diff mbox series

[v29,05/17] vfio: Add VM state change handler to know state of VM

Message ID 1603704987-20977-6-git-send-email-kwankhede@nvidia.com
State New
Headers show
Series Add migration support for VFIO devices | expand

Commit Message

Kirti Wankhede Oct. 26, 2020, 9:36 a.m. UTC 
VM state change handler is called on change in VM's state. Based on
VM state, VFIO device state should be changed.
Added read/write helper functions for migration region.
Added function to set device_state.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
---
 hw/vfio/migration.c           | 158 ++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/trace-events          |   2 +
 include/hw/vfio/vfio-common.h |   4 ++
 3 files changed, 164 insertions(+)

Comments

Alex Williamson Oct. 26, 2020, 1 p.m. UTC | #1 
On Mon, 26 Oct 2020 15:06:15 +0530
Kirti Wankhede <kwankhede@nvidia.com> wrote:

> VM state change handler is called on change in VM's state. Based on
> VM state, VFIO device state should be changed.
> Added read/write helper functions for migration region.
> Added function to set device_state.
> 
> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> Reviewed-by: Neo Jia <cjia@nvidia.com>
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> ---
>  hw/vfio/migration.c           | 158 ++++++++++++++++++++++++++++++++++++++++++
>  hw/vfio/trace-events          |   2 +
>  include/hw/vfio/vfio-common.h |   4 ++
>  3 files changed, 164 insertions(+)
> 
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index fd7faf423cdc..65ce735d667b 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
[snip]
> @@ -64,6 +216,9 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>          ret = -EINVAL;
>          goto err;
>      }
> +
> +    migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
> +                                                           vbasedev);
>      return 0;
>  
>  err:

Fails to build, @migration is not defined.  We could use
vbasedev->migration or pull defining and setting @migration from patch
06.  Thanks,

Alex
Kirti Wankhede Oct. 26, 2020, 1:48 p.m. UTC | #2 
On 10/26/2020 6:30 PM, Alex Williamson wrote:
> On Mon, 26 Oct 2020 15:06:15 +0530
> Kirti Wankhede <kwankhede@nvidia.com> wrote:
> 
>> VM state change handler is called on change in VM's state. Based on
>> VM state, VFIO device state should be changed.
>> Added read/write helper functions for migration region.
>> Added function to set device_state.
>>
>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
>> Reviewed-by: Neo Jia <cjia@nvidia.com>
>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>>   hw/vfio/migration.c           | 158 ++++++++++++++++++++++++++++++++++++++++++
>>   hw/vfio/trace-events          |   2 +
>>   include/hw/vfio/vfio-common.h |   4 ++
>>   3 files changed, 164 insertions(+)
>>
>> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
>> index fd7faf423cdc..65ce735d667b 100644
>> --- a/hw/vfio/migration.c
>> +++ b/hw/vfio/migration.c
> [snip]
>> @@ -64,6 +216,9 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>>           ret = -EINVAL;
>>           goto err;
>>       }
>> +
>> +    migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
>> +                                                           vbasedev);
>>       return 0;
>>   
>>   err:
> 
> Fails to build, @migration is not defined.  We could use
> vbasedev->migration or pull defining and setting @migration from patch
> 06.  Thanks,
> 

Pulling and setting migration from patch 06 seems better option.
Should I resend patch 5 & 6 only?

Thanks,
Kirti
Alex Williamson Oct. 26, 2020, 2:02 p.m. UTC | #3 
On Mon, 26 Oct 2020 19:18:51 +0530
Kirti Wankhede <kwankhede@nvidia.com> wrote:

> On 10/26/2020 6:30 PM, Alex Williamson wrote:
> > On Mon, 26 Oct 2020 15:06:15 +0530
> > Kirti Wankhede <kwankhede@nvidia.com> wrote:
> >   
> >> VM state change handler is called on change in VM's state. Based on
> >> VM state, VFIO device state should be changed.
> >> Added read/write helper functions for migration region.
> >> Added function to set device_state.
> >>
> >> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> >> Reviewed-by: Neo Jia <cjia@nvidia.com>
> >> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> >> ---
> >>   hw/vfio/migration.c           | 158 ++++++++++++++++++++++++++++++++++++++++++
> >>   hw/vfio/trace-events          |   2 +
> >>   include/hw/vfio/vfio-common.h |   4 ++
> >>   3 files changed, 164 insertions(+)
> >>
> >> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> >> index fd7faf423cdc..65ce735d667b 100644
> >> --- a/hw/vfio/migration.c
> >> +++ b/hw/vfio/migration.c  
> > [snip]  
> >> @@ -64,6 +216,9 @@ static int vfio_migration_init(VFIODevice *vbasedev,
> >>           ret = -EINVAL;
> >>           goto err;
> >>       }
> >> +
> >> +    migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
> >> +                                                           vbasedev);
> >>       return 0;
> >>   
> >>   err:  
> > 
> > Fails to build, @migration is not defined.  We could use
> > vbasedev->migration or pull defining and setting @migration from patch
> > 06.  Thanks,
> >   
> 
> Pulling and setting migration from patch 06 seems better option.
> Should I resend patch 5 & 6 only?

I've resolved this locally as patch 05:

@@ -38,6 +190,7 @@ static int vfio_migration_init(VFIODevice *vbasedev,
 {
     int ret;
     Object *obj;
+    VFIOMigration *migration;
 
     if (!vbasedev->ops->vfio_get_object) {
         return -EINVAL;
@@ -64,6 +217,10 @@ static int vfio_migration_init(VFIODevice *vbasedev,
         ret = -EINVAL;
         goto err;
     }
+
+    migration = vbasedev->migration;
+    migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
+                                                           vbasedev);
     return 0;
 
 err:

patch 06:

@@ -219,8 +243,11 @@ static int vfio_migration_init(VFIODevice *vbasedev,
     }
 
     migration = vbasedev->migration;
+    migration->vbasedev = vbasedev;
     migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
                                                            vbasedev);
+    migration->migration_state.notify = vfio_migration_state_notifier;
+    add_migration_state_change_notifier(&migration->migration_state);
     return 0;
 
 err:

If you're satisfied with that, no need to resend.  Thanks,

Alex
Kirti Wankhede Oct. 26, 2020, 2:37 p.m. UTC | #4 
On 10/26/2020 7:32 PM, Alex Williamson wrote:
> On Mon, 26 Oct 2020 19:18:51 +0530
> Kirti Wankhede <kwankhede@nvidia.com> wrote:
> 
>> On 10/26/2020 6:30 PM, Alex Williamson wrote:
>>> On Mon, 26 Oct 2020 15:06:15 +0530
>>> Kirti Wankhede <kwankhede@nvidia.com> wrote:
>>>    
>>>> VM state change handler is called on change in VM's state. Based on
>>>> VM state, VFIO device state should be changed.
>>>> Added read/write helper functions for migration region.
>>>> Added function to set device_state.
>>>>
>>>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
>>>> Reviewed-by: Neo Jia <cjia@nvidia.com>
>>>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>>> ---
>>>>    hw/vfio/migration.c           | 158 ++++++++++++++++++++++++++++++++++++++++++
>>>>    hw/vfio/trace-events          |   2 +
>>>>    include/hw/vfio/vfio-common.h |   4 ++
>>>>    3 files changed, 164 insertions(+)
>>>>
>>>> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
>>>> index fd7faf423cdc..65ce735d667b 100644
>>>> --- a/hw/vfio/migration.c
>>>> +++ b/hw/vfio/migration.c
>>> [snip]
>>>> @@ -64,6 +216,9 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>>>>            ret = -EINVAL;
>>>>            goto err;
>>>>        }
>>>> +
>>>> +    migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
>>>> +                                                           vbasedev);
>>>>        return 0;
>>>>    
>>>>    err:
>>>
>>> Fails to build, @migration is not defined.  We could use
>>> vbasedev->migration or pull defining and setting @migration from patch
>>> 06.  Thanks,
>>>    
>>
>> Pulling and setting migration from patch 06 seems better option.
>> Should I resend patch 5 & 6 only?
> 
> I've resolved this locally as patch 05:
> 
> @@ -38,6 +190,7 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>   {
>       int ret;
>       Object *obj;
> +    VFIOMigration *migration;
>   
>       if (!vbasedev->ops->vfio_get_object) {
>           return -EINVAL;
> @@ -64,6 +217,10 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>           ret = -EINVAL;
>           goto err;
>       }
> +
> +    migration = vbasedev->migration;
> +    migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
> +                                                           vbasedev);
>       return 0;
>   
>   err:
> 
> patch 06:
> 
> @@ -219,8 +243,11 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>       }
>   
>       migration = vbasedev->migration;
> +    migration->vbasedev = vbasedev;
>       migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
>                                                              vbasedev);
> +    migration->migration_state.notify = vfio_migration_state_notifier;
> +    add_migration_state_change_notifier(&migration->migration_state);
>       return 0;
>   
>   err:
> 
> If you're satisfied with that, no need to resend.  Thanks,
> 

Yes, this is exactly I was going to send.
Thanks for fixing it.

Thanks,
Kirti
diff mbox series

Patch

diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index fd7faf423cdc..65ce735d667b 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -10,6 +10,7 @@ 
 #include "qemu/osdep.h"
 #include <linux/vfio.h>
 
+#include "sysemu/runstate.h"
 #include "hw/vfio/vfio-common.h"
 #include "cpu.h"
 #include "migration/migration.h"
@@ -22,6 +23,157 @@ 
 #include "exec/ram_addr.h"
 #include "pci.h"
 #include "trace.h"
+#include "hw/hw.h"
+
+static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count,
+                                  off_t off, bool iswrite)
+{
+    int ret;
+
+    ret = iswrite ? pwrite(vbasedev->fd, val, count, off) :
+                    pread(vbasedev->fd, val, count, off);
+    if (ret < count) {
+        error_report("vfio_mig_%s %d byte %s: failed at offset 0x%lx, err: %s",
+                     iswrite ? "write" : "read", count,
+                     vbasedev->name, off, strerror(errno));
+        return (ret < 0) ? ret : -EINVAL;
+    }
+    return 0;
+}
+
+static int vfio_mig_rw(VFIODevice *vbasedev, __u8 *buf, size_t count,
+                       off_t off, bool iswrite)
+{
+    int ret, done = 0;
+    __u8 *tbuf = buf;
+
+    while (count) {
+        int bytes = 0;
+
+        if (count >= 8 && !(off % 8)) {
+            bytes = 8;
+        } else if (count >= 4 && !(off % 4)) {
+            bytes = 4;
+        } else if (count >= 2 && !(off % 2)) {
+            bytes = 2;
+        } else {
+            bytes = 1;
+        }
+
+        ret = vfio_mig_access(vbasedev, tbuf, bytes, off, iswrite);
+        if (ret) {
+            return ret;
+        }
+
+        count -= bytes;
+        done += bytes;
+        off += bytes;
+        tbuf += bytes;
+    }
+    return done;
+}
+
+#define vfio_mig_read(f, v, c, o)       vfio_mig_rw(f, (__u8 *)v, c, o, false)
+#define vfio_mig_write(f, v, c, o)      vfio_mig_rw(f, (__u8 *)v, c, o, true)
+
+#define VFIO_MIG_STRUCT_OFFSET(f)       \
+                                 offsetof(struct vfio_device_migration_info, f)
+/*
+ * Change the device_state register for device @vbasedev. Bits set in @mask
+ * are preserved, bits set in @value are set, and bits not set in either @mask
+ * or @value are cleared in device_state. If the register cannot be accessed,
+ * the resulting state would be invalid, or the device enters an error state,
+ * an error is returned.
+ */
+
+static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask,
+                                    uint32_t value)
+{
+    VFIOMigration *migration = vbasedev->migration;
+    VFIORegion *region = &migration->region;
+    off_t dev_state_off = region->fd_offset +
+                          VFIO_MIG_STRUCT_OFFSET(device_state);
+    uint32_t device_state;
+    int ret;
+
+    ret = vfio_mig_read(vbasedev, &device_state, sizeof(device_state),
+                        dev_state_off);
+    if (ret < 0) {
+        return ret;
+    }
+
+    device_state = (device_state & mask) | value;
+
+    if (!VFIO_DEVICE_STATE_VALID(device_state)) {
+        return -EINVAL;
+    }
+
+    ret = vfio_mig_write(vbasedev, &device_state, sizeof(device_state),
+                         dev_state_off);
+    if (ret < 0) {
+        int rret;
+
+        rret = vfio_mig_read(vbasedev, &device_state, sizeof(device_state),
+                             dev_state_off);
+
+        if ((rret < 0) || (VFIO_DEVICE_STATE_IS_ERROR(device_state))) {
+            hw_error("%s: Device in error state 0x%x", vbasedev->name,
+                     device_state);
+            return rret ? rret : -EIO;
+        }
+        return ret;
+    }
+
+    migration->device_state = device_state;
+    trace_vfio_migration_set_state(vbasedev->name, device_state);
+    return 0;
+}
+
+static void vfio_vmstate_change(void *opaque, int running, RunState state)
+{
+    VFIODevice *vbasedev = opaque;
+    VFIOMigration *migration = vbasedev->migration;
+    uint32_t value, mask;
+    int ret;
+
+    if ((vbasedev->migration->vm_running == running)) {
+        return;
+    }
+
+    if (running) {
+        /*
+         * Here device state can have one of _SAVING, _RESUMING or _STOP bit.
+         * Transition from _SAVING to _RUNNING can happen if there is migration
+         * failure, in that case clear _SAVING bit.
+         * Transition from _RESUMING to _RUNNING occurs during resuming
+         * phase, in that case clear _RESUMING bit.
+         * In both the above cases, set _RUNNING bit.
+         */
+        mask = ~VFIO_DEVICE_STATE_MASK;
+        value = VFIO_DEVICE_STATE_RUNNING;
+    } else {
+        /*
+         * Here device state could be either _RUNNING or _SAVING|_RUNNING. Reset
+         * _RUNNING bit
+         */
+        mask = ~VFIO_DEVICE_STATE_RUNNING;
+        value = 0;
+    }
+
+    ret = vfio_migration_set_state(vbasedev, mask, value);
+    if (ret) {
+        /*
+         * Migration should be aborted in this case, but vm_state_notify()
+         * currently does not support reporting failures.
+         */
+        error_report("%s: Failed to set device state 0x%x", vbasedev->name,
+                     (migration->device_state & mask) | value);
+        qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
+    }
+    vbasedev->migration->vm_running = running;
+    trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state),
+            (migration->device_state & mask) | value);
+}
 
 static void vfio_migration_exit(VFIODevice *vbasedev)
 {
@@ -64,6 +216,9 @@  static int vfio_migration_init(VFIODevice *vbasedev,
         ret = -EINVAL;
         goto err;
     }
+
+    migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
+                                                           vbasedev);
     return 0;
 
 err:
@@ -111,6 +266,9 @@  add_blocker:
 void vfio_migration_finalize(VFIODevice *vbasedev)
 {
     if (vbasedev->migration) {
+        VFIOMigration *migration = vbasedev->migration;
+
+        qemu_del_vm_change_state_handler(migration->vm_state);
         vfio_migration_exit(vbasedev);
     }
 
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index 9ced5ec6277c..41de81f12f60 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -148,3 +148,5 @@  vfio_display_edid_write_error(void) ""
 
 # migration.c
 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"
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 8275c4c68f45..9a571f1fb552 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -29,6 +29,7 @@ 
 #ifdef CONFIG_LINUX
 #include <linux/vfio.h>
 #endif
+#include "sysemu/sysemu.h"
 
 #define VFIO_MSG_PREFIX "vfio %s: "
 
@@ -58,7 +59,10 @@  typedef struct VFIORegion {
 } VFIORegion;
 
 typedef struct VFIOMigration {
+    VMChangeStateEntry *vm_state;
     VFIORegion region;
+    uint32_t device_state;
+    int vm_running;
 } VFIOMigration;
 
 typedef struct VFIOAddressSpace {