH_FINISH, >> KVM_SEV_NR_MAX, >> }; >> @@ -2076,6 +2077,19 @@ struct kvm_sev_snp_launch_update { >> __u8 vmpl1_perms; >> }; >> +#define KVM_SEV_SNP_ID_BLOCK_SIZE 96 >> +#define KVM_SEV_SNP_ID_AUTH_SIZE 4096 >> +#define KVM_SEV_SNP_FINISH_DATA_SIZE 32 >> + >> +struct kvm_sev_snp_launch_finish { >> + __u64 id_block_uaddr; >> + __u64 id_auth_uaddr; >> + __u8 id_block_en; >> + __u8 auth_key_en; >> + __u8 host_data[KVM_SEV_SNP_FINISH_DATA_SIZE]; >> + __u8 pad[6]; >> +}; >> + >> #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)
On 12/19/22 17:24, Kalra, Ashish wrote: > Hello Tom, > > On 12/19/2022 12:04 PM, Tom Lendacky wrote: >> On 12/14/22 13:40, Michael Roth wrote: >>> From: Brijesh Singh <brijesh.singh@amd.com> >>> >>> The KVM_SEV_SNP_LAUNCH_FINISH finalize the cryptographic digest and stores >>> it as the measurement of the guest at launch. >>> >>> While finalizing the launch flow, it also issues the LAUNCH_UPDATE command >>> to encrypt the VMSA pages. >>> >>> If its an SNP guest, then VMSA was added in the RMP entry as >>> a guest owned page and also removed from the kernel direct map >>> so flush it later after it is transitioned back to hypervisor >>> state and restored in the direct map. >>> >>> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >>> Signed-off-by: Harald Hoyer <harald@profian.com> >>> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> >>> Signed-off-by: Michael Roth <michael.roth@amd.com> >>> --- >>> .../virt/kvm/x86/amd-memory-encryption.rst | 22 ++++ >>> arch/x86/kvm/svm/sev.c | 119 ++++++++++++++++++ >>> include/uapi/linux/kvm.h | 14 +++ >>> 3 files changed, 155 insertions(+) >>> >>> diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst >>> b/Documentation/virt/kvm/x86/amd-memory-encryption.rst >>> index c94be8e6d657..e4b42aaab1de 100644 >>> --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst >>> +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst >>> @@ -513,6 +513,28 @@ Returns: 0 on success, -negative on error >>> See the SEV-SNP spec for further details on how to build the VMPL >>> permission >>> mask and page type. >>> +21. KVM_SNP_LAUNCH_FINISH >>> +------------------------- >>> + >>> +After completion of the SNP guest launch flow, the >>> KVM_SNP_LAUNCH_FINISH command can be >>> +issued to make the guest ready for the execution. >>> + >>> +Parameters (in): struct kvm_sev_snp_launch_finish >>> + >>> +Returns: 0 on success, -negative on error >>> + >>> +:: >>> + >>> + struct kvm_sev_snp_launch_finish { >>> + __u64 id_block_uaddr; >>> + __u64 id_auth_uaddr; >>> + __u8 id_block_en; >>> + __u8 auth_key_en; >>> + __u8 host_data[32]; >> >> This is missing the 6 bytes of padding at the end of the struct. >> > > Yes will fix this, the documentation is missing that, the structure > defination in include/uapi/linux/kvm.h includes it. > > But why do we need this padding ? > I'm assuming it was added so that any new elements added would be aligned on an 8 byte boundary (should the next element added be a __u64). I don't think that it is truly needed right now, though. Thanks, Tom
On 14.12.2022 21:40, Michael Roth wrote: > +static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) > +{ > + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; > + struct sev_data_snp_launch_update data = {}; > + int i, ret; > + > + data.gctx_paddr = __psp_pa(sev->snp_context); > + data.page_type = SNP_PAGE_TYPE_VMSA; > + > + for (i = 0; i < kvm->created_vcpus; i++) { Should be replaced with kvm_for_each_vcpu() as it was done for sev_launch_update_vmsa() in c36b16d29f3a ("KVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs"). Prevents accessing uninitialized data in struct vcpu_svm. -- Sabin. Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
On 1/11/2023 7:27 AM, Sabin Rapan wrote: > > > On 14.12.2022 21:40, Michael Roth wrote: >> +static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) >> +{ >> + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; >> + struct sev_data_snp_launch_update data = {}; >> + int i, ret; >> + >> + data.gctx_paddr = __psp_pa(sev->snp_context); >> + data.page_type = SNP_PAGE_TYPE_VMSA; >> + >> + for (i = 0; i < kvm->created_vcpus; i++) { > > Should be replaced with kvm_for_each_vcpu() as it was done for > sev_launch_update_vmsa() in c36b16d29f3a ("KVM: SVM: Use online_vcpus, > not created_vcpus, to iterate over vCPUs"). > Prevents accessing uninitialized data in struct vcpu_svm. Yes, fixed this one. Thanks, Ashish
diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst b/Documentation/virt/kvm/x86/amd-memory-encryption.rst index c94be8e6d657..e4b42aaab1de 100644 --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst @@ -513,6 +513,28 @@ Returns: 0 on success, -negative on error See the SEV-SNP spec for further details on how to build the VMPL permission mask and page type. +21. KVM_SNP_LAUNCH_FINISH +------------------------- + +After completion of the SNP guest launch flow, the KVM_SNP_LAUNCH_FINISH command can be +issued to make the guest ready for the execution. + +Parameters (in): struct kvm_sev_snp_launch_finish + +Returns: 0 on success, -negative on error + +:: + + struct kvm_sev_snp_launch_finish { + __u64 id_block_uaddr; + __u64 id_auth_uaddr; + __u8 id_block_en; + __u8 auth_key_en; + __u8 host_data[32]; + }; + + +See SEV-SNP specification for further details on launch finish input parameters. References ========== diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 379e61a9226a..6f901545bed9 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2243,6 +2243,106 @@ static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp) snp_launch_update_gfn_handler, argp); } +static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct sev_data_snp_launch_update data = {}; + int i, ret; + + data.gctx_paddr = __psp_pa(sev->snp_context); + data.page_type = SNP_PAGE_TYPE_VMSA; + + for (i = 0; i < kvm->created_vcpus; i++) { + struct vcpu_svm *svm = to_svm(xa_load(&kvm->vcpu_array, i)); + u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT; + + /* Perform some pre-encryption checks against the VMSA */ + ret = sev_es_sync_vmsa(svm); + if (ret) + return ret; + + /* Transition the VMSA page to a firmware state. */ + ret = rmp_make_private(pfn, -1, PG_LEVEL_4K, sev->asid, true); + if (ret) + return ret; + + /* Issue the SNP command to encrypt the VMSA */ + data.address = __sme_pa(svm->sev_es.vmsa); + ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_UPDATE, + &data, &argp->error); + if (ret) { + snp_page_reclaim(pfn); + return ret; + } + + svm->vcpu.arch.guest_state_protected = true; + } + + return 0; +} + +static int snp_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct kvm_sev_snp_launch_finish params; + struct sev_data_snp_launch_finish *data; + void *id_block = NULL, *id_auth = NULL; + int ret; + + if (!sev_snp_guest(kvm)) + return -ENOTTY; + + if (!sev->snp_context) + return -EINVAL; + + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, sizeof(params))) + return -EFAULT; + + /* Measure all vCPUs using LAUNCH_UPDATE before finalizing the launch flow. */ + ret = snp_launch_update_vmsa(kvm, argp); + if (ret) + return ret; + + data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT); + if (!data) + return -ENOMEM; + + if (params.id_block_en) { + id_block = psp_copy_user_blob(params.id_block_uaddr, KVM_SEV_SNP_ID_BLOCK_SIZE); + if (IS_ERR(id_block)) { + ret = PTR_ERR(id_block); + goto e_free; + } + + data->id_block_en = 1; + data->id_block_paddr = __sme_pa(id_block); + + id_auth = psp_copy_user_blob(params.id_auth_uaddr, KVM_SEV_SNP_ID_AUTH_SIZE); + if (IS_ERR(id_auth)) { + ret = PTR_ERR(id_auth); + goto e_free_id_block; + } + + data->id_auth_paddr = __sme_pa(id_auth); + + if (params.auth_key_en) + data->auth_key_en = 1; + } + + data->gctx_paddr = __psp_pa(sev->snp_context); + ret = sev_issue_cmd(kvm, SEV_CMD_SNP_LAUNCH_FINISH, data, &argp->error); + + kfree(id_auth); + +e_free_id_block: + kfree(id_block); + +e_free: + kfree(data); + + return ret; +} + int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -2339,6 +2439,9 @@ int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp) case KVM_SEV_SNP_LAUNCH_UPDATE: r = snp_launch_update(kvm, &sev_cmd); break; + case KVM_SEV_SNP_LAUNCH_FINISH: + r = snp_launch_finish(kvm, &sev_cmd); + break; default: r = -EINVAL; goto out; @@ -2794,11 +2897,27 @@ void sev_free_vcpu(struct kvm_vcpu *vcpu) svm = to_svm(vcpu); + /* + * If its an SNP guest, then VMSA was added in the RMP entry as + * a guest owned page. Transition the page to hypervisor state + * before releasing it back to the system. + * Also the page is removed from the kernel direct map, so flush it + * later after it is transitioned back to hypervisor state and + * restored in the direct map. + */ + if (sev_snp_guest(vcpu->kvm)) { + u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT; + + if (host_rmp_make_shared(pfn, PG_LEVEL_4K, true)) + goto skip_vmsa_free; + } + if (vcpu->arch.guest_state_protected) sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa); __free_page(virt_to_page(svm->sev_es.vmsa)); +skip_vmsa_free: if (svm->sev_es.ghcb_sa_free) kvfree(svm->sev_es.ghcb_sa); } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 9b6c95cc62a8..c468adc1f147 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1942,6 +1942,7 @@ enum sev_cmd_id { KVM_SEV_SNP_INIT, KVM_SEV_SNP_LAUNCH_START, KVM_SEV_SNP_LAUNCH_UPDATE, + KVM_SEV_SNP_LAUNCH_FINISH, KVM_SEV_NR_MAX, }; @@ -2076,6 +2077,19 @@ struct kvm_sev_snp_launch_update { __u8 vmpl1_perms; }; +#define KVM_SEV_SNP_ID_BLOCK_SIZE 96 +#define KVM_SEV_SNP_ID_AUTH_SIZE 4096 +#define KVM_SEV_SNP_FINISH_DATA_SIZE 32 + +struct kvm_sev_snp_launch_finish { + __u64 id_block_uaddr; + __u64 id_auth_uaddr; + __u8 id_block_en; + __u8 auth_key_en; + __u8 host_data[KVM_SEV_SNP_FINISH_DATA_SIZE]; + __u8 pad[6]; +}; + #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)