Re: [PATCH v2 0/4] hw/arm/virt: Improve address assignment for high memory regions

[Gavin Shan]

Hi Marc,

On 8/15/22 4:29 PM, Gavin Shan wrote:
> There are three high memory regions, which are VIRT_HIGH_REDIST2,
> VIRT_HIGH_PCIE_ECAM and VIRT_HIGH_PCIE_MMIO. Their base addresses
> are floating on highest RAM address. However, they can be disabled
> in several cases.
>      
> (1) One specific high memory region is disabled by developer by
>      toggling vms->highmem_{redists, ecam, mmio}.
>      
> (2) VIRT_HIGH_PCIE_ECAM region is disabled on machine, which is
>      'virt-2.12' or ealier than it.
>      
> (3) VIRT_HIGH_PCIE_ECAM region is disabled when firmware is loaded
>      on 32-bits system.
>      
> (4) One specific high memory region is disabled when it breaks the
>      PA space limit.
>      
> The current implementation of virt_set_memmap() isn't comprehensive
> because the space for one specific high memory region is always
> reserved from the PA space for case (1), (2) and (3). In the code,
> 'base' and 'vms->highest_gpa' are always increased for those three
> cases. It's unnecessary since the assigned space of the disabled
> high memory region won't be used afterwards.
>
> The series intends to improve the address assignment for these
> high memory regions:
>
> PATCH[1] and PATCH[2] are cleanup and preparatory works.
> PATCH[3] improves address assignment for these high memory regions
> PATCH[4] moves the address assignment logic into standalone helper
>
> History
> =======
> v1: https://lists.nongnu.org/archive/html/qemu-arm/2022-08/msg00013.html
>
> Changelog
> =========
> v2:
>    * Split the patches for easier review                        (Gavin)
>    * Improved changelog                                         (Marc)
>    * Use 'bool fits' in virt_set_high_memmap()                  (Eric)

Could you help to review when you have free cycles? It's just a kindly
ping :)

Thanks,
Gavin

> Gavin Shan (4):
>    hw/arm/virt: Rename variable size to region_size in virt_set_memmap()
>    hw/arm/virt: Introduce variable region_base in virt_set_memmap()
>    hw/arm/virt: Improve address assignment for high memory regions
>    virt/hw/virt: Add virt_set_high_memmap() helper
>
>   hw/arm/virt.c | 84 ++++++++++++++++++++++++++++++---------------------
>   1 file changed, 50 insertions(+), 34 deletions(-)