[PATCH 1/9] KVM: x86: set TMR when the interrupt is accepted

From: Paolo Bonzini
Date: Wed Aug 05 2015 - 11:29:53 EST


Do not compute TMR in advance. Instead, set the TMR just before the interrupt
is accepted into the IRR. This limits the coupling between IOAPIC and LAPIC.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/ioapic.c | 9 ++-------
arch/x86/kvm/ioapic.h | 3 +--
arch/x86/kvm/lapic.c | 19 ++++++++++---------
arch/x86/kvm/lapic.h | 1 -
arch/x86/kvm/x86.c | 5 +----
5 files changed, 14 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index 856f79105bb5..eaf4ec38d980 100644
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -246,8 +246,7 @@ static void update_handled_vectors(struct kvm_ioapic *ioapic)
smp_wmb();
}

-void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
- u32 *tmr)
+void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
{
struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
union kvm_ioapic_redirect_entry *e;
@@ -260,13 +259,9 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
index == RTC_GSI) {
if (kvm_apic_match_dest(vcpu, NULL, 0,
- e->fields.dest_id, e->fields.dest_mode)) {
+ e->fields.dest_id, e->fields.dest_mode))
__set_bit(e->fields.vector,
(unsigned long *)eoi_exit_bitmap);
- if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG)
- __set_bit(e->fields.vector,
- (unsigned long *)tmr);
- }
}
}
spin_unlock(&ioapic->lock);
diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
index ca0b0b4e6256..3dbd0e2aac4e 100644
--- a/arch/x86/kvm/ioapic.h
+++ b/arch/x86/kvm/ioapic.h
@@ -120,7 +120,6 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
struct kvm_lapic_irq *irq, unsigned long *dest_map);
int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
-void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
- u32 *tmr);
+void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);

#endif
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2a5ca97c263b..9be64c77d6db 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -551,15 +551,6 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu)
__clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
}

-void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
-{
- struct kvm_lapic *apic = vcpu->arch.apic;
- int i;
-
- for (i = 0; i < 8; i++)
- apic_set_reg(apic, APIC_TMR + 0x10 * i, tmr[i]);
-}
-
static void apic_update_ppr(struct kvm_lapic *apic)
{
u32 tpr, isrv, ppr, old_ppr;
@@ -781,6 +772,9 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
case APIC_DM_LOWEST:
vcpu->arch.apic_arb_prio++;
case APIC_DM_FIXED:
+ if (unlikely(trig_mode && !level))
+ break;
+
/* FIXME add logic for vcpu on reset */
if (unlikely(!apic_enabled(apic)))
break;
@@ -790,6 +784,13 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
if (dest_map)
__set_bit(vcpu->vcpu_id, dest_map);

+ if (apic_test_vector(vector, apic->regs + APIC_TMR) != !!trig_mode) {
+ if (trig_mode)
+ apic_set_vector(vector, apic->regs + APIC_TMR);
+ else
+ apic_clear_vector(vector, apic->regs + APIC_TMR);
+ }
+
if (kvm_x86_ops->deliver_posted_interrupt)
kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
else {
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 764037991d26..eb46d6bcaa75 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -57,7 +57,6 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value);
u64 kvm_lapic_get_base(struct kvm_vcpu *vcpu);
void kvm_apic_set_version(struct kvm_vcpu *vcpu);

-void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr);
void __kvm_apic_update_irr(u32 *pir, void *regs);
void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c7b6aed998e9..9e29dbe183d7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6150,17 +6150,14 @@ static void process_smi(struct kvm_vcpu *vcpu)
static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
{
u64 eoi_exit_bitmap[4];
- u32 tmr[8];

if (!kvm_apic_hw_enabled(vcpu->arch.apic))
return;

memset(eoi_exit_bitmap, 0, 32);
- memset(tmr, 0, 32);

- kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
+ kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap);
kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
- kvm_apic_update_tmr(vcpu, tmr);
}

static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
--
1.8.3.1


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