Re: [RFC v1 4/5] KVM: x86: Add arch specific routines for irqbypass manager

[Alex Williamson <alex.williamson@redhat.com>]

On Fri, 2015-07-10 at 11:00 +0800, Feng Wu wrote:
> Add the following x86 specific routines for irqbypass manger:
> 
> - kvm_arch_irq_bypass_add_producer
> - kvm_arch_irq_bypass_del_producer
> - kvm_arch_irq_bypass_stop
> - kvm_arch_irq_bypass_resume
> - kvm_arch_irq_bypass_update
> 
> Signed-off-by: Feng Wu <feng.wu@intel.com>
> ---
>  arch/x86/kvm/Kconfig |  1 +
>  arch/x86/kvm/x86.c   | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 56 insertions(+)
> 
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index 22f6fcb..ae68f2a 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -62,6 +62,7 @@ config KVM_INTEL
>  	# for perf_guest_get_msrs():
>  	depends on CPU_SUP_INTEL
>  	select IRQ_BYPASS_MANAGER
> +	select HAVE_KVM_IRQ_BYPASS
>  	---help---
>  	  Provides support for KVM on Intel processors equipped with the VT
>  	  extensions.
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index d81ac02..a59f7e3 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -49,6 +49,8 @@
>  #include <linux/pci.h>
>  #include <linux/timekeeper_internal.h>
>  #include <linux/pvclock_gtod.h>
> +#include <linux/kvm_irqfd.h>
> +#include <linux/irqbypass.h>
>  #include <trace/events/kvm.h>
>  
>  #define CREATE_TRACE_POINTS
> @@ -8023,6 +8025,59 @@ out:
>  	return ret;
>  }
>  
> +void kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
> +				      struct irq_bypass_producer *prod)
> +{
> +	int ret;
> +	struct kvm_kernel_irqfd *irqfd =
> +		container_of(cons, struct kvm_kernel_irqfd, consumer);
> +
> +	irqfd->producer = prod;
> +
> +	ret = kvm_arch_update_pi_irte(irqfd->kvm, prod->irq, irqfd->gsi, 1);
> +	WARN_ON(ret);
> +}
> +
> +void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
> +				      struct irq_bypass_producer *prod)
> +{
> +	int ret;
> +	struct kvm_kernel_irqfd *irqfd =
> +		container_of(cons, struct kvm_kernel_irqfd, consumer);
> +
> +	irqfd->producer = NULL;
> +
> +	/*
> +	 * When producer of consumer is unregistered, we change back to
> +	 * remapped mode, so we can re-use the current implementation
> +	 * when the irq is masked/disabed or the consumer side (KVM
> +	 * int this case doesn't want to receive the interrupts.
> +	 */
> +	ret = kvm_arch_update_pi_irte(irqfd->kvm, prod->irq, irqfd->gsi, 0);
> +	WARN_ON(ret);
> +}
> +
> +void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
> +{
> +}
> +
> +void kvm_arch_irq_bypass_resume(struct irq_bypass_consumer *cons)
> +{
> +}

No need for dummy functions, these callbacks will be optional.  Thanks,

Alex

> +
> +void kvm_arch_irq_bypass_update(struct irq_bypass_consumer *cons)
> +{
> +	int ret;
> +	struct kvm_kernel_irqfd *irqfd =
> +		container_of(cons, struct kvm_kernel_irqfd, consumer);
> +
> +	BUG_ON(!irqfd->producer);
> +
> +	ret = kvm_arch_update_pi_irte(irqfd->kvm, irqfd->producer->irq,
> +				      irqfd->gsi, 1);
> +	WARN_ON(ret);
> +}
> +
>  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);