hw/intc/arm_gicv3_kvm: Check KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS in reset

KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS needs to be checked before
attempting to read ICC_CTLR_EL1; otherwise kernel versions not
exposing this kvm device group will be incompatible with qemu 2.9.

Fixes: 07a5628  ("hw/intc/arm_gicv3_kvm: Reset GICv3 cpu interface registers")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reported-by: Prakash B <bjsprakash.linux@gmail.com>
Tested-by: Alexander Graf <agraf@suse.de>
Message-id: 1490721640-13052-1-git-send-email-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/hw/intc/arm_gicv3_kvm.c b/hw/intc/arm_gicv3_kvm.c
index 81f0403117d1325f3fd7dfd589ad6b89f7437545..19aab56072f9dd496ca64130cfdc698765105a79 100644 (file)
--- a/hw/intc/arm_gicv3_kvm.c
+++ b/hw/intc/arm_gicv3_kvm.c
@@ -614,12 +614,6 @@ static void arm_gicv3_icc_reset(CPUARMState *env, const ARMCPRegInfo *ri)
     s = c->gic;
     cpu = ARM_CPU(c->cpu);
 
-    /* Initialize to actual HW supported configuration */
-    kvm_device_access(s->dev_fd, KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS,
-                      KVM_VGIC_ATTR(ICC_CTLR_EL1, cpu->mp_affinity),
-                      &c->icc_ctlr_el1[GICV3_NS], false);
-
-    c->icc_ctlr_el1[GICV3_S] = c->icc_ctlr_el1[GICV3_NS];
     c->icc_pmr_el1 = 0;
     c->icc_bpr[GICV3_G0] = GIC_MIN_BPR;
     c->icc_bpr[GICV3_G1] = GIC_MIN_BPR;
@@ -628,6 +622,17 @@ static void arm_gicv3_icc_reset(CPUARMState *env, const ARMCPRegInfo *ri)
     c->icc_sre_el1 = 0x7;
     memset(c->icc_apr, 0, sizeof(c->icc_apr));
     memset(c->icc_igrpen, 0, sizeof(c->icc_igrpen));
+
+    if (s->migration_blocker) {
+        return;
+    }
+
+    /* Initialize to actual HW supported configuration */
+    kvm_device_access(s->dev_fd, KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS,
+                      KVM_VGIC_ATTR(ICC_CTLR_EL1, cpu->mp_affinity),
+                      &c->icc_ctlr_el1[GICV3_NS], false);
+
+    c->icc_ctlr_el1[GICV3_S] = c->icc_ctlr_el1[GICV3_NS];
 }
 
 static void kvm_arm_gicv3_reset(DeviceState *dev)