From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E8D8E5158B6; Tue, 29 Sep 2026 11:38:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790681883; cv=none; b=Z0r38Yue/FUWauZDtZ3e0/5ujIi5wFmX8n9MKQKypW4/FeVGCtQa98+0qk8Q57K6msElv68jTUvUNt8pfocp22VGB4xMRw1Y5jIY4NDFgbLjGbYrNPHXXcE3ROO2Xb4ENvf4/WAX7PzT6w3geOqqNr2np56mwjmhPQJoVzPAzHg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790681883; c=relaxed/simple; bh=tqjmlp+/lUnMUWbQnrX31y/+aHqlRJRtl0e4XiSbrZM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=I0ugvnN1OV3r1GQzXXTd9ecfGW9XyjjC5BXyKXZVZSyDmnjJ9vHbmPDDzDw1g4hGkdbEH4KDrchDVglcqZ8NJMKRl8ahvR4TickgOatWDoII0rF8h17XGrTDsnSVLNGiyy32FwLzjq7q33yAhTbJRdDCWYe/cmI1ETXEl7cWq0U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=d0jXuIL/; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="d0jXuIL/" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B629C1476; Tue, 29 Sep 2026 04:37:56 -0700 (PDT) Received: from LeoBrasDK.cambridge.arm.com (LeoBrasDK.cambridge.arm.com [10.2.212.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F40D33F85F; Tue, 29 Sep 2026 04:37:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790681880; bh=tqjmlp+/lUnMUWbQnrX31y/+aHqlRJRtl0e4XiSbrZM=; h=From:To:Cc:Subject:Date:From; b=d0jXuIL/6Emp4J/TGs+f2eNtHj6eC2hd23MA10VhpzQ3oX5codkrdBvd36sYXREKb wHYjOdCMGCYCRWksplqCqoSYQsrLey51qyF2LE0dbXjQNTmdPNX1v/AIb9N210rlcn If/6UsSAoT/YifI0XMo6LFEJ8PZGxXtnEcR2pmqw= From: Leonardo Bras To: Paolo Bonzini , Sean Christopherson , Shuah Khan , David Matlack , Leonardo Bras , Ackerley Tng , Marc Zyngier , Josh Hilke , Oliver Upton , Wu Fei , Steffen Eiden , Claudio Imbrenda Cc: kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v1 0/3] KVM: selftests: Add support for dirty-ring on dirty_log_perf_test Date: Tue, 29 Sep 2026 12:37:05 +0100 Message-ID: <20260929113711.2064390-1-leo.bras@arm.com> X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2850; i=leo.bras@arm.com; h=from:subject; bh=tqjmlp+/lUnMUWbQnrX31y/+aHqlRJRtl0e4XiSbrZM=; b=owGbwMvMwCX2pizjszvTwvWMp9WSGLJ2L5r+tcx4B/ODecnZDSUiZYXz+VLmZS2yP2O6QG+PX Mwpm5mLO0pZGMS4GGTFFFlkH81fxfN9SsaRKz8WwMxhZQIZwsDFKQATcf/DyPDdUOeawynG6om+ Utf2xdW85QvoL/7oMvNpq6dV5vYAJXWGP9ysr65NYnjHkxNU9/7jApHWin21KySMb6SldUw5rfN QgwUA X-Developer-Key: i=leo.bras@arm.com; a=openpgp; fpr=36E6C95AE0F111CC5B6F4D2E688C33F8A0C5B0C5 Content-Transfer-Encoding: 8bit Add support to dirty-ring on dirty_log_perf_test, so we can measure performance differences when we change / improve the mechanism. One big change in this set is that dirty-ring needs to be enabled after the VM was created, but before any cpu is created, so for that, I made a few changes on memstress so it can actually take dirty-ring size as a parameter for VM creation. (Patch #1) I honestly don't think it's pretty, but I could not think on a better way of doing this without messing too much in the code. Also added some checks in dirty-ring enable, so an error message on ring size is more informative. Please provide feedback :) Thanks! Leo Changes since RFCv4: - Series title - Rebase on v7.3-rc5 Link: https://lore.kernel.org/all/20260729161519.3778839-2-leo.bras@arm.com/ - Using acquire/release barriers to make sure there is no reorder between incrementing iteration and summing the time spent on cleaning. - Improved ring-size checks, although not perfect due to reserved entries affecting minimum size. - Do not allocate bitmaps for dirty-ring tests, as they are unused. - Improve help text - Make sure ret==0 before going back to vcpu_run in dirty-ring case Link: https://lore.kernel.org/all/20260708152232.2568907-1-leo.bras@arm.com/ Changes since RFCv2: - Added mutex to make sure only a single vcpu is collecting/cleaning at a time. This gets us the ability to test return values, and not account for kvm.slot_lock waiting time. - Stuff reported by Sashiko - Return value always positive, so assert was pointless - Concurrency inflating the time for dirty-ring cleaning Link: https://lore.kernel.org/all/20260629105950.1790259-1-leo.bras@arm.com/ Changes since RFCv1: - Stuff reported by Sashiko - Fixed elements / byte size wrapping issue - Removed element count due to concurrency - Testing exit_reason instead of ioctl return value - Some nits Link: https://lore.kernel.org/all/20260624171656.1737580-1-leo.bras@arm.com/ Leonardo Bras (3): KVM: selftests: memstress: Add option to enable dirty-ring on VM creation KVM: selftests: Check dirty-ring size before enabling KVM: selftests: dirty_log_perf_test: Add dirty-ring support .../testing/selftests/kvm/include/memstress.h | 3 +- .../selftests/kvm/access_tracking_perf_test.c | 2 +- .../selftests/kvm/demand_paging_test.c | 2 +- .../selftests/kvm/dirty_log_perf_test.c | 128 ++++++++++++++++-- tools/testing/selftests/kvm/lib/kvm_util.c | 21 ++- tools/testing/selftests/kvm/lib/memstress.c | 34 ++++- .../kvm/memslot_modification_stress_test.c | 2 +- .../kvm/x86/dirty_log_page_splitting_test.c | 2 +- 8 files changed, 167 insertions(+), 27 deletions(-) base-commit: 72d3fcf802c45d00b300f25b848a93c3a2bd7c7e -- 2.55.0