Re: [PATCH v4 6/7] KVM: arm/arm64: enable MSI routing

Christoffer Dall
2016-04-14T12:04:31Z

On Mon, Apr 04, 2016 at 10:47:36AM +0200, Eric Auger wrote:
> Up to now, only irqchip routing entries could be set. This patch
> adds the capability to insert MSI routing entries.
>
> For ARM64, let's also increase KVM_MAX_IRQ_ROUTES to 4096: this
> include SPI irqchip routes plus MSI routes. In the future this
> might be extended.
>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>
> ---
> v2 -> v3:
> - remove any reference to KVM_IRQ_ROUTING_EXTENDED_MSI type
> - unconditionnaly uapi flags and devid downto the kernel
> routing entry struct
> - handle KVM_MSI_VALID_DEVID flag in kvm_set_irq_routing
> - note about KVM_CAP_MSI_DEVID moved in the first patch file
> of the series
>
> v1 -> v2:
> - adapt to new routing entry types
>
> RFC -> PATCH:
> - move api MSI routing updates into that patch file
> - use new devid field of user api struct
> ---
> Documentation/virtual/kvm/api.txt | 5 +++++
> include/linux/kvm_host.h | 2 ++
> virt/kvm/arm/vgic/vgic_irqfd.c | 8 ++++++++
> virt/kvm/irqchip.c | 2 +-
> 4 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index 61f8f27..217b460 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -2368,6 +2368,11 @@ On arm/arm64, gsi routing being supported, the following can happen:
> - in case no routing entry is associated to this gsi, injection fails
> - in case the gsi is associated to an irqchip routing entry,
> irqchip.pin + 32 corresponds to the injected SPI ID.
> +- in case the gsi is associated to an MSI routing entry,
> + * without GICv3 ITS in-kernel emulation, MSI data matches the SPI ID
> + of the injected SPI

can we be more specific here and perhaps express this in the positive?
For example, if the user creates a KVM_DEV_TYPE_ARM_VGIC_V2, then...

> + * with GICv3 ITS in-kernel emulation, the MSI message and device ID
> + are translated into an LPI.
>
> 4.76 KVM_PPC_ALLOCATE_HTAB
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 461e480..f25613d 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1021,6 +1021,8 @@ static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
>
> #ifdef CONFIG_S390
> #define KVM_MAX_IRQ_ROUTES 4096 //FIXME: we can have more than that...
> +#elif defined(CONFIG_ARM64)
> +#define KVM_MAX_IRQ_ROUTES 4096
> #else
> #define KVM_MAX_IRQ_ROUTES 1024
> #endif
> diff --git a/virt/kvm/arm/vgic/vgic_irqfd.c b/virt/kvm/arm/vgic/vgic_irqfd.c
> index a76994f..a3a7f02 100644
> --- a/virt/kvm/arm/vgic/vgic_irqfd.c
> +++ b/virt/kvm/arm/vgic/vgic_irqfd.c
> @@ -64,6 +64,14 @@ int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
> (e->irqchip.irqchip >= KVM_NR_IRQCHIPS))
> goto out;
> break;
> + case KVM_IRQ_ROUTING_MSI:
> + e->set = kvm_set_msi;
> + e->msi.address_lo = ue->u.msi.address_lo;
> + e->msi.address_hi = ue->u.msi.address_hi;
> + e->msi.data = ue->u.msi.data;
> + e->flags = ue->flags;
> + e->devid = ue->u.msi.devid;
> + break;
> default:
> goto out;
> }
> diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
> index b4222d6..269d949 100644
> --- a/virt/kvm/irqchip.c
> +++ b/virt/kvm/irqchip.c
> @@ -211,7 +211,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
> goto out;
>
> r = -EINVAL;
> - if (ue->flags) {
> + if (ue->flags & ~KVM_MSI_VALID_DEVID) {
> kfree(e);
> goto out;
> }
> --
> 1.9.1
>