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

Christoffer Dall
2017-07-21T11:44:39Z

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?

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.

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
>