From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Extending boot protocol & bzImage for paravirt_ops Date: Sat, 26 May 2007 13:42:53 -0700 Message-ID: <46589BCD.4040807@zytor.com> References: <4656FB8F.4090604@goop.org> <1180174691.650.8.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1180174691.650.8.camel@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org To: Rusty Russell Cc: "Eric W. Biederman" , Jeremy Fitzhardinge , Chris Wright , Virtualization Mailing List , Linux Kernel Mailing List List-Id: virtualization@lists.linuxfoundation.org Rusty Russell wrote: >> >> + Bit 6 (write): KEEP_SEGMENTS >> + Protocol: 2.07+ >> + - if 0, reload the segment registers in the 32bit entry point. >> + - if 1, do not reload the segment registers in the 32bit entry point. >> + Assume that %cs %ds %ss %es are all set to flat segments with >> + a base of 0 (or the equivalent for their environment). > > You also want to skip the cli: perhaps a separate flag for this is > appropriate though. > Do we have *any* environment that enters the 32-bit code with interrupts enabled? I would think that is unsafe no matter how you do it. -hpa