Re: [PATCH kvmtool 18/21] pci: Switch trap handling to use MMIO handler

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

Hi Andre,

On 12/10/20 2:29 PM, 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.
>
> Merge the existing _in and _out handlers to adhere to that MMIO
> interface, and register these using the new registration function.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>

It looks like there's no change in functionality, the patch looks correct to me:

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

Thanks,

Alex

> ---
>  pci.c | 82 +++++++++++++++++------------------------------------------
>  1 file changed, 24 insertions(+), 58 deletions(-)
>
> diff --git a/pci.c b/pci.c
> index 2e2c0270..d6da79e0 100644
> --- a/pci.c
> +++ b/pci.c
> @@ -87,29 +87,16 @@ static void *pci_config_address_ptr(u16 port)
>  	return base + offset;
>  }
>  
> -static bool pci_config_address_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> +static void pci_config_address_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data,
> +				    u32 len, u8 is_write, void *ptr)
>  {
> -	void *p = pci_config_address_ptr(port);
> +	void *p = pci_config_address_ptr(addr);
>  
> -	memcpy(p, data, size);
> -
> -	return true;
> -}
> -
> -static bool pci_config_address_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> -{
> -	void *p = pci_config_address_ptr(port);
> -
> -	memcpy(data, p, size);
> -
> -	return true;
> +	if (is_write)
> +		memcpy(p, data, len);
> +	else
> +		memcpy(data, p, len);
>  }
> -
> -static struct ioport_operations pci_config_address_ops = {
> -	.io_in	= pci_config_address_in,
> -	.io_out	= pci_config_address_out,
> -};
> -
>  static bool pci_device_exists(u8 bus_number, u8 device_number, u8 function_number)
>  {
>  	union pci_config_address pci_config_address;
> @@ -125,49 +112,27 @@ static bool pci_device_exists(u8 bus_number, u8 device_number, u8 function_numbe
>  	return !IS_ERR_OR_NULL(device__find_dev(DEVICE_BUS_PCI, device_number));
>  }
>  
> -static bool pci_config_data_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> -{
> -	union pci_config_address pci_config_address;
> -
> -	if (size > 4)
> -		size = 4;
> -
> -	pci_config_address.w = ioport__read32(&pci_config_address_bits);
> -	/*
> -	 * If someone accesses PCI configuration space offsets that are not
> -	 * aligned to 4 bytes, it uses ioports to signify that.
> -	 */
> -	pci_config_address.reg_offset = port - PCI_CONFIG_DATA;
> -
> -	pci__config_wr(vcpu->kvm, pci_config_address, data, size);
> -
> -	return true;
> -}
> -
> -static bool pci_config_data_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> +static void pci_config_data_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data,
> +				 u32 len, u8 is_write, void *kvm)
>  {
>  	union pci_config_address pci_config_address;
>  
> -	if (size > 4)
> -		size = 4;
> +	if (len > 4)
> +		len = 4;
>  
>  	pci_config_address.w = ioport__read32(&pci_config_address_bits);
>  	/*
>  	 * If someone accesses PCI configuration space offsets that are not
>  	 * aligned to 4 bytes, it uses ioports to signify that.
>  	 */
> -	pci_config_address.reg_offset = port - PCI_CONFIG_DATA;
> +	pci_config_address.reg_offset = addr - PCI_CONFIG_DATA;
>  
> -	pci__config_rd(vcpu->kvm, pci_config_address, data, size);
> -
> -	return true;
> +	if (is_write)
> +		pci__config_wr(vcpu->kvm, pci_config_address, data, len);
> +	else
> +		pci__config_rd(vcpu->kvm, pci_config_address, data, len);
>  }
>  
> -static struct ioport_operations pci_config_data_ops = {
> -	.io_in	= pci_config_data_in,
> -	.io_out	= pci_config_data_out,
> -};
> -
>  static int pci_activate_bar(struct kvm *kvm, struct pci_device_header *pci_hdr,
>  			    int bar_num)
>  {
> @@ -512,11 +477,12 @@ int pci__init(struct kvm *kvm)
>  {
>  	int r;
>  
> -	r = ioport__register(kvm, PCI_CONFIG_DATA + 0, &pci_config_data_ops, 4, NULL);
> +	r = kvm__register_pio(kvm, PCI_CONFIG_DATA, 4,
> +				 pci_config_data_mmio, NULL);
>  	if (r < 0)
>  		return r;
> -
> -	r = ioport__register(kvm, PCI_CONFIG_ADDRESS + 0, &pci_config_address_ops, 4, NULL);
> +	r = kvm__register_pio(kvm, PCI_CONFIG_ADDRESS, 4,
> +				 pci_config_address_mmio, NULL);
>  	if (r < 0)
>  		goto err_unregister_data;
>  
> @@ -528,17 +494,17 @@ int pci__init(struct kvm *kvm)
>  	return 0;
>  
>  err_unregister_addr:
> -	ioport__unregister(kvm, PCI_CONFIG_ADDRESS);
> +	kvm__deregister_pio(kvm, PCI_CONFIG_ADDRESS);
>  err_unregister_data:
> -	ioport__unregister(kvm, PCI_CONFIG_DATA);
> +	kvm__deregister_pio(kvm, PCI_CONFIG_DATA);
>  	return r;
>  }
>  dev_base_init(pci__init);
>  
>  int pci__exit(struct kvm *kvm)
>  {
> -	ioport__unregister(kvm, PCI_CONFIG_DATA);
> -	ioport__unregister(kvm, PCI_CONFIG_ADDRESS);
> +	kvm__deregister_pio(kvm, PCI_CONFIG_DATA);
> +	kvm__deregister_pio(kvm, PCI_CONFIG_ADDRESS);
>  
>  	return 0;
>  }