KVM: Define SEV key management command id

Define Secure Encrypted Virtualization (SEV) key management command id
and structure. The command definition is available in SEV KM spec
0.14 (http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf)
and Documentation/virtual/kvm/amd-memory-encryption.txt.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>

1 files changed, 202 insertions, 0 deletions

diff --git a/Documentation/virtual/kvm/amd-memory-encryption.rst b/Documentation/virtual/kvm/amd-memory-encryption.rst
index a8ef21e737db..71d6d257074f 100644
--- a/Documentation/virtual/kvm/amd-memory-encryption.rst
+++ b/Documentation/virtual/kvm/amd-memory-encryption.rst
@@ -43,3 +43,205 @@ 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 SEV guest key management is handled by a separate processor called 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 the SEV Key Management spec [api-spec]_
+
+KVM implements the following commands to support common lifecycle events of SEV
+guests, such as launching, running, snapshotting, migrating and decommissioning.
+
+1. KVM_SEV_INIT
+---------------
+
+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.
+
+Returns: 0 on success, -negative on error
+
+2. KVM_SEV_LAUNCH_START
+-----------------------
+
+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.
+
+Parameters: struct  kvm_sev_launch_start (in/out)
+
+Returns: 0 on success, -negative on error
+
+::
+
+        struct kvm_sev_launch_start {
+                __u32 handle;           /* if zero then firmware creates a new handle */
+                __u32 policy;           /* guest's policy */
+
+                __u64 dh_uaddr;         /* userspace address pointing to the guest owner's PDH key */
+                __u32 dh_len;
+
+                __u64 session_addr;     /* userspace address which points to the guest session information */
+                __u32 session_len;
+        };
+
+On success, the 'handle' field contains a new handle and on error, a negative value.
+
+For more details, see SEV spec Section 6.2.
+
+3. KVM_SEV_LAUNCH_UPDATE_DATA
+-----------------------------
+
+The KVM_SEV_LAUNCH_UPDATE_DATA is used for encrypting a 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.
+
+Parameters (in): struct  kvm_sev_launch_update_data
+
+Returns: 0 on success, -negative on error
+
+::
+
+        struct kvm_sev_launch_update {
+                __u64 uaddr;    /* userspace address to be encrypted (must be 16-byte aligned) */
+                __u32 len;      /* length of the data to be encrypted (must be 16-byte aligned) */
+        };
+
+For more details, see SEV spec Section 6.3.
+
+4. KVM_SEV_LAUNCH_MEASURE
+-------------------------
+
+The KVM_SEV_LAUNCH_MEASURE command is used to retrieve the measurement of the
+data encrypted by the KVM_SEV_LAUNCH_UPDATE_DATA command. 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.
+
+Parameters (in): struct  kvm_sev_launch_measure
+
+Returns: 0 on success, -negative on error
+
+::
+
+        struct kvm_sev_launch_measure {
+                __u64 uaddr;    /* where to copy the measurement */
+                __u32 len;      /* length of measurement blob */
+        };
+
+For more details on the measurement verification flow, see SEV spec Section 6.4.
+
+5. KVM_SEV_LAUNCH_FINISH
+------------------------
+
+After completion of the launch flow, the KVM_SEV_LAUNCH_FINISH command can be
+issued to make the guest ready for the execution.
+
+Returns: 0 on success, -negative on error
+
+6. KVM_SEV_GUEST_STATUS
+-----------------------
+
+The KVM_SEV_GUEST_STATUS command is used to retrieve status information about a
+SEV-enabled guest.
+
+Parameters (out): struct kvm_sev_guest_status
+
+Returns: 0 on success, -negative on error
+
+::
+
+        struct kvm_sev_guest_status {
+                __u32 handle;   /* guest handle */
+                __u32 policy;   /* guest policy */
+                __u8 state;     /* guest state (see enum below) */
+        };
+
+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
+----------------------
+
+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.
+
+Parameters (in): struct kvm_sev_dbg
+
+Returns: 0 on success, -negative on error
+
+::
+
+        struct kvm_sev_dbg {
+                __u64 src_uaddr;        /* userspace address of data to decrypt */
+                __u64 dst_uaddr;        /* userspace address of destination */
+                __u32 len;              /* length of memory region to decrypt */
+        };
+
+The command returns an error if the guest policy does not allow debugging.
+
+8. KVM_SEV_DBG_ENCRYPT
+----------------------
+
+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.
+
+Parameters (in): struct kvm_sev_dbg
+
+Returns: 0 on success, -negative on error
+
+::
+
+        struct kvm_sev_dbg {
+                __u64 src_uaddr;        /* userspace address of data to encrypt */
+                __u64 dst_uaddr;        /* userspace address of destination */
+                __u32 len;              /* length of memory region to encrypt */
+        };
+
+The command returns an error if the guest policy does not allow debugging.
+
+9. KVM_SEV_LAUNCH_SECRET
+------------------------
+
+The KVM_SEV_LAUNCH_SECRET command can be used by the hypervisor to inject secret
+data after the measurement has been validated by the guest owner.
+
+Parameters (in): struct kvm_sev_launch_secret
+
+Returns: 0 on success, -negative on error
+
+::
+
+        struct kvm_sev_launch_secret {
+                __u64 hdr_uaddr;        /* userspace address containing the packet header */
+                __u32 hdr_len;
+
+                __u64 guest_uaddr;      /* the guest memory region where the secret should be injected */
+                __u32 guest_len;
+
+                __u64 trans_uaddr;      /* the hypervisor memory region which contains the secret */
+                __u32 trans_len;
+        };
+
+References
+==========
+
+.. [white-paper] http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf
+.. [api-spec] http://support.amd.com/TechDocs/55766_SEV-KM%20API_Specification.pdf
+.. [amd-apm] http://support.amd.com/TechDocs/24593.pdf (section 15.34)
+.. [kvm-forum]  http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf