Re: [PATCH kvmtool v3 20/22] arm: Reorganise and document memory map

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

Hi Andre,

On 3/15/21 3:33 PM, Andre Przywara wrote:
> The hardcoded memory map we expose to a guest is currently described
> using a series of partially interconnected preprocessor constants,
> which is hard to read and follow.
>
> In preparation for moving the UART and RTC to some different MMIO
> region, document the current map with some ASCII art, and clean up the
> definition of the sections.
>
> This changes the only internally used value of ARM_MMIO_AREA, to better
> align with its actual meaning and future extensions.
>
> No functional change.

Looks good, the values in the map match the defines, and there's no forward
declaration of the serial or RTC MMIO regions:

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

Thanks,

Alex

> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  arm/include/arm-common/kvm-arch.h | 41 ++++++++++++++++++++++---------
>  1 file changed, 29 insertions(+), 12 deletions(-)
>
> diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h
> index d84e50cd..a2e32953 100644
> --- a/arm/include/arm-common/kvm-arch.h
> +++ b/arm/include/arm-common/kvm-arch.h
> @@ -7,14 +7,33 @@
>  
>  #include "arm-common/gic.h"
>  
> +/*
> + * The memory map used for ARM guests (not to scale):
> + *
> + * 0      64K  16M     32M     48M            1GB       2GB
> + * +-------+----+-------+-------+--------+-----+---------+---......
> + * |  PCI  |////| plat  |       |        |     |         |
> + * |  I/O  |////| MMIO  | Flash | virtio | GIC |   PCI   |  DRAM
> + * | space |////|       |       |  MMIO  |     |  (AXI)  |
> + * |       |////|       |       |        |     |         |
> + * +-------+----+-------+-------+--------+-----+---------+---......
> + */
> +
>  #define ARM_IOPORT_AREA		_AC(0x0000000000000000, UL)
> -#define ARM_FLASH_AREA		_AC(0x0000000002000000, UL)
> -#define ARM_MMIO_AREA		_AC(0x0000000003000000, UL)
> +#define ARM_MMIO_AREA		_AC(0x0000000001000000, UL)
>  #define ARM_AXI_AREA		_AC(0x0000000040000000, UL)
>  #define ARM_MEMORY_AREA		_AC(0x0000000080000000, UL)
>  
> -#define ARM_LOMAP_MAX_MEMORY	((1ULL << 32) - ARM_MEMORY_AREA)
> -#define ARM_HIMAP_MAX_MEMORY	((1ULL << 40) - ARM_MEMORY_AREA)
> +#define KVM_IOPORT_AREA		ARM_IOPORT_AREA
> +#define ARM_IOPORT_SIZE		(1U << 16)
> +
> +
> +#define KVM_FLASH_MMIO_BASE	(ARM_MMIO_AREA + 0x1000000)
> +#define KVM_FLASH_MAX_SIZE	0x1000000
> +
> +#define KVM_VIRTIO_MMIO_AREA	(KVM_FLASH_MMIO_BASE + KVM_FLASH_MAX_SIZE)
> +#define ARM_VIRTIO_MMIO_SIZE	(ARM_AXI_AREA - \
> +				(KVM_VIRTIO_MMIO_AREA + ARM_GIC_SIZE))
>  
>  #define ARM_GIC_DIST_BASE	(ARM_AXI_AREA - ARM_GIC_DIST_SIZE)
>  #define ARM_GIC_CPUI_BASE	(ARM_GIC_DIST_BASE - ARM_GIC_CPUI_SIZE)
> @@ -22,19 +41,17 @@
>  #define ARM_GIC_DIST_SIZE	0x10000
>  #define ARM_GIC_CPUI_SIZE	0x20000
>  
> -#define KVM_FLASH_MMIO_BASE	ARM_FLASH_AREA
> -#define KVM_FLASH_MAX_SIZE	(ARM_MMIO_AREA - ARM_FLASH_AREA)
>  
> -#define ARM_IOPORT_SIZE		(1U << 16)
> -#define ARM_VIRTIO_MMIO_SIZE	(ARM_AXI_AREA - (ARM_MMIO_AREA + ARM_GIC_SIZE))
> +#define KVM_PCI_CFG_AREA	ARM_AXI_AREA
>  #define ARM_PCI_CFG_SIZE	(1ULL << 24)
> +#define KVM_PCI_MMIO_AREA	(KVM_PCI_CFG_AREA + ARM_PCI_CFG_SIZE)
>  #define ARM_PCI_MMIO_SIZE	(ARM_MEMORY_AREA - \
>  				(ARM_AXI_AREA + ARM_PCI_CFG_SIZE))
>  
> -#define KVM_IOPORT_AREA		ARM_IOPORT_AREA
> -#define KVM_PCI_CFG_AREA	ARM_AXI_AREA
> -#define KVM_PCI_MMIO_AREA	(KVM_PCI_CFG_AREA + ARM_PCI_CFG_SIZE)
> -#define KVM_VIRTIO_MMIO_AREA	ARM_MMIO_AREA
> +
> +#define ARM_LOMAP_MAX_MEMORY	((1ULL << 32) - ARM_MEMORY_AREA)
> +#define ARM_HIMAP_MAX_MEMORY	((1ULL << 40) - ARM_MEMORY_AREA)
> +
>  
>  #define KVM_IOEVENTFD_HAS_PIO	0
>