The command is used for creating a memory encryption context.

Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: "Radim Krčmář" <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Tom Lendacky <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Brijesh Singh <[email protected]>
---
 arch/x86/include/asm/kvm_host.h |   2 +
 arch/x86/kvm/svm.c              | 194 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 196 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6bd49e80a16d..7453ef7cb487 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -750,6 +750,8 @@ enum kvm_irqchip_mode {
 struct kvm_sev_info {
        bool active;            /* SEV enabled guest */
        unsigned int asid;      /* ASID used for this guest */
+       unsigned int handle;    /* SEV firmware handle */
+       int fd;                 /* SEV device fd */
 };
 
 struct kvm_arch {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 0149bfa75bb2..5e3e7d46270b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1540,10 +1540,54 @@ static void sev_asid_free(struct kvm *kvm)
        }
 }
 
+static void sev_decommission_handle(struct kvm *kvm)
+{
+       struct kvm_sev_info *sev = &kvm->arch.sev_info;
+       struct sev_data_decommission *data;
+
+       if (!sev->handle)
+               return;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return;
+
+       data->handle = sev->handle;
+       sev_guest_decommission(data, NULL);
+       kfree(data);
+}
+
+static void sev_deactivate_handle(struct kvm *kvm)
+{
+       struct kvm_sev_info *sev = &kvm->arch.sev_info;
+       struct sev_data_deactivate *data;
+
+       if (!sev->handle)
+               return;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return;
+
+       data->handle = sev->handle;
+       sev_guest_deactivate(data, NULL);
+
+       wbinvd_on_all_cpus();
+       sev_guest_df_flush(NULL);
+
+       kfree(data);
+}
+
 static void sev_vm_destroy(struct kvm *kvm)
 {
+       struct kvm_sev_info *sev = &kvm->arch.sev_info;
+
+       sev_deactivate_handle(kvm);
+       sev_decommission_handle(kvm);
        sev_asid_free(kvm);
        sev_firmware_exit();
+
+       memset(sev, 0x00, sizeof(*sev));
 }
 
 static void avic_vm_destroy(struct kvm *kvm)
@@ -5625,6 +5669,152 @@ static int sev_guest_init(struct kvm *kvm, struct 
kvm_sev_cmd *argp)
        return ret;
 }
 
+static int sev_activate_asid(struct kvm *kvm, unsigned int handle, int *error)
+{
+       struct kvm_sev_info *sev = &kvm->arch.sev_info;
+       struct sev_data_activate *data;
+       int asid = sev_get_asid(kvm);
+       int ret;
+
+       wbinvd_on_all_cpus();
+
+       ret = sev_guest_df_flush(error);
+       if (ret)
+               return ret;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->handle = handle;
+       data->asid   = asid;
+       ret = sev_guest_activate(data, error);
+       if (ret)
+               goto e_err;
+
+       sev->asid = asid;
+e_err:
+       kfree(data);
+       return ret;
+}
+
+static int sev_issue_cmd(int fd, int id, void *data, int *error)
+{
+       struct fd f;
+       int ret;
+
+       f = fdget(fd);
+       if (!f.file)
+               return -EBADF;
+
+       ret = sev_issue_cmd_external_user(f.file, id, data, error);
+
+       fdput(f);
+       return ret;
+}
+
+static void *copy_user_blob(u64 __user uaddr, u32 len)
+{
+       void *data;
+
+       if (!uaddr || !len)
+               return ERR_PTR(-EINVAL);
+
+       /* verify that blob length does not exceed our limit */
+       if (len > SEV_FW_BLOB_MAX_SIZE)
+               return ERR_PTR(-EINVAL);
+
+       data = kmalloc(len, GFP_KERNEL);
+       if (IS_ERR(data))
+               return ERR_PTR(-ENOMEM);
+
+       if (copy_from_user(data, (void __user *)(uintptr_t)uaddr, len))
+               goto e_free;
+
+       return data;
+e_free:
+       kfree(data);
+       return ERR_PTR(-EFAULT);
+}
+
+static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+       struct kvm_sev_info *sev = &kvm->arch.sev_info;
+       struct sev_data_launch_start *start;
+       struct kvm_sev_launch_start params;
+       void *dh_blob, *session_blob;
+       int *error = &argp->error;
+       int ret;
+
+       if (!sev_guest(kvm))
+               return -ENOTTY;
+
+       if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data,
+                          sizeof(struct kvm_sev_launch_start)))
+               return -EFAULT;
+
+       start = kzalloc(sizeof(*start), GFP_KERNEL);
+       if (!start)
+               return -ENOMEM;
+
+       dh_blob = NULL;
+       if (params.dh_uaddr) {
+               dh_blob = copy_user_blob(params.dh_uaddr, params.dh_len);
+               if (IS_ERR(dh_blob)) {
+                       ret = PTR_ERR(dh_blob);
+                       goto e_free;
+               }
+
+               start->dh_cert_address = __sme_set(__pa(dh_blob));
+               start->dh_cert_len = params.dh_len;
+       }
+
+       session_blob = NULL;
+       if (params.session_uaddr) {
+               dh_blob = copy_user_blob(params.session_uaddr, 
params.session_len);
+               if (IS_ERR(session_blob)) {
+                       ret = PTR_ERR(session_blob);
+                       goto e_free_dh;
+               }
+
+               start->session_address = __sme_set(__pa(session_blob));
+               start->session_len = params.session_len;
+       }
+
+       start->handle = params.handle;
+       start->policy = params.policy;
+
+       /* create memory encryption context */
+       ret = sev_issue_cmd(argp->sev_fd, SEV_CMD_LAUNCH_START, start, error);
+       if (ret)
+               goto e_free_session;
+
+       sev->handle = start->handle;
+
+       /* Bind ASID to this guest */
+       ret = sev_activate_asid(kvm, start->handle, error);
+       if (ret)
+               goto e_free_session;
+
+       /* return handle to userspace */
+       params.handle = start->handle;
+       if (copy_to_user((void __user *)(uintptr_t)argp->data, &params,
+                        sizeof(struct kvm_sev_launch_start))) {
+               sev_vm_destroy(kvm);
+               ret = -EFAULT;
+               goto e_free_session;
+       }
+
+       sev->fd = argp->sev_fd;
+e_free_session:
+       kfree(session_blob);
+e_free_dh:
+       kfree(dh_blob);
+e_free:
+       kfree(start);
+       return ret;
+}
+
 static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 {
        struct kvm_sev_cmd sev_cmd;
@@ -5640,6 +5830,10 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user 
*argp)
                r = sev_guest_init(kvm, &sev_cmd);
                break;
        }
+       case KVM_SEV_LAUNCH_START: {
+               r = sev_launch_start(kvm, &sev_cmd);
+               break;
+       }
        default:
                break;
        }
-- 
2.9.5

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