From patchwork Thu Oct 15 16:44:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Tyshchenko X-Patchwork-Id: 11839813 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7F0311580 for ; Thu, 15 Oct 2020 16:54:50 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 469B1206CA for ; Thu, 15 Oct 2020 16:54:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fG3fb6wo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 469B1206CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.7609.20047 (Exim 4.92) (envelope-from ) id 1kT6VB-00079w-Ed; Thu, 15 Oct 2020 16:53:17 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 7609.20047; Thu, 15 Oct 2020 16:53:17 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kT6VB-00079d-5Q; Thu, 15 Oct 2020 16:53:17 +0000 Received: by outflank-mailman (input) for mailman id 7609; Thu, 15 Oct 2020 16:53:14 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kT6Oc-0004yr-7t for xen-devel@lists.xenproject.org; Thu, 15 Oct 2020 16:46:30 +0000 Received: from mail-lj1-x241.google.com (unknown [2a00:1450:4864:20::241]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 811b3513-adc9-4cb8-b290-00b531824646; Thu, 15 Oct 2020 16:45:15 +0000 (UTC) Received: by mail-lj1-x241.google.com with SMTP id d24so3810777ljg.10 for ; Thu, 15 Oct 2020 09:45:13 -0700 (PDT) Received: from otyshchenko.www.tendawifi.com ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id v13sm1482495ljh.66.2020.10.15.09.45.11 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Oct 2020 09:45:11 -0700 (PDT) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kT6Oc-0004yr-7t for xen-devel@lists.xenproject.org; Thu, 15 Oct 2020 16:46:30 +0000 X-Inumbo-ID: 811b3513-adc9-4cb8-b290-00b531824646 Received: from mail-lj1-x241.google.com (unknown [2a00:1450:4864:20::241]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 811b3513-adc9-4cb8-b290-00b531824646; Thu, 15 Oct 2020 16:45:15 +0000 (UTC) Received: by mail-lj1-x241.google.com with SMTP id d24so3810777ljg.10 for ; Thu, 15 Oct 2020 09:45:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=47uSMzel/qyKvhdlJs+JuPDeminjR3OYh46RDdFyYQ0=; b=fG3fb6woHBFXSTVeiwPo9CpE+xX7xDaX3P/Ipp+QjUKLXEPN7utLwZsQnDYIXMZRhY sPxnO3QYtPIwozFSmAwgEqqXOZi2a3qGVy7JMgDgFFWzSAGSRUXkfhwD26mPruIIsgud 5B1pJBwOjUw1CKnNCvZpxhWVWm4PqNPaegEzPTetVmJNgAsKmJQqqLx4V2qBWXjPmZXQ XVdn043F/aLeDZ8cwaeoNLq/fRNu2MBsCkNNlY31vhkb3IwiccabZxC81G+/juWmu+0m j3PjHniDNzVNyRul3upS2vMh/XMkbfpcLh/vKfO5t+z+vtinujboWf4TBxO6hBmvrlrU /5Lg== 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; bh=47uSMzel/qyKvhdlJs+JuPDeminjR3OYh46RDdFyYQ0=; b=WsXEXKtNeJ3f6R5sdvVlN25wbpeAIAm81v4/0uwKKyq65tZar637QfDu8UodFFb88i lEukt4RjigORHCneruwrricmumQWEWktMa2Msa9lOu4H/qH3N4pzV1pWBuPML9U1pgQQ n6TgE510h83aaGMcTd+/AByKJb59x3UiD38wp5fao+gQX31r5vDjJ3miE+gn2vuRRQZZ XZ6A5zOcqBDnhdzekwtiaezWI4SI3JKVNkDSZDSaDwAwTCpcjfrcWyy7ecZiWXAflcPh HIedMZubJ65UPntoVepZ9cTxj1OjrG/7EjNzK0+GYWaF4E5KNpc//eR6f7wiC1jaq+vi qjaQ== X-Gm-Message-State: AOAM531vJpSqLL6+A0J5/8wERo4zad12c/uh3O7Ejeoqwe5JhLJ7rvdY jFiEDQtzVLOfQRnECcvhdETzgHwRLEXewQ== X-Google-Smtp-Source: ABdhPJywyMpzDJLnEtIr2K9tTpva81uus1tSMSmwnOhgcs9eIfdM4k5UwxqS97psn9uT12wdbF171g== X-Received: by 2002:a2e:8582:: with SMTP id b2mr1570200lji.376.1602780312263; Thu, 15 Oct 2020 09:45:12 -0700 (PDT) Received: from otyshchenko.www.tendawifi.com ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id v13sm1482495ljh.66.2020.10.15.09.45.11 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Oct 2020 09:45:11 -0700 (PDT) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org Cc: Oleksandr Tyshchenko , Stefano Stabellini , Julien Grall , Volodymyr Babchuk , Julien Grall Subject: [PATCH V2 19/23] xen/arm: io: Abstract sign-extension Date: Thu, 15 Oct 2020 19:44:30 +0300 Message-Id: <1602780274-29141-20-git-send-email-olekstysh@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1602780274-29141-1-git-send-email-olekstysh@gmail.com> References: <1602780274-29141-1-git-send-email-olekstysh@gmail.com> From: Oleksandr Tyshchenko In order to avoid code duplication (both handle_read() and handle_ioserv() contain the same code for the sign-extension) put this code to a common helper to be used for both. Signed-off-by: Oleksandr Tyshchenko CC: Julien Grall --- Please note, this is a split/cleanup/hardening of Julien's PoC: "Add support for Guest IO forwarding to a device emulator" Changes V1 -> V2: - new patch --- xen/arch/arm/io.c | 18 ++---------------- xen/arch/arm/ioreq.c | 17 +---------------- xen/include/asm-arm/traps.h | 24 ++++++++++++++++++++++++ 3 files changed, 27 insertions(+), 32 deletions(-) diff --git a/xen/arch/arm/io.c b/xen/arch/arm/io.c index f44cfd4..8d6ec6c 100644 --- a/xen/arch/arm/io.c +++ b/xen/arch/arm/io.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include "decode.h" @@ -39,26 +40,11 @@ static enum io_state handle_read(const struct mmio_handler *handler, * setting r). */ register_t r = 0; - uint8_t size = (1 << dabt.size) * 8; if ( !handler->ops->read(v, info, &r, handler->priv) ) return IO_ABORT; - /* - * Sign extend if required. - * Note that we expect the read handler to have zeroed the bits - * outside the requested access size. - */ - if ( dabt.sign && (r & (1UL << (size - 1))) ) - { - /* - * We are relying on register_t using the same as - * an unsigned long in order to keep the 32-bit assembly - * code smaller. - */ - BUILD_BUG_ON(sizeof(register_t) != sizeof(unsigned long)); - r |= (~0UL) << size; - } + r = sign_extend(dabt, r); set_user_reg(regs, dabt.reg, r); diff --git a/xen/arch/arm/ioreq.c b/xen/arch/arm/ioreq.c index da5ceac..ad17b80 100644 --- a/xen/arch/arm/ioreq.c +++ b/xen/arch/arm/ioreq.c @@ -28,7 +28,6 @@ enum io_state handle_ioserv(struct cpu_user_regs *regs, struct vcpu *v) const union hsr hsr = { .bits = regs->hsr }; const struct hsr_dabt dabt = hsr.dabt; /* Code is similar to handle_read */ - uint8_t size = (1 << dabt.size) * 8; register_t r = v->io.io_req.data; /* We are done with the IO */ @@ -37,21 +36,7 @@ enum io_state handle_ioserv(struct cpu_user_regs *regs, struct vcpu *v) if ( dabt.write ) return IO_HANDLED; - /* - * Sign extend if required. - * Note that we expect the read handler to have zeroed the bits - * outside the requested access size. - */ - if ( dabt.sign && (r & (1UL << (size - 1))) ) - { - /* - * We are relying on register_t using the same as - * an unsigned long in order to keep the 32-bit assembly - * code smaller. - */ - BUILD_BUG_ON(sizeof(register_t) != sizeof(unsigned long)); - r |= (~0UL) << size; - } + r = sign_extend(dabt, r); set_user_reg(regs, dabt.reg, r); diff --git a/xen/include/asm-arm/traps.h b/xen/include/asm-arm/traps.h index 997c378..e301c44 100644 --- a/xen/include/asm-arm/traps.h +++ b/xen/include/asm-arm/traps.h @@ -83,6 +83,30 @@ static inline bool VABORT_GEN_BY_GUEST(const struct cpu_user_regs *regs) (unsigned long)abort_guest_exit_end == regs->pc; } +/* Check whether the sign extension is required and perform it */ +static inline register_t sign_extend(const struct hsr_dabt dabt, register_t r) +{ + uint8_t size = (1 << dabt.size) * 8; + + /* + * Sign extend if required. + * Note that we expect the read handler to have zeroed the bits + * outside the requested access size. + */ + if ( dabt.sign && (r & (1UL << (size - 1))) ) + { + /* + * We are relying on register_t using the same as + * an unsigned long in order to keep the 32-bit assembly + * code smaller. + */ + BUILD_BUG_ON(sizeof(register_t) != sizeof(unsigned long)); + r |= (~0UL) << size; + } + + return r; +} + #endif /* __ASM_ARM_TRAPS__ */ /* * Local variables: