From patchwork Mon Mar 6 14:24:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 9606895 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EA10460414 for ; Mon, 6 Mar 2017 14:45:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DD96525D9E for ; Mon, 6 Mar 2017 14:45:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D276626907; Mon, 6 Mar 2017 14:45:43 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A418325D9E for ; Mon, 6 Mar 2017 14:45:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932482AbdCFOpf (ORCPT ); Mon, 6 Mar 2017 09:45:35 -0500 Received: from foss.arm.com ([217.140.101.70]:36174 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753785AbdCFOe0 (ORCPT ); Mon, 6 Mar 2017 09:34:26 -0500 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 23A4D1991; Mon, 6 Mar 2017 06:26:34 -0800 (PST) Received: from on-the-bus.cambridge.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2510F3F220; Mon, 6 Mar 2017 06:26:31 -0800 (PST) From: Marc Zyngier To: Russell King , Ard Biesheuvel , Catalin Marinas , cdall@linaro.org, james.morse@arm.com Cc: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: [PATCH v3 14/25] ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall Date: Mon, 6 Mar 2017 14:24:47 +0000 Message-Id: <20170306142458.8875-15-marc.zyngier@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170306142458.8875-1-marc.zyngier@arm.com> References: <20170306142458.8875-1-marc.zyngier@arm.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In order to restore HYP mode to its original condition, KVM currently implements __kvm_hyp_reset(). As we're moving towards a hyp-stub defined API, it becomes necessary to implement HVC_RESET_VECTORS. This patch adds the HVC_RESET_VECTORS hypercall to the KVM init code, which so far lacked any form of hypercall support. Signed-off-by: Marc Zyngier --- arch/arm/include/asm/virt.h | 1 + arch/arm/kernel/hyp-stub.S | 2 +- arch/arm/kvm/init.S | 33 +++++++++++++++++++++++++++------ 3 files changed, 29 insertions(+), 7 deletions(-) diff --git a/arch/arm/include/asm/virt.h b/arch/arm/include/asm/virt.h index 5186718aab68..8d5625b790b5 100644 --- a/arch/arm/include/asm/virt.h +++ b/arch/arm/include/asm/virt.h @@ -54,6 +54,7 @@ static inline void sync_boot_mode(void) void __hyp_set_vectors(unsigned long phys_vector_base); unsigned long __hyp_get_vectors(void); +void __hyp_reset_vectors(void); #else #define __boot_cpu_mode (SVC_MODE) #define sync_boot_mode() diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S index 21794d4a8f36..3cb01e8a291d 100644 --- a/arch/arm/kernel/hyp-stub.S +++ b/arch/arm/kernel/hyp-stub.S @@ -280,7 +280,7 @@ ENDPROC(__hyp_reset_vectors) #endif .align 5 -__hyp_stub_vectors: +ENTRY(__hyp_stub_vectors) __hyp_stub_reset: W(b) . __hyp_stub_und: W(b) . __hyp_stub_svc: W(b) . diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S index bf89c919efc1..9b0c735a68f7 100644 --- a/arch/arm/kvm/init.S +++ b/arch/arm/kvm/init.S @@ -23,6 +23,7 @@ #include #include #include +#include /******************************************************************** * Hypervisor initialization @@ -39,6 +40,10 @@ * - Setup the page tables * - Enable the MMU * - Profit! (or eret, if you only care about the code). + * + * Another possibility is to get a HYP stub hypercall. + * We discriminate between the two by checking if r0 contains a value + * that is less than HVC_STUB_HCALL_NR. */ .text @@ -58,6 +63,10 @@ __kvm_hyp_init: W(b) . __do_hyp_init: + @ Check for a stub hypercall + cmp r0, #HVC_STUB_HCALL_NR + blo __kvm_handle_stub_hvc + @ Set stack pointer mov sp, r0 @@ -112,19 +121,31 @@ __do_hyp_init: eret - @ r0 : stub vectors address +ENTRY(__kvm_handle_stub_hvc) + cmp r0, #HVC_RESET_VECTORS + bne 1f ENTRY(__kvm_hyp_reset) /* We're now in idmap, disable MMU */ mrc p15, 4, r1, c1, c0, 0 @ HSCTLR - ldr r2, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I) - bic r1, r1, r2 + ldr r0, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I) + bic r1, r1, r0 mcr p15, 4, r1, c1, c0, 0 @ HSCTLR - /* Install stub vectors */ - mcr p15, 4, r0, c12, c0, 0 @ HVBAR - isb + /* + * Install stub vectors, using ardb's VA->PA trick. + */ +0: adr r0, 0b @ PA(0) + movw r1, #:lower16:__hyp_stub_vectors - 0b @ VA(stub) - VA(0) + movt r1, #:upper16:__hyp_stub_vectors - 0b + add r1, r1, r0 @ PA(stub) + mcr p15, 4, r1, c12, c0, 0 @ HVBAR + b exit + +1: mov r0, #-1 +exit: eret +ENDPROC(__kvm_handle_stub_hvc) ENDPROC(__kvm_hyp_reset) .ltorg