[PATCH v2 1/1] irqchip/gic-v4.1: Disable vSGI upon (GIC CPUIF < v4.1) detection
From: Lorenzo Pieralisi
Date: Tue Mar 02 2021 - 06:28:32 EST
GIC CPU interfaces versions predating GIC v4.1 were not built to
accommodate vINTID within the vSGI range; as reported in the GIC
specifications (8.2 "Changes to the CPU interface"), it is
CONSTRAINED UNPREDICTABLE to deliver a vSGI to a PE with
ID_AA64PFR0_EL1.GIC < b0011.
Check the GIC CPUIF version by reading the SYS_ID_AA64_PFR0_EL1.
Disable vSGIs if a CPUIF version < 4.1 is detected to prevent using
vSGIs on systems where they may misbehave.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/kvm/vgic/vgic-mmio-v3.c | 4 ++--
arch/arm64/kvm/vgic/vgic-v3.c | 3 ++-
drivers/irqchip/irq-gic-v3-its.c | 6 +++++-
drivers/irqchip/irq-gic-v3.c | 22 ++++++++++++++++++++++
include/kvm/arm_vgic.h | 1 +
include/linux/irqchip/arm-gic-common.h | 2 ++
include/linux/irqchip/arm-gic-v3.h | 1 +
7 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 15a6c98ee92f..66548cd2a715 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -86,7 +86,7 @@ static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
}
break;
case GICD_TYPER2:
- if (kvm_vgic_global_state.has_gicv4_1)
+ if (kvm_vgic_global_state.has_gicv4_1_vsgi)
value = GICD_TYPER2_nASSGIcap;
break;
case GICD_IIDR:
@@ -119,7 +119,7 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
dist->enabled = val & GICD_CTLR_ENABLE_SS_G1;
/* Not a GICv4.1? No HW SGIs */
- if (!kvm_vgic_global_state.has_gicv4_1)
+ if (!kvm_vgic_global_state.has_gicv4_1_vsgi)
val &= ~GICD_CTLR_nASSGIreq;
/* Dist stays enabled? nASSGIreq is RO */
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 52915b342351..57b73100e8cc 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -533,7 +533,7 @@ int vgic_v3_map_resources(struct kvm *kvm)
return ret;
}
- if (kvm_vgic_global_state.has_gicv4_1)
+ if (kvm_vgic_global_state.has_gicv4_1_vsgi)
vgic_v4_configure_vsgis(kvm);
return 0;
@@ -589,6 +589,7 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
if (info->has_v4) {
kvm_vgic_global_state.has_gicv4 = gicv4_enable;
kvm_vgic_global_state.has_gicv4_1 = info->has_v4_1 && gicv4_enable;
+ kvm_vgic_global_state.has_gicv4_1_vsgi = info->has_v4_1_vsgi && gicv4_enable;
kvm_info("GICv4%s support %sabled\n",
kvm_vgic_global_state.has_gicv4_1 ? ".1" : "",
gicv4_enable ? "en" : "dis");
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index ed46e6057e33..ee2a2ca27d5c 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -5412,7 +5412,11 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
if (has_v4 & rdists->has_vlpis) {
const struct irq_domain_ops *sgi_ops;
- if (has_v4_1)
+ /*
+ * Enable vSGIs only if the ITS and the
+ * GIC CPUIF support them.
+ */
+ if (has_v4_1 && rdists->has_vsgi_cpuif)
sgi_ops = &its_sgi_domain_ops;
else
sgi_ops = NULL;
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index eb0ee356a629..fd6cd9a5de34 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -31,6 +31,21 @@
#include "irq-gic-common.h"
+#ifdef CONFIG_ARM64
+#include <asm/cpufeature.h>
+
+static inline bool gic_cpuif_has_vsgi(void)
+{
+ unsigned long fld, reg = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
+
+ fld = cpuid_feature_extract_unsigned_field(reg, ID_AA64PFR0_GIC_SHIFT);
+
+ return fld >= 0x3;
+}
+#else
+static inline bool gic_cpuif_has_vsgi(void) { return false; }
+#endif
+
#define GICD_INT_NMI_PRI (GICD_INT_DEF_PRI & ~0x80)
#define FLAGS_WORKAROUND_GICR_WAKER_MSM8996 (1ULL << 0)
@@ -1679,6 +1694,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
gic_data.rdists.has_direct_lpi = true;
gic_data.rdists.has_vpend_valid_dirty = true;
+ gic_data.rdists.has_vsgi_cpuif = gic_cpuif_has_vsgi();
+
if (WARN_ON(!gic_data.domain) || WARN_ON(!gic_data.rdists.rdist)) {
err = -ENOMEM;
goto out_free;
@@ -1852,6 +1869,9 @@ static void __init gic_of_setup_kvm_info(struct device_node *node)
gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid;
+ gic_v3_kvm_info.has_v4_1_vsgi = gic_data.rdists.has_vsgi_cpuif &&
+ gic_data.rdists.has_rvpeid;
+
gic_set_kvm_info(&gic_v3_kvm_info);
}
@@ -2168,6 +2188,8 @@ static void __init gic_acpi_setup_kvm_info(void)
gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid;
+ gic_v3_kvm_info.has_v4_1_vsgi = gic_data.rdists.has_vsgi_cpuif &&
+ gic_data.rdists.has_rvpeid;
gic_set_kvm_info(&gic_v3_kvm_info);
}
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 3d74f1060bd1..614f11113298 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -71,6 +71,7 @@ struct vgic_global {
/* Hardware has GICv4? */
bool has_gicv4;
bool has_gicv4_1;
+ bool has_gicv4_1_vsgi;
/* GIC system register CPU interface */
struct static_key_false gicv3_cpuif;
diff --git a/include/linux/irqchip/arm-gic-common.h b/include/linux/irqchip/arm-gic-common.h
index fa8c0455c352..c2efd1dd1790 100644
--- a/include/linux/irqchip/arm-gic-common.h
+++ b/include/linux/irqchip/arm-gic-common.h
@@ -34,6 +34,8 @@ struct gic_kvm_info {
bool has_v4;
/* rvpeid support */
bool has_v4_1;
+ /* vsgi support */
+ bool has_v4_1_vsgi;
};
const struct gic_kvm_info *gic_get_kvm_info(void);
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index f6d092fdb93d..5f00ce2535bf 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -683,6 +683,7 @@ struct rdists {
bool has_vlpis;
bool has_rvpeid;
bool has_direct_lpi;
+ bool has_vsgi_cpuif;
bool has_vpend_valid_dirty;
};
--
2.29.1