Re: [PATCH v9 13/25] iommu/arm-smmu-v3-kvm: Add MMIO emulation

[Nicolin Chen <nicolinc@nvidia.com>]

On Thu, Oct 15, 2026 at 08:08:44PM +0000, Mostafa Saleh wrote:
> +static bool smmu_dabt_handler(struct user_pt_regs *regs, u64 esr, u64 addr)
> +{
> +	struct hyp_arm_smmu_v3_device *smmu;
> +	bool ret;
> +
> +	for_each_smmu(smmu) {
> +		if (addr < smmu->mmio_addr || addr >= smmu->mmio_addr + smmu->mmio_size)
> +			continue;
> +		hyp_spin_lock(&smmu->lock);
> +		ret = smmu_dabt_device(smmu, regs, esr, addr - smmu->mmio_addr);

Going through the followup patches, I found this smmu_dabt_device
gets really too big. Perhaps it can be bisect to read and write at
least? Something like:

static bool smmu_mmio_handler(smmu, regs, esr, off)
{
        /* decode ESR: len, rd, xzr; width check */
        if (is_write)
                return smmu_mmio_write_handler(smmu, off, len, val);
        val = smmu_mmio_read_handler(smmu, off, len);
        if (!is_xzr)
                regs->regs[rd] = val;
        return true;
}

Nicolin