On Fri, Oct 03, 2014 at 12:30:52AM +0300, Nadav Amit wrote:
>KVM does not deliver x2APIC broadcast messages with physical mode. Intel SDM
>(10.12.9 ICR Operation in x2APIC Mode) states: "A destination ID value of
>FFFF_FFFFH is used for broadcast of interrupts in both logical destination and
>physical destination modes."
>
>In addition, the 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.
>
>The fix tries to combine broadcast in different modes through a unified code.
>
>One rare case occurs when the source of IPI has its APIC disabled. In such
>case, the source can still issue IPIs, but since the source is not obliged to
>have the same LAPIC mode as the enabled ones, we cannot rely on it.
>Since it is a rare case, it is unoptimized and done on the slow-path.
>
>---
>
>Changes v1->v2:
>- Follow Radim's review: setting constants, preferring simplicity to marginal
> performance gain, etc.
>- Combine the cluster mode and x2apic mode patches
>
>Signed-off-by: Nadav Amit <namit@xxxxxxxxxxxxxxxxx>
>---
Reviewed-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
> arch/x86/include/asm/kvm_host.h | 2 +-
> arch/x86/kvm/lapic.c | 28 ++++++++++++++++++++++------
> arch/x86/kvm/lapic.h | 4 ++--
> virt/kvm/ioapic.h | 2 +-
> 4 files changed, 26 insertions(+), 10 deletions(-)
>
>diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
>index 7d603a7..6f2be83 100644
>--- a/arch/x86/include/asm/kvm_host.h
>+++ b/arch/x86/include/asm/kvm_host.h
>@@ -542,7 +542,7 @@ struct kvm_apic_map {
> struct rcu_head rcu;
> u8 ldr_bits;
> /* fields bellow are used to decode ldr values in different modes */
>- u32 cid_shift, cid_mask, lid_mask;
>+ u32 cid_shift, cid_mask, lid_mask, broadcast;
> struct kvm_lapic *phys_map[256];
> /* first index is cluster id second is cpu id in a cluster */
> struct kvm_lapic *logical_map[16][16];
>diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
>index b8345dd..ee04adf 100644
>--- a/arch/x86/kvm/lapic.c
>+++ b/arch/x86/kvm/lapic.c
>@@ -68,6 +68,9 @@
> #define MAX_APIC_VECTOR 256
> #define APIC_VECTORS_PER_REG 32
>
>+#define APIC_BROADCAST 0xFF
>+#define X2APIC_BROADCAST 0xFFFFFFFFul
>+
> #define VEC_POS(v) ((v) & (32 - 1))
> #define REG_POS(v) (((v) >> 5) << 4)
>
>@@ -149,6 +152,7 @@ static void recalculate_apic_map(struct kvm *kvm)
> new->cid_shift = 8;
> new->cid_mask = 0;
> new->lid_mask = 0xff;
>+ new->broadcast = APIC_BROADCAST;
>
> kvm_for_each_vcpu(i, vcpu, kvm) {
> struct kvm_lapic *apic = vcpu->arch.apic;
>@@ -170,6 +174,7 @@ static void recalculate_apic_map(struct kvm *kvm)
> new->cid_shift = 16;
> new->cid_mask = (1 << KVM_X2APIC_CID_BITS) - 1;
> new->lid_mask = 0xffff;
>+ new->broadcast = X2APIC_BROADCAST;
> } else if (kvm_apic_sw_enabled(apic) &&
> !new->cid_mask /* flat mode */ &&
> kvm_apic_get_reg(apic, APIC_DFR) == APIC_DFR_CLUSTER) {
>@@ -558,16 +563,25 @@ static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr)
> apic_update_ppr(apic);
> }
>
>-int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest)
>+static int kvm_apic_broadcast(struct kvm_lapic *apic, u32 dest)
>+{
>+ return dest == (apic_x2apic_mode(apic) ?
>+ X2APIC_BROADCAST : APIC_BROADCAST);
>+}
>+
>+int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 dest)
> {
>- return dest == 0xff || kvm_apic_id(apic) == dest;
>+ return kvm_apic_id(apic) == dest || kvm_apic_broadcast(apic, dest);
> }
>
>-int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda)
>+int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda)
> {
> int result = 0;
> u32 logical_id;
>
>+ if (kvm_apic_broadcast(apic, mda))
>+ return 1;
>+
> if (apic_x2apic_mode(apic)) {
> logical_id = kvm_apic_get_reg(apic, APIC_LDR);
> return logical_id & mda;
>@@ -595,7 +609,7 @@ int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda)
> }
>
> int kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
>- int short_hand, int dest, int dest_mode)
>+ int short_hand, unsigned int dest, int dest_mode)
> {
> int result = 0;
> struct kvm_lapic *target = vcpu->arch.apic;
>@@ -657,9 +671,11 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
> if (!map)
> goto out;
>
>+ if (irq->dest_id == map->broadcast)
>+ goto out;
>+
> if (irq->dest_mode == 0) { /* physical mode */
>- if (irq->delivery_mode == APIC_DM_LOWEST ||
>- irq->dest_id == 0xff)
>+ if (irq->delivery_mode == APIC_DM_LOWEST)
> goto out;
> dst = &map->phys_map[irq->dest_id & 0xff];
> } else {
>diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
>index 6a11845..3fd6c22 100644
>--- a/arch/x86/kvm/lapic.h
>+++ b/arch/x86/kvm/lapic.h
>@@ -55,8 +55,8 @@ 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, u16 dest);
>-int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda);
>+int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 dest);
>+int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda);
> int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
> unsigned long *dest_map);
> int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type);
>diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
>index e23b706..31725a3 100644
>--- a/virt/kvm/ioapic.h
>+++ b/virt/kvm/ioapic.h
>@@ -83,7 +83,7 @@ static inline struct kvm_ioapic *ioapic_irqchip(struct kvm *kvm)
>
> void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu);
> int kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
>- int short_hand, int dest, int dest_mode);
>+ int short_hand, unsigned int dest, int dest_mode);
> int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2);
> void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector,
> int trigger_mode);
>--
>1.9.1
>
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