[PATCH 12/19] KVM: PPC: Book3S HV: record guest queue page address

[David Gibson]

On Mon, Jan 07, 2019 at 07:43:24PM +0100, Cédric Le Goater wrote:
> The guest physical address of the event queue will be part of the
> state to transfer in the migration. Cache its value when the queue is
> configured, it will save us an OPAL call.

That doesn't sound like a very compelling case - migration is already
a hundreds of milliseconds type operation, I wouldn't expect a few
extra OPAL calls to be an issue.

> 
> Signed-off-by: Cédric Le Goater <clg at kaod.org>
> ---
>  arch/powerpc/include/asm/xive.h       | 2 ++
>  arch/powerpc/kvm/book3s_xive_native.c | 4 ++++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h
> index 7a7aa22d8258..e90c3c5d9533 100644
> --- a/arch/powerpc/include/asm/xive.h
> +++ b/arch/powerpc/include/asm/xive.h
> @@ -74,6 +74,8 @@ struct xive_q {
>  	u32			esc_irq;
>  	atomic_t		count;
>  	atomic_t		pending_count;
> +	u64			guest_qpage;
> +	u32			guest_qsize;
>  };
>  
>  /* Global enable flags for the XIVE support */
> diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
> index 35d806740c3a..4ca75aade069 100644
> --- a/arch/powerpc/kvm/book3s_xive_native.c
> +++ b/arch/powerpc/kvm/book3s_xive_native.c
> @@ -708,6 +708,10 @@ static int kvmppc_h_int_set_queue_config(struct kvm_vcpu *vcpu,
>  	}
>  	qaddr = page_to_virt(page) + (qpage & ~PAGE_MASK);
>  
> +	/* Backup queue page address and size for migration */
> +	q->guest_qpage = qpage;
> +	q->guest_qsize = qsize;
> +
>  	rc = xive_native_configure_queue(xc->vp_id, q, priority,
>  					 (__be32 *) qaddr, qsize, true);
>  	if (rc) {

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
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