From: Marc Zyngier <marc.zyngier@arm.com>
To: Christoffer Dall <cdall@linaro.org>
Cc: Jason Cooper <jason@lakedaemon.net>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Thomas Gleixner <tglx@linutronix.de>,
kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
Date: Wed, 30 Aug 2017 10:59:46 +0100 [thread overview]
Message-ID: <4dcaea2f-f8b4-c12e-c3c1-b43a4e29279b@arm.com> (raw)
In-Reply-To: <20170828181758.GA24649@cbox>
On 28/08/17 19:17, Christoffer Dall wrote:
> On Mon, Jul 31, 2017 at 06:26:31PM +0100, Marc Zyngier wrote:
>> The redistributor needs to be told which vPE is about to be run,
>> and tells us whether there is any pending VLPI on exit.
>>
>> Let's add the scheduling calls to the vgic flush/sync functions,
>> allowing the VLPIs to be delivered to the guest.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>> virt/kvm/arm/vgic/vgic-v4.c | 24 ++++++++++++++++++++++++
>> virt/kvm/arm/vgic/vgic.c | 4 ++++
>> virt/kvm/arm/vgic/vgic.h | 1 +
>> 3 files changed, 29 insertions(+)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
>> index 50721c4e3da5..0a8deefbcf1c 100644
>> --- a/virt/kvm/arm/vgic/vgic-v4.c
>> +++ b/virt/kvm/arm/vgic/vgic-v4.c
>> @@ -119,6 +119,30 @@ void vgic_v4_teardown(struct kvm *kvm)
>> its_vm->vpes = NULL;
>> }
>>
>> +int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on)
>> +{
>> + int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
>> +
>> + if (!vgic_is_v4_capable(vcpu->kvm) || !irq)
>> + return 0;
>
> why do we need to check the its_vpe.irq here? This check is certainly
> not untuitive, as I don't understand what happened on a v4 capable
> system that somehow failed. Is it because a specific VM is configured
> to not use VLPIs, or?
Hmm. I think that's a debug leftover from my early attempt at making
things work with QEMU, which initializes things in the opposite order
as kvmtool. It should be removed (or replaced by a fat WARN_ON).
>> +
>> + /*
>> + * Before making the VPE resident, make sure the redistributor
>> + * expects us here.
>> + */
>> + if (on) {
>> + int err;
>> +
>> + err = irq_set_affinity(irq, cpumask_of(smp_processor_id()));
>
> This is pretty unintuitive, and coming here without having read your
> documentation may make people completely puzzled. Could we provide a
> pointer to the documentation that explains how the vpe irq hooks this
> all together?
Sure, will do.
>
>> + if (err) {
>> + kvm_err("failed irq_set_affinity IRQ%d (%d)\n", irq, err);
>> + return err;
>> + }
>> + }
>> +
>> + return its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, on);
>> +}
>> +
>
> I'd prefer this function be split into two and follow the vgic notation
> of having a flush and a sync function.
Yes, makes sense.
>> static struct vgic_its *vgic_get_its(struct kvm *kvm,
>> struct kvm_kernel_irq_routing_entry *irq_entry)
>> {
>> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
>> index dfac894f6f03..9ab52108989d 100644
>> --- a/virt/kvm/arm/vgic/vgic.c
>> +++ b/virt/kvm/arm/vgic/vgic.c
>> @@ -721,6 +721,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
>> {
>> struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>>
>> + WARN_ON(vgic_v4_schedule(vcpu, false));
>> +
>
> This is in the critical path, so would it be worth considering a static
> key to cater for non-GICv4 systems here?
Hey, for once I wasn't trying to optimize early! ;-) This would be
useful indeed, as I expect GICv4 systems to be the absolute minority for
the foreseeable future.
>
>> /* An empty ap_list_head implies used_lrs == 0 */
>> if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
>> return;
>> @@ -733,6 +735,8 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
>> /* Flush our emulation state into the GIC hardware before entering the guest. */
>> void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
>> {
>> + WARN_ON(vgic_v4_schedule(vcpu, true));
>> +
>> /*
>> * If there are no virtual interrupts active or pending for this
>> * VCPU, then there is no work to do and we can bail out without
>> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
>> index 1210bf4681dc..693b654acf4d 100644
>> --- a/virt/kvm/arm/vgic/vgic.h
>> +++ b/virt/kvm/arm/vgic/vgic.h
>> @@ -234,5 +234,6 @@ int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
>> bool vgic_is_v4_capable(struct kvm *kvm);
>> int vgic_v4_init(struct kvm *kvm);
>> void vgic_v4_teardown(struct kvm *kvm);
>> +int vgic_v4_schedule(struct kvm_vcpu *vcpu, bool on);
>>
>> #endif
>> --
>> 2.11.0
>>
> Functionally, this looks correct.
>
> Thanks,
> -Christoffer
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2017-08-30 9:59 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-31 17:25 [PATCH v3 00/59] irqchip: KVM: Add support for GICv4 Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 01/59] genirq: Let irq_set_vcpu_affinity() iterate over hierarchy Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 02/59] irqchip/gic-v3: Add redistributor iterator Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 03/59] irqchip/gic-v3: Add VLPI/DirectLPI discovery Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 04/59] irqchip/gic-v3-its: Move LPI definitions around Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 05/59] irqchip/gic-v3-its: Add probing for VLPI properties Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 06/59] irqchip/gic-v3-its: Macro-ize its_send_single_command Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 07/59] irqchip/gic-v3-its: Implement irq_set_irqchip_state for pending state Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 08/59] irqchip/gic-v3-its: Split out property table allocation Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 09/59] irqchip/gic-v3-its: Allow use of indirect VCPU tables Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 10/59] irqchip/gic-v3-its: Split out pending table allocation Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 11/59] irqchip/gic-v3-its: Rework LPI freeing Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 12/59] irqchip/gic-v3-its: Generalize device table allocation Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 13/59] irqchip/gic-v3-its: Generalize LPI configuration Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 14/59] irqchip/gic-v4: Add management structure definitions Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 15/59] irqchip/gic-v3-its: Add GICv4 ITS command definitions Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 16/59] irqchip/gic-v3-its: Add VLPI configuration hook Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 17/59] irqchip/gic-v3-its: Add VLPI map/unmap operations Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 18/59] irqchip/gic-v3-its: Add VLPI configuration handling Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 19/59] irqchip/gic-v3-its: Add VPE domain infrastructure Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 20/59] irqchip/gic-v3-its: Add VPE irq domain allocation/teardown Marc Zyngier
2017-07-31 17:25 ` [PATCH v3 21/59] irqchip/gic-v3-its: Add VPE irq domain [de]activation Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 22/59] irqchip/gic-v3-its: Add VPENDBASER/VPROPBASER accessors Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 23/59] irqchip/gic-v3-its: Add VPE scheduling Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 24/59] irqchip/gic-v3-its: Add VPE invalidation hook Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 25/59] irqchip/gic-v3-its: Add VPE affinity changes Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 26/59] irqchip/gic-v3-its: Add VPE interrupt masking Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 27/59] irqchip/gic-v3-its: Support VPE doorbell invalidation even when !DirectLPI Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 28/59] irqchip/gic-v3-its: Allow doorbell interrupts to be injected/cleared Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 29/59] irqchip/gic-v3-its: Set implementation defined bit to enable VLPIs Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 30/59] irqchip/gic-v4: Add per-VM VPE domain creation Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 31/59] irqchip/gic-v4: Add VPE command interface Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 32/59] irqchip/gic-v4: Add VLPI configuration interface Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 33/59] irqchip/gic-v4: Add some basic documentation Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 34/59] irqchip/gic-v4: Enable low-level GICv4 operations Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 35/59] irqchip/gic-v3: Advertise GICv4 support to KVM Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 36/59] KVM: arm: Select ARM_GIC_V3 and ARM_GIC_V3_ITS Marc Zyngier
2017-08-26 19:49 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 37/59] KVM: arm/arm64: vgic: Move kvm_vgic_destroy call around Marc Zyngier
2017-08-26 19:49 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 38/59] KVM: arm/arm64: vITS: Add MSI translation helpers Marc Zyngier
2017-08-26 19:49 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate Marc Zyngier
2017-08-26 19:49 ` Christoffer Dall
2017-08-30 9:46 ` Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 40/59] KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain Marc Zyngier
2017-08-26 19:49 ` Christoffer Dall
2017-08-30 9:50 ` Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass Marc Zyngier
2017-08-26 19:48 ` Christoffer Dall
2017-08-30 9:42 ` Marc Zyngier
2017-08-30 10:20 ` Auger Eric
2017-08-30 10:42 ` Marc Zyngier
2017-08-30 12:54 ` Auger Eric
2017-08-30 10:28 ` Marc Zyngier
2017-08-30 11:46 ` Christoffer Dall
2017-08-30 12:53 ` Marc Zyngier
2017-08-30 19:59 ` Christoffer Dall
2017-08-31 10:24 ` Marc Zyngier
2017-08-31 12:36 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 42/59] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 43/59] KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-08-30 11:03 ` Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 44/59] KVM: arm/arm64: GICv4: Handle MOVI applied to a VLPI Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-08-30 14:08 ` Marc Zyngier
2017-08-30 20:04 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 45/59] KVM: arm/arm64: GICv4: Handle CLEAR " Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 46/59] KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-08-30 14:46 ` Marc Zyngier
2017-08-30 20:10 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 47/59] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 48/59] KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-08-30 14:56 ` Marc Zyngier
2017-08-30 20:12 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 50/59] KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Marc Zyngier
2017-08-04 7:44 ` Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-08-30 10:31 ` Andrew Jones
2017-08-30 11:55 ` Christoffer Dall
2017-08-30 12:28 ` Andrew Jones
2017-08-31 12:18 ` Marc Zyngier
2017-08-31 12:41 ` Christoffer Dall
2017-08-28 18:18 ` Christoffer Dall
2017-08-30 15:36 ` Marc Zyngier
2017-08-30 20:58 ` Christoffer Dall
2017-08-31 8:19 ` Marc Zyngier
2017-09-06 9:06 ` Shannon Zhao
2017-07-31 17:26 ` [PATCH v3 52/59] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source Marc Zyngier
2017-08-28 18:19 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 53/59] KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync Marc Zyngier
2017-08-28 18:17 ` Christoffer Dall
2017-08-30 9:59 ` Marc Zyngier [this message]
2017-08-30 11:56 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered Marc Zyngier
2017-08-28 18:20 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 55/59] KVM: arm/arm64: GICv4: Enable VLPI support Marc Zyngier
2017-08-28 18:25 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 56/59] KVM: arm/arm64: GICv4: Prevent heterogenous systems from using GICv4 Marc Zyngier
2017-08-28 18:35 ` Christoffer Dall
2017-08-30 16:03 ` Marc Zyngier
2017-08-30 21:00 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 57/59] KVM: arm/arm64: GICv4: Theory of operations Marc Zyngier
2017-08-28 18:18 ` Christoffer Dall
2017-08-30 11:30 ` Marc Zyngier
2017-08-30 11:58 ` Christoffer Dall
2017-07-31 17:26 ` [PATCH v3 58/59] irqchip/gic-v3-its: Pass its_node pointer to each command bulder Marc Zyngier
2017-07-31 17:26 ` [PATCH v3 59/59] irqchip/gic-v3-its: Workaround Huawei D05 redistributor addressing Marc Zyngier
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