Re: [PATCH v2 07/17] x86/virt/tdx: Initialize Quoting extension

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Using WARN_ON_ONCE() for an optional fallback feature causes kernel panics with panic_on_warn and drops the actual hardware error code.
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commit cc6fec2434c274e836f0735b1b3ace996ebcb151
Author: Peter Fang <peter.fang@intel.com>

x86/virt/tdx: Initialize Quoting extension

This commit initializes the Quoting extension during TDX bringup as an
optional feature. It intends to allow TDX initialization to gracefully
fall back to a userspace flow if the quoting initialization fails.

> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index 4d2940f4538a2..06c42b86b05e8 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
[ ... ]
> +/* Initialize quoting extension */
> +static __init int tdx_quote_init(void)
> +{
> +	struct tdx_module_args args = {};
> +	u64 r;
> +
> +	do {
> +		r = seamcall(TDH_QUOTE_INIT, &args);
> +	} while (r == TDX_INTERRUPTED_RESUMABLE);
> +
> +	if (r != TDX_SUCCESS)
> +		return -EFAULT;

[Severity: High]
Does this discard the actual SEAMCALL error code? By returning -EFAULT
here, the specific hardware error information from TDH_QUOTE_INIT is lost,
which might make debugging initialization failures difficult.

> +
> +	return 0;
> +}
> +
> +static __init void init_tdx_quoting_extension(void)
> +{
> +	int ret;
> +
> +	if (tdx_addon_feature0 & TDX_FEATURES0_QUOTE) {
> +		ret = tdx_quote_init();
> +		WARN_ON_ONCE(ret);

[Severity: High]
The commit message explicitly states that quoting is an optional feature
and initialization failures shouldn't cause TDX bringup to fail.

Is WARN_ON_ONCE() too aggressive here? On systems configured with
panic_on_warn=1 (which is common in many environments), this will
trigger a kernel panic instead of gracefully falling back to the
userspace flow.

> +	}
> +}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260618081355.3253581-1-yilun.xu@linux.intel.com?part=7