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Re: [PATCH v26 07/17] vfio: Register SaveVMHandlers for VFIO device
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [PATCH v26 07/17] vfio: Register SaveVMHandlers for VFIO device |
Date: |
Tue, 29 Sep 2020 11:19:35 +0100 |
User-agent: |
Mutt/1.14.6 (2020-07-11) |
* Philippe Mathieu-Daudé (philmd@redhat.com) wrote:
> On 9/23/20 1:24 AM, Kirti Wankhede wrote:
> > Define flags to be used as delimeter in migration file stream.
>
> Typo "delimiter".
>
> > Added .save_setup and .save_cleanup functions. Mapped & unmapped 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 | 91
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > hw/vfio/trace-events | 2 ++
> > 2 files changed, 93 insertions(+)
> >
> > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> > index f650fe9fc3c8..8e8adaa25779 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 +28,17 @@
> > #include "trace.h"
> > #include "hw/hw.h"
> >
> > +/*
> > + * Flags used as delimiter:
> > + * 0xffffffff => MSB 32-bit all 1s
> > + * 0xef10 => emulated (virtual) function IO
> > + * 0x0000 => 16-bits reserved for flags
> > + */
> > +#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)
> > {
> > @@ -166,6 +180,65 @@ static int vfio_migration_set_state(VFIODevice
> > *vbasedev, uint32_t mask,
> > return 0;
> > }
> >
> > +/* ----------------------------------------------------------------------
> > */
> > +
> > +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) {
> > + 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 %d: %s",
> > + vbasedev->name, migration->region.nr,
> > + 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;
> > + VFIOMigration *migration = vbasedev->migration;
> > +
> > + if (migration->region.mmaps) {
> > + vfio_region_unmap(&migration->region);
> > + }
> > + 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;
> > @@ -225,6 +298,8 @@ static int vfio_migration_init(VFIODevice *vbasedev,
> > struct vfio_region_info *info)
> > {
> > int ret = -EINVAL;
> > + char id[256] = "";
> > + Object *obj;
> >
> > if (!vbasedev->ops->vfio_get_object) {
> > return ret;
> > @@ -241,6 +316,22 @@ static int vfio_migration_init(VFIODevice *vbasedev,
> > return ret;
> > }
> >
> > + obj = vbasedev->ops->vfio_get_object(vbasedev);
> > +
> > + if (obj) {
> > + DeviceState *dev = DEVICE(obj);
> > + char *oid = vmstate_if_get_id(VMSTATE_IF(dev));
> > +
> > + if (oid) {
> > + pstrcpy(id, sizeof(id), oid);
> > + pstrcat(id, sizeof(id), "/");
> > + g_free(oid);
> > + }
> > + }
> > + pstrcat(id, sizeof(id), "vfio");
>
> Alternatively (easier to review, matter of taste):
>
> g_autofree char *path = NULL;
>
> if (oid) {
> path = g_strdup_printf("%s/vfio",
> vmstate_if_get_id(VMSTATE_IF(obj)););
> } else {
> path = g_strdup("vfio");
> }
> strpadcpy(id, sizeof(id), path, '\0');
Maybe, although it's a straight copy of the magic in unregister_savevm.
Dave
> > +
> > + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1,
> > &savevm_vfio_handlers,
> > + vbasedev);
> > vbasedev->vm_state =
> > qemu_add_vm_change_state_handler(vfio_vmstate_change,
> > vbasedev);
> > vbasedev->migration_state.notify = vfio_migration_state_notifier;
> > diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> > index bcb3fa7314d7..982d8dccb219 100644
> > --- a/hw/vfio/trace-events
> > +++ b/hw/vfio/trace-events
> > @@ -152,3 +152,5 @@ 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)"
> >
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
- Re: [PATCH v26 04/17] vfio: Add migration region initialization and finalize function, (continued)
- [PATCH v26 05/17] vfio: Add VM state change handler to know state of VM, Kirti Wankhede, 2020/09/22
- [PATCH v26 06/17] vfio: Add migration state change notifier, Kirti Wankhede, 2020/09/22
- [PATCH v26 07/17] vfio: Register SaveVMHandlers for VFIO device, Kirti Wankhede, 2020/09/22
- [PATCH v26 08/17] vfio: Add save state functions to SaveVMHandlers, Kirti Wankhede, 2020/09/22
- [PATCH v26 09/17] vfio: Add load state functions to SaveVMHandlers, Kirti Wankhede, 2020/09/22
- [PATCH v26 10/17] memory: Set DIRTY_MEMORY_MIGRATION when IOMMU is enabled, Kirti Wankhede, 2020/09/22
- [PATCH v26 12/17] vfio: Add function to start and stop dirty pages tracking, Kirti Wankhede, 2020/09/22
- [PATCH v26 11/17] vfio: Get migration capability flags for container, Kirti Wankhede, 2020/09/22