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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 368D5C47253 for ; Thu, 30 Apr 2020 14:48:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A92220873 for ; Thu, 30 Apr 2020 14:48:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bC+mz6Gf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727086AbgD3Osv (ORCPT ); Thu, 30 Apr 2020 10:48:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726381AbgD3Ost (ORCPT ); Thu, 30 Apr 2020 10:48:49 -0400 Received: from mail-wm1-x343.google.com (mail-wm1-x343.google.com [IPv6:2a00:1450:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 363FDC035494 for ; Thu, 30 Apr 2020 07:48:49 -0700 (PDT) Received: by mail-wm1-x343.google.com with SMTP id u127so2252722wmg.1 for ; Thu, 30 Apr 2020 07:48:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Et31WmaEF3NVxQ9iRAHtWhBYsTOVasFwLzjZZ8UNgn4=; b=bC+mz6GfvrnkOnQEz/hwR9vsyG+MUq+E6dxIarhu6iYRLAXwYKw8e+g6X+D4R8l+IH sMOa5WsbPR2Njm/N5hvCsmHXp/J4/8BJatuBqFCFWe/11sj222cqDm5wvQ9XR0qHNVTp xKMnub7wYILsLr3ZVeu1u/oCCj2JcM5eNtGB9cdY4cRE8BBuoQzQA/57yVi+JqWiP8hk rvvSkBeHxyV4lQ5NKFuZm+q1W0ypfO7AjdnUek1NcCC7RhCM7G1EuxLxmFxCd20l/UcP e9Wu+aLysGBDvEg/WmqNk/ZVA+zl0fTKNaWy25DymyTsz7nJtrx62FMqKsazcbtU+yQg z02Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Et31WmaEF3NVxQ9iRAHtWhBYsTOVasFwLzjZZ8UNgn4=; b=tBc0vLG2ajUDFnwQw7/xcuEuIN+sA1yTqGOGOdGGCL5mgFXo0OQi7oC5zZOJfU8xlo TnCOeAyMgpNGHlH90FkniQg3ZJjcr2beW9NyZMnsft40VBSx84Xr9wjv7Oi5CqZse7Nc IAUd+xGhWReZ5/IZ/NYa17MOMg9z+ZuLCUm/lniHcD6EEZbroQ9Iccxtpa9MAMz9QPX/ KMu7YE0NwwivDoOl/cYb90qfLW7SEehPeUfpiDgx8NinmJfszvv5Dohp6ZtybUjXG8GB dF8S7EDwDQhmFMkryZROSi9KBdx6vBStrHFq86G4mAmRzdXgwvImjsRFFXTd6EBS1AwT BXPQ== X-Gm-Message-State: AGi0PuZMNBWLtrRg2wOaGr8BYGfZm+xquSVoSzRGQErhr0jOaPLNQXsK WxsrIhV0o524EANDiieIyqan7w== X-Google-Smtp-Source: APiQypLUgdRp550jRZBba6fEHIWQDJiuFtrLkN9twyuprE+II7yxmPIaRskKBXyR0JgZ3TtglMgvqw== X-Received: by 2002:a1c:9cca:: with SMTP id f193mr3308452wme.71.1588258127525; Thu, 30 Apr 2020 07:48:47 -0700 (PDT) Received: from localhost ([2a01:4b00:8523:2d03:d4b6:9828:8bd2:ce6f]) by smtp.gmail.com with ESMTPSA id v19sm4450674wra.57.2020.04.30.07.48.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Apr 2020 07:48:46 -0700 (PDT) From: David Brazdil To: Catalin Marinas , James Morse , Julien Thierry , Marc Zyngier , Suzuki K Poulose , Will Deacon Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Quentin Perret , David Brazdil Subject: [PATCH 02/15] arm64: kvm: Formalize host-hyp hypcall ABI Date: Thu, 30 Apr 2020 15:48:18 +0100 Message-Id: <20200430144831.59194-3-dbrazdil@google.com> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200430144831.59194-1-dbrazdil@google.com> References: <20200430144831.59194-1-dbrazdil@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Quentin Perret In preparation for removing the hyp code from the TCB, convert the current EL1 - EL2 KVM ABI to use hypercall numbers in lieu of direct function pointers. While this in itself does not provide any isolation, it is a first step towards having a properly defined EL2 ABI. The implementation is based on a kvm_hcall_table which holds function pointers to the hyp_text functions corresponding to each hypercall. This is highly inspired from the arm64 sys_call_table, the main difference being the lack of hcall wrappers at this stage. Signed-off-by: Quentin Perret Signed-off-by: David Brazdil --- arch/arm64/include/asm/kvm_host.h | 20 ++++++- arch/arm64/include/asm/kvm_host_hypercalls.h | 62 ++++++++++++++++++++ arch/arm64/kvm/hyp/Makefile | 2 +- arch/arm64/kvm/hyp/host_hypercall.c | 22 +++++++ arch/arm64/kvm/hyp/hyp-entry.S | 36 +++++++++++- 5 files changed, 137 insertions(+), 5 deletions(-) create mode 100644 arch/arm64/include/asm/kvm_host_hypercalls.h create mode 100644 arch/arm64/kvm/hyp/host_hypercall.c diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e61143d6602d..5dec3b06f2b7 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -447,10 +448,25 @@ int kvm_test_age_hva(struct kvm *kvm, unsigned long hva); void kvm_arm_halt_guest(struct kvm *kvm); void kvm_arm_resume_guest(struct kvm *kvm); -#define kvm_call_hyp_nvhe(hypfn, ...) \ - __kvm_call_hyp((unsigned long)kvm_ksym_ref(hypfn), ##__VA_ARGS__) +/* + * Call the hypervisor via HVC. The hcall parameter must be the name of + * a hypercall as defined in . + * + * Hypercalls take at most 6 parameters. + */ +#define kvm_call_hyp_nvhe(hcall, ...) \ + __kvm_call_hyp(KVM_HOST_HCALL_NR(hcall), ##__VA_ARGS__) /* + * u64 kvm_call_hyp(hcall, ...); + * + * Call the hypervisor. The hcall parameter must be the name of a hypercall + * defined in . In the VHE case, this will be + * translated into a direct function call. + * + * A hcall value of less than 0xfff has a special meaning and is used to + * implement hyp stubs in the same way as in arch/arm64/kernel/hyp_stub.S. + * * The couple of isb() below are there to guarantee the same behaviour * on VHE as on !VHE, where the eret to EL1 acts as a context * synchronization event. diff --git a/arch/arm64/include/asm/kvm_host_hypercalls.h b/arch/arm64/include/asm/kvm_host_hypercalls.h new file mode 100644 index 000000000000..af8ad505d816 --- /dev/null +++ b/arch/arm64/include/asm/kvm_host_hypercalls.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 Google, inc + */ + +#ifndef __KVM_HOST_HCALL +#define __KVM_HOST_HCALL(x) +#endif + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_enable_ssbs 0 +__KVM_HOST_HCALL(__kvm_enable_ssbs) + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_get_mdcr_el2 1 +__KVM_HOST_HCALL(__kvm_get_mdcr_el2) + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_timer_set_cntvoff 2 +__KVM_HOST_HCALL(__kvm_timer_set_cntvoff) + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_tlb_flush_local_vmid 3 +__KVM_HOST_HCALL(__kvm_tlb_flush_local_vmid) + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_flush_vm_context 4 +__KVM_HOST_HCALL(__kvm_flush_vm_context) + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_vcpu_run_nvhe 5 +__KVM_HOST_HCALL(__kvm_vcpu_run_nvhe) + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_tlb_flush_vmid 6 +__KVM_HOST_HCALL(__kvm_tlb_flush_vmid) + +#define __KVM_HOST_HCALL_TABLE_IDX___kvm_tlb_flush_vmid_ipa 7 +__KVM_HOST_HCALL(__kvm_tlb_flush_vmid_ipa) + +#define __KVM_HOST_HCALL_TABLE_IDX___vgic_v3_init_lrs 8 +__KVM_HOST_HCALL(__vgic_v3_init_lrs) + +#define __KVM_HOST_HCALL_TABLE_IDX___vgic_v3_get_ich_vtr_el2 9 +__KVM_HOST_HCALL(__vgic_v3_get_ich_vtr_el2) + +#define __KVM_HOST_HCALL_TABLE_IDX___vgic_v3_write_vmcr 10 +__KVM_HOST_HCALL(__vgic_v3_write_vmcr) + +#define __KVM_HOST_HCALL_TABLE_IDX___vgic_v3_restore_aprs 11 +__KVM_HOST_HCALL(__vgic_v3_restore_aprs) + +#define __KVM_HOST_HCALL_TABLE_IDX___vgic_v3_read_vmcr 12 +__KVM_HOST_HCALL(__vgic_v3_read_vmcr) + +#define __KVM_HOST_HCALL_TABLE_IDX___vgic_v3_save_aprs 13 +__KVM_HOST_HCALL(__vgic_v3_save_aprs) + +#define __KVM_HOST_HCALL_TABLE_IDX_SIZE 14 + +/* XXX - Arbitrary offset for KVM-related hypercalls */ +#define __KVM_HOST_HCALL_BASE_SHIFT 8 +#define __KVM_HOST_HCALL_BASE (1ULL << __KVM_HOST_HCALL_BASE_SHIFT) +#define __KVM_HOST_HCALL_END (__KVM_HOST_HCALL_BASE + \ + __KVM_HOST_HCALL_TABLE_IDX_SIZE) + +/* Hypercall number = kvm offset + table idx */ +#define KVM_HOST_HCALL_NR(name) (__KVM_HOST_HCALL_TABLE_IDX_##name + \ + __KVM_HOST_HCALL_BASE) diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index 8c9880783839..29e2b2cd2fbc 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -9,7 +9,7 @@ ccflags-y += -fno-stack-protector -DDISABLE_BRANCH_PROFILING \ obj-$(CONFIG_KVM) += hyp.o hyp-y := vgic-v3-sr.o timer-sr.o aarch32.o vgic-v2-cpuif-proxy.o sysreg-sr.o \ - debug-sr.o entry.o switch.o fpsimd.o tlb.o hyp-entry.o + debug-sr.o entry.o switch.o fpsimd.o tlb.o host_hypercall.o hyp-entry.o # KVM code is run at a different exception code with a different map, so # compiler instrumentation that inserts callbacks or checks into the code may diff --git a/arch/arm64/kvm/hyp/host_hypercall.c b/arch/arm64/kvm/hyp/host_hypercall.c new file mode 100644 index 000000000000..6b31310f36a8 --- /dev/null +++ b/arch/arm64/kvm/hyp/host_hypercall.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google, inc + */ + +#include + +typedef long (*kvm_hcall_fn_t)(void); + +static long __hyp_text kvm_hc_ni(void) +{ + return -ENOSYS; +} + +#undef __KVM_HOST_HCALL +#define __KVM_HOST_HCALL(name) \ + [__KVM_HOST_HCALL_TABLE_IDX_##name] = (long (*)(void))name, + +const kvm_hcall_fn_t kvm_hcall_table[__KVM_HOST_HCALL_TABLE_IDX_SIZE] = { + [0 ... __KVM_HOST_HCALL_TABLE_IDX_SIZE-1] = kvm_hc_ni, +#include +}; diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index c2a13ab3c471..1a51a0958504 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -13,6 +13,7 @@ #include #include #include +#include #include .text @@ -21,17 +22,26 @@ .macro do_el2_call /* * Shuffle the parameters before calling the function - * pointed to in x0. Assumes parameters in x[1,2,3]. + * pointed to in x0. Assumes parameters in x[1,2,3,4,5,6]. */ str lr, [sp, #-16]! mov lr, x0 mov x0, x1 mov x1, x2 mov x2, x3 + mov x3, x4 + mov x4, x5 + mov x5, x6 blr lr ldr lr, [sp], #16 .endm +/* kern_hyp_va(lm_alias(ksym)) */ +.macro ksym_hyp_va ksym, lm_offset + sub \ksym, \ksym, \lm_offset + kern_hyp_va \ksym +.endm + el1_sync: // Guest trapped into EL2 mrs x0, esr_el2 @@ -66,10 +76,32 @@ el1_sync: // Guest trapped into EL2 br x5 1: + /* Check if the hcall number is valid */ + cmp x0, #__KVM_HOST_HCALL_BASE + b.lt 2f + cmp x0, #__KVM_HOST_HCALL_END + b.lt 3f +2: + mov x0, -ENOSYS + eret + +3: + /* Compute lm_alias() offset in x9 */ + ldr_l x9, kimage_voffset + ldr_l x10, physvirt_offset + add x9, x9, x10 + + /* Find hcall function pointer in the table */ + ldr x10, =kvm_hcall_table + ksym_hyp_va x10, x9 + sub x0, x0, #__KVM_HOST_HCALL_BASE + add x0, x10, x0, lsl 3 + ldr x0, [x0] + ksym_hyp_va x0, x9 + /* * Perform the EL2 call */ - kern_hyp_va x0 do_el2_call eret -- 2.26.1