From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0B69A2D1931 for ; Mon, 6 Jul 2026 13:05:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783343108; cv=none; b=fZXEYjqUDOZrgcP+cyqFJNoM1ITeaZFkYPcOFWBvT+wcgNte/UInvUDcvKZbUz/Z3GD8lXrt9pLl2xAImY3mCvNr0iPgXtp0FfR2RUoX2oHMhMCYw3LQofP/7uLqrrzzDf08VM7pGrmBKSUVLQ+DRn8uXAA0XKwPRWYyRFmXnkI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783343108; c=relaxed/simple; bh=VRbkijzHlk465V48tu/W9c52SmEgHDhAUxxTQEEVc6I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IEQOvZnZPxZRzIshYYa1QGtP2r9Nqn4ke2EcP0NL2wCUANRfSrUpnL6cf2mSZHWPmduqrhHWqK3GcLuAViQKwsvUXHNnTMxj8wFRCCyFu9epdmNdoHUqUaAnSGNgqI1j200JJEykEI0uNm3bAokeSsPKxcThsG3RgyKABfd4tVE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=nZ9OJYHR; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="nZ9OJYHR" Received: from example.com (unknown [167.220.208.42]) by linux.microsoft.com (Postfix) with ESMTPSA id D353F20B716B; Mon, 6 Jul 2026 06:04:59 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D353F20B716B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1783343102; bh=42ZU0Iw+ebDa0/X5YhAcUnBEM087OQr1GBPIsBa3FnA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nZ9OJYHR63/bEOzubXphlQMJ7E1M4wExiXdSbfdHvzASazJByZiZh792Q+8afv4z8 DdfFlS9aaPFEOH4tHQP6l1IYG0EUAMIMpvsiOCz855WIkcbXFONjUx4JPRkLfXyxLY 0F/HyOZdF6HEJXz4mkwRo6IICRFtyJMhKYNbVTAQ= Date: Mon, 6 Jul 2026 15:05:00 +0200 From: Magnus Kulke To: Paolo Bonzini Cc: qemu-devel , kvm , Magnus Kulke , Wei Liu , "Michael S. Tsirkin" , =?iso-8859-1?Q?C=E9dric?= Le Goater , Zhao Liu , Richard Henderson , Wei Liu , Alex Williamson , Marcel Apfelbaum , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Marcelo Tosatti Subject: Re: [PATCH 26/34] accel/mshv: introduce SaveVMHandler Message-ID: References: <20260417105618.3621-1-magnuskulke@linux.microsoft.com> <20260417105618.3621-27-magnuskulke@linux.microsoft.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Jul 03, 2026 at 07:50:43PM +0200, Paolo Bonzini wrote: > There are different "schools of thought" for that. Freezing introduces an > incorrect timing on the destination, not freezing introduces a jump. > > If you choose to freeze that's fine, QEMU does the same for KVM even though > KVM has alternative ioctls that allow not freezing. > > But currently it's the wrong > > place. I'll find some more fitting place to perform this ceremony. > > > > KVM uses a device for that, see kvnclock.c. Makes sense, kvmclock looks like a good template. I'll use a similar object. > > Curiously the time-frozen source was obscuring another potentially more > > serious bug. The mshv vcpu dispatch loop currently does not honor a > > cpu->exit_request > > > Was that related to the other patch that was touching the vcpu thread loop? > yup, we need the same here, I'll address it as part of a migration-pt2 series. we only need to check for cpu->exit_request and break the loop if set. best, magnus