From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com [209.85.208.50]) (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 09C0624C080 for ; Thu, 3 Apr 2025 15:31:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743694315; cv=none; b=oHFscsTDGmV0jdECWOdDxNK4Cbshc+DpwEIgNjRdOIxjsD4hQp5auJdrxOqQAE1Mkt7ASBRsol4KpmRuZZ3p+/aQui4ERbAJX7nIQolNJdVW6+Zq0JektY0gSARkbOMunOEvLn2ZRvAp3htj2ofn6Gl0yr0CyoeuGwm+euSYwrw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743694315; c=relaxed/simple; bh=KPQddjkqY2woTfI2cLtPZbW+MJntKMtuNGsZM5WDnFU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=T9lpLxeMxQv3NFbkIopqyOgG/yIXBtaen2PE+1tEkrP2GmeIoQkk59nrAL1ady28/opK+atgTf01b336n2J3R4aphq1duHoh/n5OxlDCq0xBwd80Ejg0KaCajMaMRl9KW3HZ3e1tZGAOl95oEhirX0y8EuKSkFJlLpCVm2q+E34= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=vpy1M60v; arc=none smtp.client-ip=209.85.208.50 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=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vpy1M60v" Received: by mail-ed1-f50.google.com with SMTP id 4fb4d7f45d1cf-5e5e22e6ed2so1542961a12.3 for ; Thu, 03 Apr 2025 08:31:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1743694312; x=1744299112; darn=lists.linux.dev; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=2SVexGeljhSdSxj9UAkbIi7n+kiPxQUm8cURRQIGIRA=; b=vpy1M60v/24jx+mdAoEALnK4iDFm47VTuEGJDMB4OX7qHWxP9aAT/LSpCU7GdJqHei ExMPex9LLXrG1SYRwqTDB4KD29BVHceGC4gWpiBZ/Ug6db16Oj5lrHgUG8bUzgdKbXRv 7HHuUYYe7OLdErwj1xMSjyMjpZhm2NKRmmlzdLO6VwrmHZlRBInXaYOBe5rtq7KAkVxf I/bC7GlgYfXJoNehwkTKV1gbi8xTWtFbQ+TFyPhqppvpvTCnV167WZK2+RGWDMjqIIHY 9alQNMUlo0qG7aUHa8823WpQCd3/KBDkteTaWbgtpWF8upcOgsfwH3sK21UBEuccIUgG gUEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743694312; x=1744299112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=2SVexGeljhSdSxj9UAkbIi7n+kiPxQUm8cURRQIGIRA=; b=AR8ED/gBxrOOYK9MrxHyicvaJRdGH5MCL6Ha9J9AwEdyJlLUZw6Oq+h7cY3amQ9NjZ EOh8g5MgB5TuF1NaoNbcf+WDlHADIatXgABGPVuTAo9vLvIpMYKXAkLAt0Aij631h3V2 hUFVCJwbR4S3EAYH3i53kxW5uyXn5SGv6XgsgbdRCDhgoJD97d/HTFJk3kDTwlysT6IY 9TlAoStITVvGgJ5Rv8D3WN4L9mX3yVTU9/6z6hpjSCTWQf9/9JuQ4Gr2gdYIK4G880l/ q9BV9V9wp3NtEhVjHI5zp5+C9QMU/E7TDWyMaoBjCw+4n+2PYUKjUt6DTsD2xCtr/6el JKoA== X-Forwarded-Encrypted: i=1; AJvYcCUVtiCQ9q+NJUKTEsL+pcFtqRy+KeoLzwkXm2eL5YHwK40bEqQ6PMC5hydp5indO1NhQWbFp9Q=@lists.linux.dev X-Gm-Message-State: AOJu0YwHBtAKktxxvf0wc9twsWCwx0UGH/xFPivU6WKqX2Ve3zkWtyYi /T3KjbSHeh12Y5Kuh6H1zGZCqpA5Q0+UiQcx9sAznk9OhK+eJZHORCjBOuknUQ== X-Gm-Gg: ASbGncs6oTOV7QYJQ1BckUW+AVATokbkWqhfUr3kRJqePUtqU6uRipTGAQ3cmZw5NS+ //kqTFpkUjuqYRUiTCPVdXZMMa0+eUNXMXx4CWrKr6F/b24we05zJYBocHQRCBcYkErk4XRUvlQ ol/0D3VixxFMqPdQGpL46Ua8jCE0hKe0fPAsIiUDSUHvtcGQRoka0juh+Z4F9ZN9iU6f+b0ks5Z poOrZJwSf5JLewBIg6Xz0X4f+zxT5RALyEwPJKQAp0fM57VHqNbHnOvrZfAQqxUiI5LlRfPO8Cv e+EEeHBVolbUEDAbWVxcZF7XCGpDVgGaKPD7Ij7NjSl6b4U3e7ChKsov+ftLX78pj5BMzygT7N/ Zk66SRcFIX6WSfFT5 X-Google-Smtp-Source: AGHT+IEGEPfe6jLP9yTD8EczNIfaOYVt4yM5HvzJTIY1ayuEiVqh4iVP20QX+O0oM2W0n9OiZudOCQ== X-Received: by 2002:a05:6402:1e8e:b0:5e1:dac1:fa22 with SMTP id 4fb4d7f45d1cf-5edfdafe39dmr16976129a12.21.1743694311816; Thu, 03 Apr 2025 08:31:51 -0700 (PDT) Received: from google.com (40.162.204.35.bc.googleusercontent.com. [35.204.162.40]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5f0880a4027sm1097010a12.73.2025.04.03.08.31.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Apr 2025 08:31:50 -0700 (PDT) Date: Thu, 3 Apr 2025 15:31:47 +0000 From: Quentin Perret To: Vincent Donnefort Cc: maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v2 3/9] KVM: arm64: Add a range to __pkvm_host_unshare_guest() Message-ID: References: <20250306110038.3733649-1-vdonnefort@google.com> <20250306110038.3733649-4-vdonnefort@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250306110038.3733649-4-vdonnefort@google.com> On Thursday 06 Mar 2025 at 11:00:32 (+0000), Vincent Donnefort wrote: > @@ -1012,51 +1011,52 @@ static int __check_host_shared_guest(struct pkvm_hyp_vm *vm, u64 *__phys, u64 ip > return ret; > if (!kvm_pte_valid(pte)) > return -ENOENT; > - if (level != KVM_PGTABLE_LAST_LEVEL) > + if (kvm_granule_size(level) != size) > return -E2BIG; > > - state = guest_get_page_state(pte, ipa); > - if (state != PKVM_PAGE_SHARED_BORROWED) > - return -EPERM; > + ret = __guest_check_page_state_range(vm, ipa, size, PKVM_PAGE_SHARED_BORROWED); > + if (ret) > + return ret; Given that hard rely on kvm_granule_size(level) == size above, we should be guaranteed that the PTE covers the entire range we're interested in. So is there a point in starting a new page-table walk here? Could we just keep guest_get_page_state() directly? > > phys = kvm_pte_to_phys(pte); > - ret = check_range_allowed_memory(phys, phys + PAGE_SIZE); > + ret = check_range_allowed_memory(phys, phys + size); > if (WARN_ON(ret)) > return ret; > > - page = hyp_phys_to_page(phys); > - if (page->host_state != PKVM_PAGE_SHARED_OWNED) > - return -EPERM; > - if (WARN_ON(!page->host_share_guest_count)) > - return -EINVAL; > + for_each_hyp_page(phys, size, page) { > + if (page->host_state != PKVM_PAGE_SHARED_OWNED) > + return -EPERM; > + if (WARN_ON(!page->host_share_guest_count)) > + return -EINVAL; > + } > > *__phys = phys; > > return 0; > }