[PATCH kvmtool v3 6/6] arm64: Generate HYP timer interrupt specifiers

Andre Przywara
2025-07-29T09:58:01Z

From: Marc Zyngier <maz@kernel.org>

FEAT_VHE introduced a non-secure EL2 virtual timer, along with its
interrupt line. Consequently the arch timer DT binding introduced a fifth
interrupt to communicate this interrupt number.

Refactor the interrupts property generation code to deal with a variable
number of interrupts, and forward five interrupts instead of four in case
nested virt is enabled.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
arm64/arm-cpu.c | 4 +---
arm64/include/kvm/timer.h | 2 +-
arm64/timer.c | 29 ++++++++++++-----------------
3 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/arm64/arm-cpu.c b/arm64/arm-cpu.c
index 1e456f2c6..abdd6324f 100644
--- a/arm64/arm-cpu.c
+++ b/arm64/arm-cpu.c
@@ -12,11 +12,9 @@

static void generate_fdt_nodes(void *fdt, struct kvm *kvm)
{
- int timer_interrupts[4] = {13, 14, 11, 10};
-
gic__generate_fdt_nodes(fdt, kvm->cfg.arch.irqchip,
kvm->cfg.arch.nested_virt);
- timer__generate_fdt_nodes(fdt, kvm, timer_interrupts);
+ timer__generate_fdt_nodes(fdt, kvm);
pmu__generate_fdt_nodes(fdt, kvm);
}

diff --git a/arm64/include/kvm/timer.h b/arm64/include/kvm/timer.h
index 928e9ea7a..81e093e46 100644
--- a/arm64/include/kvm/timer.h
+++ b/arm64/include/kvm/timer.h
@@ -1,6 +1,6 @@
#ifndef ARM_COMMON__TIMER_H
#define ARM_COMMON__TIMER_H

-void timer__generate_fdt_nodes(void *fdt, struct kvm *kvm, int *irqs);
+void timer__generate_fdt_nodes(void *fdt, struct kvm *kvm);

#endif /* ARM_COMMON__TIMER_H */
diff --git a/arm64/timer.c b/arm64/timer.c
index 861f2d994..2ac6144f9 100644
--- a/arm64/timer.c
+++ b/arm64/timer.c
@@ -5,31 +5,26 @@
#include "kvm/timer.h"
#include "kvm/util.h"

-void timer__generate_fdt_nodes(void *fdt, struct kvm *kvm, int *irqs)
+void timer__generate_fdt_nodes(void *fdt, struct kvm *kvm)
{
const char compatible[] = "arm,armv8-timer\0arm,armv7-timer";
u32 cpu_mask = gic__get_fdt_irq_cpumask(kvm);
- u32 irq_prop[] = {
- cpu_to_fdt32(GIC_FDT_IRQ_TYPE_PPI),
- cpu_to_fdt32(irqs[0]),
- cpu_to_fdt32(cpu_mask | IRQ_TYPE_LEVEL_LOW),
+ int irqs[5] = {13, 14, 11, 10, 12};
+ int nr = ARRAY_SIZE(irqs);
+ u32 irq_prop[nr * 3];

- cpu_to_fdt32(GIC_FDT_IRQ_TYPE_PPI),
- cpu_to_fdt32(irqs[1]),
- cpu_to_fdt32(cpu_mask | IRQ_TYPE_LEVEL_LOW),
+ if (!kvm->cfg.arch.nested_virt)
+ nr--;

- cpu_to_fdt32(GIC_FDT_IRQ_TYPE_PPI),
- cpu_to_fdt32(irqs[2]),
- cpu_to_fdt32(cpu_mask | IRQ_TYPE_LEVEL_LOW),
-
- cpu_to_fdt32(GIC_FDT_IRQ_TYPE_PPI),
- cpu_to_fdt32(irqs[3]),
- cpu_to_fdt32(cpu_mask | IRQ_TYPE_LEVEL_LOW),
- };
+ for (int i = 0; i < nr; i++) {
+ irq_prop[i * 3 + 0] = cpu_to_fdt32(GIC_FDT_IRQ_TYPE_PPI);
+ irq_prop[i * 3 + 1] = cpu_to_fdt32(irqs[i]);
+ irq_prop[i * 3 + 2] = cpu_to_fdt32(cpu_mask | IRQ_TYPE_LEVEL_LOW);
+ }

_FDT(fdt_begin_node(fdt, "timer"));
_FDT(fdt_property(fdt, "compatible", compatible, sizeof(compatible)));
- _FDT(fdt_property(fdt, "interrupts", irq_prop, sizeof(irq_prop)));
+ _FDT(fdt_property(fdt, "interrupts", irq_prop, nr * 3 * sizeof(irq_prop[0])));
_FDT(fdt_property(fdt, "always-on", NULL, 0));
if (kvm->cfg.arch.force_cntfrq > 0)
_FDT(fdt_property_cell(fdt, "clock-frequency", kvm->cfg.arch.force_cntfrq));
--
2.25.1