Re: [PATCH kvmtool v2 17/22] virtio: Switch trap handling to use MMIO handler

[Alexandru Elisei <alexandru.elisei@arm.com>]

Hi Andre,

On 2/25/21 12:59 AM, Andre Przywara wrote:
> With the planned retirement of the special ioport emulation code, we
> need to provide an emulation function compatible with the MMIO prototype.
>
> Adjust the existing MMIO callback routine to automatically determine
> the region this trap came through, and call the existing I/O handlers.
> Register the ioport region using the new registration function.

Looks good to me:

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>

Thanks,

Alex

>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  virtio/pci.c | 46 ++++++++++++++--------------------------------
>  1 file changed, 14 insertions(+), 32 deletions(-)
>
> diff --git a/virtio/pci.c b/virtio/pci.c
> index 6eea6c68..eb91f512 100644
> --- a/virtio/pci.c
> +++ b/virtio/pci.c
> @@ -178,15 +178,6 @@ static bool virtio_pci__data_in(struct kvm_cpu *vcpu, struct virtio_device *vdev
>  	return ret;
>  }
>  
> -static bool virtio_pci__io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> -{
> -	struct virtio_device *vdev = ioport->priv;
> -	struct virtio_pci *vpci = vdev->virtio;
> -	unsigned long offset = port - virtio_pci__port_addr(vpci);
> -
> -	return virtio_pci__data_in(vcpu, vdev, offset, data, size);
> -}
> -
>  static void update_msix_map(struct virtio_pci *vpci,
>  			    struct msix_table *msix_entry, u32 vecnum)
>  {
> @@ -334,20 +325,6 @@ static bool virtio_pci__data_out(struct kvm_cpu *vcpu, struct virtio_device *vde
>  	return ret;
>  }
>  
> -static bool virtio_pci__io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> -{
> -	struct virtio_device *vdev = ioport->priv;
> -	struct virtio_pci *vpci = vdev->virtio;
> -	unsigned long offset = port - virtio_pci__port_addr(vpci);
> -
> -	return virtio_pci__data_out(vcpu, vdev, offset, data, size);
> -}
> -
> -static struct ioport_operations virtio_pci__io_ops = {
> -	.io_in	= virtio_pci__io_in,
> -	.io_out	= virtio_pci__io_out,
> -};
> -
>  static void virtio_pci__msix_mmio_callback(struct kvm_cpu *vcpu,
>  					   u64 addr, u8 *data, u32 len,
>  					   u8 is_write, void *ptr)
> @@ -455,12 +432,19 @@ static void virtio_pci__io_mmio_callback(struct kvm_cpu *vcpu,
>  {
>  	struct virtio_device *vdev = ptr;
>  	struct virtio_pci *vpci = vdev->virtio;
> -	u32 mmio_addr = virtio_pci__mmio_addr(vpci);
> +	u32 ioport_addr = virtio_pci__port_addr(vpci);
> +	u32 base_addr;
> +
> +	if (addr >= ioport_addr &&
> +	    addr < ioport_addr + pci__bar_size(&vpci->pci_hdr, 0))
> +		base_addr = ioport_addr;
> +	else
> +		base_addr = virtio_pci__mmio_addr(vpci);
>  
>  	if (!is_write)
> -		virtio_pci__data_in(vcpu, vdev, addr - mmio_addr, data, len);
> +		virtio_pci__data_in(vcpu, vdev, addr - base_addr, data, len);
>  	else
> -		virtio_pci__data_out(vcpu, vdev, addr - mmio_addr, data, len);
> +		virtio_pci__data_out(vcpu, vdev, addr - base_addr, data, len);
>  }
>  
>  static int virtio_pci__bar_activate(struct kvm *kvm,
> @@ -478,10 +462,8 @@ static int virtio_pci__bar_activate(struct kvm *kvm,
>  
>  	switch (bar_num) {
>  	case 0:
> -		r = ioport__register(kvm, bar_addr, &virtio_pci__io_ops,
> -				     bar_size, vdev);
> -		if (r > 0)
> -			r = 0;
> +		r = kvm__register_pio(kvm, bar_addr, bar_size,
> +				      virtio_pci__io_mmio_callback, vdev);
>  		break;
>  	case 1:
>  		r =  kvm__register_mmio(kvm, bar_addr, bar_size, false,
> @@ -510,7 +492,7 @@ static int virtio_pci__bar_deactivate(struct kvm *kvm,
>  
>  	switch (bar_num) {
>  	case 0:
> -		r = ioport__unregister(kvm, bar_addr);
> +		r = kvm__deregister_pio(kvm, bar_addr);
>  		break;
>  	case 1:
>  	case 2:
> @@ -625,7 +607,7 @@ int virtio_pci__exit(struct kvm *kvm, struct virtio_device *vdev)
>  	virtio_pci__reset(kvm, vdev);
>  	kvm__deregister_mmio(kvm, virtio_pci__mmio_addr(vpci));
>  	kvm__deregister_mmio(kvm, virtio_pci__msix_io_addr(vpci));
> -	ioport__unregister(kvm, virtio_pci__port_addr(vpci));
> +	kvm__deregister_pio(kvm, virtio_pci__port_addr(vpci));
>  
>  	return 0;
>  }