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[2620:137:e000::1:18]) by mx.google.com with ESMTPS id q3-20020a635043000000b003ab1cab0746si1225506pgl.67.2022.04.27.04.06.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Apr 2022 04:06:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=Uzta1YZI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id ABF7B2D2EAA; Wed, 27 Apr 2022 03:00:34 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353575AbiDZRCe (ORCPT + 99 others); Tue, 26 Apr 2022 13:02:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244109AbiDZRCb (ORCPT ); Tue, 26 Apr 2022 13:02:31 -0400 Received: from mail-yb1-xb34.google.com (mail-yb1-xb34.google.com [IPv6:2607:f8b0:4864:20::b34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 878C76EC56 for ; Tue, 26 Apr 2022 09:59:20 -0700 (PDT) Received: by mail-yb1-xb34.google.com with SMTP id i38so15065787ybj.13 for ; Tue, 26 Apr 2022 09:59:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GH43qdalFH201bywPnynKUZzlq3g2/HxF1LQk9DABhQ=; b=Uzta1YZI7Jy2BsepTIAPH2iHY8+QVbAQm2WuRTvfQjdO+Zl0TRZ5s48KpmTMOljED8 dlp+glTdjoXZ7+WRnbWOM34zoxDTa5fTmwjYVFz/zrw/gq+TTnuEA68ZkGWgFx5k062m d7NtID9A7CDm0FTV2cgPwBgxxuSD7QL05dGsXXxz21Djn9hWloPKV30mFUxO8MQndSPi ZcxzBwBKKlk43RePiPZmgRKr55YK4Jpw3zrGexCE6fuDTrHQZL275xlKSdQqnp19MZtS q9mjO9zgmXQbLR287q01cq28x/be2qK1DLQoklNucuYOBt5GJCrghmJRkrKZzb5HvEC0 oAZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=GH43qdalFH201bywPnynKUZzlq3g2/HxF1LQk9DABhQ=; b=krVwecHLWUGg61Xzajb4dHJRxh3zIAkBvk4GarmwkYgwW4VZX3UZ3lKFYnILNeaSdi 4CH4rp4JvMruoBOryHGGRAnY3T3/iLcSa9eAZ4Cd0kr4Teql9WqjM0KAZBYhIVTz2KLM ss9bGQ+YARPJrP6NfZBuC2ALsI0S71X6HgtE2NXE8nHUE9FnP9YBqQrDZ66l2WlqXdmp /2Cp4E4cLP3Boq99m4wXbDvfoYIRfhhxsJ6rGWFSB6zluSIF+meCCx9NNHZ8wi415q8x wcVcCA4xbv6b9EhxEFh6oBRh7CFc4XXYA4uTvB3eY5nqLyBy05EHBIUC6x1hWac7cTIF tAAA== X-Gm-Message-State: AOAM530zyjiQdepBAMFAYi2rS1ar9oY1rfK5Kg+zzyW8D5p5F1CBXxOs nNXOeNJQra4yRSL0hN6BQSjpDpml8OKmiBkmJ0wLQg== X-Received: by 2002:a05:6902:1242:b0:644:c30c:cfcc with SMTP id t2-20020a056902124200b00644c30ccfccmr21290240ybu.509.1650992359476; Tue, 26 Apr 2022 09:59:19 -0700 (PDT) MIME-Version: 1.0 References: <20220423000328.2103733-1-rananta@google.com> <20220423000328.2103733-9-rananta@google.com> <896e95a1-6a3e-c524-4951-8fae9697b85e@redhat.com> In-Reply-To: <896e95a1-6a3e-c524-4951-8fae9697b85e@redhat.com> From: Raghavendra Rao Ananta Date: Tue, 26 Apr 2022 09:59:08 -0700 Message-ID: Subject: Re: [PATCH v6 8/9] selftests: KVM: aarch64: Introduce hypercall ABI test To: Gavin Shan Cc: Marc Zyngier , Andrew Jones , James Morse , Alexandru Elisei , Suzuki K Poulose , kvm@vger.kernel.org, Catalin Marinas , Peter Shier , linux-kernel@vger.kernel.org, Paolo Bonzini , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-9.5 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RDNS_NONE,SPF_HELO_NONE,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Gavin, On Tue, Apr 26, 2022 at 12:50 AM Gavin Shan wrote: > > Hi Raghavendra, > > On 4/23/22 8:03 AM, Raghavendra Rao Ananta wrote: > > Introduce a KVM selftest to check the hypercall interface > > for arm64 platforms. The test validates the user-space' > > [GET|SET]_ONE_REG interface to read/write the psuedo-firmware > > registers as well as its effects on the guest upon certain > > configurations. > > > > Signed-off-by: Raghavendra Rao Ananta > > --- > > tools/testing/selftests/kvm/.gitignore | 1 + > > tools/testing/selftests/kvm/Makefile | 1 + > > .../selftests/kvm/aarch64/hypercalls.c | 335 ++++++++++++++++++ > > 3 files changed, 337 insertions(+) > > create mode 100644 tools/testing/selftests/kvm/aarch64/hypercalls.c > > > > There are comments about @false_hvc_info[] and some nits, as below. > Please evaluate and improve if it makes sense to you. Otherwise, it > looks good to me: > > Reviewed-by: Gavin Shan > > > diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore > > index 1bb575dfc42e..b17e464ec661 100644 > > --- a/tools/testing/selftests/kvm/.gitignore > > +++ b/tools/testing/selftests/kvm/.gitignore > > @@ -2,6 +2,7 @@ > > /aarch64/arch_timer > > /aarch64/debug-exceptions > > /aarch64/get-reg-list > > +/aarch64/hypercalls > > /aarch64/psci_test > > /aarch64/vcpu_width_config > > /aarch64/vgic_init > > diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile > > index c2cf4d318296..97eef0c03d3b 100644 > > --- a/tools/testing/selftests/kvm/Makefile > > +++ b/tools/testing/selftests/kvm/Makefile > > @@ -105,6 +105,7 @@ TEST_GEN_PROGS_x86_64 += system_counter_offset_test > > TEST_GEN_PROGS_aarch64 += aarch64/arch_timer > > TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions > > TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list > > +TEST_GEN_PROGS_aarch64 += aarch64/hypercalls > > TEST_GEN_PROGS_aarch64 += aarch64/psci_test > > TEST_GEN_PROGS_aarch64 += aarch64/vcpu_width_config > > TEST_GEN_PROGS_aarch64 += aarch64/vgic_init > > diff --git a/tools/testing/selftests/kvm/aarch64/hypercalls.c b/tools/testing/selftests/kvm/aarch64/hypercalls.c > > new file mode 100644 > > index 000000000000..f404343a0ae3 > > --- /dev/null > > +++ b/tools/testing/selftests/kvm/aarch64/hypercalls.c > > @@ -0,0 +1,335 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > + > > +/* hypercalls: Check the ARM64's psuedo-firmware bitmap register interface. > > + * > > + * The test validates the basic hypercall functionalities that are exposed > > + * via the psuedo-firmware bitmap register. This includes the registers' > > + * read/write behavior before and after the VM has started, and if the > > + * hypercalls are properly masked or unmasked to the guest when disabled or > > + * enabled from the KVM userspace, respectively. > > + */ > > + > > +#include > > +#include > > +#include > > +#include > > + > > +#include "processor.h" > > + > > +#define FW_REG_ULIMIT_VAL(max_feat_bit) (GENMASK(max_feat_bit, 0)) > > + > > +/* Last valid bits of the bitmapped firmware registers */ > > +#define KVM_REG_ARM_STD_BMAP_BIT_MAX 0 > > +#define KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX 0 > > +#define KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX 1 > > + > > +struct kvm_fw_reg_info { > > + uint64_t reg; /* Register definition */ > > + uint64_t max_feat_bit; /* Bit that represents the upper limit of the feature-map */ > > +}; > > + > > +#define FW_REG_INFO(r) \ > > + { \ > > + .reg = r, \ > > + .max_feat_bit = r##_BIT_MAX, \ > > + } > > + > > +static const struct kvm_fw_reg_info fw_reg_info[] = { > > + FW_REG_INFO(KVM_REG_ARM_STD_BMAP), > > + FW_REG_INFO(KVM_REG_ARM_STD_HYP_BMAP), > > + FW_REG_INFO(KVM_REG_ARM_VENDOR_HYP_BMAP), > > +}; > > + > > +enum test_stage { > > + TEST_STAGE_REG_IFACE, > > + TEST_STAGE_HVC_IFACE_FEAT_DISABLED, > > + TEST_STAGE_HVC_IFACE_FEAT_ENABLED, > > + TEST_STAGE_HVC_IFACE_FALSE_INFO, > > + TEST_STAGE_END, > > +}; > > + > > +static int stage = TEST_STAGE_REG_IFACE; > > + > > +struct test_hvc_info { > > + uint32_t func_id; > > + uint64_t arg1; > > +}; > > + > > +#define TEST_HVC_INFO(f, a1) \ > > + { \ > > + .func_id = f, \ > > + .arg1 = a1, \ > > + } > > + > > +static const struct test_hvc_info hvc_info[] = { > > + /* KVM_REG_ARM_STD_BMAP */ > > + TEST_HVC_INFO(ARM_SMCCC_TRNG_VERSION, 0), > > + TEST_HVC_INFO(ARM_SMCCC_TRNG_FEATURES, ARM_SMCCC_TRNG_RND64), > > + TEST_HVC_INFO(ARM_SMCCC_TRNG_GET_UUID, 0), > > + TEST_HVC_INFO(ARM_SMCCC_TRNG_RND32, 0), > > + TEST_HVC_INFO(ARM_SMCCC_TRNG_RND64, 0), > > + > > + /* KVM_REG_ARM_STD_HYP_BMAP */ > > + TEST_HVC_INFO(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_HV_PV_TIME_FEATURES), > > + TEST_HVC_INFO(ARM_SMCCC_HV_PV_TIME_FEATURES, ARM_SMCCC_HV_PV_TIME_ST), > > + TEST_HVC_INFO(ARM_SMCCC_HV_PV_TIME_ST, 0), > > + > > + /* KVM_REG_ARM_VENDOR_HYP_BMAP */ > > + TEST_HVC_INFO(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, > > + ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID), > > + TEST_HVC_INFO(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, 0), > > + TEST_HVC_INFO(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID, KVM_PTP_VIRT_COUNTER), > > +}; > > + > > +/* Feed false hypercall info to test the KVM behavior */ > > +static const struct test_hvc_info false_hvc_info[] = { > > + /* Feature support check against a different family of hypercalls */ > > + TEST_HVC_INFO(ARM_SMCCC_TRNG_FEATURES, ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID), > > + TEST_HVC_INFO(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_TRNG_RND64), > > + TEST_HVC_INFO(ARM_SMCCC_HV_PV_TIME_FEATURES, ARM_SMCCC_TRNG_RND64), > > +}; > > + > > I don't see too much benefits of @false_hvc_info[] because > NOT_SUPPORTED is always returned from its test case. I think > it and its test case can be removed if you agree. I'm not > sure if it was suggested by somebody else. > While this is not exactly testing the bitmap firmware registers, the idea behind introducing false_hvc_info[] was to introduce some negative tests and see if KVM handles it well. Especially with *_FEATURES func_ids, we can accidentally introduce functional bugs in KVM, and these would act as our safety net. I was planning to also test with some reserved hypercall numbers, just to test if the kernel doesn't panic for some reason. > > +static void guest_test_hvc(const struct test_hvc_info *hc_info) > > +{ > > + unsigned int i; > > + struct arm_smccc_res res; > > + unsigned int hvc_info_arr_sz; > > + > > + hvc_info_arr_sz = > > + hc_info == hvc_info ? ARRAY_SIZE(hvc_info) : ARRAY_SIZE(false_hvc_info); > > + > > + for (i = 0; i < hvc_info_arr_sz; i++, hc_info++) { > > + memset(&res, 0, sizeof(res)); > > + smccc_hvc(hc_info->func_id, hc_info->arg1, 0, 0, 0, 0, 0, 0, &res); > > + > > + switch (stage) { > > + case TEST_STAGE_HVC_IFACE_FEAT_DISABLED: > > + case TEST_STAGE_HVC_IFACE_FALSE_INFO: > > + GUEST_ASSERT_3(res.a0 == SMCCC_RET_NOT_SUPPORTED, > > + res.a0, hc_info->func_id, hc_info->arg1); > > + break; > > + case TEST_STAGE_HVC_IFACE_FEAT_ENABLED: > > + GUEST_ASSERT_3(res.a0 != SMCCC_RET_NOT_SUPPORTED, > > + res.a0, hc_info->func_id, hc_info->arg1); > > + break; > > + default: > > + GUEST_ASSERT_1(0, stage); > > + } > > + } > > +} > > + > > +static void guest_code(void) > > +{ > > + while (stage != TEST_STAGE_END) { > > + switch (stage) { > > + case TEST_STAGE_REG_IFACE: > > + break; > > + case TEST_STAGE_HVC_IFACE_FEAT_DISABLED: > > + case TEST_STAGE_HVC_IFACE_FEAT_ENABLED: > > + guest_test_hvc(hvc_info); > > + break; > > + case TEST_STAGE_HVC_IFACE_FALSE_INFO: > > + guest_test_hvc(false_hvc_info); > > + break; > > + default: > > + GUEST_ASSERT_1(0, stage); > > + } > > + > > + GUEST_SYNC(stage); > > + } > > + > > + GUEST_DONE(); > > +} > > + > > +static int set_fw_reg(struct kvm_vm *vm, uint64_t id, uint64_t val) > > +{ > > + struct kvm_one_reg reg = { > > + .id = id, > > + .addr = (uint64_t)&val, > > + }; > > + > > + return _vcpu_ioctl(vm, 0, KVM_SET_ONE_REG, ®); > > +} > > + > > +static void get_fw_reg(struct kvm_vm *vm, uint64_t id, uint64_t *addr) > > +{ > > + struct kvm_one_reg reg = { > > + .id = id, > > + .addr = (uint64_t)addr, > > + }; > > + > > + vcpu_ioctl(vm, 0, KVM_GET_ONE_REG, ®); > > +} > > + > > +struct st_time { > > + uint32_t rev; > > + uint32_t attr; > > + uint64_t st_time; > > +}; > > + > > +#define STEAL_TIME_SIZE ((sizeof(struct st_time) + 63) & ~63) > > +#define ST_GPA_BASE (1 << 30) > > + > > +static void steal_time_init(struct kvm_vm *vm) > > +{ > > + uint64_t st_ipa = (ulong)ST_GPA_BASE; > > + unsigned int gpages; > > + struct kvm_device_attr dev = { > > + .group = KVM_ARM_VCPU_PVTIME_CTRL, > > + .attr = KVM_ARM_VCPU_PVTIME_IPA, > > + .addr = (uint64_t)&st_ipa, > > + }; > > + > > + gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE); > > + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0); > > + > > + vcpu_ioctl(vm, 0, KVM_SET_DEVICE_ATTR, &dev); > > +} > > + > > +static void test_fw_regs_before_vm_start(struct kvm_vm *vm) > > +{ > > + uint64_t val; > > + unsigned int i; > > + int ret; > > + > > + for (i = 0; i < ARRAY_SIZE(fw_reg_info); i++) { > > + const struct kvm_fw_reg_info *reg_info = &fw_reg_info[i]; > > + > > + /* First 'read' should be an upper limit of the features supported */ > > + get_fw_reg(vm, reg_info->reg, &val); > > + TEST_ASSERT(val == FW_REG_ULIMIT_VAL(reg_info->max_feat_bit), > > + "Expected all the features to be set for reg: 0x%lx; expected: 0x%lx; read: 0x%lx\n", > > + reg_info->reg, FW_REG_ULIMIT_VAL(reg_info->max_feat_bit), val); > > + > > + /* Test a 'write' by disabling all the features of the register map */ > > + ret = set_fw_reg(vm, reg_info->reg, 0); > > + TEST_ASSERT(ret == 0, > > + "Failed to clear all the features of reg: 0x%lx; ret: %d\n", > > + reg_info->reg, errno); > > + > > + get_fw_reg(vm, reg_info->reg, &val); > > + TEST_ASSERT(val == 0, > > + "Expected all the features to be cleared for reg: 0x%lx\n", reg_info->reg); > > + > > + /* > > + * Test enabling a feature that's not supported. > > + * Avoid this check if all the bits are occupied. > > + */ > > + if (reg_info->max_feat_bit < 63) { > > + ret = set_fw_reg(vm, reg_info->reg, BIT(reg_info->max_feat_bit + 1)); > > + TEST_ASSERT(ret != 0 && errno == EINVAL, > > + "Unexpected behavior or return value (%d) while setting an unsupported feature for reg: 0x%lx\n", > > + errno, reg_info->reg); > > + } > > + } > > +} > > Just in case :) > > ret = set_fw_reg(vm, reg_info->reg, GENMASK(63, reg_info->max_feat_bit + 1)); > It may be better to cover the entire range, but to test only the (max_feat_bit + 1) gives us the advantage of checking if there's any discrepancy between the kernel and the test, now that *_BIT_MAX are not a part of UAPI headers. Probably also include your test along with the existing one? > > > + > > +static void test_fw_regs_after_vm_start(struct kvm_vm *vm) > > +{ > > + uint64_t val; > > + unsigned int i; > > + int ret; > > + > > + for (i = 0; i < ARRAY_SIZE(fw_reg_info); i++) { > > + const struct kvm_fw_reg_info *reg_info = &fw_reg_info[i]; > > + > > + /* > > + * Before starting the VM, the test clears all the bits. > > + * Check if that's still the case. > > + */ > > + get_fw_reg(vm, reg_info->reg, &val); > > + TEST_ASSERT(val == 0, > > + "Expected all the features to be cleared for reg: 0x%lx\n", > > + reg_info->reg); > > + > > + /* > > + * Set all the features for this register again. KVM shouldn't > > + * allow this as the VM is running. > > + */ > > + ret = set_fw_reg(vm, reg_info->reg, FW_REG_ULIMIT_VAL(reg_info->max_feat_bit)); > > + TEST_ASSERT(ret != 0 && errno == EBUSY, > > + "Unexpected behavior or return value (%d) while setting a feature while VM is running for reg: 0x%lx\n", > > + errno, reg_info->reg); > > + } > > +} > > + > > I guess you want to check -EBUSY is returned. In that case, > the comments here could be clearer, something like below > to emphasize '-EBUSY'. > > /* > * After VM runs for once, -EBUSY should be returned on attempt > * to set features. Check if the correct errno is returned. > */ > Sounds good. > > +static struct kvm_vm *test_vm_create(void) > > +{ > > + struct kvm_vm *vm; > > + > > + vm = vm_create_default(0, 0, guest_code); > > + > > + ucall_init(vm, NULL); > > + steal_time_init(vm); > > + > > + return vm; > > +} > > + > > +static struct kvm_vm *test_guest_stage(struct kvm_vm *vm) > > +{ > > + struct kvm_vm *ret_vm = vm; > > + > > + pr_debug("Stage: %d\n", stage); > > + > > + switch (stage) { > > + case TEST_STAGE_REG_IFACE: > > + test_fw_regs_after_vm_start(vm); > > + break; > > + case TEST_STAGE_HVC_IFACE_FEAT_DISABLED: > > + /* Start a new VM so that all the features are now enabled by default */ > > + kvm_vm_free(vm); > > + ret_vm = test_vm_create(); > > + break; > > + case TEST_STAGE_HVC_IFACE_FEAT_ENABLED: > > + case TEST_STAGE_HVC_IFACE_FALSE_INFO: > > + break; > > + default: > > + TEST_FAIL("Unknown test stage: %d\n", stage); > > + } > > + > > + stage++; > > + sync_global_to_guest(vm, stage); > > + > > + return ret_vm; > > +} > > + > > +static void test_run(void) > > +{ > > + struct kvm_vm *vm; > > + struct ucall uc; > > + bool guest_done = false; > > + > > + vm = test_vm_create(); > > + > > + test_fw_regs_before_vm_start(vm); > > + > > + while (!guest_done) { > > + vcpu_run(vm, 0); > > + > > + switch (get_ucall(vm, 0, &uc)) { > > + case UCALL_SYNC: > > + vm = test_guest_stage(vm); > > + break; > > + case UCALL_DONE: > > + guest_done = true; > > + break; > > + case UCALL_ABORT: > > + TEST_FAIL("%s at %s:%ld\n\tvalues: 0x%lx, 0x%lx; 0x%lx, stage: %u", > > + (const char *)uc.args[0], __FILE__, uc.args[1], > > + uc.args[2], uc.args[3], uc.args[4], stage); > > + break; > > + default: > > + TEST_FAIL("Unexpected guest exit\n"); > > + } > > + } > > + > > + kvm_vm_free(vm); > > +} > > + > > +int main(void) > > +{ > > + setbuf(stdout, NULL); > > + > > + test_run(); > > + return 0; > > +} > > > > Thanks, > Gavin > Thanks for the reviews on all the patches, Gavin. Regards, Raghavendra