Commit 5569e2e7 authored by Steve Rutherford's avatar Steve Rutherford Committed by Paolo Bonzini
Browse files

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: default avatarNathan Tempelman <natet@google.com>
Reviewed-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarSteve Rutherford <srutherford@google.com>
Message-Id: <20210412194408.2458827-1-srutherford@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent fddecf6a

Documentation/virt/kvm/amd-memory-encryption.rst

+9 −0
Original line number Diff line number Diff line
@@ -356,6 +356,15 @@ issued by the hypervisor to delete the encryption context. 


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

==========

arch/x86/kvm/svm/sev.c

+23 −0
Original line number Diff line number Diff line
@@ -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;

drivers/crypto/ccp/sev-dev.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

	}

include/linux/psp-sev.h

+10 −0
Original line number Diff line number Diff line
@@ -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,
@@ -392,6 +393,15 @@ struct sev_data_send_finish { 
	u32 handle;				/* In */

} __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

 *

include/uapi/linux/kvm.h

+2 −0
Original line number Diff line number Diff line
@@ -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,

};