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authorPeter Maydell <peter.maydell@linaro.org>2023-02-20 17:08:05 +0000
committerPeter Maydell <peter.maydell@linaro.org>2023-02-20 17:08:05 +0000
commit9b0699ab801405fe5bdf1adea83bceac9ec62f97 (patch)
tree6abd869ae56a840e6e7235ac4b3304775d6ca141 /linux-headers/linux/vfio.h
parent0aaf44776e00d9008806a4731a03271f039515a1 (diff)
parent57edb7e44489ec4d85075acba47223127ecf1521 (diff)
Merge tag 'vfio-updates-20230216.0' of https://gitlab.com/alex.williamson/qemu into staging
VFIO updates 2023-02-16 * Initial v2 migration support for vfio (Avihai Horon) * Add Cédric as vfio reviewer (Cédric Le Goater) # -----BEGIN PGP SIGNATURE----- # # iQJPBAABCAA5FiEEQvbATlQL0amee4qQI5ubbjuwiyIFAmPumhUbHGFsZXgud2ls # bGlhbXNvbkByZWRoYXQuY29tAAoJECObm247sIsijnMP/0Rz/lsGxym76mXtr5WY # OR5SDFpifpaUVi+1xTugYFPnZvN+RdnlcLrcp1g8G+lmd4ANqwT0b9XTTTI8WTau # DhSHW/05WgAOrf/jOSV29oNSf7jtGJZcDbAy8f5NXxwK/IRlJEDJfCaqxwYSyYf1 # nfC0ZwMTrBrA6pzF5OzIJSkhl/uPwlTsBxRnbN86Z22rE128ASjUtj1jir4rPLg0 # ClUn7Rrdk/Y6uXIB9c6TFC+wmG0QAVsklWIeNLUFWUak4H0gqp7AUmMlJV99i5Q7 # 3H4Zjspwn79llvGm4X1QpuLaop2QaIQaW4FTpzRSftelEosjIjkTCMrWTb4MKff1 # cgT0dmC1Hht+zQ0MPbmgeaiwPH/V7r+J9GffG6p2b4itdHmrKVsqKQMSQS/IJFBw # eiO1rENRXNcTnC29jPUhe1IS1DEwCNkWm9NgJoC5WPJYQXsiEvo4YDH/30FnByXg # KQdd5OxR7o6qJM5e4PUn4wd9sHsYU8IsIEJdKnynoS9qUdPqv0tJ+tLYWcBhQPJq # M8R+mDwImMzw0bgurg4607VgL9HJEXna2rgdd5hcMq88M+M5OpmowXlk4TTY4Ha9 # lmWSndYJG6npNY4NXcxbe4x5H8ndvHcO+g3weynsxPFjnL959NzQyWNFXFDBqBg3 # fhNVqYTrMOcEN5uv18o+mnsG # =oK7/ # -----END PGP SIGNATURE----- # gpg: Signature made Thu 16 Feb 2023 21:03:17 GMT # gpg: using RSA key 42F6C04E540BD1A99E7B8A90239B9B6E3BB08B22 # gpg: issuer "alex.williamson@redhat.com" # gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>" [full] # gpg: aka "Alex Williamson <alex@shazbot.org>" [full] # gpg: aka "Alex Williamson <alwillia@redhat.com>" [full] # gpg: aka "Alex Williamson <alex.l.williamson@gmail.com>" [full] # Primary key fingerprint: 42F6 C04E 540B D1A9 9E7B 8A90 239B 9B6E 3BB0 8B22 * tag 'vfio-updates-20230216.0' of https://gitlab.com/alex.williamson/qemu: MAINTAINERS: Add myself as VFIO reviewer docs/devel: Align VFIO migration docs to v2 protocol vfio: Alphabetize migration section of VFIO trace-events file vfio/migration: Remove VFIO migration protocol v1 vfio/migration: Implement VFIO migration protocol v2 vfio/migration: Rename functions/structs related to v1 protocol vfio/migration: Move migration v1 logic to vfio_migration_init() vfio/migration: Block multiple devices migration vfio/common: Change vfio_devices_all_running_and_saving() logic to equivalent one vfio/migration: Allow migration without VFIO IOMMU dirty tracking support vfio/migration: Fix NULL pointer dereference bug linux-headers: Update to v6.2-rc8 Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'linux-headers/linux/vfio.h')
-rw-r--r--linux-headers/linux/vfio.h136
1 files changed, 132 insertions, 4 deletions
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index bee7e42198..c59692ce0b 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -819,12 +819,20 @@ struct vfio_device_feature {
* VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P means that RUNNING_P2P
* is supported in addition to the STOP_COPY states.
*
+ * VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_PRE_COPY means that
+ * PRE_COPY is supported in addition to the STOP_COPY states.
+ *
+ * VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P | VFIO_MIGRATION_PRE_COPY
+ * means that RUNNING_P2P, PRE_COPY and PRE_COPY_P2P are supported
+ * in addition to the STOP_COPY states.
+ *
* Other combinations of flags have behavior to be defined in the future.
*/
struct vfio_device_feature_migration {
__aligned_u64 flags;
#define VFIO_MIGRATION_STOP_COPY (1 << 0)
#define VFIO_MIGRATION_P2P (1 << 1)
+#define VFIO_MIGRATION_PRE_COPY (1 << 2)
};
#define VFIO_DEVICE_FEATURE_MIGRATION 1
@@ -875,8 +883,13 @@ struct vfio_device_feature_mig_state {
* RESUMING - The device is stopped and is loading a new internal state
* ERROR - The device has failed and must be reset
*
- * And 1 optional state to support VFIO_MIGRATION_P2P:
+ * And optional states to support VFIO_MIGRATION_P2P:
* RUNNING_P2P - RUNNING, except the device cannot do peer to peer DMA
+ * And VFIO_MIGRATION_PRE_COPY:
+ * PRE_COPY - The device is running normally but tracking internal state
+ * changes
+ * And VFIO_MIGRATION_P2P | VFIO_MIGRATION_PRE_COPY:
+ * PRE_COPY_P2P - PRE_COPY, except the device cannot do peer to peer DMA
*
* The FSM takes actions on the arcs between FSM states. The driver implements
* the following behavior for the FSM arcs:
@@ -908,20 +921,48 @@ struct vfio_device_feature_mig_state {
*
* To abort a RESUMING session the device must be reset.
*
+ * PRE_COPY -> RUNNING
* RUNNING_P2P -> RUNNING
* While in RUNNING the device is fully operational, the device may generate
* interrupts, DMA, respond to MMIO, all vfio device regions are functional,
* and the device may advance its internal state.
*
+ * The PRE_COPY arc will terminate a data transfer session.
+ *
+ * PRE_COPY_P2P -> RUNNING_P2P
* RUNNING -> RUNNING_P2P
* STOP -> RUNNING_P2P
* While in RUNNING_P2P the device is partially running in the P2P quiescent
* state defined below.
*
+ * The PRE_COPY_P2P arc will terminate a data transfer session.
+ *
+ * RUNNING -> PRE_COPY
+ * RUNNING_P2P -> PRE_COPY_P2P
* STOP -> STOP_COPY
- * This arc begin the process of saving the device state and will return a
- * new data_fd.
+ * PRE_COPY, PRE_COPY_P2P and STOP_COPY form the "saving group" of states
+ * which share a data transfer session. Moving between these states alters
+ * what is streamed in session, but does not terminate or otherwise affect
+ * the associated fd.
+ *
+ * These arcs begin the process of saving the device state and will return a
+ * new data_fd. The migration driver may perform actions such as enabling
+ * dirty logging of device state when entering PRE_COPY or PER_COPY_P2P.
+ *
+ * Each arc does not change the device operation, the device remains
+ * RUNNING, P2P quiesced or in STOP. The STOP_COPY state is described below
+ * in PRE_COPY_P2P -> STOP_COPY.
*
+ * PRE_COPY -> PRE_COPY_P2P
+ * Entering PRE_COPY_P2P continues all the behaviors of PRE_COPY above.
+ * However, while in the PRE_COPY_P2P state, the device is partially running
+ * in the P2P quiescent state defined below, like RUNNING_P2P.
+ *
+ * PRE_COPY_P2P -> PRE_COPY
+ * This arc allows returning the device to a full RUNNING behavior while
+ * continuing all the behaviors of PRE_COPY.
+ *
+ * PRE_COPY_P2P -> STOP_COPY
* While in the STOP_COPY state the device has the same behavior as STOP
* with the addition that the data transfers session continues to stream the
* migration state. End of stream on the FD indicates the entire device
@@ -939,6 +980,13 @@ struct vfio_device_feature_mig_state {
* device state for this arc if required to prepare the device to receive the
* migration data.
*
+ * STOP_COPY -> PRE_COPY
+ * STOP_COPY -> PRE_COPY_P2P
+ * These arcs are not permitted and return error if requested. Future
+ * revisions of this API may define behaviors for these arcs, in this case
+ * support will be discoverable by a new flag in
+ * VFIO_DEVICE_FEATURE_MIGRATION.
+ *
* any -> ERROR
* ERROR cannot be specified as a device state, however any transition request
* can be failed with an errno return and may then move the device_state into
@@ -950,7 +998,7 @@ struct vfio_device_feature_mig_state {
* The optional peer to peer (P2P) quiescent state is intended to be a quiescent
* state for the device for the purposes of managing multiple devices within a
* user context where peer-to-peer DMA between devices may be active. The
- * RUNNING_P2P states must prevent the device from initiating
+ * RUNNING_P2P and PRE_COPY_P2P states must prevent the device from initiating
* any new P2P DMA transactions. If the device can identify P2P transactions
* then it can stop only P2P DMA, otherwise it must stop all DMA. The migration
* driver must complete any such outstanding operations prior to completing the
@@ -963,6 +1011,8 @@ struct vfio_device_feature_mig_state {
* above FSM arcs. As there are multiple paths through the FSM arcs the path
* should be selected based on the following rules:
* - Select the shortest path.
+ * - The path cannot have saving group states as interior arcs, only
+ * starting/end states.
* Refer to vfio_mig_get_next_state() for the result of the algorithm.
*
* The automatic transit through the FSM arcs that make up the combination
@@ -976,6 +1026,9 @@ struct vfio_device_feature_mig_state {
* support them. The user can discover if these states are supported by using
* VFIO_DEVICE_FEATURE_MIGRATION. By using combination transitions the user can
* avoid knowing about these optional states if the kernel driver supports them.
+ *
+ * Arcs touching PRE_COPY and PRE_COPY_P2P are removed if support for PRE_COPY
+ * is not present.
*/
enum vfio_device_mig_state {
VFIO_DEVICE_STATE_ERROR = 0,
@@ -984,8 +1037,70 @@ enum vfio_device_mig_state {
VFIO_DEVICE_STATE_STOP_COPY = 3,
VFIO_DEVICE_STATE_RESUMING = 4,
VFIO_DEVICE_STATE_RUNNING_P2P = 5,
+ VFIO_DEVICE_STATE_PRE_COPY = 6,
+ VFIO_DEVICE_STATE_PRE_COPY_P2P = 7,
+};
+
+/**
+ * VFIO_MIG_GET_PRECOPY_INFO - _IO(VFIO_TYPE, VFIO_BASE + 21)
+ *
+ * This ioctl is used on the migration data FD in the precopy phase of the
+ * migration data transfer. It returns an estimate of the current data sizes
+ * remaining to be transferred. It allows the user to judge when it is
+ * appropriate to leave PRE_COPY for STOP_COPY.
+ *
+ * This ioctl is valid only in PRE_COPY states and kernel driver should
+ * return -EINVAL from any other migration state.
+ *
+ * The vfio_precopy_info data structure returned by this ioctl provides
+ * estimates of data available from the device during the PRE_COPY states.
+ * This estimate is split into two categories, initial_bytes and
+ * dirty_bytes.
+ *
+ * The initial_bytes field indicates the amount of initial precopy
+ * data available from the device. This field should have a non-zero initial
+ * value and decrease as migration data is read from the device.
+ * It is recommended to leave PRE_COPY for STOP_COPY only after this field
+ * reaches zero. Leaving PRE_COPY earlier might make things slower.
+ *
+ * The dirty_bytes field tracks device state changes relative to data
+ * previously retrieved. This field starts at zero and may increase as
+ * the internal device state is modified or decrease as that modified
+ * state is read from the device.
+ *
+ * Userspace may use the combination of these fields to estimate the
+ * potential data size available during the PRE_COPY phases, as well as
+ * trends relative to the rate the device is dirtying its internal
+ * state, but these fields are not required to have any bearing relative
+ * to the data size available during the STOP_COPY phase.
+ *
+ * Drivers have a lot of flexibility in when and what they transfer during the
+ * PRE_COPY phase, and how they report this from VFIO_MIG_GET_PRECOPY_INFO.
+ *
+ * During pre-copy the migration data FD has a temporary "end of stream" that is
+ * reached when both initial_bytes and dirty_byte are zero. For instance, this
+ * may indicate that the device is idle and not currently dirtying any internal
+ * state. When read() is done on this temporary end of stream the kernel driver
+ * should return ENOMSG from read(). Userspace can wait for more data (which may
+ * never come) by using poll.
+ *
+ * Once in STOP_COPY the migration data FD has a permanent end of stream
+ * signaled in the usual way by read() always returning 0 and poll always
+ * returning readable. ENOMSG may not be returned in STOP_COPY.
+ * Support for this ioctl is mandatory if a driver claims to support
+ * VFIO_MIGRATION_PRE_COPY.
+ *
+ * Return: 0 on success, -1 and errno set on failure.
+ */
+struct vfio_precopy_info {
+ __u32 argsz;
+ __u32 flags;
+ __aligned_u64 initial_bytes;
+ __aligned_u64 dirty_bytes;
};
+#define VFIO_MIG_GET_PRECOPY_INFO _IO(VFIO_TYPE, VFIO_BASE + 21)
+
/*
* Upon VFIO_DEVICE_FEATURE_SET, allow the device to be moved into a low power
* state with the platform-based power management. Device use of lower power
@@ -1128,6 +1243,19 @@ struct vfio_device_feature_dma_logging_report {
#define VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT 8
+/*
+ * Upon VFIO_DEVICE_FEATURE_GET read back the estimated data length that will
+ * be required to complete stop copy.
+ *
+ * Note: Can be called on each device state.
+ */
+
+struct vfio_device_feature_mig_data_size {
+ __aligned_u64 stop_copy_length;
+};
+
+#define VFIO_DEVICE_FEATURE_MIG_DATA_SIZE 9
+
/* -------- API for Type1 VFIO IOMMU -------- */
/**