From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE13B169AE6 for ; Thu, 23 Oct 2025 15:46:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761234397; cv=none; b=JGpYt3NzXygpm6me67znBs5iGU1bjkfKxLx4ywdFHqcDIFFy/uzfPk6SbeXoNI6L38r6P5wjQsecrvAVmLDahi7Q7pgzukHtn730olPQ7K82jAmMlhiTy9MZVscRVsOZt19oadqt0UQkx+d6y243Tubyz1rTeVa9gl+Lh5JAChA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761234397; c=relaxed/simple; bh=6pTymwxV3JY+AUKKUttfqyjqfuzMSv+BI+TUzdzowfg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=UQYBhLiYNm5t3tIfzMs6CnP9Cu9LcC6OBozI1xrejwkPl75+D/+8Kph0Q4CYgsDehp8q+rTa4OCNOPW+9FW+2JekfH9V9+qWzndJr9zshQoCon+1BUlzTpkks2y4elvaY7p5hn85a76wVxJ2YlVWFb1LFeiVF4kg66QA0Ipv6Xg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=k1fG2xz0; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="k1fG2xz0" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-3324538ceb0so1575508a91.1 for ; Thu, 23 Oct 2025 08:46:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1761234395; x=1761839195; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=cA8f+nNEAJRY7EiGBsr+OimXBMbTdTa3L7KnOjbjNro=; b=k1fG2xz0uiZouoaytOLGD4vrD/kJ59W+GDHYfKywgfVu3JNWoP4BKj/ZDpfKdUIF8Q IwtaCi7aS2Y/iIB/3wKFOtsSV6UzayH2eDo74RzeIpDB5ErJByjR3uBDmVLNleNQGsBQ Dyi3qt/To8/QyKGwo+TgH1OlmnHw0mgMswNtz1rrP6a9i7RkriPiBvaphRYlmwYZKmYt /dbhoLUUEnkrPtr15bHpVim7Qn0ZaXRZmW1i8/I0a9seS0m3X49o5v7ntyys624CZFhw hHrbMukxHlFgLML/7CViW3Q7b0cvUCAHWT1Gj5M7jDTpf4GhmYlegBe0VjsorgQdO13e zttQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761234395; x=1761839195; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cA8f+nNEAJRY7EiGBsr+OimXBMbTdTa3L7KnOjbjNro=; b=GQgolC7eaBvv1SX+aL4wnVCN3+0gCnlLbvIlZiDN9mYFClu9WiffbilvUmFOgZQCQx gYCKTIesjI6rs/4hYDsQ8wA68Xq2jeuIUdXnlF6dKAftnX4VaIB/rZWQH6lgLIAk+fnF 35Y+ApEn5dCqzF3ErhI/AOmPm8zSg4vauuyZQdQ/JRid32oyznFbxe3PCoYZwsz8ghPi /lMFvzwSTMCcJSe/sHAg4r5jhtesTUr7RmbmJxbAfCjrSqWhPsDTCa0uhP5GTMb1BOjN FVP2if9LdeO1ehPupmbaVI6a/U6PNajy0yNB3X/lGdJQJr4Q3waYV8p1SvJcZdBKjrhD QSkQ== X-Forwarded-Encrypted: i=1; AJvYcCXaNN7j1/yrqJs8FivgHhT5f30tBRdjGquySYf7Oqrq+vp2wy8mmjVGC2pTzfS5VVMFBLBObTg=@lists.linux.dev X-Gm-Message-State: AOJu0Yy9jLJ+fwjLClH2zPpZktHHpC9kBZep1eNhZsDt7mZ9ZGvW5Zib A8QPSEwhGQ0I1Wiy+br+Y/7Vpxw/P72xH0eRZHFv/wrhgwoibuipyDdLbiFyXPirOiNyrXFDldm 1BtHx/g== X-Google-Smtp-Source: AGHT+IH1AC48gpV9weuwwebG5qkhyKt/sOEZ87sVL1uSftHljNqtSkYW1d4gsE3nQlKslL7141ZzFVVxScM= X-Received: from pjzm22.prod.google.com ([2002:a17:90b:696:b0:339:ee20:f620]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3c0e:b0:330:a228:d32 with SMTP id 98e67ed59e1d1-33bcf86b401mr34594579a91.10.1761234395178; Thu, 23 Oct 2025 08:46:35 -0700 (PDT) Date: Thu, 23 Oct 2025 08:46:33 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <10A5745B-411F-4EB3-A168-0BC6CA99FF4D@linux.dev> <62kml5omikxsb3ppd4yewcvbuje4xojffi6nkcnpxddsy77hpb@plprg57waxnb> Message-ID: Subject: Re: RFC KVM: arm64: selftest: stage 2 mapping helpers From: Sean Christopherson To: Yosry Ahmed Cc: Oliver Upton , Itaru Kitayama , kvmarm@lists.linux.dev, Jim Mattson Content-Type: text/plain; charset="us-ascii" On Wed, Oct 22, 2025, Yosry Ahmed wrote: > On Wed, Oct 22, 2025 at 10:47:15AM -0700, Oliver Upton wrote: > > On Wed, Oct 22, 2025 at 04:57:16PM +0000, Yosry Ahmed wrote: > > > On Wed, Oct 22, 2025 at 06:34:58AM -0700, Sean Christopherson wrote: > > IOW, the starting point for us is fine-grained control over potentially > > multiple stage-2 MMUs with modal descriptor fields that change meaning > > based on the current MMU context. > > > > > > I.e. if we envision any arch-agnositic tests that can do nested things, > > > > now's the time. E.g. running dirty logging tests in L2 maybe? > > > > We can just as easily implement an agnostic wrapper after the fact; > > enabling architectural validation of the arm64 nested implementation is > > the highest priority at the moment for us. > > Oh 100%, I was not suggesting that we need to do this now, not sure if > Sean was. I was maybe 60% suggesting that? :-) But it sounds like the underlying x86 and arm64 details are going to be much more different than I was anticipating, so I'm a-ok punting for now. E.g. I was thinking we'd want a common kvm_mmu_arch or kvm_stage2_arch, but trying to implement such structures without a concrete use case would likely be painful/ugly.