linux-kernel - Re: [PATCH v3 2/2] x86/sev: Add support to unaccept memory after hot-remove

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Message-ID: <16aa84a9-83ce-4748-bc73-ccf5cb6ce376@intel.com>
Date: Wed, 28 Jan 2026 13:15:06 -0800
From: Dave Hansen <dave.hansen@...el.com>
To: "Pratik R. Sampat" <prsampat@....com>, linux-mm@...ck.org,
 linux-coco@...ts.linux.dev, x86@...nel.org, linux-kernel@...r.kernel.org
Cc: tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com, kas@...nel.org, ardb@...nel.org,
 akpm@...ux-foundation.org, david@...nel.org, osalvador@...e.de,
 thomas.lendacky@....com, michael.roth@....com
Subject: Re: [PATCH v3 2/2] x86/sev: Add support to unaccept memory after
 hot-remove

On 1/28/26 12:41, Pratik R. Sampat wrote:
> +static inline void arch_unaccept_memory(phys_addr_t start, phys_addr_t end)
> +{
> +	if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) {
> +		snp_unaccept_memory(start, end);
> +	} else {
> +		panic("Cannot unaccept memory: unknown platform\n");
> +	}
> +}

This panic() is pretty nasty.

Can't we just disable memory hotplug up front if it's:

	!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)

?