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 2BCF81A680B; Fri, 19 Jun 2026 00:31:51 +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=1781829111; cv=none; b=TWhnLI5EnVOO+o8oO3eXFL+dm18Q+AlEfz9X9qHpXd5KmdHkNJT+f0UCgaQSGO8B1/IvO8q9hUm63WdV8azzQDnUXLxF5No18KP3PbbumIcMkDYDAEyWP8AGVyH1D7bpRF1N6ROJCPl7hj1kee8W/nWX58g6NnBpNRJVKm32A1Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781829111; c=relaxed/simple; bh=WAKMADTKt6O7kXXejUyNTeb3Eo6paCLBo0p3xffhwco=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=JsUEvBvGW2wIP8Z/NHXXWfl2j7rQ6pL31ucZ238KAQCzyIhMcFUj68w9KH96COxPK2m/DBPzgELUAlF7923hl7hbErdvFefPK/+TGxcF+LB2xUaaQ8He4J2FrmC6NeA3e7KmijEmMm009FRNnp9SLb2ERvGTX4pZXBsWV+nvNUo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pStgbSQ2; 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="pStgbSQ2" Received: by smtp.kernel.org (Postfix) with ESMTPS id E7D9DC4DDE3; Fri, 19 Jun 2026 00:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1781829111; bh=WAKMADTKt6O7kXXejUyNTeb3Eo6paCLBo0p3xffhwco=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=pStgbSQ2h11d1WPWC9k0eA32vwoQcrGhdQdekC+/WHrfD68n2B6AwP/6JxoLiluEe l4cA1guIxhDPTaGSXJwgXI0TsSw9TuSL2Wz+rHAdsOMhjofwbkU+QF4PYu3C0u0hAb VRLZsJDJsjENb85pnJAAAQOAIdQpLAz4zjG4QDPFHioxgUNxMiooMF2jS9TlRKUQXs RALziDG9qveXEifabMXGlmn8qIvS9vTUP9n0fGKA5kxAnSOYoVBMLuE6JBenC8pEA4 CvvZaPIWElLi4yMG8dHjifWKDI7IH2y7yY4C/N+XbKPMK+bh3lXbNSUQHR/7TL0DoT xp5xdZxIIym2w== 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 DA054CDB466; Fri, 19 Jun 2026 00:31:50 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Thu, 18 Jun 2026 17:32:17 -0700 Subject: [PATCH v8 40/46] KVM: selftests: Reset shared memory after hole-punching Precedence: bulk X-Mailing-List: linux-kernel@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: <20260618-gmem-inplace-conversion-v8-40-9d2959357853@google.com> References: <20260618-gmem-inplace-conversion-v8-0-9d2959357853@google.com> In-Reply-To: <20260618-gmem-inplace-conversion-v8-0-9d2959357853@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, 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 , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , 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=1781829104; l=2495; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=igS9huamOm4v4JvNfe5w6YBKw3+2FuoejUp2nlG0FvU=; b=pCifBfxclI7NobLZIuHYqQsS3pr5Iuhjk3gv8HVyjjx3XOEbwNCWg/2MHXDW6FskpMp3GEgR6 iGlD8sgX9gtCzcEQxL+owaYUWzgmXF2EGVplcjtqHLscCN1CdaJCtl9 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); } } -- 2.55.0.rc0.738.g0c8ab3ebcc-goog