From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34631) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zph1R-0006bm-5T for qemu-devel@nongnu.org; Fri, 23 Oct 2015 14:25:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zph1N-0004X2-73 for qemu-devel@nongnu.org; Fri, 23 Oct 2015 14:25:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35932) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zph1N-0004We-0r for qemu-devel@nongnu.org; Fri, 23 Oct 2015 14:24:57 -0400 References: <1445364840-7056-1-git-send-email-lersek@redhat.com> <20151021183625.26940.67906@jljusten-ivb> <5628A0E8.8050705@redhat.com> <20151022180407.GA9969@morn.lan> <56293D30.3080507@redhat.com> <20151023044115.30810.77352@jljusten-ivb> <5629E12E.4090409@redhat.com> <562A2DBD.7070404@redhat.com> <20151023182032.29864.87635@jljusten-ivb> From: Paolo Bonzini Message-ID: <562A7B73.7080604@redhat.com> Date: Fri, 23 Oct 2015 20:24:51 +0200 MIME-Version: 1.0 In-Reply-To: <20151023182032.29864.87635@jljusten-ivb> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] hw/isa/lpc_ich9: inject the SMI on the VCPU that is writing to APM_CNT List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jordan Justen , Laszlo Ersek , Kevin O'Connor Cc: Michael Kinney , Gerd Hoffmann , qemu-devel@nongnu.org, "Michael S. Tsirkin" On 23/10/2015 20:20, Jordan Justen wrote: >>>> It's not worth the hassle to relocate the SMBASE of the APs? >>>> So, basically, write to 0x30000-0x38000, then send an SMI IPI to the >>>> AP and now you have the AP running in SMI and it has extra privileges? >>> >>> Extra privileges compared to what? Legacy BIOS does not really put >>> anything privileged in SMRAM, > > Why does seabios even bother relocating the BSP's SMBASE if it doesn't > relocate the SMBASE for the APs? It uses SMM to run INT 13h in 32-bit real mode, basically. It's for MS-DOS usage only, so the APs don't matter. >> So what are we thinking about a magic APM_STS value to trigger an SMI >> for all VCPUs? 0x51 ('Q') would be cool. :) > > This seems like a further deviation from the actual hardware. I > understand that QEMU draws a line about strict hardware emulation, but > I just wanted to point out the discrepancy. Yeah, I am also a bit doubtful about that. > So, the trouble with changing QEMU to better emulate the hardware is > that seabios can't handle multiple processors entering SMM? Yes. Paolo