From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5657C388F9 for ; Sat, 31 Oct 2020 14:04:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 985DF206D5 for ; Sat, 31 Oct 2020 14:04:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hiqsyTuM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727708AbgJaOE4 (ORCPT ); Sat, 31 Oct 2020 10:04:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:33855 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727407AbgJaOE4 (ORCPT ); Sat, 31 Oct 2020 10:04:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604153093; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UqhtiqEB1bu49kWYY3RTo+Lr7N9/OE+hsqGWxhP+PuI=; b=hiqsyTuMYpNU3JlfoxSQdQCHSqb0p0gT4cBv6dRVao01ejfTc4aZ4EpcGCNZpG0xSA8DB1 e4kkBxmUdTQphe7Pe93PgonCg/N8zs6bA1/HBLBKV3XEtmiYvzd5AMyb09ajPIf8UGCLee 8yq8YGrby0SVZZOgmpM8Evi8RMIerAY= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-364-wPT-8wYBOnC5Zbn_4u-Z8w-1; Sat, 31 Oct 2020 10:04:50 -0400 X-MC-Unique: wPT-8wYBOnC5Zbn_4u-Z8w-1 Received: by mail-wm1-f71.google.com with SMTP id r23so889590wmh.0 for ; Sat, 31 Oct 2020 07:04:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=UqhtiqEB1bu49kWYY3RTo+Lr7N9/OE+hsqGWxhP+PuI=; b=Q/hzpvvvoWMRlqHjTMyB04rt1d5aU+ADMT3PS9dpA3pWiexK9UKeOps2Ihq/SpQYOK 16LC+g7IzTC/tYvmlo/KoVW2tnkpUfGJj9eiyBHnMI4enVqvJ8IjQ+qmItxlhZuIBR43 O6EzBquuG5CC9nHJI9MoliYxPBvnP6wWKTwpqAXaRrPksihH74GSXZ//HG2dMjYEooMj 8JVWcJSA2g7wFaswI9j8KPwxEfcfWn9NCTCkz+BnslR2y/Nz6lAYRZH26YxKeZ26fS5W eACrV5xex8A6IfVsFR2rNNU6nGfFmtYoCXy7F2CNJ3ByW+5SAYNp0qzR/ZqnZ+UhBfLp 2iAg== X-Gm-Message-State: AOAM533JU+sEFuZh0GrZ60XOYY2KzKi2fK7VDe9OcWuj1tBioBzKeuCr 2CUnJysHqYEuaKg/CBdhjkHwhRBgf8DDxanm3gyWaQZVwv+pHPW6CrbhDQvDbXY0HZgufQrfNT+ eUPMaOpkqsyL/ X-Received: by 2002:a5d:4e48:: with SMTP id r8mr9230257wrt.141.1604153089224; Sat, 31 Oct 2020 07:04:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzAI1TSAwokQAhbHe/PnAn3gvUyOFFcR/JsaQj7QxcgdHk9YHla/81UTpqrQMyPZLVekAnCWQ== X-Received: by 2002:a5d:4e48:: with SMTP id r8mr9230226wrt.141.1604153088935; Sat, 31 Oct 2020 07:04:48 -0700 (PDT) Received: from [192.168.178.64] ([151.20.250.56]) by smtp.gmail.com with ESMTPSA id v123sm8713361wme.7.2020.10.31.07.04.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 31 Oct 2020 07:04:48 -0700 (PDT) Subject: Re: [PATCH] KVM: selftests: test behavior of unmapped L2 APIC-access address To: Jim Mattson , kvm@vger.kernel.org Cc: Ricardo Koller , Peter Shier References: <20201026180922.3120555-1-jmattson@google.com> From: Paolo Bonzini Message-ID: Date: Sat, 31 Oct 2020 15:04:47 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <20201026180922.3120555-1-jmattson@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 26/10/20 19:09, Jim Mattson wrote: > Add a regression test for commit 671ddc700fd0 ("KVM: nVMX: Don't leak > L1 MMIO regions to L2"). > > First, check to see that an L2 guest can be launched with a valid > APIC-access address that is backed by a page of L1 physical memory. > > Next, set the APIC-access address to a (valid) L1 physical address > that is not backed by memory. KVM can't handle this situation, so > resuming L2 should result in a KVM exit for internal error > (emulation). > > Signed-off-by: Jim Mattson > Reviewed-by: Ricardo Koller > Reviewed-by: Peter Shier > --- > tools/testing/selftests/kvm/.gitignore | 1 + > tools/testing/selftests/kvm/Makefile | 1 + > .../selftests/kvm/include/x86_64/vmx.h | 6 + > tools/testing/selftests/kvm/lib/x86_64/vmx.c | 9 ++ > .../kvm/x86_64/vmx_apic_access_test.c | 142 ++++++++++++++++++ > 5 files changed, 159 insertions(+) > create mode 100644 tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c > > diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore > index 307ceaadbbb9..d2c2d6205008 100644 > --- a/tools/testing/selftests/kvm/.gitignore > +++ b/tools/testing/selftests/kvm/.gitignore > @@ -15,6 +15,7 @@ > /x86_64/vmx_preemption_timer_test > /x86_64/svm_vmcall_test > /x86_64/sync_regs_test > +/x86_64/vmx_apic_access_test > /x86_64/vmx_close_while_nested_test > /x86_64/vmx_dirty_log_test > /x86_64/vmx_set_nested_state_test > diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile > index 7ebe71fbca53..30afbad36cd5 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -49,6 +49,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/state_test > TEST_GEN_PROGS_x86_64 += x86_64/vmx_preemption_timer_test > TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_test > TEST_GEN_PROGS_x86_64 += x86_64/sync_regs_test > +TEST_GEN_PROGS_x86_64 += x86_64/vmx_apic_access_test > TEST_GEN_PROGS_x86_64 += x86_64/vmx_close_while_nested_test > TEST_GEN_PROGS_x86_64 += x86_64/vmx_dirty_log_test > TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test > diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h > index 54d624dd6c10..e78d7e26ba61 100644 > --- a/tools/testing/selftests/kvm/include/x86_64/vmx.h > +++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h > @@ -573,6 +573,10 @@ struct vmx_pages { > void *eptp_hva; > uint64_t eptp_gpa; > void *eptp; > + > + void *apic_access_hva; > + uint64_t apic_access_gpa; > + void *apic_access; > }; > > union vmx_basic { > @@ -615,5 +619,7 @@ void nested_map_memslot(struct vmx_pages *vmx, struct kvm_vm *vm, > uint32_t memslot, uint32_t eptp_memslot); > void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm, > uint32_t eptp_memslot); > +void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm, > + uint32_t eptp_memslot); > > #endif /* SELFTEST_KVM_VMX_H */ > diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c > index f1e00d43eea2..2448b30e8efa 100644 > --- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c > +++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c > @@ -542,3 +542,12 @@ void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm, > vmx->eptp_hva = addr_gva2hva(vm, (uintptr_t)vmx->eptp); > vmx->eptp_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->eptp); > } > + > +void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm, > + uint32_t eptp_memslot) > +{ > + vmx->apic_access = (void *)vm_vaddr_alloc(vm, getpagesize(), > + 0x10000, 0, 0); > + vmx->apic_access_hva = addr_gva2hva(vm, (uintptr_t)vmx->apic_access); > + vmx->apic_access_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->apic_access); > +} > diff --git a/tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c b/tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c > new file mode 100644 > index 000000000000..1f65342d6cb7 > --- /dev/null > +++ b/tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c > @@ -0,0 +1,142 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * vmx_apic_access_test > + * > + * Copyright (C) 2020, Google LLC. > + * > + * This work is licensed under the terms of the GNU GPL, version 2. > + * > + * The first subtest simply checks to see that an L2 guest can be > + * launched with a valid APIC-access address that is backed by a > + * page of L1 physical memory. > + * > + * The second subtest sets the APIC-access address to a (valid) L1 > + * physical address that is not backed by memory. KVM can't handle > + * this situation, so resuming L2 should result in a KVM exit for > + * internal error (emulation). This is not an architectural > + * requirement. It is just a shortcoming of KVM. The internal error > + * is unfortunate, but it's better than what used to happen! > + */ > + > +#include "test_util.h" > +#include "kvm_util.h" > +#include "processor.h" > +#include "vmx.h" > + > +#include > +#include > + > +#include "kselftest.h" > + > +#define VCPU_ID 0 > + > +/* The virtual machine object. */ > +static struct kvm_vm *vm; > + > +static void l2_guest_code(void) > +{ > + /* Exit to L1 */ > + __asm__ __volatile__("vmcall"); > +} > + > +static void l1_guest_code(struct vmx_pages *vmx_pages, unsigned long high_gpa) > +{ > +#define L2_GUEST_STACK_SIZE 64 > + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; > + uint32_t control; > + > + GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages)); > + GUEST_ASSERT(load_vmcs(vmx_pages)); > + > + /* Prepare the VMCS for L2 execution. */ > + prepare_vmcs(vmx_pages, l2_guest_code, > + &l2_guest_stack[L2_GUEST_STACK_SIZE]); > + control = vmreadz(CPU_BASED_VM_EXEC_CONTROL); > + control |= CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; > + vmwrite(CPU_BASED_VM_EXEC_CONTROL, control); > + control = vmreadz(SECONDARY_VM_EXEC_CONTROL); > + control |= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; > + vmwrite(SECONDARY_VM_EXEC_CONTROL, control); > + vmwrite(APIC_ACCESS_ADDR, vmx_pages->apic_access_gpa); > + > + /* Try to launch L2 with the memory-backed APIC-access address. */ > + GUEST_SYNC(vmreadz(APIC_ACCESS_ADDR)); > + GUEST_ASSERT(!vmlaunch()); > + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); > + > + vmwrite(APIC_ACCESS_ADDR, high_gpa); > + > + /* Try to resume L2 with the unbacked APIC-access address. */ > + GUEST_SYNC(vmreadz(APIC_ACCESS_ADDR)); > + GUEST_ASSERT(!vmresume()); > + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); > + > + GUEST_DONE(); > +} > + > +int main(int argc, char *argv[]) > +{ > + unsigned long apic_access_addr = ~0ul; > + unsigned int paddr_width; > + unsigned int vaddr_width; > + vm_vaddr_t vmx_pages_gva; > + unsigned long high_gpa; > + struct vmx_pages *vmx; > + bool done = false; > + > + nested_vmx_check_supported(); > + > + vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code); > + vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); > + > + kvm_get_cpu_address_width(&paddr_width, &vaddr_width); > + high_gpa = (1ul << paddr_width) - getpagesize(); > + if ((unsigned long)DEFAULT_GUEST_PHY_PAGES * getpagesize() > high_gpa) { > + print_skip("No unbacked physical page available"); > + exit(KSFT_SKIP); > + } > + > + vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva); > + prepare_virtualize_apic_accesses(vmx, vm, 0); > + vcpu_args_set(vm, VCPU_ID, 2, vmx_pages_gva, high_gpa); > + > + while (!done) { > + volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID); > + struct ucall uc; > + > + vcpu_run(vm, VCPU_ID); > + if (apic_access_addr == high_gpa) { > + TEST_ASSERT(run->exit_reason == > + KVM_EXIT_INTERNAL_ERROR, > + "Got exit reason other than KVM_EXIT_INTERNAL_ERROR: %u (%s)\n", > + run->exit_reason, > + exit_reason_str(run->exit_reason)); > + TEST_ASSERT(run->internal.suberror == > + KVM_INTERNAL_ERROR_EMULATION, > + "Got internal suberror other than KVM_INTERNAL_ERROR_EMULATION: %u\n", > + run->internal.suberror); > + break; > + } > + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, > + "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n", > + run->exit_reason, > + exit_reason_str(run->exit_reason)); > + > + switch (get_ucall(vm, VCPU_ID, &uc)) { > + case UCALL_ABORT: > + TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0], > + __FILE__, uc.args[1]); > + /* NOT REACHED */ > + case UCALL_SYNC: > + apic_access_addr = uc.args[1]; > + break; > + case UCALL_DONE: > + done = true; > + break; > + default: > + TEST_ASSERT(false, "Unknown ucall %lu", uc.cmd); > + } > + } > + kvm_vm_free(vm); > + return 0; > +} > Queued, thanks. Paolo