RE: KVM Live migration with GICv3

[Pavel Fedin <p.fedin@samsung.com>]

 Hello!

>    I have prototyped Live migration with GICv3.

 This is interesting of course, i will need this for my project too and i was also going to take a look at this later.

> For this I have made following changes
> 
> 1) Save and Restore of GICv3 registers in QEMU.
>     - For GICv2, QEMU is saving/restoring GICD, GICC  registers. For GICv3,
>      we have to save/restore GICD, GICR and ICC registers.
>      However ICC registers are system registers which cannot be
> accessed @ EL0 level (SRE=1). So these ICC registers should be
> accessed as mmio registers by QEMU, for this we have to add ioctl to
> access ICC @ EL1 level similar to GICC registers of GICv2.

 Sorry, your description is a bit fuzzy. What ioctl's did you have to add and why?
 The kernel already has KVM_GET_ONE_REG and KVM_SET_ONE_REG ioctl's. And they can be used to access anything inside the VM, including system registers. I believe you would need only to implement handlers for GICv3 registers.

> Please provide your initial feedback.

 Would be nice to take a look at patches.

> I am attending KVM-forum next week @ Seattle. We can discuss there as well.

 I would love to go there, and my company wanted to send me there. But it appears to be extremely difficult for a tech specialist from Russia to get a US visa. They are still considering me and the time is running out, so i'm unlikely to attend, unfortunately.

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia