From patchwork Fri Mar 19 10:01:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quentin Perret X-Patchwork-Id: 12150551 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=-17.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E3CCCC433DB for ; Fri, 19 Mar 2021 10:09:26 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C66264E45 for ; Fri, 19 Mar 2021 10:09:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C66264E45 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Cc:To:From:Subject:References:Mime-Version: Message-Id:In-Reply-To:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=jeahDZLWKx/t9M26YBu2CuHyZObbtkemumK3viIQ/MI=; b=OXeHi0Ykn0iaNs jAERdib2PZssz3X2/pn6do8eKudDCkCtmpHH7huhMbJVMTvR+UqwSYDQPpQa56mmdKH4KQhBKmQSM m53pLPwoK/ofvztbcjS/zli7blkJxky0j1Lc0m4Gp2hL92zBEdrAKYjp2L1oJ+Fthdp7+8oF2aFx9 iP2ZdBcDc179Xv38+eFPHTZ0Q9cTFH59hoaQ7cEpttQmTeUIqR/mhEm+nKCdHRUwwzVPU30HunCfF WSeAHGoe/m7bNGwjlqq/Jm6OoYdQBsOi37WM+26JL8TkRJpPhfkerbsVxwYCDYmkd6HUR8N6stXHr WayQ8l5RdQiE3ielC0rg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lNC2e-0072dF-TV; Fri, 19 Mar 2021 10:07:41 +0000 Received: from mail-wm1-x349.google.com ([2a00:1450:4864:20::349]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lNBxd-0070H4-F9 for linux-arm-kernel@lists.infradead.org; Fri, 19 Mar 2021 10:02:32 +0000 Received: by mail-wm1-x349.google.com with SMTP id n17so4390548wmi.2 for ; Fri, 19 Mar 2021 03:02:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Z09WkKOyMVt9BFTsG2ZmNBIXPuUsH3bDRh2M/fNBZAw=; b=Ync8JwPZGWTva1UJmCKrL94V9RnPhuigC4Ue8Wu0gk+wz0MHTv7zN+j2x0gy049cCM UHzY4r3xOW1NZ9Nmor7xc5tEfUyXAiW6guQbktnUmzNVKBw2yQlxk3P32leO4xR+mg3D kmxamzckf03y/YVDdKOy0/2tnsG3jHJL3nAfiyaPMW6YjIWtEF16EQLXvQnS52Ls7zyB 7WpWguDWAL/H9bCPLFYiQGzNzMWRItprM02ZDeGP4M/505keFpGx915adFh9wQi0qyBO rerXyrApYterwm26H0NjwoxCfsr95yvKK0RHaFJ+6dk5/4hwAkzwig8HtUQHF9x/+4xF oZfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Z09WkKOyMVt9BFTsG2ZmNBIXPuUsH3bDRh2M/fNBZAw=; b=uHFTwTE75nr1mGNm0J3ba5Eb/xsBJVNR3/mVuPquxUNWAt0c+TT/LmHs4oA+focJGr dJx/wPfC3qX/ZLeT9o/Y9ujzYthwG07VWmqsclRtWSYnAv9tWb9ThrwkIg5QV/TDAUIT PScOtDd8TZ+lZJhvOomnlu2VeteWfxSn8i9uU+7AVVXV7/QGcO3t9o8Nmj2C/sBVuCsp LfuojBd76oKOpQ2poJq4Kj+ZUm6a5Z2AvkSK/MWd+wy1RQ5gBwgN/WN34D5DvDVdd2LI Du+MmOskEjwfjSnwPGnjMR3mu47KW0ALlj6kIUPPZlGb8m/B4QHxM3L5WTxAs+qGzwmh aWjA== X-Gm-Message-State: AOAM531Xewd1W+TcFIl8IvMr3rZrN4SyX990IcZLMKIFBE3NLPg3rBHE A9ryKhly8hd0xt6jJKHW5VC/D8i1Kbic X-Google-Smtp-Source: ABdhPJy6I6/ztyy3H73D48LIWJ8bZ+jmiddaB5B8Rf1VlsxYPGassP5fKX8GSWSpoCRyGZyYf+6B+Zbg7IT7 X-Received: from r2d2-qp.c.googlers.com ([fda3:e722:ac3:10:28:9cb1:c0a8:1652]) (user=qperret job=sendgmr) by 2002:a1c:60c2:: with SMTP id u185mr2876383wmb.157.1616148148011; Fri, 19 Mar 2021 03:02:28 -0700 (PDT) Date: Fri, 19 Mar 2021 10:01:26 +0000 In-Reply-To: <20210319100146.1149909-1-qperret@google.com> Message-Id: <20210319100146.1149909-19-qperret@google.com> Mime-Version: 1.0 References: <20210319100146.1149909-1-qperret@google.com> X-Mailer: git-send-email 2.31.0.rc2.261.g7f71774620-goog Subject: [PATCH v6 18/38] KVM: arm64: Elevate hypervisor mappings creation at EL2 From: Quentin Perret To: catalin.marinas@arm.com, will@kernel.org, maz@kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com Cc: android-kvm@google.com, seanjc@google.com, mate.toth-pal@arm.com, linux-kernel@vger.kernel.org, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@android.com, kvmarm@lists.cs.columbia.edu, tabba@google.com, ardb@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, qperret@google.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210319_100230_524528_10025B6D X-CRM114-Status: GOOD ( 22.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Previous commits have introduced infrastructure to enable the EL2 code to manage its own stage 1 mappings. However, this was preliminary work, and none of it is currently in use. Put all of this together by elevating the mapping creation at EL2 when memory protection is enabled. In this case, the host kernel running at EL1 still creates _temporary_ EL2 mappings, only used while initializing the hypervisor, but frees them right after. As such, all calls to create_hyp_mappings() after kvm init has finished turn into hypercalls, as the host now has no 'legal' way to modify the hypevisor page tables directly. Acked-by: Will Deacon Signed-off-by: Quentin Perret --- arch/arm64/include/asm/kvm_mmu.h | 2 +- arch/arm64/kvm/arm.c | 87 +++++++++++++++++++++++++++++--- arch/arm64/kvm/mmu.c | 43 ++++++++++++++-- 3 files changed, 120 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 5c42ec023cc7..ce02a4052dcf 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -166,7 +166,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu); phys_addr_t kvm_mmu_get_httbr(void); phys_addr_t kvm_get_idmap_vector(void); -int kvm_mmu_init(void); +int kvm_mmu_init(u32 *hyp_va_bits); static inline void *__kvm_vector_slot2addr(void *base, enum arm64_hyp_spectre_vector slot) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e2c471117bff..d93ea0b82491 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1426,7 +1426,7 @@ static void cpu_prepare_hyp_mode(int cpu) kvm_flush_dcache_to_poc(params, sizeof(*params)); } -static void cpu_init_hyp_mode(void) +static void hyp_install_host_vector(void) { struct kvm_nvhe_init_params *params; struct arm_smccc_res res; @@ -1444,6 +1444,11 @@ static void cpu_init_hyp_mode(void) params = this_cpu_ptr_nvhe_sym(kvm_init_params); arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res); WARN_ON(res.a0 != SMCCC_RET_SUCCESS); +} + +static void cpu_init_hyp_mode(void) +{ + hyp_install_host_vector(); /* * Disabling SSBD on a non-VHE system requires us to enable SSBS @@ -1486,7 +1491,10 @@ static void cpu_set_hyp_vector(void) struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data); void *vector = hyp_spectre_vector_selector[data->slot]; - *this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)vector; + if (!is_protected_kvm_enabled()) + *this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)vector; + else + kvm_call_hyp_nvhe(__pkvm_cpu_set_vector, data->slot); } static void cpu_hyp_reinit(void) @@ -1494,13 +1502,14 @@ static void cpu_hyp_reinit(void) kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt); cpu_hyp_reset(); - cpu_set_hyp_vector(); if (is_kernel_in_hyp_mode()) kvm_timer_init_vhe(); else cpu_init_hyp_mode(); + cpu_set_hyp_vector(); + kvm_arm_init_debug(); if (vgic_present) @@ -1696,18 +1705,59 @@ static void teardown_hyp_mode(void) } } +static int do_pkvm_init(u32 hyp_va_bits) +{ + void *per_cpu_base = kvm_ksym_ref(kvm_arm_hyp_percpu_base); + int ret; + + preempt_disable(); + hyp_install_host_vector(); + ret = kvm_call_hyp_nvhe(__pkvm_init, hyp_mem_base, hyp_mem_size, + num_possible_cpus(), kern_hyp_va(per_cpu_base), + hyp_va_bits); + preempt_enable(); + + return ret; +} + +static int kvm_hyp_init_protection(u32 hyp_va_bits) +{ + void *addr = phys_to_virt(hyp_mem_base); + int ret; + + ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP); + if (ret) + return ret; + + ret = do_pkvm_init(hyp_va_bits); + if (ret) + return ret; + + free_hyp_pgds(); + + return 0; +} + /** * Inits Hyp-mode on all online CPUs */ static int init_hyp_mode(void) { + u32 hyp_va_bits; int cpu; - int err = 0; + int err = -ENOMEM; + + /* + * The protected Hyp-mode cannot be initialized if the memory pool + * allocation has failed. + */ + if (is_protected_kvm_enabled() && !hyp_mem_base) + goto out_err; /* * Allocate Hyp PGD and setup Hyp identity mapping */ - err = kvm_mmu_init(); + err = kvm_mmu_init(&hyp_va_bits); if (err) goto out_err; @@ -1823,6 +1873,14 @@ static int init_hyp_mode(void) goto out_err; } + if (is_protected_kvm_enabled()) { + err = kvm_hyp_init_protection(hyp_va_bits); + if (err) { + kvm_err("Failed to init hyp memory protection\n"); + goto out_err; + } + } + return 0; out_err: @@ -1831,6 +1889,16 @@ static int init_hyp_mode(void) return err; } +static int finalize_hyp_mode(void) +{ + if (!is_protected_kvm_enabled()) + return 0; + + static_branch_enable(&kvm_protected_mode_initialized); + + return 0; +} + static void check_kvm_target_cpu(void *ret) { *(int *)ret = kvm_target_cpu(); @@ -1942,8 +2010,15 @@ int kvm_arch_init(void *opaque) if (err) goto out_hyp; + if (!in_hyp_mode) { + err = finalize_hyp_mode(); + if (err) { + kvm_err("Failed to finalize Hyp protection\n"); + goto out_hyp; + } + } + if (is_protected_kvm_enabled()) { - static_branch_enable(&kvm_protected_mode_initialized); kvm_info("Protected nVHE mode initialized successfully\n"); } else if (in_hyp_mode) { kvm_info("VHE mode initialized successfully\n"); diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index e583f7fb3620..de0ad79d2c90 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -221,15 +221,39 @@ void free_hyp_pgds(void) if (hyp_pgtable) { kvm_pgtable_hyp_destroy(hyp_pgtable); kfree(hyp_pgtable); + hyp_pgtable = NULL; } mutex_unlock(&kvm_hyp_pgd_mutex); } +static bool kvm_host_owns_hyp_mappings(void) +{ + if (static_branch_likely(&kvm_protected_mode_initialized)) + return false; + + /* + * This can happen at boot time when __create_hyp_mappings() is called + * after the hyp protection has been enabled, but the static key has + * not been flipped yet. + */ + if (!hyp_pgtable && is_protected_kvm_enabled()) + return false; + + WARN_ON(!hyp_pgtable); + + return true; +} + static int __create_hyp_mappings(unsigned long start, unsigned long size, unsigned long phys, enum kvm_pgtable_prot prot) { int err; + if (!kvm_host_owns_hyp_mappings()) { + return kvm_call_hyp_nvhe(__pkvm_create_mappings, + start, size, phys, prot); + } + mutex_lock(&kvm_hyp_pgd_mutex); err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot); mutex_unlock(&kvm_hyp_pgd_mutex); @@ -291,6 +315,16 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, unsigned long base; int ret = 0; + if (!kvm_host_owns_hyp_mappings()) { + base = kvm_call_hyp_nvhe(__pkvm_create_private_mapping, + phys_addr, size, prot); + if (IS_ERR_OR_NULL((void *)base)) + return PTR_ERR((void *)base); + *haddr = base; + + return 0; + } + mutex_lock(&kvm_hyp_pgd_mutex); /* @@ -1270,10 +1304,9 @@ static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = { .virt_to_phys = kvm_host_pa, }; -int kvm_mmu_init(void) +int kvm_mmu_init(u32 *hyp_va_bits) { int err; - u32 hyp_va_bits; hyp_idmap_start = __pa_symbol(__hyp_idmap_text_start); hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE); @@ -1287,8 +1320,8 @@ int kvm_mmu_init(void) */ BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK); - hyp_va_bits = 64 - ((idmap_t0sz & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET); - kvm_debug("Using %u-bit virtual addresses at EL2\n", hyp_va_bits); + *hyp_va_bits = 64 - ((idmap_t0sz & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET); + kvm_debug("Using %u-bit virtual addresses at EL2\n", *hyp_va_bits); kvm_debug("IDMAP page: %lx\n", hyp_idmap_start); kvm_debug("HYP VA range: %lx:%lx\n", kern_hyp_va(PAGE_OFFSET), @@ -1313,7 +1346,7 @@ int kvm_mmu_init(void) goto out; } - err = kvm_pgtable_hyp_init(hyp_pgtable, hyp_va_bits, &kvm_hyp_mm_ops); + err = kvm_pgtable_hyp_init(hyp_pgtable, *hyp_va_bits, &kvm_hyp_mm_ops); if (err) goto out_free_pgtable;