From patchwork Tue Sep 10 23:44:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ackerley Tng X-Patchwork-Id: 13799549 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DCDBD1C3302 for ; Tue, 10 Sep 2024 23:45:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726011937; cv=none; b=sgMyso1G326KgJ2EBDXlW3uDiO7qxqFh9EXleMQ8ylWyACvgAVMJ6/P+Zgo7E6IXAT/d3KZF3yeiun1VBLWdTiFg/prKAl7PvGtMWnjEagemPt1wyze2K7YOZG/E3l7TwNtyRHiyHV1deO+heqmLSr4gizBYrcHjSerr5Jb6L6U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726011937; c=relaxed/simple; bh=xDhJT0jtukUSht8M1rW68Et+r1brKb18kxNSu0XqBak=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Wj50XXPuG77m6A4x0R6TH2PNtElCZFXJYpjeRLc0D5qejXGoYPDe2RlvdGJmioS7YOoVvCGidlciuIJYbL9Dl+3ukoE5TymyA9EKKNtzqFrDH6/eDCV4Dtb1lQIX/ykPR5Yzght5kwbNcgXdeGndbyOKy9bD1wYS3bCHNT0DGvs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ackerleytng.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ryFoj5lE; arc=none smtp.client-ip=209.85.214.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ackerleytng.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ryFoj5lE" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2070e327014so13337335ad.1 for ; Tue, 10 Sep 2024 16:45:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1726011934; x=1726616734; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=PU0eLeT/Khb6QlOSfPgwKdSujIEPbf2Mi98Qjlq+ljA=; b=ryFoj5lEkrpo5/Oin/SfkYzGXzKADf/1aAH+vux+vxk9jWoiuWcQCyLE4oT1FIB7Tu LzR5Q6RPxnEiEha2NzW4AxVN5YlXiB9Q8UE36XAOSURV1kHiXngHx5KVsdmgPnKR60yI j4/g6Qm/BvA160B9TYg1HPdT6gI6+K4My0v3IheLzqbN1lmXS1Zm6BVbc5gUe6KJo7Nx FgGBfCQCpA3GusBRgEDavhyo9PsMQuPE3LTkWskm4KJKtEH4UIDfGiacNWQEvnIoJrsl uIBhWJ4vh72sRLkAbtKyxx78s9UQWq5ynUf5UwLwlcu8sMrpeif44qKb9trZWSU+d088 rFKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726011934; x=1726616734; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=PU0eLeT/Khb6QlOSfPgwKdSujIEPbf2Mi98Qjlq+ljA=; b=kh43n9Y21TrfmAfuiSrlaxcp5ZRpSN9ptFwTrI5wSRqW9oWRk1daj3oeu5ZYGVw+Ml XS0qLgV7XmksHHZPEivTJ0pFB9UdlW8S3+OgrLs02NlHWEfvQIZykKXx702mG3KJ4/5P 3VwSf9uEHuE6d7mjvFsm4zZYh3XbZFEWtGjQ2FXnihp3KuY0OeWM5Y6Y/MUx5euDORGk egQ1Jk28XBbqyfpl5AntNXLvyCykgh/XR3kUFcHyEv7B9fuAKCxwK5Wg8VS9whT52wWx Y2yQNx1nMSP0Dr+vC7N6cp3chEIF/nzFY3p/4m9dScLcWollfXwd/er2SYL/0rn3bW8p +3tg== X-Forwarded-Encrypted: i=1; AJvYcCVFZOxzH3fqsbzbVF5YeCZ8boim2IWLpfD7jtx59MxkXGnYjzEvU9AWHpeP5/nnUJTlSIY=@vger.kernel.org X-Gm-Message-State: AOJu0Yy7tOLQsUCSBiq67cza4zmm7zUstm/HMS2BvYVXena5m5D9U8+E /LT4ahRFQq0IPf040wFXR7S/U99fPE/7/BQrX8AKmJIarZz5DGjo6uGlJpTjv2ax1HShWgm49QG 2whV3pcWBtwKll4EMXnXUag== X-Google-Smtp-Source: AGHT+IFVTG93FUeTatq9dmJkXI56Xlmri3CwyYIl4IemmSnQkPMQ4ndLEBPGw8YCyak9fs0iNwaTmELdbdpO3NZKxw== X-Received: from ackerleytng-ctop.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:13f8]) (user=ackerleytng job=sendgmr) by 2002:a17:902:f687:b0:206:c776:4f11 with SMTP id d9443c01a7336-207522167damr522595ad.8.1726011933308; Tue, 10 Sep 2024 16:45:33 -0700 (PDT) Date: Tue, 10 Sep 2024 23:44:06 +0000 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.46.0.598.g6f2099f65c-goog Message-ID: <09892ae14d06596aee8b766b5908c8a7fdda85b4.1726009989.git.ackerleytng@google.com> Subject: [RFC PATCH 35/39] KVM: selftests: Test that pinned pages block KVM from setting memory attributes to PRIVATE From: Ackerley Tng To: tabba@google.com, quic_eberman@quicinc.com, roypat@amazon.co.uk, jgg@nvidia.com, peterx@redhat.com, david@redhat.com, rientjes@google.com, fvdl@google.com, jthoughton@google.com, seanjc@google.com, pbonzini@redhat.com, zhiquan1.li@intel.com, fan.du@intel.com, jun.miao@intel.com, isaku.yamahata@intel.com, muchun.song@linux.dev, mike.kravetz@oracle.com Cc: erdemaktas@google.com, vannapurve@google.com, ackerleytng@google.com, qperret@google.com, jhubbard@nvidia.com, willy@infradead.org, shuah@kernel.org, brauner@kernel.org, bfoster@redhat.com, kent.overstreet@linux.dev, pvorel@suse.cz, rppt@kernel.org, richard.weiyang@gmail.com, anup@brainfault.org, haibo1.xu@intel.com, ajones@ventanamicro.com, vkuznets@redhat.com, maciej.wieczor-retman@intel.com, pgonda@google.com, oliver.upton@linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-fsdevel@kvack.org CONFIG_GUP_TEST provides userspace with an ioctl to invoke pin_user_pages(), and this test uses the ioctl to pin pages, to check that memory attributes cannot be set to private if shared pages are pinned. Signed-off-by: Ackerley Tng --- tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/guest_memfd_pin_test.c | 104 ++++++++++++++++++ 2 files changed, 105 insertions(+) create mode 100644 tools/testing/selftests/kvm/guest_memfd_pin_test.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 3c1f35456bfc..c5a1c8c7125a 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -136,6 +136,7 @@ TEST_GEN_PROGS_x86_64 += dirty_log_perf_test TEST_GEN_PROGS_x86_64 += guest_memfd_test TEST_GEN_PROGS_x86_64 += guest_memfd_hugetlb_reporting_test TEST_GEN_PROGS_x86_64 += guest_memfd_sharing_test +TEST_GEN_PROGS_x86_64 += guest_memfd_pin_test TEST_GEN_PROGS_x86_64 += guest_print_test TEST_GEN_PROGS_x86_64 += hardware_disable_test TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus diff --git a/tools/testing/selftests/kvm/guest_memfd_pin_test.c b/tools/testing/selftests/kvm/guest_memfd_pin_test.c new file mode 100644 index 000000000000..b45fb8024970 --- /dev/null +++ b/tools/testing/selftests/kvm/guest_memfd_pin_test.c @@ -0,0 +1,104 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Test that pinned pages block KVM from setting memory attributes to PRIVATE. + * + * Copyright (c) 2024, Google LLC. + */ +#include +#include +#include + +#include "test_util.h" +#include "kvm_util.h" +#include "../../../../mm/gup_test.h" + +#define GUEST_MEMFD_PIN_TEST_SLOT 10 +#define GUEST_MEMFD_PIN_TEST_GPA 0x50000000ULL +#define GUEST_MEMFD_PIN_TEST_OFFSET 0 + +static int gup_test_fd; + +void pin_pages(void *vaddr, uint64_t size) +{ + const struct pin_longterm_test args = { + .addr = (uint64_t)vaddr, + .size = size, + .flags = PIN_LONGTERM_TEST_FLAG_USE_WRITE, + }; + + TEST_ASSERT_EQ(ioctl(gup_test_fd, PIN_LONGTERM_TEST_START, &args), 0); +} + +void unpin_pages(void) +{ + TEST_ASSERT_EQ(ioctl(gup_test_fd, PIN_LONGTERM_TEST_STOP), 0); +} + +void run_test(void) +{ + struct kvm_vm *vm; + size_t page_size; + void *mem; + int fd; + + vm = vm_create_barebones_type(KVM_X86_SW_PROTECTED_VM); + + page_size = getpagesize(); + fd = vm_create_guest_memfd(vm, page_size, 0); + + mem = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, + GUEST_MEMFD_PIN_TEST_OFFSET); + TEST_ASSERT(mem != MAP_FAILED, "mmap should return valid address"); + + /* + * Setting up this memslot with a KVM_X86_SW_PROTECTED_VM marks all + * offsets in the file as shared. + */ + vm_set_user_memory_region2(vm, GUEST_MEMFD_PIN_TEST_SLOT, + KVM_MEM_GUEST_MEMFD, + GUEST_MEMFD_PIN_TEST_GPA, page_size, mem, fd, + GUEST_MEMFD_PIN_TEST_OFFSET); + + /* Before pinning pages, toggling memory attributes should be fine. */ + vm_mem_set_private(vm, GUEST_MEMFD_PIN_TEST_GPA, page_size); + vm_mem_set_shared(vm, GUEST_MEMFD_PIN_TEST_GPA, page_size); + + pin_pages(mem, page_size); + + /* + * Pinning also faults pages in, so remove these pages from userspace + * page tables to properly test that pinning blocks setting memory + * attributes to private. + */ + TEST_ASSERT_EQ(madvise(mem, page_size, MADV_DONTNEED), 0); + + /* Should fail since the page is still faulted in. */ + TEST_ASSERT_EQ(__vm_set_memory_attributes(vm, GUEST_MEMFD_PIN_TEST_GPA, + page_size, + KVM_MEMORY_ATTRIBUTE_PRIVATE), + -1); + TEST_ASSERT_EQ(errno, EINVAL); + + unpin_pages(); + + /* With the pages unpinned, kvm can set this page to private. */ + vm_mem_set_private(vm, GUEST_MEMFD_PIN_TEST_GPA, page_size); + + kvm_vm_free(vm); + close(fd); +} + +int main(int argc, char *argv[]) +{ + gup_test_fd = open("/sys/kernel/debug/gup_test", O_RDWR); + /* + * This test depends on CONFIG_GUP_TEST to provide a kernel module that + * exposes pin_user_pages() to userspace. + */ + TEST_REQUIRE(gup_test_fd != -1); + TEST_REQUIRE(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM)); + + run_test(); + + return 0; +}