[Acked] [Utopic/Trusty][SRU][PATCH] KVM: PPC: BOOK3S: HV: CMA: Reserve cma region only in hypervisor mode

[Andy Whitcroft]

On Tue, Dec 16, 2014 at 05:19:36PM -0600, Chris J Arges wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1400209
> 
> We use cma reserved area for creating guest hash page table.
> Don't do the reservation in non-hypervisor mode. This avoids unnecessary
> CMA reservation when booting with limited memory configs like
> fadump and kdump.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> Reviewed-by: Alexander Graf <agraf at suse.de>
> Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
> (cherry picked from commit cec26bc3c125b5dd12a02f04133cd91eae3f1622)
> Signed-off-by: Chris J Arges <chris.j.arges at canonical.com>
> ---
>  arch/powerpc/kvm/book3s_hv_builtin.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
> index 7cde8a6..73f19fb 100644
> --- a/arch/powerpc/kvm/book3s_hv_builtin.c
> +++ b/arch/powerpc/kvm/book3s_hv_builtin.c
> @@ -157,6 +157,12 @@ void __init kvm_cma_reserve(void)
>  	unsigned long align_size;
>  	struct memblock_region *reg;
>  	phys_addr_t selected_size = 0;
> +
> +	/*
> +	 * We need CMA reservation only when we are in HV mode
> +	 */
> +	if (!cpu_has_feature(CPU_FTR_HVMODE))
> +		return;
>  	/*
>  	 * We cannot use memblock_phys_mem_size() here, because
>  	 * memblock_analyze() has not been called yet.

Looks reasonable.  Upstream cherry-pick, very targetted.

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw