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

[Chris J Arges]

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.
-- 
1.9.1