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 79BF42E0B5C; Fri, 19 Jun 2026 00:31:50 +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=1781829110; cv=none; b=i/YoYFjoqNNdPf5NbK6bLrdUzvH3RbSHOsKlzjDtAt6zh5Fqh4wIdCmyVnJbfkyKa9OdaJJGlfdr1X32yiqEpu4fgmzpttIzeY7+kNbdW+e/Bvv1/3gl9bnOBgcDsbeS7+wHegUa7TQ1xIDk6mkBZxSmAyFq1B7Z+Rsbwo4MdRA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781829110; c=relaxed/simple; bh=JkvclheYVlQtJ9I3iH/etiaf/3XqpA61pAgrrx+kTUI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=H3tGL9pYvYXmgjG0Od29LZkGtAKbOIrnI7OX9RmqltYT19O7fMJGgsdW5fImMpHLDxvmTKqkGiZ+KlGu+QrYYJa1ubV5ZuGTGE2Ynrk8C4Cs+TC+jy1/kNxmG5tFnqH+iMQtBA+21uwUjvd8DBSMA06R5mdKaQwDQGCH9Teuz0M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=t09WmX41; 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="t09WmX41" Received: by smtp.kernel.org (Postfix) with ESMTPS id 4FE14C2BCFA; 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=1781829110; bh=JkvclheYVlQtJ9I3iH/etiaf/3XqpA61pAgrrx+kTUI=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=t09WmX41eda+CqTn15EgAmytgpz7Ua/gEJEnRS1lp61+0Np4HwgpmLPRFEcX3eO4D cEqzfK2eY4lv4eupQo46MR9jvlMH9Ao2F9cx3hvnBDnfI9+LElwm3LEx8a5to8cmtR XRHNJ8lbiIhACll0LSLHFjFLOHQF8nugB00xwiafsSb0lxQ586EisZLHMoheBDcdbQ k2r46Ks4fqtLLB85E0512uJnNa+YSEjAeWxutz0bUVF1JGeW86FSF/m0sF0200+cE1 /GkZQif6KJRsyCxNtOV5MhNrhTdwzZ9xCStQxI1fL7t872aqebUMp45QLQhVg3a3R4 5r4P5rk+mRBOw== 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 4287ECDB461; Fri, 19 Jun 2026 00:31:50 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Thu, 18 Jun 2026 17:32:10 -0700 Subject: [PATCH v8 33/46] KVM: selftests: Test conversion precision in guest_memfd 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-v8-33-9d2959357853@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=4417; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=089n8PdIwc6Nzy+S0Dr0pyuiLBsVGX1VHcRJ4aNhwe0=; b=Ol33//zzG7S4Cf0R2tiw/KbaraN9iueOKWcWAH8BqXxv523zdKwhgqX3OG9ABfUSm5N+1xj+t jGDWy5zD4fzAs3CICeIJp54yu78eCA2tGonKppYT0+iIUbLFiiI2CMF 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 The existing guest_memfd conversion tests only use single-page memory regions. This provides no coverage for multi-page guest_memfd objects, specifically whether KVM correctly handles the page index for conversion operations. An incorrect implementation could, for example, always operate on the first page regardless of the index provided. Add a new test case to verify that conversions between private and shared memory correctly target the specified page within a multi-page guest_memfd. This test also verifies the precision of memory conversions by converting a single page an then iterating through all other pages ensure they remain in their original state. To support this test, add a new GMEM_CONVERSION_MULTIPAGE_TEST_INIT_SHARED macro that handles setting up and tearing down the VM for each page iteration. The teardown logic is adjusted to prevent a double-free in this new scenario. Signed-off-by: Ackerley Tng Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson --- .../kvm/x86/guest_memfd_conversions_test.c | 66 ++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c index 5b070d3374eae..8e17d5c08aeb8 100644 --- a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c +++ b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c @@ -61,8 +61,13 @@ static void gmem_conversions_do_setup(test_data_t *t, int nr_pages, static void gmem_conversions_do_teardown(test_data_t *t) { + /* Use NULL to avoid second free in FIXTURE_TEARDOWN (multipage tests). */ + if (!t->vcpu) + return; + /* No need to close gmem_fd, it's owned by the VM structure. */ kvm_vm_free(t->vcpu->vm); + t->vcpu = NULL; } FIXTURE_TEARDOWN(gmem_conversions) @@ -101,6 +106,29 @@ static void __gmem_conversions_##test(test_data_t *t, int nr_pages) \ #define GMEM_CONVERSION_TEST_INIT_SHARED(test) \ __GMEM_CONVERSION_TEST_INIT_SHARED(test, 1) +/* + * Repeats test over nr_pages in a guest_memfd of size nr_pages, providing each + * test iteration with test_page, the index of the page under test in + * guest_memfd. test_page takes values 0..(nr_pages - 1) inclusive. + */ +#define GMEM_CONVERSION_MULTIPAGE_TEST_INIT_SHARED(test, __nr_pages) \ +static void __gmem_conversions_multipage_##test(test_data_t *t, int nr_pages, \ + const int test_page); \ + \ +TEST_F(gmem_conversions, test) \ +{ \ + const u64 flags = GUEST_MEMFD_FLAG_MMAP | GUEST_MEMFD_FLAG_INIT_SHARED; \ + int i; \ + \ + for (i = 0; i < __nr_pages; ++i) { \ + gmem_conversions_do_setup(self, __nr_pages, flags); \ + __gmem_conversions_multipage_##test(self, __nr_pages, i); \ + gmem_conversions_do_teardown(self); \ + } \ +} \ +static void __gmem_conversions_multipage_##test(test_data_t *t, int nr_pages, \ + const int test_page) + struct guest_check_data { void *mem; char expected_val; @@ -199,6 +227,44 @@ GMEM_CONVERSION_TEST_INIT_SHARED(init_shared) test_convert_to_shared(t, 0, 'C', 'D', 'E'); } +GMEM_CONVERSION_MULTIPAGE_TEST_INIT_SHARED(indexing, 4) +{ + int i; + + /* Get a char that varies with both i and n. */ +#define combine(x, n) ((x << 4) + (n)) +#define i_(n) (combine(i, n)) +#define t_(n) (combine(test_page, n)) + + /* + * Start with the highest index, to catch any errors when, perhaps, the + * first page is returned even for the last index. + */ + for (i = nr_pages - 1; i >= 0; --i) + test_shared(t, i, 0, i_(0), i_(2)); + + test_convert_to_private(t, test_page, t_(2), t_(3)); + + for (i = 0; i < nr_pages; ++i) { + if (i == test_page) + test_private(t, test_page, t_(3), t_(4)); + else + test_shared(t, i, i_(2), i_(3), i_(4)); + } + + test_convert_to_shared(t, test_page, t_(4), t_(5), t_(6)); + + for (i = 0; i < nr_pages; ++i) { + char expected = i == test_page ? t_(6) : i_(4); + + test_shared(t, i, expected, i_(7), i_(8)); + } + +#undef t_ +#undef i_ +#undef combine +} + int main(int argc, char *argv[]) { TEST_REQUIRE(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM)); -- 2.55.0.rc0.738.g0c8ab3ebcc-goog