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[209.51.188.17]) by mx.google.com with ESMTPS id o15-20020ad45c8f000000b004733c2889e8si10743009qvh.85.2022.07.26.12.23.55 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 26 Jul 2022 12:23:55 -0700 (PDT) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=mt1ohbEC; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:53092 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oGQ9r-0003D5-6u for patch@linaro.org; Tue, 26 Jul 2022 15:23:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48824) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oGQ7x-0003A8-2j for qemu-devel@nongnu.org; Tue, 26 Jul 2022 15:21:58 -0400 Received: from mail-wr1-x431.google.com ([2a00:1450:4864:20::431]:34712) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1oGQ7v-0002HB-19 for qemu-devel@nongnu.org; Tue, 26 Jul 2022 15:21:56 -0400 Received: by mail-wr1-x431.google.com with SMTP id h8so21433247wrw.1 for ; Tue, 26 Jul 2022 12:21:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=6BvLwU4GMUiq3XaMcxliYSNhOBL1ZkQfbeog0e1G+vA=; b=mt1ohbECoxDfdXXNDvr9KKtjfVbd+NVKnnkfCVDDhFvlwNG4HIIzvyNWQQLSD8wQmn pbdABLCpv7rjUNNO+WMOl1/jQyM37XEDX17CfpPQLbTIhNK7sBK2+BDLiEl+PT95O8B3 JVKEsl40oEk+idmRiGxMPGcDsk9zMERlqZ9n/9orfiDYL29ApEbSpWx9Lv81cgXLAFtr VbKksMkGBTlGNB5qxzkMouFyk1zWTPZovfBjxDPZ7P1lLQNBQIHg8jXMYiLkkyn2LF6i TmtZjpJ2LMe2yo/yhFEsxGvjWs/u7q552qERMgeZc97yQbrWrexNrUGg7+32gt9+nplV Xkcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=6BvLwU4GMUiq3XaMcxliYSNhOBL1ZkQfbeog0e1G+vA=; b=ROfCGoZmL5FNmh2tHa7c2D2tnLHJNq+YAW2EMVZqS7DjcK90hVFoEX617nY4i5gtkO xgyyTFmhi1TR7/ktB7auTbry2gRl2OdqJT/OFrd3CodHQXA6phIzHYCkP1k3iEGAntOH Zf9qe5HUvKo4INZ3Mmu4Slg3rlJ6UZw8lxGKrIPk0WFyxwxlyYQXONZAxIClsG8MzF1i lIZ2puAa68o2aZpbwSOwC4LnT+gFXsVV/q9iVi1LJBHsqpyzaw6w2H4mZ9eskD/oU+Mm dtJ6HikB5BzQ2XK1pjTRZG0CO7yxOnguopgwL6ZEmzOtGDH1sGyYW/YiKs+Kl3P9MraO BuAQ== X-Gm-Message-State: AJIora+OLQihayU5YKcC0lTrhspvGFbYWVs8yucWI8dqcSo3f2P6KdkB ScWwdkpfr3sMf0BVKoTM4s3VXQ== X-Received: by 2002:a5d:64e2:0:b0:21d:38e8:2497 with SMTP id g2-20020a5d64e2000000b0021d38e82497mr11011148wri.142.1658863313836; Tue, 26 Jul 2022 12:21:53 -0700 (PDT) Received: from zen.linaroharston ([185.81.254.11]) by smtp.gmail.com with ESMTPSA id v1-20020adfe281000000b0021e5adb92desm14236233wri.60.2022.07.26.12.21.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Jul 2022 12:21:51 -0700 (PDT) Received: from zen.lan (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 728F11FFB8; Tue, 26 Jul 2022 20:21:50 +0100 (BST) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: qemu-devel@nongnu.org Cc: slp@redhat.com, mst@redhat.com, marcandre.lureau@redhat.com, stefanha@redhat.com, mathieu.poirier@linaro.org, viresh.kumar@linaro.org, mark.cave-ayland@ilande.co.uk, jasowang@redhat.com, =?utf-8?q?Alex_Benn?= =?utf-8?q?=C3=A9e?= Subject: [PATCH v3 01/21] include/hw/virtio: more comment for VIRTIO_F_BAD_FEATURE Date: Tue, 26 Jul 2022 20:21:30 +0100 Message-Id: <20220726192150.2435175-2-alex.bennee@linaro.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220726192150.2435175-1-alex.bennee@linaro.org> References: <20220726192150.2435175-1-alex.bennee@linaro.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::431; envelope-from=alex.bennee@linaro.org; helo=mail-wr1-x431.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" When debugging a new vhost user you may be surprised to see VHOST_USER_F_PROTOCOL getting squashed in the maze of backend_features, acked_features and guest_features. Expand the description here to help the next poor soul trying to work through this. Signed-off-by: Alex Bennée --- v3 - s/vhost/vhost-user/ --- include/hw/virtio/virtio.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index db1c0ddf6b..9bb2485415 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -24,7 +24,12 @@ #include "qom/object.h" #include "hw/virtio/vhost.h" -/* A guest should never accept this. It implies negotiation is broken. */ +/* + * A guest should never accept this. It implies negotiation is broken + * between the driver frontend and the device. This bit is re-used for + * vhost-user to advertise VHOST_USER_F_PROTOCOL_FEATURES between QEMU + * and a vhost-user backend. + */ #define VIRTIO_F_BAD_FEATURE 30 #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \