From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21DD3C43334 for ; Tue, 21 Jun 2022 21:26:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356204AbiFUV00 (ORCPT ); Tue, 21 Jun 2022 17:26:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356431AbiFUVZw (ORCPT ); Tue, 21 Jun 2022 17:25:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 696BB30F65; Tue, 21 Jun 2022 14:21:47 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0932B615A8; Tue, 21 Jun 2022 21:21:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97576C3411D; Tue, 21 Jun 2022 21:21:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1655846506; bh=3+kfBJXx7bJFsPBrjotmt2oV78Cw71odr1QKUuLojLM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KJJq2VgXa+HRfEWPrWr6wGrH+KLybyVRS3X29halPEF+fdhKVk8eCcIC1pamlw2sM R7Ne+cBgx1qbNzTgtw/0YL/UXvWWoZ9rCiMRMJw/NClyPi246FStSKOJGjnXDc4E1j dddHKRbdgP9qUfv0z9TMDiwhwyBkeOde5OInh55dqd2NGigPUr7cyQvb2y/eRlHDO0 RAdQsQFa2q919yDxwUBFh1m5A7bj7nAcSeBmR9sNYLvW7oSb2dnwbdHv5qW9eb9Nfv GDCS+aR9vhdSJXEdTUNn5tQp5gliSo3ze80cISGnWcjJKNdPq/B9gnCy5T3DDcMz+4 xaMaVDqas3dvg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Matlack , Sean Christopherson , Paolo Bonzini , Sasha Levin , shuah@kernel.org, bgardon@google.com, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH MANUALSEL 5.17 3/3] KVM: selftests: Restrict test region to 48-bit physical addresses when using nested Date: Tue, 21 Jun 2022 17:21:39 -0400 Message-Id: <20220621212139.251808-3-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220621212139.251808-1-sashal@kernel.org> References: <20220621212139.251808-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Matlack [ Upstream commit e0f3f46e42064a51573914766897b4ab95d943e3 ] The selftests nested code only supports 4-level paging at the moment. This means it cannot map nested guest physical addresses with more than 48 bits. Allow perf_test_util nested mode to work on hosts with more than 48 physical addresses by restricting the guest test region to 48-bits. While here, opportunistically fix an off-by-one error when dealing with vm_get_max_gfn(). perf_test_util.c was treating this as the maximum number of GFNs, rather than the maximum allowed GFN. This didn't result in any correctness issues, but it did end up shifting the test region down slightly when using huge pages. Suggested-by: Sean Christopherson Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-12-dmatlack@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- .../testing/selftests/kvm/lib/perf_test_util.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c index 722df3a28791..ddd68ba0c99f 100644 --- a/tools/testing/selftests/kvm/lib/perf_test_util.c +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c @@ -110,6 +110,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, struct kvm_vm *vm; uint64_t guest_num_pages; uint64_t backing_src_pagesz = get_backing_src_pagesz(backing_src); + uint64_t region_end_gfn; int i; pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); @@ -144,18 +145,29 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, pta->vm = vm; + /* Put the test region at the top guest physical memory. */ + region_end_gfn = vm_get_max_gfn(vm) + 1; + +#ifdef __x86_64__ + /* + * When running vCPUs in L2, restrict the test region to 48 bits to + * avoid needing 5-level page tables to identity map L2. + */ + if (pta->nested) + region_end_gfn = min(region_end_gfn, (1UL << 48) / pta->guest_page_size); +#endif /* * If there should be more memory in the guest test region than there * can be pages in the guest, it will definitely cause problems. */ - TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm), + TEST_ASSERT(guest_num_pages < region_end_gfn, "Requested more guest memory than address space allows.\n" " guest pages: %" PRIx64 " max gfn: %" PRIx64 " vcpus: %d wss: %" PRIx64 "]\n", - guest_num_pages, vm_get_max_gfn(vm), vcpus, + guest_num_pages, region_end_gfn - 1, vcpus, vcpu_memory_bytes); - pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size; + pta->gpa = (region_end_gfn - guest_num_pages) * pta->guest_page_size; pta->gpa = align_down(pta->gpa, backing_src_pagesz); #ifdef __s390x__ /* Align to 1M (segment size) */ -- 2.35.1