From: Marc Zyngier <marc.zyngier@arm.com>
Date: Thu, 29 Aug 2013 10:08:23 +0000 (+0100)
Subject: ARM: KVM: vgic: fix GICD_ICFGRn access
X-Git-Tag: firefly_0821_release~3680^2~36^2~16^2^2~229
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=635c887f2931a200a52694170122e2b62d1b6218;p=firefly-linux-kernel-4.4.55.git

ARM: KVM: vgic: fix GICD_ICFGRn access

All the code in handle_mmio_cfg_reg() assumes the offset has
been shifted right to accomodate for the 2:1 bit compression,
but this is only done when getting the register address.

Shift the offset early so the code works mostly unchanged.

Reported-by: Zhaobo (Bob, ERC) <zhaobo@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 6545eae3d7a1b6dc2edb8ede9107998aee1207ef)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index a2d478aec046..902789ff4abb 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -541,8 +541,12 @@ static bool handle_mmio_cfg_reg(struct kvm_vcpu *vcpu,
 				struct kvm_exit_mmio *mmio, phys_addr_t offset)
 {
 	u32 val;
-	u32 *reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_cfg,
-				       vcpu->vcpu_id, offset >> 1);
+	u32 *reg;
+
+	offset >>= 1;
+	reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_cfg,
+				  vcpu->vcpu_id, offset);
+
 	if (offset & 2)
 		val = *reg >> 16;
 	else