[Part2 PATCH v5 16/31] KVM: Define SEV key management command id

From: Brijesh Singh
Date: Wed Oct 04 2017 - 09:22:12 EST


Define Secure Encrypted Virtualization (SEV) key management command id
and structure. The command definition is available in SEV KM [1] spec
0.14 and Documentation/virtual/kvm/amd-memory-encryption.txt

[1] http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf

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>
---
.../virtual/kvm/amd-memory-encryption.txt | 191 +++++++++++++++++++++
include/uapi/linux/kvm.h | 79 +++++++++
2 files changed, 270 insertions(+)

diff --git a/Documentation/virtual/kvm/amd-memory-encryption.txt b/Documentation/virtual/kvm/amd-memory-encryption.txt
index 26472b4cdbaf..8c79946b4d43 100644
--- a/Documentation/virtual/kvm/amd-memory-encryption.txt
+++ b/Documentation/virtual/kvm/amd-memory-encryption.txt
@@ -36,3 +36,194 @@ setting the SEV bit before executing VMRUN.
SEV hardware uses ASIDs to associate a memory encryption key with a VM.
Hence, the ASID for the SEV-enabled guests must be from 1 to a maximum value
defined in the CPUID 0x8000001f[ecx] field.
+
+SEV Key Management
+------------------
+The Key management for the SEV guest is handled by a separate processor known as
+the AMD Secure Processor (AMD-SP). Firmware running inside the AMD-SP provides a
+secure key management interface to perform common hypervisor activities such as
+encrypting bootstrap code, snapshot, migrating and debugging the guest. For
+more information, see SEV Key Management spec at
+
+http://support.amd.com/TechDocs/55766_SEV-KM%20API_Specification.pdf
+
+KVM implements the following commands to support SEV guests common lifecycle
+events such as launching, running, snapshotting, migrating and decommissioning
+guests.
+
+1. KVM_SEV_INIT
+
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_INIT command is used by the hypervisor to initialize the SEV platform
+context. In a typical workflow, this command should be the first command issued.
+
+2. KVM_SEV_LAUNCH_START
+
+Parameters: struct kvm_sev_launch_start (in/out)
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_LAUNCH_START command is used for creating the memory encryption
+context. To create the encryption context, user must provide a guest policy,
+the owner's public Diffie-Hellman (PDH) key and session information.
+
+struct kvm_sev_launch_start {
+ /* if zero then firmware creates a new handle */
+ __u32 handle;
+
+ /* guest's policy */
+ __u32 policy;
+
+ /* userspace address pointing to the guest owner's PDH key */
+ __u64 dh_uaddr;
+ __u32 dh_len;
+
+ /* userspace address which points to the guest session information */
+ __u64 session_addr;
+ __u32 session_len;
+};
+
+On success, the 'handle' field contain a new handle and on error, a negative value.
+
+For more details, see SEV spec Section 6.2.
+
+3. KVM_SEV_LAUNCH_UPDATE_DATA
+
+Parameters (in): struct kvm_sev_launch_update_data
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_LAUNCH_UPDATE_DATA is used for encrypting the memory region. It also
+calculates a measurement of the memory contents. The measurement is a signature
+of the memory contents that can be sent to the guest owner as an attestation
+that the memory was encrypted correctly by the firmware.
+
+struct kvm_sev_launch_update {
+ /* userspace address need to be encrypted (must be 16-byte aligned) */
+ __u64 uaddr;
+
+ /* length of the data to be encrypted (must be 16-byte aligned) */
+ __u32 len;
+};
+
+For more details, see SEV spec Section 6.3.
+
+4. KVM_SEV_LAUNCH_MEASURE
+
+Parameters (in): struct kvm_sev_launch_measure
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_LAUNCH_MEASURE command is used to retrieve the measurement
+of the data encrypted by the KVM_SEV_LAUNCH_UPDATE_DATA. The guest owner
+may wait to provide the guest with confidential information until it can
+verify the measurement. Since the guest owner knows the initial contents
+of the guest at boot, the measurement can be verified by comparing it to
+what the guest owner expects.
+
+struct kvm_sev_launch_measure {
+ /* where to copy the measurement */
+ __u64 uaddr;
+
+ /* length of measurement blob */
+ __u32 len;
+};
+
+For more details on the measurement verification flow, see SEV spec Section 6.4
+
+5. KVM_SEV_LAUNCH_FINISH
+
+Returns: 0 on success, -negative on error
+
+After completion of the launch flow, the KVM_SEV_LAUNCH_FINISH command can be
+issued to make the guest ready for the execution.
+
+6. KVM_SEV_GUEST_STATUS
+
+Parameters (out): struct kvm_sev_guest_status
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_GUEST_STATUS command is used to retrieve status information about a
+SEV-enabled guest.
+
+struct kvm_sev_guest_status {
+ /* guest handle */
+ __u32 handle;
+
+ /* guest policy */
+ __u32 policy;
+
+ /* guest state (see below) */
+ __u8 state;
+};
+
+SEV guest state:
+
+enum {
+ SEV_STATE_INVALID = 0;
+ SEV_STATE_LAUNCHING, /* guest is currently being launched */
+ SEV_STATE_SECRET, /* guest is being launched and ready to accept the ciphertext data */
+ SEV_STATE_RUNNING, /* guest is fully launched and running */
+ SEV_STATE_RECEIVING, /* guest is being migrated in from another SEV machine */
+ SEV_STATE_SENDING /* guest is getting migrated out to another SEV machine */
+};
+
+7. KVM_SEV_DBG_DECRYPT
+
+Parameters (in): struct kvm_sev_dbg
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_DEBUG_DECRYPT command can be used by the hypervisor to request the
+firmware to decrypt the data at the given memory region.
+
+struct kvm_sev_dbg {
+ /* userspace address of data to decrypt */
+ __u64 src_uaddr;
+ /* userspace address of destination */
+ __u64 dst_uaddr;
+
+ /* length of memory region to decrypt */
+ __u32 len;
+};
+
+The command returns an error if guest policy does not allow debugging.
+
+8. KVM_SEV_DBG_ENCRYPT
+
+Parameters (in): struct kvm_sev_dbg
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_DEBUG_ENCRYPT command can be used by the hypervisor to request the
+firmware to encrypt the data at the given memory region.
+
+struct kvm_sev_dbg {
+ /* userspace address of data to encrypt */
+ __u64 src_uaddr;
+ /* userspace address of destination */
+ __u64 dst_uaddr;
+
+ /* length of memory region to encrypt */
+ __u32 len;
+};
+
+The command returns an error if guest policy does not allow debugging.
+
+9. KVM_SEV_LAUNCH_SECRET
+
+Parameters (in): struct kvm_sev_launch_secret
+Returns: 0 on success, -negative on error
+
+The KVM_SEV_LAUNCH_SECRET command can be used by the hypervisor to inject a secret
+data after the measurement has been validated by the guest owner.
+
+struct kvm_sev_launch_secret {
+ /* userspace address containing the packet header */
+ __u64 hdr_uaddr;
+ __u32 hdr_len;
+
+ /* the guest memory region where the secret should be injected */
+ __u64 guest_uaddr;
+ __u32 guest_len;
+
+ /* the hypervisor memory region which contains the secret */
+ __u64 trans_uaddr;
+ __u32 trans_len;
+};
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index d595d3970390..115c75156711 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1368,6 +1368,85 @@ struct kvm_enc_region {
struct kvm_enc_region)
#define KVM_MEMORY_ENCRYPT_UNREGISTER_REGION _IOR(KVMIO, 0xbc,\
struct kvm_enc_region)
+/* Secure Encrypted Virtualization command */
+enum sev_cmd_id {
+ /* Guest initialization commands */
+ KVM_SEV_INIT = 0,
+ KVM_SEV_ES_INIT,
+ /* Guest launch commands */
+ KVM_SEV_LAUNCH_START,
+ KVM_SEV_LAUNCH_UPDATE_DATA,
+ KVM_SEV_LAUNCH_UPDATE_VMSA,
+ KVM_SEV_LAUNCH_SECRET,
+ KVM_SEV_LAUNCH_MEASURE,
+ KVM_SEV_LAUNCH_FINISH,
+ /* Guest migration commands (outgoing) */
+ KVM_SEV_SEND_START,
+ KVM_SEV_SEND_UPDATE_DATA,
+ KVM_SEV_SEND_UPDATE_VMSA,
+ KVM_SEV_SEND_FINISH,
+ /* Guest migration commands (incoming) */
+ KVM_SEV_RECEIVE_START,
+ KVM_SEV_RECEIVE_UPDATE_DATA,
+ KVM_SEV_RECEIVE_UPDATE_VMSA,
+ KVM_SEV_RECEIVE_FINISH,
+ /* Guest status and debug commands */
+ KVM_SEV_GUEST_STATUS,
+ KVM_SEV_DBG_DECRYPT,
+ KVM_SEV_DBG_ENCRYPT,
+ /* Guest certificates commands */
+ KVM_SEV_CERT_EXPORT,
+
+ KVM_SEV_NR_MAX,
+};
+
+struct kvm_sev_cmd {
+ __u32 id;
+ __u64 data;
+ __u32 error;
+ __u32 sev_fd;
+};
+
+struct kvm_sev_launch_start {
+ __u32 handle;
+ __u32 policy;
+ __u64 dh_uaddr;
+ __u32 dh_len;
+ __u64 session_uaddr;
+ __u32 session_len;
+};
+
+struct kvm_sev_launch_update_data {
+ __u64 uaddr;
+ __u32 len;
+};
+
+
+struct kvm_sev_launch_secret {
+ __u64 hdr_uaddr;
+ __u32 hdr_len;
+ __u64 guest_uaddr;
+ __u32 guest_len;
+ __u64 trans_uaddr;
+ __u32 trans_len;
+};
+
+struct kvm_sev_launch_measure {
+ __u64 uaddr;
+ __u32 len;
+};
+
+struct kvm_sev_guest_status {
+ __u32 handle;
+ __u32 policy;
+ __u32 state;
+};
+
+struct kvm_sev_dbg {
+ __u64 src_uaddr;
+ __u64 dst_uaddr;
+ __u32 len;
+};

#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1)
--
2.9.5