From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:45786) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Rswal-0000g1-7H for qemu-devel@nongnu.org; Thu, 02 Feb 2012 08:20:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Rswaf-0001hr-Ik for qemu-devel@nongnu.org; Thu, 02 Feb 2012 08:20:47 -0500 Received: from mail-vx0-f173.google.com ([209.85.220.173]:43645) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Rswaf-0001hk-Eh for qemu-devel@nongnu.org; Thu, 02 Feb 2012 08:20:41 -0500 Received: by vcbfl17 with SMTP id fl17so1820890vcb.4 for ; Thu, 02 Feb 2012 05:20:40 -0800 (PST) MIME-Version: 1.0 Sender: arena431@gmail.com Date: Thu, 2 Feb 2012 22:20:40 +0900 Message-ID: From: kazushi takahashi Content-Type: text/plain; charset=ISO-8859-1 Subject: [Qemu-devel] Question about IDE TRIM Command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Hi all I have a question about IDE TRIM Command. As you know, QEMU have supported TRIM command since QEMU 0.15.0. Some QEMU disk images such as qcow2 support bdrv_discard function which will be called when guest OS executes ATA TRIM command. So, I think qcow2 image has a function to delete the disk pages which are recognized as discarded by guest OS. I think that to enable TRIM Command, we have to emulate guest HDD as Solid State Drive. However, it seems QEMU does not emulate guest HDD as Solid State Drive. Thus, I think that bdrv_discard functions in qemu images are never called by guest OS. Is my thinking correct? Thanks, Kazushi Takahashi