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authorSascha Bischoff <Sascha.Bischoff@arm.com>2025-12-08 15:28:22 +0000
committerMarc Zyngier <maz@kernel.org>2026-01-27 14:06:26 +0000
commitda63758c1876d899031066a9d4b8050af767ceb8 (patch)
tree4aafb8a0fe4dd48ad693a787d2938812d3c991a3
parent9ace4753a5202b02191d54e9fdf7f9e3d02b85eb (diff)
KVM: arm64: gic: Enable GICv3 CPUIF trapping on GICv5 hosts if required
Factor out the enable (and printing of) the GICv3 CPUIF traps from the main GICv3 probe into a separate function. Call said function from the GICv5 probe for legacy support, ensuring that any required GICv3 CPUIF traps on GICv5 hosts will be correctly handled, rather than injecting an undef into the guest. Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com> Link: https://patch.msgid.link/20251208152724.3637157-3-sascha.bischoff@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
-rw-r--r--arch/arm64/kvm/vgic/vgic-v3.c25
-rw-r--r--arch/arm64/kvm/vgic/vgic-v5.c2
-rw-r--r--arch/arm64/kvm/vgic/vgic.h1
3 files changed, 18 insertions, 10 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 1d6dd1b545bd..4b03a726f164 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -880,6 +880,20 @@ void noinstr kvm_compute_ich_hcr_trap_bits(struct alt_instr *alt,
*updptr = cpu_to_le32(insn);
}
+void vgic_v3_enable_cpuif_traps(void)
+{
+ u64 traps = vgic_ich_hcr_trap_bits();
+
+ if (traps) {
+ kvm_info("GICv3 sysreg trapping enabled ([%s%s%s%s], reduced performance)\n",
+ (traps & ICH_HCR_EL2_TALL0) ? "G0" : "",
+ (traps & ICH_HCR_EL2_TALL1) ? "G1" : "",
+ (traps & ICH_HCR_EL2_TC) ? "C" : "",
+ (traps & ICH_HCR_EL2_TDIR) ? "D" : "");
+ static_branch_enable(&vgic_v3_cpuif_trap);
+ }
+}
+
/**
* vgic_v3_probe - probe for a VGICv3 compatible interrupt controller
* @info: pointer to the GIC description
@@ -891,7 +905,6 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
{
u64 ich_vtr_el2 = kvm_call_hyp_ret(__vgic_v3_get_gic_config);
bool has_v2;
- u64 traps;
int ret;
has_v2 = ich_vtr_el2 >> 63;
@@ -955,15 +968,7 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
kvm_vgic_global_state.ich_vtr_el2 &= ~ICH_VTR_EL2_SEIS;
}
- traps = vgic_ich_hcr_trap_bits();
- if (traps) {
- kvm_info("GICv3 sysreg trapping enabled ([%s%s%s%s], reduced performance)\n",
- (traps & ICH_HCR_EL2_TALL0) ? "G0" : "",
- (traps & ICH_HCR_EL2_TALL1) ? "G1" : "",
- (traps & ICH_HCR_EL2_TC) ? "C" : "",
- (traps & ICH_HCR_EL2_TDIR) ? "D" : "");
- static_branch_enable(&vgic_v3_cpuif_trap);
- }
+ vgic_v3_enable_cpuif_traps();
kvm_vgic_global_state.vctrl_base = NULL;
kvm_vgic_global_state.type = VGIC_V3;
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 2d3811f4e117..331651087e2c 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -48,5 +48,7 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
kvm_info("GCIE legacy system register CPU interface\n");
+ vgic_v3_enable_cpuif_traps();
+
return 0;
}
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 5f0fc96b4dc2..c9b3bb07e483 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -324,6 +324,7 @@ void vgic_v3_configure_hcr(struct kvm_vcpu *vcpu, struct ap_list_summary *als);
void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
void vgic_v3_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
void vgic_v3_reset(struct kvm_vcpu *vcpu);
+void vgic_v3_enable_cpuif_traps(void);
int vgic_v3_probe(const struct gic_kvm_info *info);
int vgic_v3_map_resources(struct kvm *kvm);
int vgic_v3_lpi_sync_pending_status(struct kvm *kvm, struct vgic_irq *irq);