From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f44.google.com (mail-ed1-f44.google.com [209.85.208.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D17F763EE for ; Thu, 18 Jul 2024 07:41:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721288500; cv=none; b=BV0d0dlSR06qAs7FFD23rnJ09VLf3n9hcCNn85czKIMEkG5sRCME3p46XYFvVcXk6fEwQIhDP+Vbw3rWc85sfyTXis3PL/hDHtBc6aiVZejPS2s4eCZCA+JTdIn22QS92iJKH+u4vOPFY8RryzAaTDbMU/WszEVMDV8kU4l59hE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721288500; c=relaxed/simple; bh=wVE+yx4Ss1MhXuj3+RhJnfm27yiEuBz9TzoY7IgOcqs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iZkY29yViQAG+Egi1SB3cIfRWYOJb2kKNlAlOAdXKwE8msdgth8H66UVoq6h5L8pLHYEiFLP9sYi0OFNEQl7THIj7SQUt2JAmZ3FrSkZyobW5GpMI0zDOZ6W/gKRA79jPBfqKckI3haOdS1oWi+/gr/cXBqHqjQkWWzGrZUiZyI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=Bp/qcbxN; arc=none smtp.client-ip=209.85.208.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Bp/qcbxN" Received: by mail-ed1-f44.google.com with SMTP id 4fb4d7f45d1cf-5a1fcb611baso193586a12.1 for ; Thu, 18 Jul 2024 00:41:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1721288497; x=1721893297; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=jsCgYHs9veGqQPIzZ9BstB5GAjg0LaX8Lo7wNPsbkjQ=; b=Bp/qcbxNpe1XK+TMf0fF+TVD5z0PcDAV9GSnUo1SXXdcgmRI+ryUIj5CbWbNjFF8Sk 6l2HA9LP7Yr4+cO72M3cD2QkNOK88Wj/KyvtCKPI5oZjpvl5HtpdXfyhQo151k8yASfQ AFw8TfL7MmVO2UA2VdVUrWj5w1Gwjpv1E4agLQawl2UYIxjh5PFqfwNN98hn8uPimifC dUjejV/kVZxd2oNhPwCu3J02LGzEQ/Ck+xX1lCnOQv5ggg+8uus1ISYiLclMBenqiuy6 0I0RB79snd+8kBODtldaowKhJ6NvttWTI33VkyjYvZ1nNNi2n+mUtRcg3DNR0eeXwQll lUhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721288497; x=1721893297; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=jsCgYHs9veGqQPIzZ9BstB5GAjg0LaX8Lo7wNPsbkjQ=; b=L6zHWrwZdb0Vh4k5XaQTB3hUbSr441ZDp1pgA7CstgNqxe9lxmEWvEww8I+0Nc6ViQ 3ST7txE7py7qn3jcbJHSUAzu2HP9I0XWNFSJlpO1oFfnV6rXwvwApl/ziMULaAx6xzXY 2QugCNr2tlIjjp0opT+sGAlb1YqaykS3P84Eauxye/HCwphqAANjy29mZKM5pf+OUc99 PFQ+rh6wCHUOBENkB2PSTpPVlDgBxIn8x+5/ujjAjb1BxuVDEq4m33hDd7VlnvBVdYr4 BxG026yUkrq0WmDIdljlFq258iFryIxZYH5pYYAiAdtV7697aXrsPA4aMehezUgXimX4 YwAA== X-Forwarded-Encrypted: i=1; AJvYcCU0POCIY4iUMquNZSdY0dgKkAoR+gpOZ4rDvg1tUHsKbbcT/X/Rd/dmITev5oNXowq4vBYwl8jmuAUVSMgLvsT/sI8Rch2r X-Gm-Message-State: AOJu0YwxUVV+9G1PgxJ7sFUPbgaNJ+QQSz5NXkSHnF6vELNmfAFhsht9 SfQf2u1SUk4ChwCiYwYZiVcsrVwK3QKmWLCVi6flfHnQAXZSrW3FgBxiMcvsyhE= X-Google-Smtp-Source: AGHT+IEahCzpsXdtrUWST/QB1gRZe+xS2I35R5EcstokAOmYiTArd2LOanE3HiK0z0ovnLW0y3eZDw== X-Received: by 2002:a05:6402:210d:b0:5a1:f360:9a6b with SMTP id 4fb4d7f45d1cf-5a1f360a5bbmr494938a12.6.1721288496755; Thu, 18 Jul 2024 00:41:36 -0700 (PDT) Received: from ?IPV6:2a02:8109:aa0d:be00::7424? ([2a02:8109:aa0d:be00::7424]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-59b268a293csm8021740a12.67.2024.07.18.00.41.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 18 Jul 2024 00:41:36 -0700 (PDT) Message-ID: Date: Thu, 18 Jul 2024 09:41:34 +0200 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] soc: qcom: cmd-db: Map shared memory as WC, not WB To: Maulik Shah , Bjorn Andersson , Konrad Dybcio Cc: stephan@gerhold.net, swboyd@chromium.org, dianders@chromium.org, robdclark@gmail.com, nikita@trvn.ru, quic_eberman@quicinc.com, quic_pkondeti@quicinc.com, quic_lsrao@quicinc.com, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Volodymyr Babchuk , stable@vger.kernel.org References: <20240718-cmd_db_uncached-v2-1-f6cf53164c90@quicinc.com> Content-Language: en-US From: Caleb Connolly In-Reply-To: <20240718-cmd_db_uncached-v2-1-f6cf53164c90@quicinc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 18/07/2024 08:03, Maulik Shah wrote: > From: Volodymyr Babchuk > > Linux does not write into cmd-db region. This region of memory is write > protected by XPU. XPU may sometime falsely detect clean cache eviction > as "write" into the write protected region leading to secure interrupt > which causes an endless loop somewhere in Trust Zone. > > The only reason it is working right now is because Qualcomm Hypervisor > maps the same region as Non-Cacheable memory in Stage 2 translation > tables. The issue manifests if we want to use another hypervisor (like > Xen or KVM), which does not know anything about those specific mappings. > > Changing the mapping of cmd-db memory from MEMREMAP_WB to MEMREMAP_WT/WC > removes dependency on correct mappings in Stage 2 tables. This patch > fixes the issue by updating the mapping to MEMREMAP_WC. > > I tested this on SA8155P with Xen. > > Fixes: 312416d9171a ("drivers: qcom: add command DB driver") > Cc: stable@vger.kernel.org # 5.4+ > Signed-off-by: Volodymyr Babchuk > Tested-by: Nikita Travkin # sc7180 WoA in EL2 > Signed-off-by: Maulik Shah Reviewed-by: Caleb Connolly > --- > Changes in v2: > - Use MEMREMAP_WC instead of MEMREMAP_WT > - Update commit message from comments in v1 > - Add Fixes tag and Cc to stable > - Link to v1: https://lore.kernel.org/lkml/20240327200917.2576034-1-volodymyr_babchuk@epam.com > --- > drivers/soc/qcom/cmd-db.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/soc/qcom/cmd-db.c b/drivers/soc/qcom/cmd-db.c > index d84572662017..ae66c2623d25 100644 > --- a/drivers/soc/qcom/cmd-db.c > +++ b/drivers/soc/qcom/cmd-db.c > @@ -349,7 +349,7 @@ static int cmd_db_dev_probe(struct platform_device *pdev) > return -EINVAL; > } > > - cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WB); > + cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WC); > if (!cmd_db_header) { > ret = -ENOMEM; > cmd_db_header = NULL; > > --- > base-commit: 797012914d2d031430268fe512af0ccd7d8e46ef > change-id: 20240718-cmd_db_uncached-e896da5c5296 > > Best regards, -- // Caleb (they/them)