From c017e49ed1381001ba7a6521daae8f968b11cf09 Mon Sep 17 00:00:00 2001 From: Sascha Bischoff Date: Fri, 27 Jun 2025 10:09:02 +0000 Subject: KVM: arm64: gic-v5: Support GICv3 compat Add support for GICv3 compat mode (FEAT_GCIE_LEGACY) which allows a GICv5 host to run GICv3-based VMs. This change enables the VHE/nVHE/hVHE/protected modes, but does not support nested virtualization. A lazy-disable approach is taken for compat mode; it is enabled on the vgic_v3_load path but not disabled on the vgic_v3_put path. A non-GICv3 VM, i.e., one based on GICv5, is responsible for disabling compat mode on the corresponding vgic_v5_load path. Currently, GICv5 is not supported, and hence compat mode is not disabled again once it is enabled, and this function is intentionally omitted from the code. Co-authored-by: Timothy Hayes Signed-off-by: Timothy Hayes Signed-off-by: Sascha Bischoff Link: https://lore.kernel.org/r/20250627100847.1022515-5-sascha.bischoff@arm.com Signed-off-by: Oliver Upton --- include/kvm/arm_vgic.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 4a34f7f0a864..5c293e0ff5c1 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -38,6 +38,7 @@ enum vgic_type { VGIC_V2, /* Good ol' GICv2 */ VGIC_V3, /* New fancy GICv3 */ + VGIC_V5, /* Newer, fancier GICv5 */ }; /* same for all guests, as depending only on the _host's_ GIC model */ @@ -77,9 +78,12 @@ struct vgic_global { /* Pseudo GICv3 from outer space */ bool no_hw_deactivation; - /* GIC system register CPU interface */ + /* GICv3 system register CPU interface */ struct static_key_false gicv3_cpuif; + /* GICv3 compat mode on a GICv5 host */ + bool has_gcie_v3_compat; + u32 ich_vtr_el2; }; -- cgit v1.2.3