[Devel] [PATCH RHEL7 COMMIT] ms/KVM: x86: set TMR when the interrupt is accepted

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-327.4.5.vz7.11.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.4.5.vz7.11.4
------>
commit f44377c8f6490b16fe46a127ff509b3c09c99e53
Author: Paolo Bonzini <pbonzini at redhat.com>
Date:   Fri Feb 19 13:30:27 2016 +0400

    ms/KVM: x86: set TMR when the interrupt is accepted
    
    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 at redhat.com>
    
    ms commit: bdaffe1d93e7eddbcc71d074a5d49eba7fe1c765
    
    Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
    Reviewed-by: Roman Kagan <rkagan at virtuozzo.com>
---
 arch/x86/kvm/ioapic.c |  6 +-----
 arch/x86/kvm/ioapic.h |  3 +--
 arch/x86/kvm/lapic.c  | 19 ++++++++++---------
 arch/x86/kvm/lapic.h  |  1 -
 arch/x86/kvm/x86.c    |  6 +-----
 5 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index d442d94..dc2ae8d 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;
@@ -265,9 +264,6 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
 			     kvm_apic_pending_eoi(vcpu, e->fields.vector))) {
 				__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);
 			}
 		}
 	}
diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
index a5cdfc0..652d5c5 100644
--- a/arch/x86/kvm/ioapic.h
+++ b/arch/x86/kvm/ioapic.h
@@ -114,7 +114,6 @@ 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 fa98d0b..d6d6b52 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -549,15 +549,6 @@ 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;
@@ -762,6 +753,9 @@ 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;
@@ -771,6 +765,13 @@ 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 (vcpu->arch.apicv_active)
 			kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
 		else {
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 9e8e614..4cb2a08 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(struct kvm_vcpu *vcpu, u32 *pir);
 int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 dest);
 int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 06cd0cb..4b14f95 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6270,22 +6270,18 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
 	u64 ioapic_eoi_exit_bitmap[4];
 	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);
 
 	if (vcpu->arch.apicv_active)
 		kvm_x86_ops->sync_pir_to_irr(vcpu);
 
-	kvm_ioapic_scan_entry(vcpu, ioapic_eoi_exit_bitmap, tmr);
+	kvm_ioapic_scan_entry(vcpu, ioapic_eoi_exit_bitmap);
 	bitmap_or((ulong *)eoi_exit_bitmap, (ulong *)ioapic_eoi_exit_bitmap,
 		  vcpu_to_synic(vcpu)->vec_bitmap, 256);
 	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
-	kvm_apic_update_tmr(vcpu, tmr);
 }
 
 void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)