From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 8DAB81459E3 for ; Wed, 10 Jul 2024 21:56:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720648593; cv=none; b=gO2akBm3gzAW/ExVq3JItajdl+PDGIhPOKIQPZAGVAqbkePVVxNSuLxcQIb+rL1DnfNPj8abk1dFZ4Law4Fepd/3QEHqmpdEx7SjtFGoSztJU6CaKJtIump//5VIrWsP/uybAK8gFd8HqBL1740u5a2Gywfw9LwzUhTHnZt0Qtw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720648593; c=relaxed/simple; bh=v9gwvodIALaLZTiFk6iAF1MBNoj2kgdUYunqdySS94Q=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=eGuZ9pDoon3Xy12LETwMXMMWGmRU2yV25QgPwjRXkDKVw2I6kq2QPqh92aQETjOmUv91g4h5lIVM6hi+RjQQNUZo++OAPh/xeX/P7gP4Jj2L0GIGABYzAaDUXgBMvyE2lhQuqDFC9R/nudwK2wQ9YDIKjTzk3/l5TZtEB7XrfHg= 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=x+JLRtdo; arc=none smtp.client-ip=209.85.214.202 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="x+JLRtdo" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-1fb05cfe1cbso1273095ad.2 for ; Wed, 10 Jul 2024 14:56:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1720648592; x=1721253392; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:from:to:cc:subject:date:message-id :reply-to; bh=UOPY7FMtYeUU5dmTWp7HgAObmI5uYd1GYWNtWLDcPCg=; b=x+JLRtdoenShBIQt+J2J4r4i2Jzf4EFsIFG1RcyMtwoBV5Lfxi1zw0VtDsJ1ee5uTS SvOSgOrHnysBNoVL0aROIW6qbGzS2Rau4cOo5ujjicB2O2cCBPFRyNjM1WEnbcpTywJ9 zmSy6B7Obzyi0nF5e7pGSKmnNJ3VmsrorT0jE04k6fJu24AF3OcAKHk2CnG2pcplk/Kc hhMNL3rpESY8VH12B4+4uGkIISUEHK8bkazHE9Q5lN3NRrBnLc88cJJq05HAuF1iF4I6 0khy1v8ki4k/gi3jKN5ZQyB/lQkYkbP3Kf15m6K5e2UneBstb+0/HA+F8OY6XCIJ7WR7 p2Rg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720648592; x=1721253392; h=content-transfer-encoding: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=UOPY7FMtYeUU5dmTWp7HgAObmI5uYd1GYWNtWLDcPCg=; b=j1AtCjNpLqbcjb30MdJfkjspW7jeu+oTav/TGDud86XFLXCtgt5qCpGdmMNpG92xjG tai6L8MFHmlKcR9Y5Gh0Gpv7YBN3keCYhVRXfiPeAOoWe8Wns37ZBhn9tSJE+BI5d4ko XTzAE8CCOoXZjqaafxd1VzUoZKlFhHLmzAfknWZNa6+Ze/jHB+5qSiLh7tvHvjaFcGfx aFaY+VygadHdzbdaSXw8/MrLQTpVXAinVChvHGh69wADkrhaVLDsoLXJAUGB7A/LMzJS YjWeG6+2V62aEq5qErqDtRt5yp+LA9Zi2C6cP3ZHrPdxDW5Fbg1tHV/B6F56lVeAj5XC L77g== X-Forwarded-Encrypted: i=1; AJvYcCUKe3F3MwWb3E/viqZ9phl/WmKCaIcvjDGMm1G7GRGRiuMg8Iv5a/QUByvqbBDT7uRfjMX5OV81vNghW3m0iJjpJSEV X-Gm-Message-State: AOJu0YxECGngzfFd3yM9eYfd9Zrql+U7h8Kq84lFkoVMCMkMqIVr0yHc XX3S1McatqCqDnG45IChTFUjUQ+9JHB2eWdXbB9n7r0Kle9FNXva9cRQJTtuqIIlQy0Tc56OHcG FAg== X-Google-Smtp-Source: AGHT+IEQe0aTdA93AgOP3bdo/+RIy3w6WTsIhnoelP3F0c9LSyPhjCsXCn6PU46FDaxB5eEK34EWvS5/yeU= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:e541:b0:1f6:fbea:7959 with SMTP id d9443c01a7336-1fbb6c228a7mr4802475ad.0.1720648591757; Wed, 10 Jul 2024 14:56:31 -0700 (PDT) Date: Wed, 10 Jul 2024 14:56:30 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240710174031.312055-1-pbonzini@redhat.com> <20240710174031.312055-3-pbonzini@redhat.com> Message-ID: Subject: Re: [PATCH v5 2/7] KVM: Add KVM_PRE_FAULT_MEMORY vcpu ioctl to pre-populate guest memory From: Sean Christopherson To: Anish Moorthy Cc: Paolo Bonzini , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, isaku.yamahata@intel.com, binbin.wu@linux.intel.com, xiaoyao.li@intel.com, Rick Edgecombe Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Wed, Jul 10, 2024, Anish Moorthy wrote: > On Wed, Jul 10, 2024 at 10:41=E2=80=AFAM Paolo Bonzini wrote: > > > > + if (!PAGE_ALIGNED(range->gpa) || > > + !PAGE_ALIGNED(range->size) || > > ... > > + return -EINVAL; >=20 > If 'gpa' and 'size' must be page-aligned anyways, doesn't it make > sense to just take a 'gfn' and 'num_pages' and eliminate this error > condition? The downside is that taking gfn+num_pages prevents supporting sub-page pre-= faulting in the future. I highly doubt that sub-page mappings will ever be a thing = in KVM, but two PAGE_ALIGNED() checks is super cheap, so it's soft of a "why not?" = scenario.