Re: [PATCH v2 2/5] irqchip/gic-v5: Populate struct gic_kvm_info
From: Lorenzo Pieralisi <lpieralisi@kernel.org>
Date: 2025-07-01 09:46:04
Also in:
kvm, kvmarm, lkml
On Fri, Jun 27, 2025 at 10:09:01AM +0000, Sascha Bischoff wrote:
Populate the gic_kvm_info struct based on support for FEAT_GCIE_LEGACY. The struct is used by KVM to probe for a compatible GIC. Co-authored-by: Timothy Hayes [off-list ref] Signed-off-by: Timothy Hayes <redacted> Signed-off-by: Sascha Bischoff <redacted> --- drivers/irqchip/irq-gic-v5.c | 33 +++++++++++++++++++++++++++ include/linux/irqchip/arm-vgic-info.h | 4 ++++ 2 files changed, 37 insertions(+)
Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
quoted hunk ↗ jump to hunk
diff --git a/drivers/irqchip/irq-gic-v5.c b/drivers/irqchip/irq-gic-v5.c index 6b42c4af5c79..9ba43ec9318b 100644 --- a/drivers/irqchip/irq-gic-v5.c +++ b/drivers/irqchip/irq-gic-v5.c@@ -13,6 +13,7 @@ #include <linux/irqchip.h> #include <linux/irqchip/arm-gic-v5.h> +#include <linux/irqchip/arm-vgic-info.h> #include <asm/cpufeature.h> #include <asm/exception.h>@@ -1049,6 +1050,36 @@ static void gicv5_set_cpuif_idbits(void) } } +#ifdef CONFIG_KVM +static struct gic_kvm_info gic_v5_kvm_info __initdata; + +static bool __init gicv5_cpuif_has_gcie_legacy(void) +{ + u64 idr0 = read_sysreg_s(SYS_ICC_IDR0_EL1); + return !!FIELD_GET(ICC_IDR0_EL1_GCIE_LEGACY, idr0); +} + +static void __init gic_of_setup_kvm_info(struct device_node *node) +{ + gic_v5_kvm_info.type = GIC_V5; + gic_v5_kvm_info.has_gcie_v3_compat = gicv5_cpuif_has_gcie_legacy(); + + /* GIC Virtual CPU interface maintenance interrupt */ + gic_v5_kvm_info.no_maint_irq_mask = false; + gic_v5_kvm_info.maint_irq = irq_of_parse_and_map(node, 0); + if (!gic_v5_kvm_info.maint_irq) { + pr_warn("cannot find GICv5 virtual CPU interface maintenance interrupt\n"); + return; + } + + vgic_set_kvm_info(&gic_v5_kvm_info); +} +#else +static inline void __init gic_of_setup_kvm_info(struct device_node *node) +{ +} +#endif // CONFIG_KVM + static int __init gicv5_of_init(struct device_node *node, struct device_node *parent) { int ret = gicv5_irs_of_probe(node);@@ -1081,6 +1112,8 @@ static int __init gicv5_of_init(struct device_node *node, struct device_node *pa gicv5_irs_its_probe(); + gic_of_setup_kvm_info(node); + return 0; out_int:diff --git a/include/linux/irqchip/arm-vgic-info.h b/include/linux/irqchip/arm-vgic-info.h index a75b2c7de69d..ca1713fac6e3 100644 --- a/include/linux/irqchip/arm-vgic-info.h +++ b/include/linux/irqchip/arm-vgic-info.h@@ -15,6 +15,8 @@ enum gic_type { GIC_V2, /* Full GICv3, optionally with v2 compat */ GIC_V3, + /* Full GICv5, optionally with v3 compat */ + GIC_V5, }; struct gic_kvm_info {@@ -34,6 +36,8 @@ struct gic_kvm_info { bool has_v4_1; /* Deactivation impared, subpar stuff */ bool no_hw_deactivation; + /* v3 compat support (GICv5 hosts, only) */ + bool has_gcie_v3_compat; }; #ifdef CONFIG_KVM-- 2.34.1