KVM: arm64: Don't perform vgic-v2 lazy init on timer injection
Marc Zyngier
maintainerv2 cover KVM: arm64: Don't perform vgic-v2 lazy init on timer injection
This is the second version of this series aiming at fixing issues with vgic-v2 being initialised from non-preemptible context.
* From v1 [1]:
- Repaint kvm_timer_irq_can_fire() to kvm_timer_enabled()
- Drop duplicate kvm_timer_update_status() call
- Force lazy init on the irqfd slow-path for SPIs
[1] https://lore.kernel.org/r/[email protected]
Marc Zyngier (4):
KVM: arm64: timer: Repaint kvm_timer_{should,irq_can}_fire() to
kvm_timer_{pending,enabled}()
KVM: arm64: timer: Kill the per-timer level cache
KVM: arm64: vgic-v2: Force vgic init on injection outside the run loop
KVM: arm64: vgic-v2: Don't init the vgic on in-kernel interrupt
injection
arch/arm64/kvm/arch_timer.c | 59 +++++++++++++++----------------- arch/arm64/kvm/arm.c | 7 ++++ arch/arm64/kvm/vgic/vgic-irqfd.c | 6 ++++ arch/arm64/kvm/vgic/vgic.c | 6 ++-- include/kvm/arm_arch_timer.h | 5 --- 5 files changed, 43 insertions(+), 40 deletions(-)
Signature · 1 line
2.47.3
Marc Zyngier
maintainerPATCH v2 1/4 KVM: arm64: timer: Repaint kvm_timer_{should,irq_can}_fire() to kvm_timer_{pending,enabled}()
kvm_timer_should_fire() seems to date back to a time where the author of the timer code didn't seem to have made the word "pending" part of their vocabulary.
Having since slightly improved on that front, let's rename this predicate to kvm_timer_pending(), which clearly indicates whether the timer interrupt is pending or not.
Similarly, kvm_timer_irq_can_fire() is renamed to kvm_timer_enabled().
Signed-off-by Marc Zyngier <[email protected]>
--- arch/arm64/kvm/arch_timer.c | 49 ++++++++++++++++++------------------- 1 file changed, 24 insertions(+), 25 deletions(-)
arch/arm64/kvm/arch_timer.c +24 -25
@@ -39,10 +39,9 @@ static const u8 default_ppi[] = { [TIMER_HVTIMER] = 28, }; -static bool kvm_timer_irq_can_fire (struct arch_timer_context *timer_ctx);static void kvm_timer_update_irq (struct kvm_vcpu *vcpu,bool new_level,struct arch_timer_context *timer_ctx); -static bool kvm_timer_should_fire (struct arch_timer_context *timer_ctx); +static bool kvm_timer_pending (struct arch_timer_context *timer_ctx); static void kvm_arm_timer_write(struct kvm_vcpu *vcpu, struct arch_timer_context *timer, enum kvm_arch_timer_regs treg,
@@ -224,7 +223,7 @@ static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)else ctx = map.direct_ptimer; -if (kvm_timer_should_fire (ctx)) +if (kvm_timer_pending (ctx))kvm_timer_update_irq (vcpu, true, ctx); if (userspace_irqchip(vcpu->kvm) &&
@@ -257,7 +256,7 @@ static u64 kvm_timer_compute_delta(struct arch_timer_context *timer_ctx)return kvm_counter_compute_delta (timer_ctx,timer_get_cval (timer_ctx)); } -static bool kvm_timer_irq_can_fire (struct arch_timer_context *timer_ctx) +static bool kvm_timer_enabled (struct arch_timer_context *timer_ctx) {WARN_ON (timer_ctx && timer_ctx->loaded); return timer_ctx &&
@@ -294,7 +293,7 @@ static u64 kvm_timer_earliest_exp(struct kvm_vcpu *vcpu)struct arch_timer_context *ctx = &vcpu->arch.timer_cpu.timers[i];WARN (ctx->loaded,"timer %d loaded\n" , i); -if (kvm_timer_irq_can_fire (ctx)) +if (kvm_timer_enabled (ctx)) min_delta =min (min_delta,kvm_timer_compute_delta (ctx)); }
@@ -358,7 +357,7 @@ static enum hrtimer_restart kvm_hrtimer_expire(struct hrtimer *hrt)return HRTIMER_NORESTART ; } -static bool kvm_timer_should_fire (struct arch_timer_context *timer_ctx) +static bool kvm_timer_pending (struct arch_timer_context *timer_ctx) {enum kvm_arch_timers index;u64 cval, now;
@@ -391,7 +390,7 @@ static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx) !(cnt_ctl &ARCH_TIMER_CTRL_IT_MASK ); } -if (!kvm_timer_irq_can_fire (timer_ctx)) +if (!kvm_timer_enabled (timer_ctx))return false; cval =timer_get_cval (timer_ctx);
@@ -417,9 +416,9 @@ void kvm_timer_update_run(struct kvm_vcpu *vcpu)/* Populate the device bitmap with the timer states */ regs->device_irq_level &= ~(KVM_ARM_DEV_EL1_VTIMER |KVM_ARM_DEV_EL1_PTIMER ); -if (kvm_timer_should_fire (vtimer)) +if (kvm_timer_pending (vtimer)) regs->device_irq_level |=KVM_ARM_DEV_EL1_VTIMER ; -if (kvm_timer_should_fire (ptimer)) +if (kvm_timer_pending (ptimer)) regs->device_irq_level |=KVM_ARM_DEV_EL1_PTIMER ; }
@@ -473,21 +472,21 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,/* Only called for a fully emulated timer */ static void timer_emulate (struct arch_timer_context *ctx) { -bool should_fire =kvm_timer_should_fire (ctx); +bool pending =kvm_timer_pending (ctx); -trace_kvm_timer_emulate (ctx, should_fire); +trace_kvm_timer_emulate (ctx, pending); -if (should_fire != ctx->irq.level) -kvm_timer_update_irq (timer_context_to_vcpu (ctx), should_fire, ctx); +if (pending != ctx->irq.level) +kvm_timer_update_irq (timer_context_to_vcpu (ctx), pending, ctx); -kvm_timer_update_status (ctx, should_fire); +kvm_timer_update_status (ctx, pending);/* * If the timer can fire now, we don't need to have a soft timer * scheduled for the future. If the timer cannot fire at all, * then we also don't need a soft timer. */ -if (should_fire || !kvm_timer_irq_can_fire (ctx)) +if (pending || !kvm_timer_enabled (ctx))return ;soft_timer_start (&ctx->hrtimer,kvm_timer_compute_delta (ctx));
@@ -594,10 +593,10 @@ static void kvm_timer_blocking(struct kvm_vcpu *vcpu)* If no timers are capable of raising interrupts (disabled or * masked), then there's no more work for us to do. */ -if (!kvm_timer_irq_can_fire (map.direct_vtimer) && - !kvm_timer_irq_can_fire (map.direct_ptimer) && - !kvm_timer_irq_can_fire (map.emul_vtimer) && - !kvm_timer_irq_can_fire (map.emul_ptimer) && +if (!kvm_timer_enabled (map.direct_vtimer) && + !kvm_timer_enabled (map.direct_ptimer) && + !kvm_timer_enabled (map.emul_vtimer) && + !kvm_timer_enabled (map.emul_ptimer) && !vcpu_has_wfit_active (vcpu))return ;
@@ -685,7 +684,7 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)* this point and the register restoration, we'll take the * interrupt anyway. */ -kvm_timer_update_irq (vcpu,kvm_timer_should_fire (ctx), ctx); +kvm_timer_update_irq (vcpu,kvm_timer_pending (ctx), ctx);if (irqchip_in_kernel (vcpu->kvm)) phys_active =kvm_vgic_map_is_active (vcpu,timer_irq (ctx));
@@ -706,7 +705,7 @@ static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)* this point and the register restoration, we'll take the * interrupt anyway. */ -kvm_timer_update_irq (vcpu,kvm_timer_should_fire (vtimer), vtimer); +kvm_timer_update_irq (vcpu,kvm_timer_pending (vtimer), vtimer);/* * When using a userspace irqchip with the architected timers and a
@@ -917,8 +916,8 @@ bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu) vlevel = sregs->device_irq_level &KVM_ARM_DEV_EL1_VTIMER ; plevel = sregs->device_irq_level &KVM_ARM_DEV_EL1_PTIMER ; -return kvm_timer_should_fire (vtimer) != vlevel || -kvm_timer_should_fire (ptimer) != plevel; +return kvm_timer_pending (vtimer) != vlevel || +kvm_timer_pending (ptimer) != plevel; }void kvm_timer_vcpu_put (struct kvm_vcpu *vcpu)
@@ -1006,7 +1005,7 @@ static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu) {struct arch_timer_context *vtimer =vcpu_vtimer (vcpu); -if (!kvm_timer_should_fire (vtimer)) { +if (!kvm_timer_pending (vtimer)) {kvm_timer_update_irq (vcpu, false, vtimer);if (static_branch_likely (&has_gic_active_state))set_timer_irq_phys_active (vtimer, false);
@@ -1579,7 +1578,7 @@ static bool kvm_arch_timer_get_input_level(int vintid) ctx =vcpu_get_timer (vcpu, i);if (timer_irq (ctx) == vintid) -return kvm_timer_should_fire (ctx); +return kvm_timer_pending (ctx); }/* A timer IRQ has fired, but no matching timer was found? */
Signature · 1 line
2.47.3
Re: [PATCH v2 1/4] KVM: arm64: timer: Repaint kvm_timer_{should,irq_can}_fire() to kvm_timer_{pending,enabled}()
Quoted 11 lines · Marc Zyngier
kvm_timer_should_fire()seems to date back to a time where the author of the timer code didn't seem to have made the word "pending" part of their vocabulary.Having since slightly improved on that front, let's rename this predicate to
kvm_timer_pending(), which clearly indicates whether the timer interrupt is pending or not.Similarly,
kvm_timer_irq_can_fire()is renamed tokvm_timer_enabled().Signed-off-by Marc Zyngier <[email protected]>
Minor comment below.
Reviewed-by Joey Gouly <[email protected]>
Quoted 90 lines
--- arch/arm64/kvm/arch_timer.c | 49 ++++++++++++++++++------------------- 1 file changed, 24 insertions(+), 25 deletions(-)arch/arm64/kvm/arch_timer.c +11
-13@@ -39,10 +39,9 @@ static const u8 default_ppi[] = { [TIMER_HVTIMER] = 28, }; -static bool kvm_timer_irq_can_fire (struct arch_timer_context *timer_ctx);static void kvm_timer_update_irq (struct kvm_vcpu *vcpu,bool new_level,struct arch_timer_context *timer_ctx); -static bool kvm_timer_should_fire (struct arch_timer_context *timer_ctx); +static bool kvm_timer_pending (struct arch_timer_context *timer_ctx); static void kvm_arm_timer_write(struct kvm_vcpu *vcpu, struct arch_timer_context *timer, enum kvm_arch_timer_regs treg,@@ -224,7 +223,7 @@ static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)else ctx = map.direct_ptimer; -if (kvm_timer_should_fire (ctx)) +if (kvm_timer_pending (ctx))kvm_timer_update_irq (vcpu, true, ctx); if (userspace_irqchip(vcpu->kvm) &&@@ -257,7 +256,7 @@ static u64 kvm_timer_compute_delta(struct arch_timer_context *timer_ctx)return kvm_counter_compute_delta (timer_ctx,timer_get_cval (timer_ctx)); } -static bool kvm_timer_irq_can_fire (struct arch_timer_context *timer_ctx) +static bool kvm_timer_enabled (struct arch_timer_context *timer_ctx) {WARN_ON (timer_ctx && timer_ctx->loaded); return timer_ctx &&@@ -294,7 +293,7 @@ static u64 kvm_timer_earliest_exp(struct kvm_vcpu *vcpu)struct arch_timer_context *ctx = &vcpu->arch.timer_cpu.timers[i];WARN (ctx->loaded,"timer %d loaded\n" , i); -if (kvm_timer_irq_can_fire (ctx)) +if (kvm_timer_enabled (ctx)) min_delta =min (min_delta,kvm_timer_compute_delta (ctx)); }@@ -358,7 +357,7 @@ static enum hrtimer_restart kvm_hrtimer_expire(struct hrtimer *hrt)return HRTIMER_NORESTART ; } -static bool kvm_timer_should_fire (struct arch_timer_context *timer_ctx) +static bool kvm_timer_pending (struct arch_timer_context *timer_ctx) {enum kvm_arch_timers index;u64 cval, now;@@ -391,7 +390,7 @@ static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx) !(cnt_ctl &ARCH_TIMER_CTRL_IT_MASK ); } -if (!kvm_timer_irq_can_fire (timer_ctx)) +if (!kvm_timer_enabled (timer_ctx))return false; cval =timer_get_cval (timer_ctx);@@ -417,9 +416,9 @@ void kvm_timer_update_run(struct kvm_vcpu *vcpu)/* Populate the device bitmap with the timer states */ regs->device_irq_level &= ~(KVM_ARM_DEV_EL1_VTIMER |KVM_ARM_DEV_EL1_PTIMER ); -if (kvm_timer_should_fire (vtimer)) +if (kvm_timer_pending (vtimer)) regs->device_irq_level |=KVM_ARM_DEV_EL1_VTIMER ; -if (kvm_timer_should_fire (ptimer)) +if (kvm_timer_pending (ptimer)) regs->device_irq_level |=KVM_ARM_DEV_EL1_PTIMER ; }@@ -473,21 +472,21 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,/* Only called for a fully emulated timer */ static void timer_emulate (struct arch_timer_context *ctx) { -bool should_fire =kvm_timer_should_fire (ctx); +bool pending =kvm_timer_pending (ctx); -trace_kvm_timer_emulate (ctx, should_fire); +trace_kvm_timer_emulate (ctx, pending); -if (should_fire != ctx->irq.level) -kvm_timer_update_irq (timer_context_to_vcpu (ctx), should_fire, ctx); +if (pending != ctx->irq.level)
arch/arm64/kvm/arch_timer.c static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level, · line 488
Quoted 10 lines
arch/arm64/kvm/arch_timer.c +2
-1+kvm_timer_update_irq (timer_context_to_vcpu (ctx), pending, ctx); -kvm_timer_update_status (ctx, should_fire); +kvm_timer_update_status (ctx, pending);/* * If the timer can fire now, we don't need to have a soft timer * scheduled for the future. If the timer cannot fire at all, * then we also don't need a soft timer. */
Could update this comment to use pending/enabled now?
Quoted 70 lines
arch/arm64/kvm/arch_timer.c +11
-11-if (should_fire || !kvm_timer_irq_can_fire (ctx)) +if (pending || !kvm_timer_enabled (ctx))return ;soft_timer_start (&ctx->hrtimer,kvm_timer_compute_delta (ctx));@@ -594,10 +593,10 @@ static void kvm_timer_blocking(struct kvm_vcpu *vcpu)* If no timers are capable of raising interrupts (disabled or * masked), then there's no more work for us to do. */ -if (!kvm_timer_irq_can_fire (map.direct_vtimer) && - !kvm_timer_irq_can_fire (map.direct_ptimer) && - !kvm_timer_irq_can_fire (map.emul_vtimer) && - !kvm_timer_irq_can_fire (map.emul_ptimer) && +if (!kvm_timer_enabled (map.direct_vtimer) && + !kvm_timer_enabled (map.direct_ptimer) && + !kvm_timer_enabled (map.emul_vtimer) && + !kvm_timer_enabled (map.emul_ptimer) && !vcpu_has_wfit_active (vcpu))return ;@@ -685,7 +684,7 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)* this point and the register restoration, we'll take the * interrupt anyway. */ -kvm_timer_update_irq (vcpu,kvm_timer_should_fire (ctx), ctx); +kvm_timer_update_irq (vcpu,kvm_timer_pending (ctx), ctx);if (irqchip_in_kernel (vcpu->kvm)) phys_active =kvm_vgic_map_is_active (vcpu,timer_irq (ctx));@@ -706,7 +705,7 @@ static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)* this point and the register restoration, we'll take the * interrupt anyway. */ -kvm_timer_update_irq (vcpu,kvm_timer_should_fire (vtimer), vtimer); +kvm_timer_update_irq (vcpu,kvm_timer_pending (vtimer), vtimer);/* * When using a userspace irqchip with the architected timers and a @@ -917,8 +916,8 @@ bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu) vlevel = sregs->device_irq_level &KVM_ARM_DEV_EL1_VTIMER ; plevel = sregs->device_irq_level &KVM_ARM_DEV_EL1_PTIMER ; -return kvm_timer_should_fire (vtimer) != vlevel || -kvm_timer_should_fire (ptimer) != plevel; +return kvm_timer_pending (vtimer) != vlevel || +kvm_timer_pending (ptimer) != plevel; }void kvm_timer_vcpu_put (struct kvm_vcpu *vcpu)@@ -1006,7 +1005,7 @@ static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu) {struct arch_timer_context *vtimer =vcpu_vtimer (vcpu); -if (!kvm_timer_should_fire (vtimer)) { +if (!kvm_timer_pending (vtimer)) {kvm_timer_update_irq (vcpu, false, vtimer);if (static_branch_likely (&has_gic_active_state))set_timer_irq_phys_active (vtimer, false);@@ -1579,7 +1578,7 @@ static bool kvm_arch_timer_get_input_level(int vintid) ctx =vcpu_get_timer (vcpu, i);if (timer_irq (ctx) == vintid) -return kvm_timer_should_fire (ctx); +return kvm_timer_pending (ctx); }/* A timer IRQ has fired, but no matching timer was found? */ Signature · 1 line
2.47.3
Marc Zyngier
maintainerPATCH v2 2/4 KVM: arm64: timer: Kill the per-timer level cache
In reply to Marc ZyngierThe timer code makes use of a per-timer irq level cache, which looks like a very minor optimisation to avoid taking a lock upon updating the GIC view of the interrupt when it is unchanged from the previous state.
This is coming in the way of more important correctness issues, so get rid of the cache, which simplifies a couple of minor things.
Signed-off-by Marc Zyngier <[email protected]>
--- arch/arm64/kvm/arch_timer.c | 20 +++++++++----------- include/kvm/arm_arch_timer.h | 5 ----- 2 files changed, 9 insertions(+), 16 deletions(-)
arch/arm64/kvm/arch_timer.c +9 -11
@@ -445,9 +445,8 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level, {kvm_timer_update_status (timer_ctx, new_level); - timer_ctx->irq.level = new_level;trace_kvm_timer_update_irq (vcpu->vcpu_id,timer_irq (timer_ctx), - timer_ctx->irq.level); + new_level);if (userspace_irqchip (vcpu->kvm))return ;
@@ -465,7 +464,7 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,kvm_vgic_inject_irq (vcpu->kvm, vcpu,timer_irq (timer_ctx), - timer_ctx->irq.level, + new_level, timer_ctx); }
@@ -476,10 +475,7 @@ static void timer_emulate(struct arch_timer_context *ctx)trace_kvm_timer_emulate (ctx, pending); -if (pending != ctx->irq.level) -kvm_timer_update_irq (timer_context_to_vcpu (ctx), pending, ctx); - -kvm_timer_update_status (ctx, pending); +kvm_timer_update_irq (timer_context_to_vcpu (ctx), pending, ctx);/* * If the timer can fire now, we don't need to have a soft timer
@@ -676,6 +672,7 @@ static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, boostatic void kvm_timer_vcpu_load_gic (struct arch_timer_context *ctx) {struct kvm_vcpu *vcpu =timer_context_to_vcpu (ctx); +bool pending =kvm_timer_pending (ctx);bool phys_active = false;/*
@@ -684,12 +681,12 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)* this point and the register restoration, we'll take the * interrupt anyway. */ -kvm_timer_update_irq (vcpu,kvm_timer_pending (ctx), ctx); +kvm_timer_update_irq (vcpu, pending, ctx);if (irqchip_in_kernel (vcpu->kvm)) phys_active =kvm_vgic_map_is_active (vcpu,timer_irq (ctx)); - phys_active |= ctx->irq.level; + phys_active |= pending; phys_active |=vgic_is_v5 (vcpu->kvm);set_timer_irq_phys_active (ctx, phys_active);
@@ -698,6 +695,7 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)static void kvm_timer_vcpu_load_nogic (struct kvm_vcpu *vcpu) {struct arch_timer_context *vtimer =vcpu_vtimer (vcpu); +bool pending =kvm_timer_pending (vtimer);/* * Update the timer output so that it is likely to match the
@@ -705,7 +703,7 @@ static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)* this point and the register restoration, we'll take the * interrupt anyway. */ -kvm_timer_update_irq (vcpu,kvm_timer_pending (vtimer), vtimer); +kvm_timer_update_irq (vcpu, pending, vtimer);/* * When using a userspace irqchip with the architected timers and a
@@ -717,7 +715,7 @@ static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)* being de-asserted, we unmask the interrupt again so that we exit * from the guest when the timer fires. */ -if (vtimer->irq.level) +if (pending)disable_percpu_irq (host_vtimer_irq);else enable_percpu_irq (host_vtimer_irq, host_vtimer_irq_flags);
include/kvm/arm_arch_timer.h +0 -5
@@ -66,11 +66,6 @@ struct arch_timer_context {*/ bool loaded; -/* Output level of the timer IRQ */ -struct { -bool level; - } irq; -/* Who am I? */ enum kvm_arch_timers timer_id;
Signature · 1 line
2.47.3
Marc Zyngier
maintainerPATCH v2 3/4 KVM: arm64: vgic-v2: Force vgic init on injection outside the run loop
In reply to Marc ZyngierMake sure that any attempt to inject an interrupt from userspace or an irqfd results in the GICv2 lazy init to take place.
This is not currently necessary as the init is also performed on *any* interrupt injection. But as we're about to remove that, let's introduce it here.
Signed-off-by Marc Zyngier <[email protected]>
--- arch/arm64/kvm/arm.c | 7 +++++++ arch/arm64/kvm/vgic/vgic-irqfd.c | 6 ++++++ 2 files changed, 13 insertions(+)
arch/arm64/kvm/arm.c +7 -0
@@ -51,6 +51,7 @@#include <linux/irqchip/arm-gic-v5.h> +#include "vgic/vgic.h" #include "sys_regs.h" static enum kvm_mode kvm_mode =KVM_MODE_DEFAULT ;
@@ -1475,6 +1476,12 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,trace_kvm_irq_line (irq_type, vcpu_id, irq_num, irq_level->level); +if (irqchip_in_kernel (kvm)) { +int ret =vgic_lazy_init (kvm); +if (ret) +return ret; + } +switch (irq_type) {case KVM_ARM_IRQ_TYPE_CPU :if (irqchip_in_kernel (kvm))
arch/arm64/kvm/vgic/vgic-irqfd.c +6 -0
@@ -20,9 +20,15 @@ static int vgic_irqfd_set_irq(struct kvm_kernel_irq_routing_entry *e, int level, bool line_status) {unsigned int spi_id = e->irqchip.pin +VGIC_NR_PRIVATE_IRQS ; +int ret;if (!vgic_valid_spi (kvm, spi_id))return -EINVAL ; + + ret =vgic_lazy_init (kvm); +if (ret) +return ret; +return kvm_vgic_inject_irq (kvm,NULL , spi_id, level,NULL ); }
Signature · 1 line
2.47.3
Marc Zyngier
maintainerPATCH v2 4/4 KVM: arm64: vgic-v2: Don't init the vgic on in-kernel interrupt injection
In reply to Marc ZyngierWe how have the lazy init on three paths:
- on first run of a vcpu
- on first injection of an interrupt from userspace and irqfd
- on first injection of an interrupt from kernel space as part of the device emulation (timers, PMU, vgic MI)
Given that we recompute the state of each in-kernel interrupt every time we are about to enter the guest, we can drop the lazy init from the kernel injection path.
This solves a bunch of issues related to vgic_lazy_init() being called in non-preemptible context, such as vcpu reset.
Signed-off-by Marc Zyngier <[email protected]>
--- arch/arm64/kvm/vgic/vgic.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
arch/arm64/kvm/vgic/vgic.c +2 -4
@@ -534,11 +534,9 @@ int kvm_vgic_inject_irq(struct kvm *kvm, struct kvm_vcpu *vcpu, {struct vgic_irq *irq;unsigned long flags; -int ret; - ret =vgic_lazy_init (kvm); -if (ret) -return ret; +if (unlikely (!vgic_initialized (kvm))) +return 0 ;if (!vcpu &&irq_is_private (kvm, intid))return -EINVAL ;
Signature · 1 line
2.47.3