Files
linux/include/kvm/arm_arch_timer.h
Sascha Bischoff 9491c63b6c KVM: arm64: gic-v5: Enlighten arch timer for GICv5
Now that GICv5 has arrived, the arch timer requires some TLC to
address some of the key differences introduced with GICv5.

For PPIs on GICv5, the queue_irq_unlock irq_op is used as AP lists are
not required at all for GICv5. The arch timer also introduces an
irq_op - get_input_level. Extend the arch-timer-provided irq_ops to
include the PPI op for vgic_v5 guests.

When possible, DVI (Direct Virtual Interrupt) is set for PPIs when
using a vgic_v5, which directly inject the pending state into the
guest. This means that the host never sees the interrupt for the guest
for these interrupts. This has three impacts.

* First of all, the kvm_cpu_has_pending_timer check is updated to
  explicitly check if the timers are expected to fire.

* Secondly, for mapped timers (which use DVI) they must be masked on
  the host prior to entering a GICv5 guest, and unmasked on the return
  path. This is handled in set_timer_irq_phys_masked.

* Thirdly, it makes zero sense to attempt to inject state for a DVI'd
  interrupt. Track which timers are direct, and skip the call to
  kvm_vgic_inject_irq() for these.

The final, but rather important, change is that the architected PPIs
for the timers are made mandatory for a GICv5 guest. Attempts to set
them to anything else are actively rejected. Once a vgic_v5 is
initialised, the arch timer PPIs are also explicitly reinitialised to
ensure the correct GICv5-compatible PPIs are used - this also adds in
the GICv5 PPI type to the intid.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260319154937.3619520-32-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-19 18:21:28 +00:00

199 lines
5.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#ifndef __ASM_ARM_KVM_ARCH_TIMER_H
#define __ASM_ARM_KVM_ARCH_TIMER_H
#include <linux/clocksource.h>
#include <linux/hrtimer.h>
#include <linux/irqchip/arm-gic-v5.h>
enum kvm_arch_timers {
TIMER_PTIMER,
TIMER_VTIMER,
NR_KVM_EL0_TIMERS,
TIMER_HVTIMER = NR_KVM_EL0_TIMERS,
TIMER_HPTIMER,
NR_KVM_TIMERS
};
enum kvm_arch_timer_regs {
TIMER_REG_CNT,
TIMER_REG_CVAL,
TIMER_REG_TVAL,
TIMER_REG_CTL,
TIMER_REG_VOFF,
};
struct arch_timer_offset {
/*
* If set, pointer to one of the offsets in the kvm's offset
* structure. If NULL, assume a zero offset.
*/
u64 *vm_offset;
/*
* If set, pointer to one of the offsets in the vcpu's sysreg
* array. If NULL, assume a zero offset.
*/
u64 *vcpu_offset;
};
struct arch_timer_vm_data {
/* Offset applied to the virtual timer/counter */
u64 voffset;
/* Offset applied to the physical timer/counter */
u64 poffset;
/* The PPI for each timer, global to the VM */
u32 ppi[NR_KVM_TIMERS];
};
struct arch_timer_context {
/* Emulated Timer (may be unused) */
struct hrtimer hrtimer;
u64 ns_frac;
/* Offset for this counter/timer */
struct arch_timer_offset offset;
/*
* We have multiple paths which can save/restore the timer state onto
* the hardware, so we need some way of keeping track of where the
* latest state is.
*/
bool loaded;
/* Output level of the timer IRQ */
struct {
bool level;
} irq;
/* Who am I? */
enum kvm_arch_timers timer_id;
/* Duplicated state from arch_timer.c for convenience */
u32 host_timer_irq;
/* Is this a direct timer? */
bool direct;
};
struct timer_map {
struct arch_timer_context *direct_vtimer;
struct arch_timer_context *direct_ptimer;
struct arch_timer_context *emul_vtimer;
struct arch_timer_context *emul_ptimer;
};
void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map);
struct arch_timer_cpu {
struct arch_timer_context timers[NR_KVM_TIMERS];
/* Background timer used when the guest is not running */
struct hrtimer bg_timer;
/* Is the timer enabled */
bool enabled;
};
int __init kvm_timer_hyp_init(bool has_gic);
int kvm_timer_enable(struct kvm_vcpu *vcpu);
void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu);
void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu);
void kvm_timer_sync_nested(struct kvm_vcpu *vcpu);
void kvm_timer_sync_user(struct kvm_vcpu *vcpu);
bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu);
void kvm_timer_update_run(struct kvm_vcpu *vcpu);
void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu);
void kvm_timer_init_vm(struct kvm *kvm);
int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
u64 kvm_phys_timer_read(void);
void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu);
void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu);
void kvm_timer_init_vhe(void);
#define vcpu_timer(v) (&(v)->arch.timer_cpu)
#define vcpu_get_timer(v,t) (&vcpu_timer(v)->timers[(t)])
#define vcpu_vtimer(v) (&(v)->arch.timer_cpu.timers[TIMER_VTIMER])
#define vcpu_ptimer(v) (&(v)->arch.timer_cpu.timers[TIMER_PTIMER])
#define vcpu_hvtimer(v) (&(v)->arch.timer_cpu.timers[TIMER_HVTIMER])
#define vcpu_hptimer(v) (&(v)->arch.timer_cpu.timers[TIMER_HPTIMER])
#define arch_timer_ctx_index(ctx) ((ctx)->timer_id)
#define timer_context_to_vcpu(ctx) container_of((ctx), struct kvm_vcpu, arch.timer_cpu.timers[(ctx)->timer_id])
#define timer_vm_data(ctx) (&(timer_context_to_vcpu(ctx)->kvm->arch.timer_data))
#define timer_irq(ctx) (timer_vm_data(ctx)->ppi[arch_timer_ctx_index(ctx)])
#define get_vgic_ppi(k, i) (((k)->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V5) ? \
(i) : (FIELD_PREP(GICV5_HWIRQ_ID, i) | \
FIELD_PREP(GICV5_HWIRQ_TYPE, GICV5_HWIRQ_TYPE_PPI)))
u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu,
enum kvm_arch_timers tmr,
enum kvm_arch_timer_regs treg);
void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
enum kvm_arch_timers tmr,
enum kvm_arch_timer_regs treg,
u64 val);
/* Needed for tracing */
u32 timer_get_ctl(struct arch_timer_context *ctxt);
u64 timer_get_cval(struct arch_timer_context *ctxt);
/* CPU HP callbacks */
void kvm_timer_cpu_up(void);
void kvm_timer_cpu_down(void);
/* CNTKCTL_EL1 valid bits as of DDI0487J.a */
#define CNTKCTL_VALID_BITS (BIT(17) | GENMASK_ULL(9, 0))
DECLARE_STATIC_KEY_FALSE(broken_cntvoff_key);
static inline bool has_broken_cntvoff(void)
{
return static_branch_unlikely(&broken_cntvoff_key);
}
static inline bool has_cntpoff(void)
{
return (has_vhe() && cpus_have_final_cap(ARM64_HAS_ECV_CNTPOFF));
}
static inline u64 timer_get_offset(struct arch_timer_context *ctxt)
{
u64 offset = 0;
if (!ctxt)
return 0;
if (ctxt->offset.vm_offset)
offset += *ctxt->offset.vm_offset;
if (ctxt->offset.vcpu_offset)
offset += *ctxt->offset.vcpu_offset;
return offset;
}
static inline void timer_set_offset(struct arch_timer_context *ctxt, u64 offset)
{
if (!ctxt->offset.vm_offset) {
WARN(offset, "timer %d\n", arch_timer_ctx_index(ctxt));
return;
}
WRITE_ONCE(*ctxt->offset.vm_offset, offset);
}
#endif