From patchwork Fri Feb 22 16:25:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 10826563 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5C82613B5 for ; Fri, 22 Feb 2019 16:28:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 45938313C6 for ; Fri, 22 Feb 2019 16:28:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 39B27315BD; Fri, 22 Feb 2019 16:28:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D3CEF313C6 for ; Fri, 22 Feb 2019 16:28:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Xb1K1tLe4wdXuQ+B78KvPVBmLVHOKhC+hTY3FAPdm58=; b=eTv8V9XqBqY1xn h/QXjgQniUZQ9UIJG33V/IAbmTmI0Z4iSH9mfwmxl0ivCaI6RpH8PlIaNIeUwHM8h3G/8uqdpBa6P MIhO3h2aS1lbSxrLZuip7VW/QiGXVybuj3Yf7tCtGV59HWZa6b9hWeq9WuYaWNOazbiY6thVsksAM PbQty1hf28ca0R7OfO5TbSeI96O08T+DM29c8r7PiUYfOs/XETJYVpeiaBY6lauDvCc7RkyyL4y8V vVGESMBJ+gFgSBmiBOCe9ZTABpZgyLpU0vdcfv6NS7EVzUq3/wBkv4jle4c/WWXp0hhii+2ZE/exk sAEQZh88xiZw7Gj9ySlg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gxDgC-00086D-2F; Fri, 22 Feb 2019 16:28:04 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gxDfT-0007FI-J8 for linux-arm-kernel@lists.infradead.org; Fri, 22 Feb 2019 16:27:24 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 430ED80D; Fri, 22 Feb 2019 08:27:19 -0800 (PST) Received: from big-swifty.lan (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 71F9C3F5C1; Fri, 22 Feb 2019 08:27:14 -0800 (PST) From: Marc Zyngier To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Subject: [PATCH 05/27] ARM: KVM: Teach some form of type-safety to kvm_call_hyp Date: Fri, 22 Feb 2019 16:25:43 +0000 Message-Id: <20190222162605.5054-6-marc.zyngier@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190222162605.5054-1-marc.zyngier@arm.com> References: <20190222162605.5054-1-marc.zyngier@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190222_082720_250421_A0C2136F X-CRM114-Status: GOOD ( 13.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Julien Thierry , kvm@vger.kernel.org, Ard Biesheuvel , Andre Przywara , Daniel Lezcano , Christoffer Dall , kvmarm@lists.cs.columbia.edu, Shaokun Zhang , Masahiro Yamada , James Morse , linux-arm-kernel@lists.infradead.org, Zenghui Yu , Colin Ian King , Dave Martin , Suzuki K Poulose Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Just like on arm64, and for the same reasons, kvm_call_hyp removes any form of type safety when calling into HYP. But we can still try to tell the compiler what we're trying to achieve. Here, we can add code that would do the function call if it wasn't guarded by an always-false predicate. Hopefully, the compiler is dumb enough to do the type checking and clever enough to not emit the corresponding code... Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 31 ++++++++++++++++++++++++++++--- arch/arm/kvm/hyp/hyp-entry.S | 2 +- arch/arm/kvm/interrupts.S | 4 ++-- 3 files changed, 31 insertions(+), 6 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 023c9f2b1eea..4b6193f2f0f6 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -215,8 +215,33 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices); int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); -unsigned long kvm_call_hyp(void *hypfn, ...); -#define kvm_call_hyp_ret(f, ...) kvm_call_hyp(f, ##__VA_ARGS__) +unsigned long __kvm_call_hyp(void *hypfn, ...); + +/* + * The has_vhe() part doesn't get emitted, but is used for type-checking. + */ +#define kvm_call_hyp(f, ...) \ + do { \ + if (has_vhe()) { \ + f(__VA_ARGS__); \ + } else { \ + __kvm_call_hyp(kvm_ksym_ref(f), ##__VA_ARGS__); \ + } \ + } while(0) + +#define kvm_call_hyp_ret(f, ...) \ + ({ \ + typeof(f(__VA_ARGS__)) ret; \ + \ + if (has_vhe()) { \ + ret = f(__VA_ARGS__); \ + } else { \ + ret = __kvm_call_hyp(kvm_ksym_ref(f), \ + ##__VA_ARGS__); \ + } \ + \ + ret; \ + }) void force_vm_exit(const cpumask_t *mask); int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, @@ -268,7 +293,7 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, * compliant with the PCS!). */ - kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr); + __kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr); } static inline void __cpu_init_stage2(void) diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S index aa3f9a9837ac..6ed3cf23fe89 100644 --- a/arch/arm/kvm/hyp/hyp-entry.S +++ b/arch/arm/kvm/hyp/hyp-entry.S @@ -176,7 +176,7 @@ THUMB( orr lr, lr, #PSR_T_BIT ) msr spsr_cxsf, lr ldr lr, =panic msr ELR_hyp, lr - ldr lr, =kvm_call_hyp + ldr lr, =__kvm_call_hyp clrex eret ENDPROC(__hyp_do_panic) diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S index 80a1d6cd261c..a08e6419ebe9 100644 --- a/arch/arm/kvm/interrupts.S +++ b/arch/arm/kvm/interrupts.S @@ -42,7 +42,7 @@ * r12: caller save * rest: callee save */ -ENTRY(kvm_call_hyp) +ENTRY(__kvm_call_hyp) hvc #0 bx lr -ENDPROC(kvm_call_hyp) +ENDPROC(__kvm_call_hyp)