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Fri, 21 Feb 2020 10:15:25 -0800 (PST) Subject: Re: [PATCH] hw/char/pl011: Output characters using best-effort mode To: Peter Maydell References: <20200220060108.143668-1-gshan@redhat.com> From: Paolo Bonzini Message-ID: <1ae86c0b-d4ab-8063-747b-ebea4950e76d@redhat.com> Date: Fri, 21 Feb 2020 19:15:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gavin Shan , Marc Zyngier , QEMU Developers , qemu-arm , =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= , Shan Gavin Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 21/02/20 14:14, Peter Maydell wrote: > The initial case reported by Gavin in this thread is > "-serial tcp:127.0.0.1:50900" with the other end being a program which > listens on TCP port 50900 and then sleeps without accepting any incoming > connections, which blocks the serial port output and effectively blocks > the guest bootup. If you want to insulate the guest from badly > behaved consumers like that (or the related consumer who accepts > the connection and then just doesn't read data from it) you probably > need to deal with more than just POLLHUP. But I'm not sure how much > we should care about these cases as opposed to just telling users > not to do that... No, I think we don't do anything (on purpose; that is, it was considered the lesser evil) for x86 in that case. Paolo