KVM: arm64: Enable GICv3 Group-0 sysreg trapping via command-line

Now that we're able to safely handle Group-0 sysreg access, let's
give the user the opportunity to enable it by passing a specific
command-line option (vgic_v3.group0_trap).

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 42fe395be6c8d4a24f3ad8022f68b57a37522b34..88bdc421351f6ff18648554a0bf44d52b5b0f86b 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1829,6 +1829,10 @@
                        for all guests.
                        Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
 
+       kvm-arm.vgic_v3_group0_trap=
+                       [KVM,ARM] Trap guest accesses to GICv3 group-0
+                       system registers
+
        kvm-arm.vgic_v3_group1_trap=
                        [KVM,ARM] Trap guest accesses to GICv3 group-1
                        system registers

diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 39046ee5be2547b5b33269a82974c0c86ed5ed15..828ca7f9a0606f266a4ac9a5216d4c288637a5fe 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -438,6 +438,12 @@ out:
 
 DEFINE_STATIC_KEY_FALSE(vgic_v3_cpuif_trap);
 
+static int __init early_group0_trap_cfg(char *buf)
+{
+       return strtobool(buf, &group0_trap);
+}
+early_param("kvm-arm.vgic_v3_group0_trap", early_group0_trap_cfg);
+
 static int __init early_group1_trap_cfg(char *buf)
 {
        return strtobool(buf, &group1_trap);