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 054A34BCACB; Thu, 7 May 2026 20:22:53 +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=1778185373; cv=none; b=SRROXWk0LjZpgIgxQCtJ6p5QgDsTVh+9PkPkNRBKyd0NaXyU6f3973mUEvRflQnJ6HGPOprjUt3z4XarnUgv3W/g1Lx1KscdelXaA9IzYYhsqk462bWQvYVBgxVBgAhvMBGJagjf+mVb6iewPsTTx/4S+jDMmfeQ2Uox5olj/OU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778185373; c=relaxed/simple; bh=zfDV4nZkXWnXZy8e7YdOI6gWyOMZ4XLCe/7kCqmTNLU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=MT0Xlaz0E420qVHZYy7DtYj4EwDB/JT0GRRkaSk3rpeRSx99PiX/GbRg3TLw7nTAW2loVbsKu2W15rdgIXpJnURHoSqBjR3GAJwGK0AaidC76Qf3zbmtHIaOf1XgPqyLOHKwQxdp1+JMHqUn9bRRTZAB5Hrvfh2xhTnqUIBW9rw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iIGL2i5x; 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="iIGL2i5x" Received: by smtp.kernel.org (Postfix) with ESMTPS id DABE2C2BCB8; Thu, 7 May 2026 20:22:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778185372; bh=zfDV4nZkXWnXZy8e7YdOI6gWyOMZ4XLCe/7kCqmTNLU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=iIGL2i5xCi66Yh2s2DYZQDYiPFfzIpeJTPcnIStmvB6sD0WAkg3YtoDVNDoGf9BQ5 sV+rJpa72fjuarV4q5Ro64XvcjbTcFDD0ZOXY0W0wkYgRfDiWPuYVsyYcCeDpiNGTf nlNlaoLIW2W29SC/RSMldruw3IseUyfU3tiyXRGGQIXqu4g669dXzFfUWCSURZTGk3 hqyuNgdlNGsunV2cdZqlnIvtuSpmkBxtHGfAqf2t4CDjwoMwE4wccjhLmZ7e7xSyVq 6nMwbX7PNRyzGHZWH22RuA5V4OyIen4gRzfeAXfRQqdDDNE4gK6586py44s4gqj37s wQkz3jy84rCGA== 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 CCBF6CD3447; Thu, 7 May 2026 20:22:52 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Thu, 07 May 2026 13:22:55 -0700 Subject: [PATCH v6 36/43] 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: <20260507-gmem-inplace-conversion-v6-36-91ab5a8b19a4@google.com> References: <20260507-gmem-inplace-conversion-v6-0-91ab5a8b19a4@google.com> In-Reply-To: <20260507-gmem-inplace-conversion-v6-0-91ab5a8b19a4@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, ira.weiny@intel.com, 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, tabba@google.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 , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Jason Gunthorpe , Vlastimil Babka 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=1778185365; l=2491; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=6YboUEoN1FNkEuAz1Rbt6iWG3XFdNoXIyLA0OoRsryU=; b=FW5T5m19X+5M58CPrsoz+TiCvWD5Py/54qi2D8+8h1xevW5f1j0FBXPooGL7Us4kf6PffON2s a2nCl2Ie6lJCh9XCzGp+BfN12eCmUVthquwJ4grscnaKAcUjS7yVGH8 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") 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 861baff201e78..289ad10063fca 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); } } -- 2.54.0.563.g4f69b47b94-goog