2014-07-30 07:03:21

by Nadav Amit

Subject: [PATCH] KVM: x86: cluster mode broadcast does not work

Local-apic enables cluster mode broadcast. As Intel SDM 10.6.2.2 says:
"Broadcast to all local APICs is achieved by setting all destination bits to
one." This patch enables cluster mode broadcast.

Signed-off-by: Nadav Amit <[email protected]>
---
arch/x86/kvm/lapic.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index efb1939..05c9a46 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -560,8 +560,8 @@ int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda)
result = 1;
break;
case APIC_DFR_CLUSTER:
- if (((logical_id >> 4) == (mda >> 0x4))
- && (logical_id & mda & 0xf))
+ if ((((logical_id >> 4) == (mda >> 0x4))
+ && (logical_id & mda & 0xf)) || mda == 0xff)
result = 1;
break;
default:
@@ -644,6 +644,10 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
} else {
u32 mda = irq->dest_id << (32 - map->ldr_bits);

+ if (irq->dest_id == 0xff &&
+ kvm_apic_get_reg(src, APIC_DFR) == APIC_DFR_CLUSTER)
+ goto out; /* cluster mode broadcast */
+
dst = map->logical_map[apic_cluster_id(map, mda)];

bitmap = apic_logical_id(map, mda);
--
1.9.1

2014-07-31 17:46:29

by Nadav Amit

Subject: Re: [PATCH] KVM: x86: cluster mode broadcast does not work

cc'ing the kvm mailing list that was mistakenly omitted.

On 7/30/14 10:03 AM, Nadav Amit wrote:
> Local-apic enables cluster mode broadcast. As Intel SDM 10.6.2.2 says:
> "Broadcast to all local APICs is achieved by setting all destination bits to
> one." This patch enables cluster mode broadcast.
>
> Signed-off-by: Nadav Amit <[email protected]>
> ---
> arch/x86/kvm/lapic.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index efb1939..05c9a46 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -560,8 +560,8 @@ int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda)
> result = 1;
> break;
> case APIC_DFR_CLUSTER:
> - if (((logical_id >> 4) == (mda >> 0x4))
> - && (logical_id & mda & 0xf))
> + if ((((logical_id >> 4) == (mda >> 0x4))
> + && (logical_id & mda & 0xf)) || mda == 0xff)
> result = 1;
> break;
> default:
> @@ -644,6 +644,10 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
> } else {
> u32 mda = irq->dest_id << (32 - map->ldr_bits);
>
> + if (irq->dest_id == 0xff &&
> + kvm_apic_get_reg(src, APIC_DFR) == APIC_DFR_CLUSTER)
> + goto out; /* cluster mode broadcast */
> +
> dst = map->logical_map[apic_cluster_id(map, mda)];
>
> bitmap = apic_logical_id(map, mda);
>