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 9A9043368A7; Wed, 29 Jul 2026 00:35:10 +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=1785285310; cv=none; b=CAH32DPSOpdvisueTgZLLSP32M2hJ2F6EbXz6edNyh24wYIGasOUSRRsHv+vCc9yh+HvBUPDs6lMmU7ckGcRzgxhHwyefMbE/N3dujn6GquOBCBOj39GOpAv/nG2GrqwNRg8ZpGY9KYeToaM13A9rBh/udzxlY4CMt6V2KdPJiQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785285310; c=relaxed/simple; bh=1JQNdh4DTRcD0JOIKHjtjkpSS42mmFJgCVctRlKn/as=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=uPoA5mEqdOXa1xRW9qtlF6PNNHYBLI2pZQajJtHkFxkcAWZodTKkR2z6b0NlkLuippYAjErnGYGU3u8zdOgb9N5xRuRB6htCzafmfpzR0nV4YIjCH+GYwCdBPjrz29Gf01CT1Jbu3eULbrQzlUXwDbKmQYurmeosecLsJ3ey6xQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g87sYffm; 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="g87sYffm" Received: by smtp.kernel.org (Postfix) with ESMTPS id 37488C4AF63; Wed, 29 Jul 2026 00:35:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1785285310; bh=1JQNdh4DTRcD0JOIKHjtjkpSS42mmFJgCVctRlKn/as=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=g87sYffm6OXh1KgFt4W0xGJ39S7iuVXQvNPAuoioMapAR76KGjjkxDqfIdG7pymDA y3uejZCHw7c8644nRK0EaeNDrEsHShrKgd218eIck5k8s7TuCoXjA+dYZ6nEmt86T7 ycJA5RmX+sU8hhPYd26y/boyFbc7b30yStyolWW0QSTbN3gD/z4O+6FY1CPQJq5+2G Tz5UGum6WIBx2Cigwt/V+R+F6aws8oVSr/Zaun4bjsUphc+QAUtk3Rqeck5BDrBfOb yvWYOysSXUXvw/5DwByHFatRO5/3n92yTl74ZJBVsKqf4nxceeH5R1+JaY8LSmNzQY EB2bn9KiZ9Iwg== 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 18860C54F52; Wed, 29 Jul 2026 00:35:10 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Tue, 28 Jul 2026 17:35:28 -0700 Subject: [PATCH v9 29/41] KVM: selftests: Test conversion precision in guest_memfd Precedence: bulk X-Mailing-List: linux-trace-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: <20260728-gmem-inplace-conversion-v9-29-35f9aec2aed2@google.com> References: <20260728-gmem-inplace-conversion-v9-0-35f9aec2aed2@google.com> In-Reply-To: <20260728-gmem-inplace-conversion-v9-0-35f9aec2aed2@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 , John Hubbard , Peter Xu , 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=1785285305; l=4501; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=knW3oEUmnPUSo1gpuqMigsR+t1Q/MFkz7O8GozByUvU=; b=fUXw40FC3/ChFHnmqc3VbvieVKq/kEnvWrEo0D03rJCacRFc8ThJ7uLfQzZnHhE22ixPpJhQc O27XDvaqfvxBLbgtpjqXv7wxaeb8V+TWRBvfzxuPcZKtdRwums97nOV 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. Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Reviewed-by: Fuad Tabba Tested-by: Shivank Garg Signed-off-by: Ackerley Tng --- .../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)); -- 2.55.0.508.g3f0d502094-goog