Re: [PATCH 1/2] kvm: libkvm: support for irq routing

[Sheng Yang <sheng@linux.intel.com>]

On Wednesday 14 January 2009 21:53:10 Avi Kivity wrote:
> Signed-off-by: Avi Kivity <avi@redhat.com>

Do we need a lock for the table?

-- 
regards
Yang, Sheng

> ---
>  libkvm/kvm-common.h |    4 ++
>  libkvm/libkvm.c     |  107
> +++++++++++++++++++++++++++++++++++++++++++++++++++ libkvm/libkvm.h     |  
> 62 +++++++++++++++++++++++++++++
>  3 files changed, 173 insertions(+), 0 deletions(-)
>
> diff --git a/libkvm/kvm-common.h b/libkvm/kvm-common.h
> index c5beacc..e09c07c 100644
> --- a/libkvm/kvm-common.h
> +++ b/libkvm/kvm-common.h
> @@ -61,6 +61,10 @@ struct kvm_context {
>  	int pit_in_kernel;
>  	/// in-kernel coalesced mmio
>  	int coalesced_mmio;
> +#ifdef KVM_CAP_IRQ_ROUTING
> +	struct kvm_irq_routing *irq_routes;
> +	int nr_allocated_irq_routes;
> +#endif
>  };
>
>  void init_slots(void);
> diff --git a/libkvm/libkvm.c b/libkvm/libkvm.c
> index 0408fdb..1004fa6 100644
> --- a/libkvm/libkvm.c
> +++ b/libkvm/libkvm.c
> @@ -381,6 +381,14 @@ int kvm_create_vm(kvm_context_t kvm)
>  {
>  	int fd = kvm->fd;
>
> +#ifdef KVM_CAP_IRQ_ROUTING
> +	kvm->irq_routes = malloc(sizeof(*kvm->irq_routes));
> +	if (!kvm->irq_routes)
> +		return -ENOMEM;
> +	memset(kvm->irq_routes, 0, sizeof(*kvm->irq_routes));
> +	kvm->nr_allocated_irq_routes = 0;
> +#endif
> +
>  	kvm->vcpu_fd[0] = -1;
>
>  	fd = ioctl(fd, KVM_CREATE_VM, 0);
> @@ -1164,3 +1172,102 @@ int kvm_reinject_control(kvm_context_t kvm, int
> pit_reinject) #endif
>  	return -ENOSYS;
>  }
> +
> +int kvm_has_gsi_routing(kvm_context_t kvm)
> +{
> +    int r = 0;
> +
> +#ifdef KVM_CAP_IRQ_ROUTING
> +    r = kvm_check_extension(kvm, KVM_CAP_IRQ_ROUTING);
> +#endif
> +    return r;
> +}
> +
> +int kvm_get_gsi_count(kvm_context_t kvm)
> +{
> +#ifdef KVM_CAP_IRQ_ROUTING
> +	return kvm_check_extension(kvm, KVM_CAP_IRQ_ROUTING);
> +#else
> +	return -EINVAL;
> +#endif
> +}
> +
> +int kvm_clear_gsi_routes(kvm_context_t kvm)
> +{
> +#ifdef KVM_CAP_IRQ_ROUTING
> +	kvm->irq_routes->nr = 0;
> +	return 0;
> +#else
> +	return -EINVAL;
> +#endif
> +}
> +
> +int kvm_add_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin)
> +{
> +#ifdef KVM_CAP_IRQ_ROUTING
> +	struct kvm_irq_routing *z;
> +	struct kvm_irq_routing_entry *e;
> +	int n, size;
> +
> +	if (kvm->irq_routes->nr == kvm->nr_allocated_irq_routes) {
> +		n = kvm->nr_allocated_irq_routes * 2;
> +		if (n < 64)
> +			n = 64;
> +		size = sizeof(struct kvm_irq_routing);
> +		size += n * sizeof(*e);
> +		z = realloc(kvm->irq_routes, size);
> +		if (!z)
> +			return -ENOMEM;
> +		kvm->nr_allocated_irq_routes = n;
> +		kvm->irq_routes = z;
> +	}
> +	n = kvm->irq_routes->nr++;
> +	e = &kvm->irq_routes->entries[n];
> +	memset(e, 0, sizeof(*e));
> +	e->gsi = gsi;
> +	e->type = KVM_IRQ_ROUTING_IRQCHIP;
> +	e->flags = 0;
> +	e->u.irqchip.irqchip = irqchip;
> +	e->u.irqchip.pin = pin;
> +	return 0;
> +#else
> +	return -ENOSYS;
> +#endif
> +}
> +
> +int kvm_del_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin)
> +{
> +#ifdef KVM_CAP_IRQ_ROUTING
> +	struct kvm_irq_routing_entry *e, *p;
> +	int i;
> +
> +	for (i = 0; i < kvm->irq_routes->nr; ++i) {
> +		e = &kvm->irq_routes->entries[i];
> +		if (e->type == KVM_IRQ_ROUTING_IRQCHIP
> +		    && e->gsi == gsi
> +		    && e->u.irqchip.irqchip == irqchip
> +		    && e->u.irqchip.pin == pin) {
> +			p = &kvm->irq_routes->entries[--kvm->irq_routes->nr];
> +			*e = *p;
> +			return 0;
> +		}
> +	}
> +	return -ESRCH;
> +#else
> +	return -ENOSYS;
> +#endif
> +}
> +
> +int kvm_commit_irq_routes(kvm_context_t kvm)
> +{
> +#ifdef KVM_CAP_IRQ_ROUTING
> +	int r;
> +
> +	kvm->irq_routes->flags = 0;
> +	r = ioctl(kvm->vm_fd, KVM_SET_GSI_ROUTING, kvm->irq_routes);
> +	if (r == -1)
> +		r = -errno;
> +#else
> +	return -ENOSYS;
> +#endif
> +}
> diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
> index ee1ba68..85012ff 100644
> --- a/libkvm/libkvm.h
> +++ b/libkvm/libkvm.h
> @@ -720,4 +720,66 @@ int kvm_assign_irq(kvm_context_t kvm,
>   */
>  int kvm_destroy_memory_region_works(kvm_context_t kvm);
>  #endif
> +
> +
> +/*!
> + * \brief Checks whether the generic irq routing capability is present
> + *
> + * Checks whether kvm can reroute interrupts among the various interrupt
> + * controllers.
> + *
> + * \param kvm Pointer to the current kvm_context
> + */
> +int kvm_has_gsi_routing(kvm_context_t kvm);
> +
> +/*!
> + * \brief Determines the number of gsis that can be routed
> + *
> + * Returns the number of distinct gsis that can be routed by kvm.  This is
> + * also the number of distinct routes (if a gsi has two routes, than
> another + * gsi cannot be used...)
> + *
> + * \param kvm Pointer to the current kvm_context
> + */
> +int kvm_get_gsi_count(kvm_context_t kvm);
> +
> +/*!
> + * \brief Clears the temporary irq routing table
> + *
> + * Clears the temporary irq routing table.  Nothing is committed to the
> + * running VM.
> + *
> + * \param kvm Pointer to the current kvm_context
> + */
> +int kvm_clear_gsi_routes(kvm_context_t kvm);
> +
> +/*!
> + * \brief Adds an irq route to the temporary irq routing table
> + *
> + * Adds an irq route to the temporary irq routing table.  Nothing is
> + * committed to the running VM.
> + *
> + * \param kvm Pointer to the current kvm_context
> + */
> +int kvm_add_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin);
> +
> +/*!
> + * \brief Removes an irq route from the temporary irq routing table
> + *
> + * Adds an irq route to the temporary irq routing table.  Nothing is
> + * committed to the running VM.
> + *
> + * \param kvm Pointer to the current kvm_context
> + */
> +int kvm_del_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin);
> +
> +/*!
> + * \brief Commit the temporary irq routing table
> + *
> + * Commit the temporary irq routing table to the running VM.
> + *
> + * \param kvm Pointer to the current kvm_context
> + */
> +int kvm_commit_irq_routes(kvm_context_t kvm);
> +
>  #endif