Re: [PATCH v2 4/8] KVM: arm/arm64: vgic: restructure kvm_vgic_(un)map_phys_irq

Auger Eric
2017-08-22T14:33:53Z

Hi Christoffer,

On 21/07/2017 13:44, Christoffer Dall wrote:
> On Thu, Jun 15, 2017 at 02:52:36PM +0200, Eric Auger wrote:
>> We want to reuse the core of the map/unmap functions for IRQ
>> forwarding. Let's move the computation of the hwirq in
>> kvm_vgic_map_phys_irq and pass the linux IRQ as parameter.
>> the host_irq is added to struct vgic_irq.
>>
>> We introduce kvm_vgic_map/unmap_irq which take a struct vgic_irq
>> handle as a parameter.
>
> So this is to avoid the linux-to-hardware irq number translation in
> other callers?
Yes that's correct. Also forwarding code caller needs to hold the lock,
reason why I pass a vgic_irq as a param.
>
> I am sort of guessing that we need to store the host_irq number so that
> we can probe into the physical GIC in later patches? That may be good
> to note in this commit message if you respin.
done

Thanks

Eric
>
> Thanks,
> -Christoffer
>
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> ---
>> include/kvm/arm_vgic.h | 8 ++++---
>> virt/kvm/arm/arch_timer.c | 24 +------------------
>> virt/kvm/arm/vgic/vgic.c | 60 +++++++++++++++++++++++++++++++++++------------
>> 3 files changed, 51 insertions(+), 41 deletions(-)
>>
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index ef71858..cceb31d 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -112,6 +112,7 @@ struct vgic_irq {
>> bool hw; /* Tied to HW IRQ */
>> struct kref refcount; /* Used for LPIs */
>> u32 hwintid; /* HW INTID number */
>> + unsigned int host_irq; /* linux irq corresponding to hwintid */
>> union {
>> u8 targets; /* GICv2 target VCPUs mask */
>> u32 mpidr; /* GICv3 target VCPU */
>> @@ -301,9 +302,10 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
>> bool level);
>> int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid, unsigned int intid,
>> bool level);
>> -int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, u32 virt_irq, u32 phys_irq);
>> -int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq);
>> -bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq);
>> +int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
>> + u32 vintid);
>> +int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid);
>> +bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid);
>>
>> int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
>>
>> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
>> index 5976609..57a30ab 100644
>> --- a/virt/kvm/arm/arch_timer.c
>> +++ b/virt/kvm/arm/arch_timer.c
>> @@ -617,9 +617,6 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
>> {
>> struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
>> struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
>> - struct irq_desc *desc;
>> - struct irq_data *data;
>> - int phys_irq;
>> int ret;
>>
>> if (timer->enabled)
>> @@ -632,26 +629,7 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
>> if (!vgic_initialized(vcpu->kvm))
>> return -ENODEV;
>>
>> - /*
>> - * Find the physical IRQ number corresponding to the host_vtimer_irq
>> - */
>> - desc = irq_to_desc(host_vtimer_irq);
>> - if (!desc) {
>> - kvm_err("%s: no interrupt descriptor\n", __func__);
>> - return -EINVAL;
>> - }
>> -
>> - data = irq_desc_get_irq_data(desc);
>> - while (data->parent_data)
>> - data = data->parent_data;
>> -
>> - phys_irq = data->hwirq;
>> -
>> - /*
>> - * Tell the VGIC that the virtual interrupt is tied to a
>> - * physical interrupt. We do that once per VCPU.
>> - */
>> - ret = kvm_vgic_map_phys_irq(vcpu, vtimer->irq.irq, phys_irq);
>> + ret = kvm_vgic_map_phys_irq(vcpu, host_vtimer_irq, vtimer->irq.irq);
>> if (ret)
>> return ret;
>>
>> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
>> index 83b24d2..075f073 100644
>> --- a/virt/kvm/arm/vgic/vgic.c
>> +++ b/virt/kvm/arm/vgic/vgic.c
>> @@ -17,6 +17,8 @@
>> #include <linux/kvm.h>
>> #include <linux/kvm_host.h>
>> #include <linux/list_sort.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/irq.h>
>>
>> #include "vgic.h"
>>
>> @@ -392,38 +394,66 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
>> return 0;
>> }
>>
>> -int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, u32 virt_irq, u32 phys_irq)
>> +/* @irq->irq_lock must be held */
>> +static int kvm_vgic_map_irq(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
>> + unsigned int host_irq)
>> {
>> - struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
>> + struct irq_desc *desc;
>> + struct irq_data *data;
>>
>> - BUG_ON(!irq);
>> -
>> - spin_lock(&irq->irq_lock);
>> + /*
>> + * Find the physical IRQ number corresponding to @host_irq
>> + */
>> + desc = irq_to_desc(host_irq);
>> + if (!desc) {
>> + kvm_err("%s: no interrupt descriptor\n", __func__);
>> + return -EINVAL;
>> + }
>> + data = irq_desc_get_irq_data(desc);
>> + while (data->parent_data)
>> + data = data->parent_data;
>>
>> irq->hw = true;
>> - irq->hwintid = phys_irq;
>> + irq->host_irq = host_irq;
>> + irq->hwintid = data->hwirq;
>> + return 0;
>> +}
>> +
>> +/* @irq->irq_lock must be held */
>> +static inline void kvm_vgic_unmap_irq(struct vgic_irq *irq)
>> +{
>> + irq->hw = false;
>> + irq->hwintid = 0;
>> +}
>> +
>> +int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
>> + u32 vintid)
>> +{
>> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, vintid);
>> + int ret;
>>
>> + BUG_ON(!irq);
>> +
>> + spin_lock(&irq->irq_lock);
>> + ret = kvm_vgic_map_irq(vcpu, irq, host_irq);
>> spin_unlock(&irq->irq_lock);
>> vgic_put_irq(vcpu->kvm, irq);
>>
>> - return 0;
>> + return ret;
>> }
>>
>> -int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq)
>> +int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid)
>> {
>> struct vgic_irq *irq;
>>
>> if (!vgic_initialized(vcpu->kvm))
>> return -EAGAIN;
>>
>> - irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
>> + irq = vgic_get_irq(vcpu->kvm, vcpu, vintid);
>> BUG_ON(!irq);
>>
>> spin_lock(&irq->irq_lock);
>> -
>> - irq->hw = false;
>> - irq->hwintid = 0;
>> -
>> + kvm_vgic_unmap_irq(irq);
>> spin_unlock(&irq->irq_lock);
>> vgic_put_irq(vcpu->kvm, irq);
>>
>> @@ -726,9 +756,9 @@ void vgic_kick_vcpus(struct kvm *kvm)
>> }
>> }
>>
>> -bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq)
>> +bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid)
>> {
>> - struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
>> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, vintid);
>> bool map_is_active;
>>
>> spin_lock(&irq->irq_lock);
>> --
>> 2.5.5
>>