Re: [PATCH] arm64: realm: Fix PTE_NS_SHARED for 52bit PA support

[Catalin Marinas <catalin.marinas@arm.com>]

On Mon, Mar 16, 2026 at 04:19:01PM +0000, Suzuki K Poulose wrote:
> With LPA/LPA2, the top bits of the PFN (Bits[51:48]) end up in the lower bits
> of the PTE. So, simply creating a mask of the "top IPA bit" doesn't work well
> for these configurations to set the "top" bit at the output of Stage1
> translation.
> 
> Fix this by using the __phys_to_pte_val() to do the right thing for all
> configurations.
> 
> Tested using, kvmtool, placing the memory at a higher address (-m <size>@<Addr>).
> 
>  e.g:
>  # lkvm run --realm -c 4 -m 512M@@128T -k Image --console serial
> 
>  sh-5.0# dmesg | grep "LPA2\|RSI"
> [    0.000000] RME: Using RSI version 1.0
> [    0.000000] CPU features: detected: 52-bit Virtual Addressing (LPA2)
> [    0.777354] CPU features: detected: 52-bit Virtual Addressing for KVM (LPA2)
> 
> Fixes: 399306954996 ("arm64: realm: Query IPA size from the RMM")
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Steven Price <steven.price@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>