KVM: SVM: Add support for KVM_SEV_SEND_CANCEL command
After completion of SEND_START, but before SEND_FINISH, the source VMM can
issue the SEND_CANCEL command to stop a migration. This is necessary so
that a cancelled migration can restart with a new target later.
Reviewed-by: Nathan Tempelman <natet@google.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Steve Rutherford <srutherford@google.com>
Message-Id: <20210412194408.2458827-1-srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst
index 03f2518..c36a129 100644
--- a/Documentation/virt/kvm/amd-memory-encryption.rst
+++ b/Documentation/virt/kvm/amd-memory-encryption.rst
@@ -356,6 +356,15 @@
Returns: 0 on success, -negative on error
+14. KVM_SEV_SEND_CANCEL
+------------------------
+
+After completion of SEND_START, but before SEND_FINISH, the source VMM can issue the
+SEND_CANCEL command to stop a migration. This is necessary so that a cancelled
+migration can restart with a new target later.
+
+Returns: 0 on success, -negative on error
+
References
==========
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index f25c52a..552f477 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1377,6 +1377,26 @@ static int sev_send_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
return ret;
}
+static int sev_send_cancel(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+ struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+ struct sev_data_send_cancel *data;
+ int ret;
+
+ if (!sev_guest(kvm))
+ return -ENOTTY;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->handle = sev->handle;
+ ret = sev_issue_cmd(kvm, SEV_CMD_SEND_CANCEL, data, &argp->error);
+
+ kfree(data);
+ return ret;
+}
+
int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
{
struct kvm_sev_cmd sev_cmd;
@@ -1448,6 +1468,9 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
case KVM_SEV_SEND_FINISH:
r = sev_send_finish(kvm, &sev_cmd);
break;
+ case KVM_SEV_SEND_CANCEL:
+ r = sev_send_cancel(kvm, &sev_cmd);
+ break;
default:
r = -EINVAL;
goto out;
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index cb9b4c4..4172a1a 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -129,6 +129,7 @@ static int sev_cmd_buffer_len(int cmd)
case SEV_CMD_DOWNLOAD_FIRMWARE: return sizeof(struct sev_data_download_firmware);
case SEV_CMD_GET_ID: return sizeof(struct sev_data_get_id);
case SEV_CMD_ATTESTATION_REPORT: return sizeof(struct sev_data_attestation_report);
+ case SEV_CMD_SEND_CANCEL: return sizeof(struct sev_data_send_cancel);
default: return 0;
}
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 73da511..d48a719 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -73,6 +73,7 @@ enum sev_cmd {
SEV_CMD_SEND_UPDATE_DATA = 0x041,
SEV_CMD_SEND_UPDATE_VMSA = 0x042,
SEV_CMD_SEND_FINISH = 0x043,
+ SEV_CMD_SEND_CANCEL = 0x044,
/* Guest migration commands (incoming) */
SEV_CMD_RECEIVE_START = 0x050,
@@ -393,6 +394,15 @@ struct sev_data_send_finish {
} __packed;
/**
+ * struct sev_data_send_cancel - SEND_CANCEL command parameters
+ *
+ * @handle: handle of the VM to process
+ */
+struct sev_data_send_cancel {
+ u32 handle; /* In */
+} __packed;
+
+/**
* struct sev_data_receive_start - RECEIVE_START command parameters
*
* @handle: handle of the VM to perform receive operation
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index d07be69..5d1adeb 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1674,6 +1674,8 @@ enum sev_cmd_id {
KVM_SEV_CERT_EXPORT,
/* Attestation report */
KVM_SEV_GET_ATTESTATION_REPORT,
+ /* Guest Migration Extension */
+ KVM_SEV_SEND_CANCEL,
KVM_SEV_NR_MAX,
};