[Part2 PATCH v4 23/29] KVM: SVM: Add support for SEV LAUNCH_SECRET command

From: Brijesh Singh
Date: Tue Sep 19 2017 - 16:50:07 EST


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

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim KrÄmÃÅ" <rkrcmar@xxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
arch/x86/kvm/svm.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 79 insertions(+)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 16b338d9dc87..dadfb8e15db9 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6392,6 +6392,81 @@ static int sev_dbg_encrypt(struct kvm *kvm, struct kvm_sev_cmd *argp)
return sev_dbg_crypt(kvm, argp, false);
}

+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(struct kvm_sev_launch_secret)))
+ return -EFAULT;
+
+ /* verify that request has a valid guest memory region and length */
+ if (!params.guest_uaddr ||
+ !params.guest_len ||
+ (params.guest_len > SEV_FW_BLOB_MAX_SIZE))
+ return -EINVAL;
+
+ /* pin the guest memory region */
+ 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 pinned memory pages are contiguous otherwise fail the 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;
+
+ /* copy the secret from userspace into a kernel buffer */
+ blob = 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;
+
+ /* copy the packet header from userspace into a kernel buffer */
+ hdr = 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 +6510,10 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
r = sev_dbg_encrypt(kvm, &sev_cmd);
break;
}
+ case KVM_SEV_LAUNCH_SECRET: {
+ r = sev_launch_secret(kvm, &sev_cmd);
+ break;
+ }
default:
break;
}
--
2.9.5