From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CD43028315D; Mon, 31 Aug 2026 00:25:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788135923; cv=none; b=f48fHxMNjUPqIUNafKijFikSkph2cbn1hgJSCki5k8m21ti+joGSnBBnbsmH+SJyYA1KoDOs6wufHhkpQfufmbLRIgVZmLd53hmhvFZVLCptJQvTSWEN/zMAWjzizVloq0Xjs+2HhmFGgU+f45E/epW4LIF/nwvhFyRUE9m2PMk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788135923; c=relaxed/simple; bh=MBsdJBcO4TQvHjj9pDczibnuw9xpxWQnfVZGWTJVKUg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=X6gsvteom7SRq/dr7N9gVZ8mHDhQE2qyT8vFp/LYn0YRvdlQa3lYjocjQ7eNORqC9pmKNbr52dIjpQPNhSn0KH0alLQye5DlPWh//kPXoBuXlg1ZEEAc8Lujz9xQutQVM4O8pG7/bvUwOmbKHBTXsKWZqo9j8I+vfFpKWne38Bk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TbZGfcdq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TbZGfcdq" Received: by smtp.kernel.org (Postfix) with ESMTPS id A56CBC2BD05; Mon, 31 Aug 2026 00:25:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1788135923; bh=MBsdJBcO4TQvHjj9pDczibnuw9xpxWQnfVZGWTJVKUg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=TbZGfcdq7kzK5CCsa3AykZxdq6sTTAfupmtjkchE+NV99+G/oXHy/z32qCaBG7yil 9WrCpttCdJesYEqjoYscTa5LPn6hBJ9lJIvghrBPbP0LTL1lSKIhn0dRgaZ5oPHzlm NtHTPWAFdbkEyOSvLgkSxbm1/0JEvdxU82qzQ5QaH5WZpr3D34nFvw6VKaSJ4SV2zg m5V4ti0tiMJM3cLO1P89RafdUv96KHCQ5ZPh3NMtWFGAdGY2VHr1pg6ixUI15GdHoz lklc7TXC7dPcSjRY38X+LQvhpoUXxXjmwsyauWIyZ+Bj9Ogs5qgKvlcG06xLwK6Mbc pNF1/5ioaidzA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84BD6C61DE4; Mon, 31 Aug 2026 00:25:23 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Sun, 30 Aug 2026 17:25:40 -0700 Subject: [PATCH v12 39/45] KVM: selftests: Reset shared memory after hole-punching Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260830-gmem-inplace-conversion-v12-39-85e5fd25252a@google.com> References: <20260830-gmem-inplace-conversion-v12-0-85e5fd25252a@google.com> In-Reply-To: <20260830-gmem-inplace-conversion-v12-0-85e5fd25252a@google.com> To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , John Hubbard , Peter Xu , tarunsahu@google.com, Randy Dunlap , Lorenzo Stoakes , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jason Gunthorpe , Fuad Tabba , Vlastimil Babka , Baoquan He Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1788135916; l=2579; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=uV08q4RDK3FyngpumGt+e56rGp5WLQvKfEyZx0mVgVY=; b=iT+PS0xDjfvKp4QdlflKy+7dtweWMwhTAxNwE8dsJVeEO94OnCnUEaqmPrG+y6GLz0nP34akA 1N1NalAM+U6DNWnLRM30OqjSc6w6dw8krqKqAhRtjiHKWDOuBdx1it5 X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com From: Ackerley Tng private_mem_conversions_test used to reset the shared memory that was used for the test to an initial pattern at the end of each test iteration. Then, it would punch out the pages, which would zero memory. Without in-place conversion, the resetting would write shared memory, and hole-punching will zero private memory, hence resetting the test to the state at the beginning of the for loop. With in-place conversion, resetting writes memory as shared, and hole-punching zeroes the same physical memory, hence undoing the reset done before the hole punch. Move the resetting after the hole-punching, and reset the entire PER_CPU_DATA_SIZE instead of just the tested range. With in-place conversion, this zeroes and then resets the same physical memory. Without in-place conversion, the private memory is zeroed, and the shared memory is reset to init_p. This is sufficient since at each test stage, the memory is assumed to start as shared, and private memory is always assumed to start zeroed. Conversion zeroes memory, so the future test stages will work as expected. Fixes: 43f623f350ce1 ("KVM: selftests: Add x86-only selftest for private memory conversions") Reviewed-by: Fuad Tabba Tested-by: Shivank Garg Signed-off-by: Ackerley Tng --- tools/testing/selftests/kvm/x86/private_mem_conversions_test.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c b/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c index f3de2a4ab0551..cf50e9a332c5b 100644 --- a/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c +++ b/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c @@ -202,15 +202,18 @@ static void guest_test_explicit_conversion(u64 base_gpa, bool do_fallocate) guest_sync_shared(gpa, size, p3, p4); memcmp_g(gpa, p4, size); - /* Reset the shared memory back to the initial pattern. */ - memset((void *)gpa, init_p, size); - /* * Free (via PUNCH_HOLE) *all* private memory so that the next * iteration starts from a clean slate, e.g. with respect to * whether or not there are pages/folios in guest_mem. */ guest_map_shared(base_gpa, PER_CPU_DATA_SIZE, true); + + /* + * Hole-punching above zeroed private memory. Reset shared + * memory in preparation for the next GUEST_STAGE. + */ + memset((void *)base_gpa, init_p, PER_CPU_DATA_SIZE); } } -- 2.55.0.897.gb25b4bd76c-goog