| Message ID | 1603449643-12851-8-git-send-email-kwankhede@nvidia.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add migration support for VFIO devices | expand |
On Fri, 23 Oct 2020 16:10:33 +0530 Kirti Wankhede <kwankhede@nvidia.com> wrote: > Define flags to be used as delimiter in migration stream for VFIO devices. > Added .save_setup and .save_cleanup functions. Map & unmap migration > region from these functions at source during saving or pre-copy phase. > > Set VFIO device state depending on VM's state. During live migration, VM is > running when .save_setup is called, _SAVING | _RUNNING state is set for VFIO > device. During save-restore, VM is paused, _SAVING state is set for VFIO device. > > Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> > Reviewed-by: Neo Jia <cjia@nvidia.com> > --- > hw/vfio/migration.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++ > hw/vfio/trace-events | 2 + > 2 files changed, 104 insertions(+) Reviewed-by: Cornelia Huck <cohuck@redhat.com>
On Fri, Oct 23, 2020 at 04:10:33PM +0530, Kirti Wankhede wrote: > Define flags to be used as delimiter in migration stream for VFIO devices. > Added .save_setup and .save_cleanup functions. Map & unmap migration > region from these functions at source during saving or pre-copy phase. > > Set VFIO device state depending on VM's state. During live migration, VM is > running when .save_setup is called, _SAVING | _RUNNING state is set for VFIO > device. During save-restore, VM is paused, _SAVING state is set for VFIO device. > > Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> > Reviewed-by: Neo Jia <cjia@nvidia.com> > --- > hw/vfio/migration.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++ > hw/vfio/trace-events | 2 + > 2 files changed, 104 insertions(+) > > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c > index a0f0e79b9b73..94d2bdae5c54 100644 > --- a/hw/vfio/migration.c > +++ b/hw/vfio/migration.c > @@ -8,12 +8,15 @@ > */ > > #include "qemu/osdep.h" > +#include "qemu/main-loop.h" > +#include "qemu/cutils.h" > #include <linux/vfio.h> > > #include "sysemu/runstate.h" > #include "hw/vfio/vfio-common.h" > #include "cpu.h" > #include "migration/migration.h" > +#include "migration/vmstate.h" > #include "migration/qemu-file.h" > #include "migration/register.h" > #include "migration/blocker.h" > @@ -25,6 +28,22 @@ > #include "trace.h" > #include "hw/hw.h" > > +/* > + * Flags to be used as unique delimiters for VFIO devices in the migration > + * stream. These flags are composed as: > + * 0xffffffff => MSB 32-bit all 1s > + * 0xef10 => Magic ID, represents emulated (virtual) function IO > + * 0x0000 => 16-bits reserved for flags > + * > + * The beginning of state information is marked by _DEV_CONFIG_STATE, > + * _DEV_SETUP_STATE, or _DEV_DATA_STATE, respectively. The end of a > + * certain state information is marked by _END_OF_STATE. > + */ > +#define VFIO_MIG_FLAG_END_OF_STATE (0xffffffffef100001ULL) > +#define VFIO_MIG_FLAG_DEV_CONFIG_STATE (0xffffffffef100002ULL) > +#define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL) > +#define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL) > + > static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count, > off_t off, bool iswrite) > { > @@ -129,6 +148,75 @@ static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask, > return 0; > } > > +static void vfio_migration_cleanup(VFIODevice *vbasedev) > +{ > + VFIOMigration *migration = vbasedev->migration; > + > + if (migration->region.mmaps) { > + vfio_region_unmap(&migration->region); > + } > +} > + > +/* ---------------------------------------------------------------------- */ > + > +static int vfio_save_setup(QEMUFile *f, void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + VFIOMigration *migration = vbasedev->migration; > + int ret; > + > + trace_vfio_save_setup(vbasedev->name); > + > + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); > + > + if (migration->region.mmaps) { > + /* > + * Calling vfio_region_mmap() from migration thread. Memory API called > + * from this function require locking the iothread when called from > + * outside the main loop thread. > + */ > + qemu_mutex_lock_iothread(); > + ret = vfio_region_mmap(&migration->region); > + qemu_mutex_unlock_iothread(); > + if (ret) { > + error_report("%s: Failed to mmap VFIO migration region: %s", > + vbasedev->name, strerror(-ret)); > + error_report("%s: Falling back to slow path", vbasedev->name); > + } > + } > + > + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_MASK, > + VFIO_DEVICE_STATE_SAVING); > + if (ret) { > + error_report("%s: Failed to set state SAVING", vbasedev->name); > + return ret; > + } > + is it possible to call vfio_update_pending() and vfio_save_buffer() here? so that vendor driver has a chance to hook compatibility checking string early in save_setup stage and can avoid to hook the string in both precopy iteration stage and stop and copy stage. But I think it's ok if we agree to add this later. Besides that, Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> > + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); > + > + ret = qemu_file_get_error(f); > + if (ret) { > + return ret; > + } > + > + return 0; > +} > + > +static void vfio_save_cleanup(void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + > + vfio_migration_cleanup(vbasedev); > + trace_vfio_save_cleanup(vbasedev->name); > +} > + > +static SaveVMHandlers savevm_vfio_handlers = { > + .save_setup = vfio_save_setup, > + .save_cleanup = vfio_save_cleanup, > +}; > + > +/* ---------------------------------------------------------------------- */ > + > static void vfio_vmstate_change(void *opaque, int running, RunState state) > { > VFIODevice *vbasedev = opaque; > @@ -217,6 +305,8 @@ static int vfio_migration_init(VFIODevice *vbasedev, > int ret; > Object *obj; > VFIOMigration *migration; > + char id[256] = ""; > + g_autofree char *path = NULL, *oid = NULL; > > if (!vbasedev->ops->vfio_get_object) { > return -EINVAL; > @@ -247,6 +337,18 @@ static int vfio_migration_init(VFIODevice *vbasedev, > } > > migration->vbasedev = vbasedev; > + > + oid = vmstate_if_get_id(VMSTATE_IF(DEVICE(obj))); > + if (oid) { > + path = g_strdup_printf("%s/vfio", oid); > + } else { > + path = g_strdup("vfio"); > + } > + strpadcpy(id, sizeof(id), path, '\0'); > + > + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, &savevm_vfio_handlers, > + vbasedev); > + > migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change, > vbasedev); > migration->migration_state.notify = vfio_migration_state_notifier; > diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events > index 78d7d83b5ef8..f148b5e828c1 100644 > --- a/hw/vfio/trace-events > +++ b/hw/vfio/trace-events > @@ -151,3 +151,5 @@ vfio_migration_probe(const char *name, uint32_t index) " (%s) Region %d" > vfio_migration_set_state(const char *name, uint32_t state) " (%s) state %d" > vfio_vmstate_change(const char *name, int running, const char *reason, uint32_t dev_state) " (%s) running %d reason %s device state %d" > vfio_migration_state_notifier(const char *name, const char *state) " (%s) state %s" > +vfio_save_setup(const char *name) " (%s)" > +vfio_save_cleanup(const char *name) " (%s)" > -- > 2.7.0 >
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index a0f0e79b9b73..94d2bdae5c54 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -8,12 +8,15 @@ */ #include "qemu/osdep.h" +#include "qemu/main-loop.h" +#include "qemu/cutils.h" #include <linux/vfio.h> #include "sysemu/runstate.h" #include "hw/vfio/vfio-common.h" #include "cpu.h" #include "migration/migration.h" +#include "migration/vmstate.h" #include "migration/qemu-file.h" #include "migration/register.h" #include "migration/blocker.h" @@ -25,6 +28,22 @@ #include "trace.h" #include "hw/hw.h" +/* + * Flags to be used as unique delimiters for VFIO devices in the migration + * stream. These flags are composed as: + * 0xffffffff => MSB 32-bit all 1s + * 0xef10 => Magic ID, represents emulated (virtual) function IO + * 0x0000 => 16-bits reserved for flags + * + * The beginning of state information is marked by _DEV_CONFIG_STATE, + * _DEV_SETUP_STATE, or _DEV_DATA_STATE, respectively. The end of a + * certain state information is marked by _END_OF_STATE. + */ +#define VFIO_MIG_FLAG_END_OF_STATE (0xffffffffef100001ULL) +#define VFIO_MIG_FLAG_DEV_CONFIG_STATE (0xffffffffef100002ULL) +#define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL) +#define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL) + static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count, off_t off, bool iswrite) { @@ -129,6 +148,75 @@ static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask, return 0; } +static void vfio_migration_cleanup(VFIODevice *vbasedev) +{ + VFIOMigration *migration = vbasedev->migration; + + if (migration->region.mmaps) { + vfio_region_unmap(&migration->region); + } +} + +/* ---------------------------------------------------------------------- */ + +static int vfio_save_setup(QEMUFile *f, void *opaque) +{ + VFIODevice *vbasedev = opaque; + VFIOMigration *migration = vbasedev->migration; + int ret; + + trace_vfio_save_setup(vbasedev->name); + + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); + + if (migration->region.mmaps) { + /* + * Calling vfio_region_mmap() from migration thread. Memory API called + * from this function require locking the iothread when called from + * outside the main loop thread. + */ + qemu_mutex_lock_iothread(); + ret = vfio_region_mmap(&migration->region); + qemu_mutex_unlock_iothread(); + if (ret) { + error_report("%s: Failed to mmap VFIO migration region: %s", + vbasedev->name, strerror(-ret)); + error_report("%s: Falling back to slow path", vbasedev->name); + } + } + + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_MASK, + VFIO_DEVICE_STATE_SAVING); + if (ret) { + error_report("%s: Failed to set state SAVING", vbasedev->name); + return ret; + } + + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); + + ret = qemu_file_get_error(f); + if (ret) { + return ret; + } + + return 0; +} + +static void vfio_save_cleanup(void *opaque) +{ + VFIODevice *vbasedev = opaque; + + vfio_migration_cleanup(vbasedev); + trace_vfio_save_cleanup(vbasedev->name); +} + +static SaveVMHandlers savevm_vfio_handlers = { + .save_setup = vfio_save_setup, + .save_cleanup = vfio_save_cleanup, +}; + +/* ---------------------------------------------------------------------- */ + static void vfio_vmstate_change(void *opaque, int running, RunState state) { VFIODevice *vbasedev = opaque; @@ -217,6 +305,8 @@ static int vfio_migration_init(VFIODevice *vbasedev, int ret; Object *obj; VFIOMigration *migration; + char id[256] = ""; + g_autofree char *path = NULL, *oid = NULL; if (!vbasedev->ops->vfio_get_object) { return -EINVAL; @@ -247,6 +337,18 @@ static int vfio_migration_init(VFIODevice *vbasedev, } migration->vbasedev = vbasedev; + + oid = vmstate_if_get_id(VMSTATE_IF(DEVICE(obj))); + if (oid) { + path = g_strdup_printf("%s/vfio", oid); + } else { + path = g_strdup("vfio"); + } + strpadcpy(id, sizeof(id), path, '\0'); + + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, &savevm_vfio_handlers, + vbasedev); + migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change, vbasedev); migration->migration_state.notify = vfio_migration_state_notifier; diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index 78d7d83b5ef8..f148b5e828c1 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -151,3 +151,5 @@ vfio_migration_probe(const char *name, uint32_t index) " (%s) Region %d" vfio_migration_set_state(const char *name, uint32_t state) " (%s) state %d" vfio_vmstate_change(const char *name, int running, const char *reason, uint32_t dev_state) " (%s) running %d reason %s device state %d" vfio_migration_state_notifier(const char *name, const char *state) " (%s) state %s" +vfio_save_setup(const char *name) " (%s)" +vfio_save_cleanup(const char *name) " (%s)"