From patchwork Sat Sep 14 00:49:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Orr X-Patchwork-Id: 11145527 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EC1B613BD for ; Sat, 14 Sep 2019 00:49:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B986E2089F for ; Sat, 14 Sep 2019 00:49:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lD694Pfq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390867AbfINAt3 (ORCPT ); Fri, 13 Sep 2019 20:49:29 -0400 Received: from mail-pl1-f201.google.com ([209.85.214.201]:47994 "EHLO mail-pl1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388932AbfINAt3 (ORCPT ); Fri, 13 Sep 2019 20:49:29 -0400 Received: by mail-pl1-f201.google.com with SMTP id m8so11934984plt.14 for ; Fri, 13 Sep 2019 17:49:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=oJhIsB4KlXnuRIGDe2avywLhhe8p8rV5iQ5s3ifo640=; b=lD694PfqTOQEfoAneKzH8zu9d68FENGeZ8+sdZx8gSxgejqdIYxHNNuk36TBKXHQUk 3s1j/gYDNQqqhsESbkaIoftWlGl0sX009Kb0f4eUlOg1Olu9n9XOgFkQgqquNDSaf7lN aW2yhvedmc9PLflAse8AzsIsvYu7VQEFarwAQMHCEVvJ8+2Lthp3dGAoxW4IXf8y3OJj wLxAXzlR2glxG20Tl5aod+W1eQtCFfWlfRwPf6EtAGXxVilxtJNLlD3mfLnr2PT69Kb+ 4hRQVH88yMMP1SYq/hMuzj55tw5ATvcoH+N+CXRof9KJTFhq3+lZTZfTDP1IhqaWPMxZ h8SQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=oJhIsB4KlXnuRIGDe2avywLhhe8p8rV5iQ5s3ifo640=; b=bhQSwzeckouXdzL8D1pZgHojboVGq00rvehZ82xt1ywZNb2AmBVb12j4kXc/lWeqV8 N2QltEqXsvqX7aE6yUlO/+xJgs0qQCyAYxBGznPrpFyzb8x+kv23MsbdYMfnvHnTjiKV SPB1ywsZqCIwCei6WCRO4TZGv5kFtGbKAdMJ4fjHJcU6LvHoXFuY0axQika/UIgdbgRu QvvmGMhclS86g8+bq1FZPadnWKa++UD0Rd3UDdRnp+TQYGEuVVaL6x3P15eI+ntPHAjA auLgPGGD5+ZmMxLXH/iK/d8F5t9yF2zi0PSrHriV9z02UltDxmnMOXNZ9isSVEIipWRk eD4A== X-Gm-Message-State: APjAAAVy4vRLfYQ5kee9lm1byRHicN2vegHKgysR3zjUFJ/w9tA3kXxz R8PZGsH1kqsXfUJHu5wyQWLfZ8jH1J/B73H2kC8ZEp/FOIsSkIC1SpgJAKzSqZ7k0M3KNUaPJkv 8JV9lEtw3dHS46ByCGd+8gwTY3mwLgC+SgQH4FhFqhbMAoMLo9dApiKYh/uPJ X-Google-Smtp-Source: APXvYqxLjoHn+3yeyUjOSE4ozPPJUJg3KcTk8BdcvxUI7LLAuBdTC/1VMAljjsz/uZL9f8aIVcAjky9fCy3w X-Received: by 2002:a63:3585:: with SMTP id c127mr9924375pga.93.1568422166463; Fri, 13 Sep 2019 17:49:26 -0700 (PDT) Date: Fri, 13 Sep 2019 17:49:19 -0700 Message-Id: <20190914004919.256530-1-marcorr@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.23.0.237.gc6a4ce50a0-goog Subject: [kvm-unit-tests PATCH v2] x86: nvmx: test max atomic switch MSRs From: Marc Orr To: kvm@vger.kernel.org, jmattson@google.com, pshier@google.com, sean.j.christopherson@intel.com Cc: Marc Orr Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Excerise nested VMX's atomic MSR switch code (e.g., VM-entry MSR-load list) at the maximum number of MSRs supported, as described in the SDM, in the appendix chapter titled "MISCELLANEOUS DATA". Suggested-by: Jim Mattson Signed-off-by: Marc Orr --- v1 -> v2 * Replaced 2M page allocations with 128 kB allocations. * Broadly, updated test to follow Sean's draft: * Got rid of loop + individual test cases. Instead combined all test cases. * Got rid of configure_atomic_switch_msr_limit_test(). * Updated cleanup code to free memory. I added a new helper, free_pages_by_order() to help here. * Changed virt_to_phys() to explicit u64 cast. * Renamed original test case from atomic_switch_msr_limit_test() to atomic_switch_max_msrs_test(). Added opt-in atomic_switch_overflow_msrs_test() test case to test failure code path during VM-entry. * Fixed a bug in transitioning VMX launched state when the first VM-entry fails. lib/alloc_page.c | 5 ++ lib/alloc_page.h | 1 + x86/unittests.cfg | 2 +- x86/vmx.c | 2 +- x86/vmx_tests.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 139 insertions(+), 2 deletions(-) diff --git a/lib/alloc_page.c b/lib/alloc_page.c index 97d13395ff08..ed236389537e 100644 --- a/lib/alloc_page.c +++ b/lib/alloc_page.c @@ -53,6 +53,11 @@ void free_pages(void *mem, unsigned long size) spin_unlock(&lock); } +void free_pages_by_order(void *mem, unsigned long order) +{ + free_pages(mem, 1ul << (order + PAGE_SHIFT)); +} + void *alloc_page() { void *p; diff --git a/lib/alloc_page.h b/lib/alloc_page.h index 5cdfec57a0a8..739a91def979 100644 --- a/lib/alloc_page.h +++ b/lib/alloc_page.h @@ -14,5 +14,6 @@ void *alloc_page(void); void *alloc_pages(unsigned long order); void free_page(void *page); void free_pages(void *mem, unsigned long size); +void free_pages_by_order(void *mem, unsigned long order); #endif diff --git a/x86/unittests.cfg b/x86/unittests.cfg index 694ee3d42f3a..05122cf91ea1 100644 --- a/x86/unittests.cfg +++ b/x86/unittests.cfg @@ -227,7 +227,7 @@ extra_params = -cpu qemu64,+umip [vmx] file = vmx.flat -extra_params = -cpu host,+vmx -append "-exit_monitor_from_l2_test -ept_access* -vmx_smp* -vmx_vmcs_shadow_test" +extra_params = -cpu host,+vmx -append "-exit_monitor_from_l2_test -ept_access* -vmx_smp* -vmx_vmcs_shadow_test -atomic_switch_overflow_msrs_test" arch = x86_64 groups = vmx diff --git a/x86/vmx.c b/x86/vmx.c index 6079420db33a..7313c78f15c2 100644 --- a/x86/vmx.c +++ b/x86/vmx.c @@ -1820,7 +1820,7 @@ static void __enter_guest(u8 abort_flag, struct vmentry_failure *failure) abort(); } - if (!failure->early) { + if (!failure->early && !(vmcs_read(EXI_REASON) & VMX_ENTRY_FAILURE)) { launched = 1; check_for_guest_termination(); } diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c index f035f24a771a..fb665f38b1e5 100644 --- a/x86/vmx_tests.c +++ b/x86/vmx_tests.c @@ -8570,6 +8570,134 @@ static int invalid_msr_entry_failure(struct vmentry_failure *failure) return VMX_TEST_VMEXIT; } +/* + * The max number of MSRs in an atomic switch MSR list is: + * (111B + 1) * 512 = 4096 + * + * Each list entry consumes: + * 4-byte MSR index + 4 bytes reserved + 8-byte data = 16 bytes + * + * Allocate 128 kB to cover max_msr_list_size (i.e., 64 kB) and then some. + */ +static const u32 msr_list_page_order = 5; + +static void atomic_switch_msr_limit_test_guest(void) +{ + vmcall(); +} + +static void populate_msr_list(struct vmx_msr_entry *msr_list, + size_t byte_capacity, int count) +{ + int i; + + for (i = 0; i < count; i++) { + msr_list[i].index = MSR_IA32_TSC; + msr_list[i].reserved = 0; + msr_list[i].value = 0x1234567890abcdef; + } + + memset(msr_list + count, 0xff, + byte_capacity - count * sizeof(*msr_list)); +} + +static int max_msr_list_size(void) +{ + u32 vmx_misc = rdmsr(MSR_IA32_VMX_MISC); + u32 factor = ((vmx_misc & GENMASK(27, 25)) >> 25) + 1; + + return factor * 512; +} + +static void atomic_switch_msrs_test(int count) +{ + struct vmx_msr_entry *vm_enter_load; + struct vmx_msr_entry *vm_exit_load; + struct vmx_msr_entry *vm_exit_store; + int max_allowed = max_msr_list_size(); + int byte_capacity = 1ul << (msr_list_page_order + PAGE_SHIFT); + /* Exceeding the max MSR list size at exit trigers KVM to abort. */ + int exit_count = count > max_allowed ? max_allowed : count; + int cleanup_count = count > max_allowed ? 2 : 1; + int i; + + /* + * Check for the IA32_TSC MSR, + * available with the "TSC flag" and used to populate the MSR lists. + */ + if (!(cpuid(1).d & (1 << 4))) { + report_skip(__func__); + return; + } + + /* Set L2 guest. */ + test_set_guest(atomic_switch_msr_limit_test_guest); + + /* Setup atomic MSR switch lists. */ + vm_enter_load = alloc_pages(msr_list_page_order); + vm_exit_load = alloc_pages(msr_list_page_order); + vm_exit_store = alloc_pages(msr_list_page_order); + + vmcs_write(ENTER_MSR_LD_ADDR, (u64)vm_enter_load); + vmcs_write(EXIT_MSR_LD_ADDR, (u64)vm_exit_load); + vmcs_write(EXIT_MSR_ST_ADDR, (u64)vm_exit_store); + + /* + * VM-Enter should succeed up to the max number of MSRs per list, and + * should not consume junk beyond the last entry. + */ + populate_msr_list(vm_enter_load, byte_capacity, count); + populate_msr_list(vm_exit_load, byte_capacity, exit_count); + populate_msr_list(vm_exit_store, byte_capacity, exit_count); + + vmcs_write(ENT_MSR_LD_CNT, count); + vmcs_write(EXI_MSR_LD_CNT, exit_count); + vmcs_write(EXI_MSR_ST_CNT, exit_count); + + if (count <= max_allowed) { + enter_guest(); + assert_exit_reason(VMX_VMCALL); + skip_exit_vmcall(); + } else { + u32 exit_reason; + u32 exit_reason_want; + u32 exit_qual; + + enter_guest_with_invalid_guest_state(); + + exit_reason = vmcs_read(EXI_REASON); + exit_reason_want = VMX_FAIL_MSR | VMX_ENTRY_FAILURE; + report("exit_reason, %u, is %u.", + exit_reason == exit_reason_want, exit_reason, + exit_reason_want); + + exit_qual = vmcs_read(EXI_QUALIFICATION); + report("exit_qual, %u, is %u.", exit_qual == max_allowed + 1, + exit_qual, max_allowed + 1); + } + + /* Cleanup. */ + vmcs_write(ENT_MSR_LD_CNT, 0); + vmcs_write(EXI_MSR_LD_CNT, 0); + vmcs_write(EXI_MSR_ST_CNT, 0); + for (i = 0; i < cleanup_count; i++) { + enter_guest(); + skip_exit_vmcall(); + } + free_pages_by_order(vm_enter_load, msr_list_page_order); + free_pages_by_order(vm_exit_load, msr_list_page_order); + free_pages_by_order(vm_exit_store, msr_list_page_order); +} + +static void atomic_switch_max_msrs_test(void) +{ + atomic_switch_msrs_test(max_msr_list_size()); +} + +static void atomic_switch_overflow_msrs_test(void) +{ + atomic_switch_msrs_test(max_msr_list_size() + 1); +} #define TEST(name) { #name, .v2 = name } @@ -8660,5 +8788,8 @@ struct vmx_test vmx_tests[] = { TEST(ept_access_test_paddr_read_execute_ad_enabled), TEST(ept_access_test_paddr_not_present_page_fault), TEST(ept_access_test_force_2m_page), + /* Atomic MSR switch tests. */ + TEST(atomic_switch_max_msrs_test), + TEST(atomic_switch_overflow_msrs_test), { NULL, NULL, NULL, NULL, NULL, {0} }, };