Re: [PATCH v8 33/43] arm64: RME: Hide KVM_CAP_READONLY_MEM for realm guests

[Gavin Shan]

On 4/16/25 11:41 PM, Steven Price wrote:
> For protected memory read only isn't supported by the RMM. While it may
> be possible to support read only for unprotected memory, this isn't
> supported at the present time.
>
> Note that this does mean that ROM (or flash) data cannot be emulated
> correctly by the VMM as the stage 2 mappings are either always
> read/write or are trapped as MMIO (so don't support operations where the
> syndrome information doesn't allow emulation, e.g. load/store pair).
>
> This restriction can be lifted in the future by allowing the stage 2
> mappings to be made read only.
>
> Signed-off-by: Steven Price <steven.price@xxxxxxx>
> ---
> Changes since v7:
>   * Updated commit message to spell out the impact on ROM/flash
>     emulation.
> ---
>   arch/arm64/kvm/arm.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>