* [PATCH 1/3] KVM: x86: Move kvm_irq_delivery_to_apic() from irq.c to lapic.c
2025-08-21 21:42 [PATCH 0/3] KVM: x86: Clean up lowest priority IRQ code Sean Christopherson
@ 2025-08-21 21:42 ` Sean Christopherson
2025-08-21 21:42 ` [PATCH 2/3] KVM: x86: Make "lowest priority" helpers local " Sean Christopherson
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Sean Christopherson @ 2025-08-21 21:42 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini; +Cc: kvm, linux-kernel
Move kvm_irq_delivery_to_apic() to lapic.c as it is specific to local APIC
emulation. This will allow burying more local APIC code in lapic.c, e.g.
the various "lowest priority" helpers.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/irq.c | 57 --------------------------------------------
arch/x86/kvm/irq.h | 4 ----
arch/x86/kvm/lapic.c | 57 ++++++++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/lapic.h | 3 +++
4 files changed, 60 insertions(+), 61 deletions(-)
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 16da89259011..a6b122f732be 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -195,63 +195,6 @@ bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
return irqchip_in_kernel(kvm);
}
-int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
- struct kvm_lapic_irq *irq, struct dest_map *dest_map)
-{
- int r = -1;
- struct kvm_vcpu *vcpu, *lowest = NULL;
- unsigned long i, dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
- unsigned int dest_vcpus = 0;
-
- if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
- return r;
-
- if (irq->dest_mode == APIC_DEST_PHYSICAL &&
- irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
- pr_info("apic: phys broadcast and lowest prio\n");
- irq->delivery_mode = APIC_DM_FIXED;
- }
-
- memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
-
- kvm_for_each_vcpu(i, vcpu, kvm) {
- if (!kvm_apic_present(vcpu))
- continue;
-
- if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
- irq->dest_id, irq->dest_mode))
- continue;
-
- if (!kvm_lowest_prio_delivery(irq)) {
- if (r < 0)
- r = 0;
- r += kvm_apic_set_irq(vcpu, irq, dest_map);
- } else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
- if (!kvm_vector_hashing_enabled()) {
- if (!lowest)
- lowest = vcpu;
- else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
- lowest = vcpu;
- } else {
- __set_bit(i, dest_vcpu_bitmap);
- dest_vcpus++;
- }
- }
- }
-
- if (dest_vcpus != 0) {
- int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
- dest_vcpu_bitmap, KVM_MAX_VCPUS);
-
- lowest = kvm_get_vcpu(kvm, idx);
- }
-
- if (lowest)
- r = kvm_apic_set_irq(lowest, irq, dest_map);
-
- return r;
-}
-
static void kvm_msi_to_lapic_irq(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e,
struct kvm_lapic_irq *irq)
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 5e62c1f79ce6..34f4a78a7a01 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -121,8 +121,4 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu);
int apic_has_pending_timer(struct kvm_vcpu *vcpu);
-int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
- struct kvm_lapic_irq *irq,
- struct dest_map *dest_map);
-
#endif
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index ed636c1f5e58..129ade22efca 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1251,6 +1251,63 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq,
return ret;
}
+int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
+ struct kvm_lapic_irq *irq, struct dest_map *dest_map)
+{
+ int r = -1;
+ struct kvm_vcpu *vcpu, *lowest = NULL;
+ unsigned long i, dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
+ unsigned int dest_vcpus = 0;
+
+ if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
+ return r;
+
+ if (irq->dest_mode == APIC_DEST_PHYSICAL &&
+ irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
+ pr_info("apic: phys broadcast and lowest prio\n");
+ irq->delivery_mode = APIC_DM_FIXED;
+ }
+
+ memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!kvm_apic_present(vcpu))
+ continue;
+
+ if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
+ irq->dest_id, irq->dest_mode))
+ continue;
+
+ if (!kvm_lowest_prio_delivery(irq)) {
+ if (r < 0)
+ r = 0;
+ r += kvm_apic_set_irq(vcpu, irq, dest_map);
+ } else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
+ if (!kvm_vector_hashing_enabled()) {
+ if (!lowest)
+ lowest = vcpu;
+ else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
+ lowest = vcpu;
+ } else {
+ __set_bit(i, dest_vcpu_bitmap);
+ dest_vcpus++;
+ }
+ }
+ }
+
+ if (dest_vcpus != 0) {
+ int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
+ dest_vcpu_bitmap, KVM_MAX_VCPUS);
+
+ lowest = kvm_get_vcpu(kvm, idx);
+ }
+
+ if (lowest)
+ r = kvm_apic_set_irq(lowest, irq, dest_map);
+
+ return r;
+}
+
/*
* Add a pending IRQ into lapic.
* Return 1 if successfully added and 0 if discarded.
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 8b00e29741de..edfed763cf89 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -119,6 +119,9 @@ void kvm_inhibit_apic_access_page(struct kvm_vcpu *vcpu);
bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
struct kvm_lapic_irq *irq, int *r, struct dest_map *dest_map);
+int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
+ struct kvm_lapic_irq *irq,
+ struct dest_map *dest_map);
void kvm_apic_send_ipi(struct kvm_lapic *apic, u32 icr_low, u32 icr_high);
int kvm_apic_set_base(struct kvm_vcpu *vcpu, u64 value, bool host_initiated);
--
2.51.0.261.g7ce5a0a67e-goog
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 2/3] KVM: x86: Make "lowest priority" helpers local to lapic.c
2025-08-21 21:42 [PATCH 0/3] KVM: x86: Clean up lowest priority IRQ code Sean Christopherson
2025-08-21 21:42 ` [PATCH 1/3] KVM: x86: Move kvm_irq_delivery_to_apic() from irq.c to lapic.c Sean Christopherson
@ 2025-08-21 21:42 ` Sean Christopherson
2025-08-21 21:42 ` [PATCH 3/3] KVM: x86: Move vector_hashing into lapic.c Sean Christopherson
2025-09-16 0:25 ` [PATCH 0/3] KVM: x86: Clean up lowest priority IRQ code Sean Christopherson
3 siblings, 0 replies; 5+ messages in thread
From: Sean Christopherson @ 2025-08-21 21:42 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini; +Cc: kvm, linux-kernel
Make various helpers for resolving lowest priority IRQs local to lapic.c
now that kvm_irq_delivery_to_apic() lives in lapic.c as well.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/lapic.c | 19 ++++++++++++-------
arch/x86/kvm/lapic.h | 9 ---------
2 files changed, 12 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 129ade22efca..1a8bc81973e3 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1063,8 +1063,8 @@ bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
}
EXPORT_SYMBOL_GPL(kvm_apic_match_dest);
-int kvm_vector_to_index(u32 vector, u32 dest_vcpus,
- const unsigned long *bitmap, u32 bitmap_size)
+static int kvm_vector_to_index(u32 vector, u32 dest_vcpus,
+ const unsigned long *bitmap, u32 bitmap_size)
{
int idx = find_nth_bit(bitmap, bitmap_size, vector % dest_vcpus);
@@ -1099,6 +1099,16 @@ static bool kvm_apic_is_broadcast_dest(struct kvm *kvm, struct kvm_lapic **src,
return false;
}
+static bool kvm_lowest_prio_delivery(struct kvm_lapic_irq *irq)
+{
+ return (irq->delivery_mode == APIC_DM_LOWEST || irq->msi_redir_hint);
+}
+
+static int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2)
+{
+ return vcpu1->arch.apic_arb_prio - vcpu2->arch.apic_arb_prio;
+}
+
/* Return true if the interrupt can be handled by using *bitmap as index mask
* for valid destinations in *dst array.
* Return false if kvm_apic_map_get_dest_lapic did nothing useful.
@@ -1451,11 +1461,6 @@ void kvm_bitmap_or_dest_vcpus(struct kvm *kvm, struct kvm_lapic_irq *irq,
rcu_read_unlock();
}
-int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2)
-{
- return vcpu1->arch.apic_arb_prio - vcpu2->arch.apic_arb_prio;
-}
-
static bool kvm_ioapic_handles_vector(struct kvm_lapic *apic, int vector)
{
return test_bit(vector, apic->vcpu->arch.ioapic_handled_vectors);
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index edfed763cf89..50123fe7f58f 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -105,7 +105,6 @@ void kvm_apic_set_version(struct kvm_vcpu *vcpu);
void kvm_apic_after_set_mcg_cap(struct kvm_vcpu *vcpu);
bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
int shorthand, unsigned int dest, int dest_mode);
-int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2);
void kvm_apic_clear_irr(struct kvm_vcpu *vcpu, int vec);
bool __kvm_apic_update_irr(unsigned long *pir, void *regs, int *max_irr);
bool kvm_apic_update_irr(struct kvm_vcpu *vcpu, unsigned long *pir, int *max_irr);
@@ -225,12 +224,6 @@ static inline bool kvm_apic_init_sipi_allowed(struct kvm_vcpu *vcpu)
!kvm_x86_call(apic_init_signal_blocked)(vcpu);
}
-static inline bool kvm_lowest_prio_delivery(struct kvm_lapic_irq *irq)
-{
- return (irq->delivery_mode == APIC_DM_LOWEST ||
- irq->msi_redir_hint);
-}
-
static inline int kvm_lapic_latched_init(struct kvm_vcpu *vcpu)
{
return lapic_in_kernel(vcpu) && test_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
@@ -245,8 +238,6 @@ void kvm_bitmap_or_dest_vcpus(struct kvm *kvm, struct kvm_lapic_irq *irq,
bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq,
struct kvm_vcpu **dest_vcpu);
-int kvm_vector_to_index(u32 vector, u32 dest_vcpus,
- const unsigned long *bitmap, u32 bitmap_size);
void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu);
void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu);
void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu);
--
2.51.0.261.g7ce5a0a67e-goog
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 3/3] KVM: x86: Move vector_hashing into lapic.c
2025-08-21 21:42 [PATCH 0/3] KVM: x86: Clean up lowest priority IRQ code Sean Christopherson
2025-08-21 21:42 ` [PATCH 1/3] KVM: x86: Move kvm_irq_delivery_to_apic() from irq.c to lapic.c Sean Christopherson
2025-08-21 21:42 ` [PATCH 2/3] KVM: x86: Make "lowest priority" helpers local " Sean Christopherson
@ 2025-08-21 21:42 ` Sean Christopherson
2025-09-16 0:25 ` [PATCH 0/3] KVM: x86: Clean up lowest priority IRQ code Sean Christopherson
3 siblings, 0 replies; 5+ messages in thread
From: Sean Christopherson @ 2025-08-21 21:42 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini; +Cc: kvm, linux-kernel
Move the vector_hashing module param into lapic.c now that all usage is
contained within the local APIC emulation code.
Opportunistically drop the accessor and append "_enabled" to the variable
to help capture that it's a boolean module param.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/lapic.c | 8 ++++++--
arch/x86/kvm/x86.c | 8 --------
arch/x86/kvm/x86.h | 1 -
3 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 1a8bc81973e3..6fac6fb86c19 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -74,6 +74,10 @@ module_param(lapic_timer_advance, bool, 0444);
#define LAPIC_TIMER_ADVANCE_NS_MAX 5000
/* step-by-step approximation to mitigate fluctuation */
#define LAPIC_TIMER_ADVANCE_ADJUST_STEP 8
+
+static bool __read_mostly vector_hashing_enabled = true;
+module_param_named(vector_hashing, vector_hashing_enabled, bool, 0444);
+
static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data);
static int kvm_lapic_msr_write(struct kvm_lapic *apic, u32 reg, u64 data);
@@ -1152,7 +1156,7 @@ static inline bool kvm_apic_map_get_dest_lapic(struct kvm *kvm,
if (!kvm_lowest_prio_delivery(irq))
return true;
- if (!kvm_vector_hashing_enabled()) {
+ if (!vector_hashing_enabled) {
lowest = -1;
for_each_set_bit(i, bitmap, 16) {
if (!(*dst)[i])
@@ -1293,7 +1297,7 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
r = 0;
r += kvm_apic_set_irq(vcpu, irq, dest_map);
} else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
- if (!kvm_vector_hashing_enabled()) {
+ if (!vector_hashing_enabled) {
if (!lowest)
lowest = vcpu;
else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7ba2cdfdac44..554b36de700c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -164,9 +164,6 @@ module_param(kvmclock_periodic_sync, bool, 0444);
static u32 __read_mostly tsc_tolerance_ppm = 250;
module_param(tsc_tolerance_ppm, uint, 0644);
-static bool __read_mostly vector_hashing = true;
-module_param(vector_hashing, bool, 0444);
-
bool __read_mostly enable_vmware_backdoor = false;
module_param(enable_vmware_backdoor, bool, 0444);
EXPORT_SYMBOL_GPL(enable_vmware_backdoor);
@@ -13552,11 +13549,6 @@ bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma);
-bool kvm_vector_hashing_enabled(void)
-{
- return vector_hashing;
-}
-
bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
{
return (vcpu->arch.msr_kvm_poll_control & 1) == 0;
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index eb3088684e8a..786e36fcd0fb 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -431,7 +431,6 @@ void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu,
int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data);
int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata);
-bool kvm_vector_hashing_enabled(void);
void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_code);
int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type,
void *insn, int insn_len);
--
2.51.0.261.g7ce5a0a67e-goog
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 0/3] KVM: x86: Clean up lowest priority IRQ code
2025-08-21 21:42 [PATCH 0/3] KVM: x86: Clean up lowest priority IRQ code Sean Christopherson
` (2 preceding siblings ...)
2025-08-21 21:42 ` [PATCH 3/3] KVM: x86: Move vector_hashing into lapic.c Sean Christopherson
@ 2025-09-16 0:25 ` Sean Christopherson
3 siblings, 0 replies; 5+ messages in thread
From: Sean Christopherson @ 2025-09-16 0:25 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini; +Cc: kvm, linux-kernel
On Thu, 21 Aug 2025 14:42:06 -0700, Sean Christopherson wrote:
> Move some local APIC specific code into lapic.c that has no business being
> exposed outside of local APIC emulation. The lowest priority vector
> hashing code in particular is *very* specific to lapic.c internals, but
> that's not at all obvious from the globally-visible symbols.
>
> Sean Christopherson (3):
> KVM: x86: Move kvm_irq_delivery_to_apic() from irq.c to lapic.c
> KVM: x86: Make "lowest priority" helpers local to lapic.c
> KVM: x86: Move vector_hashing into lapic.c
>
> [...]
Applied to kvm-x86 misc, thanks!
[1/3] KVM: x86: Move kvm_irq_delivery_to_apic() from irq.c to lapic.c
https://github.com/kvm-x86/linux/commit/cbf5d9457462
[2/3] KVM: x86: Make "lowest priority" helpers local to lapic.c
https://github.com/kvm-x86/linux/commit/73473f31a4bf
[3/3] KVM: x86: Move vector_hashing into lapic.c
https://github.com/kvm-x86/linux/commit/aac057dd6231
--
https://github.com/kvm-x86/linux/tree/next
^ permalink raw reply [flat|nested] 5+ messages in thread