Re: [PATCH 1/3] KVM: Ioctls for init MSI-X entry

[Marcelo Tosatti <mtosatti@redhat.com>]

On Mon, Feb 16, 2009 at 01:49:29PM +0800, Sheng Yang wrote:
> (oops... fix a typo)
> 
> Introduce KVM_SET_MSIX_NR and KVM_SET_MSIX_ENTRY two ioctls.
> 
> This two ioctls are used by userspace to specific guest device MSI-X entry
> number and correlate MSI-X entry with GSI during the initialization stage.
> 
> MSI-X should be well initialzed before enabling.
> 
> Don't support change MSI-X entry number for now.
> 
> Signed-off-by: Sheng Yang <sheng@linux.intel.com>
> ---
>  include/linux/kvm.h      |   16 +++++++
>  include/linux/kvm_host.h |    3 +
>  virt/kvm/kvm_main.c      |  103 ++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 122 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/kvm.h b/include/linux/kvm.h
> index 2163b3d..a2dfbe0 100644
> --- a/include/linux/kvm.h
> +++ b/include/linux/kvm.h
> @@ -475,6 +475,8 @@ struct kvm_irq_routing {
>  #define KVM_ASSIGN_IRQ _IOR(KVMIO, 0x70, \
>  			    struct kvm_assigned_irq)
>  #define KVM_REINJECT_CONTROL      _IO(KVMIO, 0x71)
> +#define KVM_SET_MSIX_NR _IOR(KVMIO, 0x72, struct kvm_assigned_msix_nr)
> +#define KVM_SET_MSIX_ENTRY _IOR(KVMIO, 0x73, struct kvm_assigned_msix_entry)
>  
>  /*
>   * ioctls for vcpu fds
> @@ -595,4 +597,18 @@ struct kvm_assigned_irq {
>  #define KVM_DEV_IRQ_ASSIGN_MSI_ACTION	KVM_DEV_IRQ_ASSIGN_ENABLE_MSI
>  #define KVM_DEV_IRQ_ASSIGN_ENABLE_MSI	(1 << 0)
>  
> +struct kvm_assigned_msix_nr {
> +	__u32 assigned_dev_id;
> +	__u16 entry_nr;
> +	__u16 padding;
> +};
> +
> +#define KVM_MAX_MSIX_PER_DEV		512
> +struct kvm_assigned_msix_entry {
> +	__u32 assigned_dev_id;
> +	__u32 gsi;
> +	__u16 entry; /* The index of entry in the MSI-X table */
> +	__u16 padding[3];
> +};
> +
>  #endif
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 7c7096d..ac4d63c 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -326,9 +326,12 @@ struct kvm_assigned_dev_kernel {
>  	int assigned_dev_id;
>  	int host_busnr;
>  	int host_devfn;
> +	int entries_nr;
>  	int host_irq;
>  	bool host_irq_disabled;
> +	struct msix_entry *host_msix_entries;
>  	int guest_irq;
> +	struct msix_entry *guest_msix_entries;
>  #define KVM_ASSIGNED_DEV_GUEST_INTX	(1 << 0)
>  #define KVM_ASSIGNED_DEV_GUEST_MSI	(1 << 1)
>  #define KVM_ASSIGNED_DEV_HOST_INTX	(1 << 8)
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 266bdaf..bb4aa73 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1593,6 +1593,87 @@ static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
>  	return 0;
>  }
>  
> +static int kvm_vm_ioctl_set_msix_nr(struct kvm *kvm,
> +				    struct kvm_assigned_msix_nr *entry_nr)
> +{
> +	int r = 0;
> +	struct kvm_assigned_dev_kernel *adev;
> +
> +	mutex_lock(&kvm->lock);
> +
> +	adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
> +				      entry_nr->assigned_dev_id);
> +	if (!adev) {
> +		r = -EINVAL;
> +		goto msix_nr_out;
> +	}
> +
> +	if (adev->entries_nr == 0) {
> +		adev->entries_nr = entry_nr->entry_nr;
> +		if (adev->entries_nr == 0 ||

                                    <= 0 ? 

> +		    adev->entries_nr >= KVM_MAX_MSIX_PER_DEV)

Otherwise looks OK, thanks.