Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1542899

[PATCH v3 3/4] KVM: x86: make interrupt delivery fast and slow path behave the same

Show all headers | View raw

Slow path tried to prevent IPIs from x2APIC VCPUs from being delivered
to xAPIC VCPUs and vice-versa.  Make slow path behave like fast path,
which never distinguished that.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
 arch/x86/kvm/lapic.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 81cc93580c40..519b72bbf947 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -606,7 +606,7 @@ static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda)
 	if (apic_x2apic_mode(apic))
 		return mda == kvm_x2apic_id(apic);
 
-	return mda == SET_APIC_DEST_FIELD(kvm_xapic_id(apic));
+	return mda == kvm_xapic_id(apic);
 }
 
 static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda)
@@ -623,7 +623,6 @@ static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda)
 		       && (logical_id & mda & 0xffff) != 0;
 
 	logical_id = GET_APIC_LOGICAL_ID(logical_id);
-	mda = GET_APIC_DEST_FIELD(mda);
 
 	switch (kvm_lapic_get_reg(apic, APIC_DFR)) {
 	case APIC_DFR_FLAT:
@@ -640,9 +639,9 @@ static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda)
 
 /* The KVM local APIC implementation has two quirks:
  *
- *  - the xAPIC MDA stores the destination at bits 24-31, while this
- *    is not true of struct kvm_lapic_irq's dest_id field.  This is
- *    just a quirk in the API and is not problematic.
+ *  - Real hardware delivers interrupts destined to x2APIC ID > 0xff to LAPICs
+ *    in xAPIC mode if the "destination & 0xff" matches its xAPIC ID.
+ *    KVM doesn't do that aliasing.
  *
  *  - in-kernel IOAPIC messages have to be delivered directly to
  *    x2APIC, because the kernel does not support interrupt remapping.
@@ -658,13 +657,12 @@ static u32 kvm_apic_mda(struct kvm_vcpu *vcpu, unsigned int dest_id,
 		struct kvm_lapic *source, struct kvm_lapic *target)
 {
 	bool ipi = source != NULL;
-	bool x2apic_mda = apic_x2apic_mode(ipi ? source : target);
 
 	if (!vcpu->kvm->arch.x2apic_broadcast_quirk_disabled &&
-	    !ipi && dest_id == APIC_BROADCAST && x2apic_mda)
+	    !ipi && dest_id == APIC_BROADCAST && apic_x2apic_mode(target))
 		return X2APIC_BROADCAST;
 
-	return x2apic_mda ? dest_id : SET_APIC_DEST_FIELD(dest_id);
+	return dest_id;
 }
 
 bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
-- 
2.11.0

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[PATCH v3 3/4] KVM: x86: make interrupt delivery fast and slow path behave the same Radim Krčmář <rkrcmar@redhat.com> - 2016-12-15 18:10 +0100
  Re: [PATCH v3 3/4] KVM: x86: make interrupt delivery fast and slow  path behave the same David Hildenbrand <david@redhat.com> - 2016-12-16 17:50 +0100
    Re: [PATCH v3 3/4] KVM: x86: make interrupt delivery fast and slow  path behave the same Paolo Bonzini <pbonzini@redhat.com> - 2016-12-16 18:00 +0100
      [PATCH v4 3/4] KVM: x86: make interrupt delivery fast and slow path  behave the same Radim Krčmář <rkrcmar@redhat.com> - 2016-12-16 18:10 +0100
        Re: [PATCH v4 3/4] KVM: x86: make interrupt delivery fast and slow  path behave the same David Hildenbrand <david@redhat.com> - 2016-12-19 16:00 +0100

csiph-web