From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9F9DF158545 for ; Thu, 25 Sep 2025 22:47:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.184 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758840423; cv=none; b=ooz/7UkKHBDwi5kfH29GOY6ypNw6TEgx7zRdEYxzLWb/mA8fUoblg0gibSlm3LSU6GBjE/fEcn6E4WiWR/aZf08RymNUBK5hnIcUT+SLCWZQ2Ugip46m74n5m3esKUoaBq4hLVT7VPuQrdMFrN0VS/sWP4J5mHFaWK6UGPMqMAk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758840423; c=relaxed/simple; bh=a1sAzZtMIVzsVStFgqsULDjOFyrrQTy18Vek1hP1hnQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gIq2bm2cZrXewCcPsT3NmeYidQsRQNNPDJFT8IV10Al4Hv8yTwUfJVVVAN8BUyUSDRgtugaMmPMH4sFnavAt9++R2XvzE3qZSgREbgBxvg4LkUn6MpnEie07Q9EG3HZAqKAA2YzjUdLma0ePGEGieBrFg+jmVmbeDEuQhp4AFUg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=XTW7y5n9; arc=none smtp.client-ip=91.218.175.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="XTW7y5n9" Date: Thu, 25 Sep 2025 15:46:51 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1758840418; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UCxr7/EDa6kIX3HdLra6Zg2rSstiBXln9nQtEteQlFQ=; b=XTW7y5n9nkSgFryqJqKb8JmIPTPe0jZLmS08sdhnNRkfPD6WgsUgZNQverhMDkfBEY0Atu W7jyN4VpOf5eFGFRBoay+IDq2/TlcEDX8V29hB69iFjW7oJEkOTApCfJC7F1edpKUdL7K+ 8z15tGH8edDxNopsvfmaZV61oo1xS1U= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: Jan Kotas , "kvmarm@lists.linux.dev" Subject: Re: KVM NV + SVE host OS warning Message-ID: References: <799DD5E5-8BC2-47B3-A919-33429D3FB2F1@global.cadence.com> <865xd61tt5.wl-maz@kernel.org> <864isq1r66.wl-maz@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <864isq1r66.wl-maz@kernel.org> X-Migadu-Flow: FLOW_OUT On Thu, Sep 25, 2025 at 04:35:13PM +0100, Marc Zyngier wrote: > On Thu, 25 Sep 2025 16:10:22 +0100, > Jan Kotas wrote: > > > > Hi Marc, > > > > Thank you for a quick response. > > > > > On 25 Sep 2025, at 16:38, Marc Zyngier wrote: > > > > > > EXTERNAL MAIL > > > > > > > > > [+Oliver for the SVE stuff] > > > > > > Hi Jan, > > [...] > > > > > > > I would also recommend to update to 6.17 -- 6.16 was the first release > > > with NV, and while it may work, it will also have a lot of ugly bugs. > > > > I will try, but as I don’t own this machine, changing kernels might > > be… challenging. > > Well, you're already passing something on the command-line that is > documented as "experimental and should be used with extreme caution". > Changing the kernel is a walk in the park compared to that ;-). +1, also it'd be good to know what you're doing in the L1 and the L2 that leads to this bug. I just tried the original test setup I used when doing NV SVE and things appear to work (kvmarm/next + initramfs at L1 + L2, tested with sve-stress selftest). > > If there’s anything else I can provide to help track it down, > > please let me know. > > Testing the provided patch would be good -- I would if I could. Although I didn't repro the bug, the patch itself LGTM. Thanks, Oliver