From patchwork Tue Jun 26 03:41:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Huang X-Patchwork-Id: 10487903 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8D2B9603B5 for ; Tue, 26 Jun 2018 03:42:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0797C285D8 for ; Tue, 26 Jun 2018 03:42:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EFB782869A; Tue, 26 Jun 2018 03:42:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6B488285D8 for ; Tue, 26 Jun 2018 03:42:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965341AbeFZDmA (ORCPT ); Mon, 25 Jun 2018 23:42:00 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40672 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965340AbeFZDl7 (ORCPT ); Mon, 25 Jun 2018 23:41:59 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D2CF2400224C; Tue, 26 Jun 2018 03:41:58 +0000 (UTC) Received: from virtlab404.virt.lab.eng.bos.redhat.com (virtlab404.virt.lab.eng.bos.redhat.com [10.19.152.5]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3AC5A111AF11; Tue, 26 Jun 2018 03:41:58 +0000 (UTC) From: Wei Huang To: linux-kernel@vger.kernel.org Cc: linux-kselftest@vger.kernel.org, pbonzini@redhat.com, shuah@kernel.org, hofsass@google.com, peng.hao2@zte.com.cn Subject: [PATCH 1/1] kvm: selftests: add cr4_cpuid_sync_test Date: Mon, 25 Jun 2018 23:41:57 -0400 Message-Id: <1529984517-7843-1-git-send-email-wei@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Tue, 26 Jun 2018 03:41:58 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Tue, 26 Jun 2018 03:41:58 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'wei@redhat.com' RCPT:'' Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP KVM is supposed to update some guest VM's CPUID bits (e.g. OSXSAVE) when CR4 is changed. A bug was found in KVM recently and it was fixed by Commit c4d2188206ba ("KVM: x86: Update cpuid properly when CR4.OSXAVE or CR4.PKE is changed"). This patch adds a test to verify the synchronization between guest VM's CR4 and CPUID bits. Signed-off-by: Wei Huang --- tools/testing/selftests/kvm/Makefile | 1 + tools/testing/selftests/kvm/cr4_cpuid_sync_test.c | 129 ++++++++++++++++++++++ 2 files changed, 130 insertions(+) create mode 100644 tools/testing/selftests/kvm/cr4_cpuid_sync_test.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index d9d0031..65bda4f 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -9,6 +9,7 @@ LIBKVM_x86_64 = lib/x86.c lib/vmx.c TEST_GEN_PROGS_x86_64 = set_sregs_test TEST_GEN_PROGS_x86_64 += sync_regs_test TEST_GEN_PROGS_x86_64 += vmx_tsc_adjust_test +TEST_GEN_PROGS_x86_64 += cr4_cpuid_sync_test TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M)) LIBKVM += $(LIBKVM_$(UNAME_M)) diff --git a/tools/testing/selftests/kvm/cr4_cpuid_sync_test.c b/tools/testing/selftests/kvm/cr4_cpuid_sync_test.c new file mode 100644 index 0000000..dbbaf3c --- /dev/null +++ b/tools/testing/selftests/kvm/cr4_cpuid_sync_test.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CR4 and CPUID sync test + * + * Copyright 2018, Red Hat, Inc. and/or its affiliates. + * + * Author: + * Wei Huang + */ + +#include +#include +#include +#include +#include + +#include "test_util.h" + +#include "kvm_util.h" +#include "x86.h" + +#define X86_FEATURE_XSAVE (1<<26) +#define X86_FEATURE_OSXSAVE (1<<27) +#define VCPU_ID 1 + +enum { + GUEST_UPDATE_CR4 = 0x1000, + GUEST_FAILED, + GUEST_DONE, +}; + +static void exit_to_hv(uint16_t port) +{ + __asm__ __volatile__("in %[port], %%al" + : + : [port]"d"(port) + : "rax"); +} + +static inline bool cr4_cpuid_is_sync(void) +{ + int func, subfunc; + uint32_t eax, ebx, ecx, edx; + uint64_t cr4; + + func = 0x1; + subfunc = 0x0; + __asm__ __volatile__("cpuid" + : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) + : "a"(func), "c"(subfunc)); + + cr4 = get_cr4(); + + return (!!(ecx & X86_FEATURE_OSXSAVE)) == (!!(cr4 & X86_CR4_OSXSAVE)); +} + +static void guest_code(void) +{ + uint64_t cr4; + + /* turn on CR4.OSXSAVE */ + cr4 = get_cr4(); + cr4 |= X86_CR4_OSXSAVE; + set_cr4(cr4); + + /* verify CR4.OSXSAVE == CPUID.OSXSAVE */ + if (!cr4_cpuid_is_sync()) + exit_to_hv(GUEST_FAILED); + + /* notify hypervisor to change CR4 */ + exit_to_hv(GUEST_UPDATE_CR4); + + /* check again */ + if (!cr4_cpuid_is_sync()) + exit_to_hv(GUEST_FAILED); + + exit_to_hv(GUEST_DONE); +} + +int main(int argc, char *argv[]) +{ + struct kvm_run *run; + struct kvm_vm *vm; + struct kvm_sregs sregs; + struct kvm_cpuid_entry2 *entry; + int rc; + + entry = kvm_get_supported_cpuid_entry(1); + if (!(entry->ecx & X86_FEATURE_XSAVE)) { + printf("XSAVE feature not supported, skipping test\n"); + return 0; + } + + /* Tell stdout not to buffer its content */ + setbuf(stdout, NULL); + + /* Create VM */ + vm = vm_create_default_vmx(VCPU_ID, guest_code); + vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); + run = vcpu_state(vm, VCPU_ID); + + while (1) { + rc = _vcpu_run(vm, VCPU_ID); + + if (run->exit_reason == KVM_EXIT_IO) { + switch (run->io.port) { + case GUEST_UPDATE_CR4: + /* emulate hypervisor clearing CR4.OSXSAVE */ + vcpu_sregs_get(vm, VCPU_ID, &sregs); + sregs.cr4 &= ~X86_CR4_OSXSAVE; + vcpu_sregs_set(vm, VCPU_ID, &sregs); + break; + case GUEST_FAILED: + TEST_ASSERT(false, "Guest CR4 bit (OSXSAVE) unsynchronized with CPUID bit."); + break; + case GUEST_DONE: + goto done; + default: + TEST_ASSERT(false, "Unknown port 0x%x.", + run->io.port); + } + } + } + + kvm_vm_free(vm); + +done: + return 0; +}