[Part2 PATCH v9 34/38] KVM: SVM: Add support for SEV LAUNCH_SECRET command

[Brijesh Singh]

The command is used for injecting a secret into the guest memory region.

Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: "Radim Krčmář" <rkrc...@redhat.com>
Cc: Joerg Roedel <j...@8bytes.org>
Cc: Borislav Petkov <b...@suse.de>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: x...@kernel.org
Cc: k...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
Reviewed-by: Borislav Petkov <b...@suse.de>
---
 arch/x86/kvm/svm.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 11d4860997d9..8a499425bf7e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6397,6 +6397,71 @@ static int sev_dbg_crypt(struct kvm *kvm, struct 
kvm_sev_cmd *argp, bool dec)
        return ret;
 }
 
+static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+       struct kvm_sev_info *sev = &kvm->arch.sev_info;
+       struct sev_data_launch_secret *data;
+       struct kvm_sev_launch_secret params;
+       struct page **pages;
+       void *blob, *hdr;
+       unsigned long n;
+       int ret;
+
+       if (!sev_guest(kvm))
+               return -ENOTTY;
+
+       if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, 
sizeof(params)))
+               return -EFAULT;
+
+       pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 
1);
+       if (!pages)
+               return -ENOMEM;
+
+       /*
+        * The secret must be copied into contiguous memory region, lets verify
+        * that userspace memory pages are contiguous before we issue command.
+        */
+       if (get_num_contig_pages(0, pages, n) != n) {
+               ret = -EINVAL;
+               goto e_unpin_memory;
+       }
+
+       ret = -ENOMEM;
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               goto e_unpin_memory;
+
+       blob = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
+       if (IS_ERR(blob)) {
+               ret = PTR_ERR(blob);
+               goto e_free;
+       }
+
+       data->trans_address = __psp_pa(blob);
+       data->trans_len = params.trans_len;
+
+       hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
+       if (IS_ERR(hdr)) {
+               ret = PTR_ERR(hdr);
+               goto e_free_blob;
+       }
+       data->trans_address = __psp_pa(blob);
+       data->trans_len = params.trans_len;
+
+       data->handle = sev->handle;
+       ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_SECRET, data, 
&argp->error);
+
+       kfree(hdr);
+
+e_free_blob:
+       kfree(blob);
+e_free:
+       kfree(data);
+e_unpin_memory:
+       sev_unpin_memory(kvm, pages, n);
+       return ret;
+}
+
 static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 {
        struct kvm_sev_cmd sev_cmd;
@@ -6435,6 +6500,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user 
*argp)
        case KVM_SEV_DBG_ENCRYPT:
                r = sev_dbg_crypt(kvm, &sev_cmd, false);
                break;
+       case KVM_SEV_LAUNCH_SECRET:
+               r = sev_launch_secret(kvm, &sev_cmd);
+               break;
        default:
                r = -EINVAL;
                goto out;
-- 
2.9.5