From patchwork Fri Apr 14 06:25:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Gao X-Patchwork-Id: 13211044 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 C49DAC77B70 for ; Fri, 14 Apr 2023 06:30:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230030AbjDNGaA (ORCPT ); Fri, 14 Apr 2023 02:30:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229689AbjDNG37 (ORCPT ); Fri, 14 Apr 2023 02:29:59 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7DB77685; Thu, 13 Apr 2023 23:29:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1681453777; x=1712989777; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=rKAAs3mBhH6XPw5i/mAYs8vA60XsTk1j5n1Dr6j7stk=; b=P5e+NrS+NsEy0W3+22FV4mkN9p+8DiMHzRrUz1pST0cbE76KYXhvLa7a r7h80ChWniX2Y2E0jJKTRkbmlRs/1lXoRPqjCbzVrXdQjYBmTEqcIrxX7 GSVabxgx4x39VwjG9YJZO9NyLC2bxscfAE/PQe47gUgLAJvkR1bDLbNa+ kdVoqlTS+2gZQvYxTPsQBjrw7GohZqoF68kTwOMGci6iUyqqFsZwfL9gR fHkhhuhDCNrojzuPEXMAkp0bKpX1NUfI1V3Iwa5wTQ05ZuA2nTsPZnVCx 8vF080rrLg2LvyeX1IRPQRToixIg0xzCVnZeYFMIaHgD8ue1UBKleAShR g==; X-IronPort-AV: E=McAfee;i="6600,9927,10679"; a="341892916" X-IronPort-AV: E=Sophos;i="5.99,195,1677571200"; d="scan'208";a="341892916" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2023 23:26:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10679"; a="935885985" X-IronPort-AV: E=Sophos;i="5.99,195,1677571200"; d="scan'208";a="935885985" Received: from spr.sh.intel.com ([10.239.53.106]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2023 23:26:49 -0700 From: Chao Gao To: kvm@vger.kernel.org Cc: Jiaan Lu , Chao Gao , Paolo Bonzini , Shuah Khan , Arnaldo Carvalho de Melo , Borislav Petkov , Pawan Gupta , Zhang Chen , Daniel Sneddon , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [RFC PATCH v2 10/11] KVM: selftests: Add tests for virtual enumeration/mitigation MSRs Date: Fri, 14 Apr 2023 14:25:31 +0800 Message-Id: <20230414062545.270178-11-chao.gao@intel.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230414062545.270178-1-chao.gao@intel.com> References: <20230414062545.270178-1-chao.gao@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Three virtual MSRs added for guest to report the usage of software mitigations. They are enumerated in an architectural way. Try to access the three MSRs to ensure the behavior is expected: Specifically, 1. below three cases should cause #GP: * access to a non-present MSR * write to read-only MSRs * toggling reserved bit of a writeable MSR 2. rdmsr/wrmsr in other cases should succeed 3. rdmsr should return the value last written Signed-off-by: Chao Gao --- tools/arch/x86/include/asm/msr-index.h | 23 +++ tools/testing/selftests/kvm/Makefile | 1 + .../kvm/x86_64/virtual_mitigation_msr_test.c | 175 ++++++++++++++++++ 3 files changed, 199 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/virtual_mitigation_msr_test.c diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h index 6079a5fdb40b..55f75e9ebbb7 100644 --- a/tools/arch/x86/include/asm/msr-index.h +++ b/tools/arch/x86/include/asm/msr-index.h @@ -166,6 +166,7 @@ * IA32_XAPIC_DISABLE_STATUS MSR * supported */ +#define ARCH_CAP_VIRTUAL_ENUM BIT_ULL(63) /* MSR_VIRTUAL_ENUMERATION supported */ #define MSR_IA32_FLUSH_CMD 0x0000010b #define L1D_FLUSH BIT(0) /* @@ -1103,6 +1104,28 @@ #define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14) #define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29) #define MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE 0x1F + +/* Intel virtual MSRs */ +#define MSR_VIRTUAL_ENUMERATION 0x50000000 +#define VIRT_ENUM_MITIGATION_CTRL_SUPPORT BIT(0) /* + * Mitigation ctrl via virtual + * MSRs supported + */ + +#define MSR_VIRTUAL_MITIGATION_ENUM 0x50000001 +#define MITI_ENUM_BHB_CLEAR_SEQ_S_SUPPORT BIT(0) /* VMM supports BHI_DIS_S */ +#define MITI_ENUM_RETPOLINE_S_SUPPORT BIT(1) /* VMM supports RRSBA_DIS_S */ + +#define MSR_VIRTUAL_MITIGATION_CTRL 0x50000002 +#define MITI_CTRL_BHB_CLEAR_SEQ_S_USED BIT(0) /* + * Request VMM to deploy + * BHI_DIS_S mitigation + */ +#define MITI_CTRL_RETPOLINE_S_USED BIT(1) /* + * Request VMM to deploy + * RRSBA_DIS_S mitigation + */ + /* AMD-V MSRs */ #define MSR_VM_CR 0xc0010114 diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 84a627c43795..9db9a7e49a54 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -115,6 +115,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/sev_migrate_tests TEST_GEN_PROGS_x86_64 += x86_64/amx_test TEST_GEN_PROGS_x86_64 += x86_64/max_vcpuid_cap_test TEST_GEN_PROGS_x86_64 += x86_64/triple_fault_event_test +TEST_GEN_PROGS_x86_64 += x86_64/virtual_mitigation_msr_test TEST_GEN_PROGS_x86_64 += access_tracking_perf_test TEST_GEN_PROGS_x86_64 += demand_paging_test TEST_GEN_PROGS_x86_64 += dirty_log_test diff --git a/tools/testing/selftests/kvm/x86_64/virtual_mitigation_msr_test.c b/tools/testing/selftests/kvm/x86_64/virtual_mitigation_msr_test.c new file mode 100644 index 000000000000..4d924a0cf2dd --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/virtual_mitigation_msr_test.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2023, Intel, Inc. + * + * tests for virtual mitigation MSR accesses + */ + +#include +#include +#include +#include +#include + +#include "test_util.h" + +#include "kvm_util.h" +#include "processor.h" + +static int guest_exception_count; +static int expected_exception_count; +static void guest_gp_handler(struct ex_regs *regs) +{ + /* RDMSR/WRMSR are 2 bytes */ + regs->rip += 2; + ++guest_exception_count; +} + +static void write_msr_expect_gp(uint32_t msr, uint64_t val) +{ + uint64_t old_val; + + old_val = rdmsr(msr); + wrmsr(msr, val); + expected_exception_count++; + GUEST_ASSERT_2(guest_exception_count == expected_exception_count, + guest_exception_count, expected_exception_count); + GUEST_ASSERT_2(rdmsr(msr) == old_val, rdmsr(msr), old_val); +} + +static void write_msr_expect_no_gp(uint32_t msr, uint64_t val) +{ + wrmsr(msr, val); + GUEST_ASSERT_EQ(guest_exception_count, expected_exception_count); + GUEST_ASSERT_EQ(rdmsr(msr), val); +} + +static void read_msr_expect_gp(uint32_t msr) +{ + (void)rdmsr(msr); + expected_exception_count++; + GUEST_ASSERT_2(guest_exception_count == expected_exception_count, + guest_exception_count, expected_exception_count); +} + +static void guest_code_with_virtual_mitigation_ctrl(void) +{ + uint64_t val, miti_ctrl = 0; + int i; + + val = rdmsr(MSR_VIRTUAL_ENUMERATION); + /* MSR_VIRTUAL_ENUMERATION is read-only. #GP is expected on write */ + write_msr_expect_gp(MSR_VIRTUAL_ENUMERATION, val); + + val = rdmsr(MSR_VIRTUAL_MITIGATION_ENUM); + /* MSR_VIRTUAL_MITIGATION_ENUM is read-only. #GP is expected on write */ + write_msr_expect_gp(MSR_VIRTUAL_MITIGATION_ENUM, val); + + for (i = 0; i < 64; i++) { + if (val & BIT_ULL(i)) { + miti_ctrl |= BIT_ULL(i); + write_msr_expect_no_gp(MSR_VIRTUAL_MITIGATION_CTRL, miti_ctrl); + } else { + write_msr_expect_gp(MSR_VIRTUAL_MITIGATION_CTRL, miti_ctrl | BIT_ULL(i)); + } + } + + write_msr_expect_no_gp(MSR_VIRTUAL_MITIGATION_CTRL, 0); + GUEST_DONE(); +} + +static void guest_code_no_virtual_enumeration(void) +{ + read_msr_expect_gp(MSR_VIRTUAL_ENUMERATION); + read_msr_expect_gp(MSR_VIRTUAL_MITIGATION_ENUM); + read_msr_expect_gp(MSR_VIRTUAL_MITIGATION_CTRL); + GUEST_DONE(); +} + +bool kvm_cpu_has_virtual_mitigation_ctrl(void) +{ + const struct kvm_msr_list *feature_list; + u64 virt_enum = 0; + int i; + + feature_list = kvm_get_feature_msr_index_list(); + for (i = 0; i < feature_list->nmsrs; i++) { + if (feature_list->indices[i] == MSR_VIRTUAL_ENUMERATION) + virt_enum = kvm_get_feature_msr(MSR_VIRTUAL_ENUMERATION); + } + + return virt_enum & VIRT_ENUM_MITIGATION_CTRL_SUPPORT; +} + +static void enable_virtual_mitigation_ctrl(struct kvm_vcpu *vcpu) +{ + vcpu_set_msr(vcpu, MSR_IA32_ARCH_CAPABILITIES, ARCH_CAP_VIRTUAL_ENUM); + vcpu_set_msr(vcpu, MSR_VIRTUAL_ENUMERATION, VIRT_ENUM_MITIGATION_CTRL_SUPPORT); + vcpu_set_msr(vcpu, MSR_VIRTUAL_MITIGATION_ENUM, + kvm_get_feature_msr(MSR_VIRTUAL_MITIGATION_ENUM)); +} + +static void disable_virtual_enumeration(struct kvm_vcpu *vcpu) +{ + vcpu_set_msr(vcpu, MSR_IA32_ARCH_CAPABILITIES, 0); +} + +static void test_virtual_mitiation_ctrl(bool enable) +{ + struct kvm_vcpu *vcpu; + struct kvm_run *run; + struct kvm_vm *vm; + struct ucall uc; + void *guest_code; + + guest_code = enable ? guest_code_with_virtual_mitigation_ctrl : + guest_code_no_virtual_enumeration; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + run = vcpu->run; + + if (enable) + enable_virtual_mitigation_ctrl(vcpu); + else + disable_virtual_enumeration(vcpu); + + + /* Register #GP handler */ + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); + vm_install_exception_handler(vm, GP_VECTOR, guest_gp_handler); + + while (1) { + vcpu_run(vcpu); + + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, + "Unexpected exit reason: %u (%s),\n", + run->exit_reason, + exit_reason_str(run->exit_reason)); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT_2(uc, "real %ld expected %ld"); + break; + case UCALL_DONE: + goto done; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + } + } + +done: + kvm_vm_free(vm); +} + +int main(int argc, char *argv[]) +{ + TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)); + TEST_REQUIRE(kvm_has_cap(KVM_CAP_GET_MSR_FEATURES)); + TEST_REQUIRE(kvm_cpu_has_virtual_mitigation_ctrl()); + + test_virtual_mitiation_ctrl(true); + test_virtual_mitiation_ctrl(false); + + return 0; +}