From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8E880379EF1 for ; Sat, 28 Feb 2026 18:07:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302049; cv=none; b=G26pvOBY3Gp/lsLQh3wXV92FmjohUh1/HVbTVK/CUAJJ6VER4KRA09Q5Wd/XVAjGWnl2Y5bYF+B4hiK9N0LOskVzLdmpzPzOMfC+wfr1cN/GnZz95tsaZ7FPmeyMWk1UrqV7HkKrs54baiKCTc0/LKg29dQ7yjGiTayY6IVswBY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302049; c=relaxed/simple; bh=4aIeTImStaS5QuL/sWUjQivKC4NYdyFGlsiRCkbyiso=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fGffSchcYkhDiSaExF35zP9ezj8ZyUHubZ2MyVGBPUkWkft8xtFJPazV4tNRdhPv56Y4rnWMgZTXfvZb76nas1kSLGnyTLg3Akx8rlx7pAt6F/MtKf87hP2moGbcHemdvu8cTWVBWfeoPFeXy0cj6TLsQwtllRYjqPDKcf+KAIE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ikxVq7LW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ikxVq7LW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0673C116D0; Sat, 28 Feb 2026 18:07:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302049; bh=4aIeTImStaS5QuL/sWUjQivKC4NYdyFGlsiRCkbyiso=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ikxVq7LWG23aBiIAJE8HDQgzsA7daYhnMK0hpGLSeF2mqrIv0uZ9P55ecnpYoSEUW LI2SZKgn9ycBQ8Ze8dBtzlhfftcZJTLx4n4CESpTxHry5By1dOErxB9EpQqTq1mIaM HW6UH1hx14b8FvgXhI18971dHUs1Lt4lc1miL+5TNZtZ/EytmEayvWairkKQBdPB4N dciVm+E4e/Qin6zxNxgM1VguAplwAitE52yli43hr4UsLakC76+0ZhV+WiUSsaANnL HpKFFLuTjJtOEAVV+7Z6NSzHJvAksCsr7JkMwuZpMANjOXsNB9cMtKkOmoEv8yhpOg a+zew8m5MqmSQ== From: Sasha Levin To: patches@lists.linux.dev Cc: Teddy Astie , Juergen Gross , Sasha Levin Subject: [PATCH 6.6 023/283] xen/virtio: Don't use grant-dma-ops when running as Dom0 Date: Sat, 28 Feb 2026 13:02:45 -0500 Message-ID: <20260228180709.1583486-23-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228180709.1583486-1-sashal@kernel.org> References: <20260228180709.1583486-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Teddy Astie [ Upstream commit dc8ea8714311e549ee93a2b0bdd5487d20bfadbf ] Dom0 inherit devices from the machine and is usually in PV mode. If we are running in a virtual that has virtio devices, these devices would be considered as using grants with Dom0 as backend, while being the said Dom0 itself, while we want to use these devices like regular PCI devices. Fix this by preventing grant-dma-ops from being used when running as Dom0 (initial domain). We still keep the device-tree logic as-is. Signed-off-by: Teddy Astie Fixes: 61367688f1fb0 ("xen/virtio: enable grant based virtio on x86") Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <6698564dd2270a9f7377b78ebfb20cb425cabbe8.1767720955.git.teddy.astie@vates.tech> Signed-off-by: Sasha Levin --- drivers/xen/grant-dma-ops.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c index 76f6f26265a3b..12fbe89382593 100644 --- a/drivers/xen/grant-dma-ops.c +++ b/drivers/xen/grant-dma-ops.c @@ -362,7 +362,8 @@ static int xen_grant_init_backend_domid(struct device *dev, if (np) { ret = xen_dt_grant_init_backend_domid(dev, np, backend_domid); of_node_put(np); - } else if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT) || xen_pv_domain()) { + } else if (!xen_initial_domain() && + (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT) || xen_pv_domain())) { dev_info(dev, "Using dom0 as backend\n"); *backend_domid = 0; ret = 0; -- 2.51.0