[for,3.12.y,stable,06/63] ARM: KVM: fix L2CTLR to be per-cluster

Message ID 1429853281-6136-7-git-send-email-shannon.zhao@linaro.org
State New
Headers show

Commit Message

Shannon Zhao April 24, 2015, 5:27 a.m.
From: Marc Zyngier <marc.zyngier@arm.com>

commit 9cbb6d969cb6561de45d917b8bb9281cb374bb35 upstream.

The L2CTLR register contains the number of CPUs in this cluster.

Make sure the register content is actually relevant to the vcpu
that is being configured by computing the number of cores that are
part of its cluster.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
---
 arch/arm/kvm/coproc_a15.c | 4 ++++
 1 file changed, 4 insertions(+)

Patch

diff --git a/arch/arm/kvm/coproc_a15.c b/arch/arm/kvm/coproc_a15.c
index 8611c5c..935fa0f 100644
--- a/arch/arm/kvm/coproc_a15.c
+++ b/arch/arm/kvm/coproc_a15.c
@@ -79,6 +79,10 @@  static void reset_l2ctlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
 	asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
 	l2ctlr &= ~(3 << 24);
 	ncores = atomic_read(&vcpu->kvm->online_vcpus) - 1;
+	/* How many cores in the current cluster and the next ones */
+	ncores -= (vcpu->vcpu_id & ~3);
+	/* Cap it to the maximum number of cores in a single cluster */
+	ncores = min(ncores, 3U);
 	l2ctlr |= (ncores & 3) << 24;
 
 	vcpu->arch.cp15[c9_L2CTLR] = l2ctlr;