Re: [PATCH mlx5-next 2/7] vfio: Add an API to check migration state transition validity

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 9/29/2021 7:14 PM, Jason Gunthorpe wrote:
On Wed, Sep 29, 2021 at 06:28:44PM +0300, Max Gurtovoy wrote:

So you have a device that's actively modifying its internal state,
performing I/O, including DMA (thereby dirtying VM memory), all while
in the _STOP state?  And you don't see this as a problem?
I don't see how is it different from vfio-pci situation.
vfio-pci provides no way to observe the migration state. It isn't
"000b"

Alex said that there is a problem of compatibility.

I migration SW is not involved, nobody will read this migration state.

Maybe we need to rename STOP state. We can call it READY or LIVE or
NON_MIGRATION_STATE.
It was a poor choice to use 000b as stop, but it doesn't really
matter. The mlx5 driver should just pre-init this readable to running.

I guess we can do it for this reason. There is no functional problem nor compatibility issue here as was mentioned.

But still we need the kernel to track transitions. We don't want to allow moving from RESUMING to SAVING state for example. How this transition can be allowed ?

In this case we need to fail the request from the migration SW...



Jason



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux