From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 664E532145F for ; Thu, 14 Aug 2025 16:51:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755190294; cv=none; b=lWaHkcXcbqwSZy8gIYhQ0TzonXRqEonrOIeFYoW7UYwAinYiIh1hibyY6QmQD8K/qvWKpZA7KqvzU8BhRJbuU/2UX7+T5usZMFj7GjyuWaHPQQpRuUw+dsP8Tp2/I6YgVndH//rb+3k8Cu7Pieq8CvnPfj3TPxE9swTtrXsGjtw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755190294; c=relaxed/simple; bh=0EMXvJzbVCGk9QgY+RKdDXUf1vYpGiJfjW30bH6I/7A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=quNNvyAb0rcmdhpRHNNGftTIVHMgMhCzdM/jS5WWePBBo40OmMfiez3xtU67six8uxASOJffj0dvK9KaQkiOqKa60Vr1m/305psZZ0VB64XgvjzXUIqvrGA7bVdFhMLfxOEeCfH2OGkzVTQeOQNJ6kcaJ/wLj7wrufELE2cmAu4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=XuxKjmvY; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=GP94c3/o; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="XuxKjmvY"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="GP94c3/o" Date: Thu, 14 Aug 2025 18:51:28 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1755190291; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=0EMXvJzbVCGk9QgY+RKdDXUf1vYpGiJfjW30bH6I/7A=; b=XuxKjmvYIv7UtmU3BEb6+bSkqGY3iIkNBowRwnLMr/q8iIXpo5RhL8vIXjYtPUi7W4n3JU 8tP9SMJddSczEogydLSNAZMT3SrfQ6WSxt8FOyX9MMoPBUtezoRhKuSoKxVKlQ41pYrTwW 5grCX5aHseHLG8ZA5ZtP31yxJCDbky3++DgV+sks6SnvwRwMHYwfbryXsSMfetWp3PUEeO iKrlks9vpwq6kGc2OCwOkVF3OabNKyjy5bXz0Ih4tegvXF10YSjLsktWMXbKxMnn2rX0NE ZdepIFia3DGTdL7UiKiQxSUYucJkrOigA3YQ8m0S6t7776yo+r+0hL/IpHu93g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1755190291; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=0EMXvJzbVCGk9QgY+RKdDXUf1vYpGiJfjW30bH6I/7A=; b=GP94c3/oohPKRigNtIZXXTTvmrfAs4DSRI122oy0T9M1qY+LjOI9lPJlncWLw++Vv2tq4A crJhUO53eKDOgQAA== From: "Ahmed S. Darwish" To: David Woodhouse Cc: Borislav Petkov , Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , linux-kernel@vger.kernel.org, Konstantin Belousov , John Baldwin Subject: Re: [RFC PATCH] x86/bhyve: Detect FreeBSD Bhyve hypervisor Message-ID: References: <98dd43553b2d63edd3d994816f378985d1a19d72.camel@infradead.org> <20250814101552.GAaJ23WBZ-O3Yuu64t@fat_crate.local> <8ff6b4cad51167c6226304483544a6828d3f7e0c.camel@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8ff6b4cad51167c6226304483544a6828d3f7e0c.camel@infradead.org> On Thu, 14 Aug 2025, David Woodhouse wrote: > On Thu, 2025-08-14 at 12:15 +0200, Borislav Petkov wrote: > > > > > Which makes it, what, 0x4000_0001? > > > > I presume there's an agreement among all the hypervisors...? > > There is no such agreement about CPUID; by *coincidence* most of them > seem to use 0x4000_0?01 as their feature leaf, but the feature bits in > each such leaf are completely different and the guest doesn't look at a > given leaf unless it knows that specific hypervisor. Which is why the > 15-bit enlightenment is advertised differently by each hypervisor > despite being precisely the same enlightenment across them all. > For what it takes, such hypervisor leaves, in the 0x40000000 range, will be converted by the ongoing x86-cpuid-db CPUID parser work at some point. (Another iteration of the CPUID parser is to be posted today.) Thanks, Ahmed