From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 B9548EEB2 for ; Mon, 3 Feb 2025 01:07:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738544852; cv=pass; b=QBYE4ZtdVa4rBgdBOsp13anWJ81DaThMdsngLfktsKo1jPWWekgjaQ1OY2Ncrb03LVhsaPiWjsuz5IBJHAG61CzHFuWRAxeFWrmmnMCa20VE5BOv754dFX6A9yCpvecgKnGtuQH8jj5g+ZJ0dWw3PCYdbCdofQSL+0bjUbqfaig= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738544852; c=relaxed/simple; bh=Wqr2EkVFL2Enyi5Q6AQ3cOAHr+yM4TJjXKSOKedIOG8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rUsluEsLAA28wYbQIJHzr2wlJYfF17eXDgCmEUxYWIc4Y0LWqKklT4Hk2tnbB4ni/QXGhRLfLKneL3pRBFxhwgH8hHoioTwhSLdWbtJuF7hFPBiS+8hf2JpivvgLmPVN8M57c+QKO75E7LQBQT4pK4JAhh5Um0jgyksG5KobDH8= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=dmitry.osipenko@collabora.com header.b=Ri8gky45; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=dmitry.osipenko@collabora.com header.b="Ri8gky45" ARC-Seal: i=1; a=rsa-sha256; t=1738544841; cv=none; d=zohomail.com; s=zohoarc; b=PAWag2A7a1OVTqEWxPEBABzr/en3f0pfIR7P/gedajimLiPSMcIbkNL0Gwx005BUwrnOjk1izQP6cTMltoLjmt8jLIGtj/tpstdJKLNXNKYcQY9jAGdziW4YMlTItOQ/E/C8X3p5haehrAUIsHLF/PuVzKItGNHsOC+CwnTehog= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1738544841; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=KnGTluyypwtazBIRrVkSvKuikw6cFhABGbbWmFW2RaU=; b=IkF66q/QuaoBGxJLPPQdrXWXQ4EB92JbYzhWn6GGTfqs0y9ku0y+N57XclzvyiIj/HMjJyEp8MD661hAvxXpw3qri16GOTeQzQZ3vy1udJ5ubYhztlnNunUt2RERmrRfWeNxsgZm1wu98MSEVcHG6iTWdF2uIJQV+a7i0nDUm1Y= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=dmitry.osipenko@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1738544841; s=zohomail; d=collabora.com; i=dmitry.osipenko@collabora.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:References:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=KnGTluyypwtazBIRrVkSvKuikw6cFhABGbbWmFW2RaU=; b=Ri8gky45buTDhbjOUQq6J3IB83+m70o013N/TwbbklDQuDh4V8cbe5XTVUUDw1i4 Y8BTk7EuubEXjs1qZfCj+6WjfGslR+isUEyZojA/ao69nVsxwNAVSxp2LwygQfB0VCP b5pmdp/fTDp/+8meJiYsazgbWgsBED8CNXpmOtvI= Received: by mx.zohomail.com with SMTPS id 1738544837827544.081124145429; Sun, 2 Feb 2025 17:07:17 -0800 (PST) Message-ID: Date: Mon, 3 Feb 2025 04:07:13 +0300 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5] drm/virtio: Add drm_panic support To: Jocelyn Falempe , Ryosuke Yasuoka , airlied@redhat.com, kraxel@redhat.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, daniel@ffwll.ch, christophe.jaillet@wanadoo.fr Cc: virtualization@lists.linux.dev, spice-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org References: <20241129122408.4167150-1-ryasuoka@redhat.com> <3ca0382c-a410-4424-a5a4-7c1b8be7ebed@collabora.com> Content-Language: en-US From: Dmitry Osipenko In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ZohoMailClient: External On 12/2/24 20:19, Jocelyn Falempe wrote: >>> >>> I've now noticed that drm_gem_shmem_vmap() expects BO reservation lock >>> to be held and we can't take lock it at a panic time. >>> >>> https://elixir.bootlin.com/linux/v6.12.1/source/drivers/gpu/drm/ >>> drm_gem_shmem_helper.c#L330 >>> >>> This resv warning isn't triggered because bo->base.vaddr is set for VT >>> framebufffer BO when panic happens. > > I usually test using gnome desktop in the VM, and in this case vaddr is > not set, and calling vmap() is needed. (and I don't get the warning, I > will check why). All those get_pages() and vmap() that drm_gem_shmem_vmap() uses may sleep. You'll need to add atomic variants for the vmap funcs if it's really needed. Like I said in the comment to v6, let's start with rejecting BOs that aren't vmapped. If atomic vmap will become needed, it will be a separate problem to solve. -- Best regards, Dmitry