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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DA83C433EF for ; Fri, 1 Jul 2022 10:50:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235992AbiGAKuJ (ORCPT ); Fri, 1 Jul 2022 06:50:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234901AbiGAKuH (ORCPT ); Fri, 1 Jul 2022 06:50:07 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E46DF7C190 for ; Fri, 1 Jul 2022 03:50:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A0728B82F52 for ; Fri, 1 Jul 2022 10:50:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47832C3411E; Fri, 1 Jul 2022 10:50:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656672604; bh=KL3HCbfmIFwpgQxHgKNqdfe68KZEBjGoiTLhKkW04Vc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BZ8+LMQYkO8E3V0b8x4/wGg6JBNFWqJgwC4FRyMHck0/WTp19N4v4FQPnclu+j6uR tto47Kdud5bf028XT5T9xTI4e8nCc0FwS2yNCid9JchnCytU5A2DqvMnnV1o6H8AXA ZEZLW9NYPVGbKq/79ooZL4bkpTAoYHmbp3C3xXaCYGp1pSzxy79HHc46bmn4yxF8zr VCl0gB3p81ePFR2Vheu2BXxncQd+PVrwLIO3tivUDNPMDfYiYf0vSgoXhJohV70HtW UbCx/X16K93C/U1017ms10b96VSYr9qHLl1IymA5e1ONQD/z+1HQ16HBR6cxEH+Plz B4+WTj3FrWRmw== Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1o7EDp-004Z3B-EI; Fri, 01 Jul 2022 11:50:01 +0100 MIME-Version: 1.0 Date: Fri, 01 Jul 2022 11:50:01 +0100 From: Marc Zyngier To: Schspa Shi Cc: james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: arm64: Fix 64 bit mmio handle In-Reply-To: References: <20220630161220.53449-1-schspa@gmail.com> <87mtdu15ok.wl-maz@kernel.org> User-Agent: Roundcube Webmail/1.4.13 Message-ID: X-Sender: maz@kernel.org Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: schspa@gmail.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-06-30 17:50, Schspa Shi wrote: > Marc Zyngier writes: > >> On Thu, 30 Jun 2022 17:12:20 +0100, >> Schspa Shi wrote: >>> >>> If the len is 8 bytes, we can't get the correct sign extend for >>> be system. >> >> I'm afraid you'll have to give me a bit more details. >> >>> >>> Fix the mask type len and the comparison of length. >>> >>> Signed-off-by: Schspa Shi >>> --- >>> arch/arm64/kvm/mmio.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c >>> index 3dd38a151d2a6..0692f8b18f35c 100644 >>> --- a/arch/arm64/kvm/mmio.c >>> +++ b/arch/arm64/kvm/mmio.c >>> @@ -81,8 +81,8 @@ unsigned long kvm_mmio_read_buf(const void *buf, >>> unsigned int len) >>> int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) >>> { >>> unsigned long data; >>> + unsigned long mask; >>> unsigned int len; >>> - int mask; >>> /* Detect an already handled MMIO return */ >>> if (unlikely(!vcpu->mmio_needed)) >>> @@ -97,7 +97,7 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) >>> data = kvm_mmio_read_buf(run->mmio.data, len); >>> if (kvm_vcpu_dabt_issext(vcpu) && >>> - len < sizeof(unsigned long)) { >>> + len <= sizeof(unsigned long)) { >> >> If you're reading an 8 byte quantity, what is there to sign-extend? >> Sign extension only makes sense if what you're reading is *smaller* >> than the size of the register you are targeting. >> > > Yes, you are correct, sorry for my bad patch. > Please ignore this patch. > >> I must be missing something. And how is that related to running BE? BE >> in the host? The guest? > > I mean BE is for guest running with BE mode. So what problem did you see? If you have noticed something going wrong, I'd like to get it fixed. Thanks, M. -- Jazz is not dead. It just smells funny...