Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751781Ab3HTTfP (ORCPT ); Tue, 20 Aug 2013 15:35:15 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:40690 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751188Ab3HTTfN (ORCPT ); Tue, 20 Aug 2013 15:35:13 -0400 Date: Tue, 20 Aug 2013 15:35:07 -0400 From: Konrad Rzeszutek Wilk To: Ian Campbell Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Subject: Re: [Xen-devel] [PATCH] xen/hvc: If we use xen_raw_printk let it also work on HVM guests. Message-ID: <20130820193507.GI12037@phenom.dumpdata.com> References: <1376060133-6382-1-git-send-email-konrad.wilk@oracle.com> <1376425904.9273.25.camel@hastur.hellion.org.uk> <20130813205332.GA10243@phenom.dumpdata.com> <1376427570.9273.39.camel@hastur.hellion.org.uk> <1376432405.9273.54.camel@hastur.hellion.org.uk> <20130814001050.GA10492@phenom.dumpdata.com> <1376464556.9273.75.camel@hastur.hellion.org.uk> <20130814124647.GD10764@phenom.dumpdata.com> <1376577638.9273.188.camel@hastur.hellion.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1376577638.9273.188.camel@hastur.hellion.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4777 Lines: 130 On Thu, Aug 15, 2013 at 03:40:38PM +0100, Ian Campbell wrote: > On Wed, 2013-08-14 at 08:46 -0400, Konrad Rzeszutek Wilk wrote: > > On Wed, Aug 14, 2013 at 08:15:56AM +0100, Ian Campbell wrote: > > > On Tue, 2013-08-13 at 20:10 -0400, Konrad Rzeszutek Wilk wrote: > > > > On Tue, Aug 13, 2013 at 11:20:05PM +0100, Ian Campbell wrote: > > > > > On Tue, 2013-08-13 at 21:59 +0100, Ian Campbell wrote: > > > > > > > > > > > > What it should be is: > > > > > > > > > > > > > > > > > > void xen_raw_console_write(const char *str) > > > > > > > > > { > > > > > > > > > - dom0_write_console(0, str, strlen(str)); > > > > > > > > > + if (!xen_domain()) > > > > > > > > > + return; > > > > > > > > > + > > > > > > > > > + if (xen_pv_domain()) > > > > > > > xen_domain() > > > > > > > > > > > > > > > > + dom0_write_console(0, str, strlen(str)); > > > > > > > > > + else if (xen_hvm_domain() || xen_cpuid_base()) { > > > > > > > > > > > > > > else if (xen_cpuid_base()) { > > > > > > > > > > > > > > > > + /* The hyperpage has not been setup yet. */ > > > > > > > > > + int i, len = strlen(str); > > > > > > > > > + for (i = 0; i < len; i++) > > > > > > > > > + outb(str[i], 0xe9); > > > > > > > > > + } > > > > > > > > > } > > > > > > > > > > > > > > And then that should adhere to what I wrote up. > > > > > > > > > > > > I think it does too. > > > > > > > > > > Except as Daniel notes in <520A7145.5010306@tycho.nsa.gov> for unrelated > > > > > reasons: > > > > > > > > > > > HVM guests can still use the PV output - they just need to use the console > > > > > > write hypercall instead of the HVM I/O port. I would think that PVH guests > > > > > > would default to using the hypercall as it is more efficient (it takes a > > > > > > string rather than one character per write). > > > > > > > > > > > > Actually, checking... the console_io hypercall would need to be added to > > > > > > the hvm_hypercall{32,64}_table for an HVM guest to be able to use it; they > > > > > > currently must use the I/O port. I didn't check the PVH patches. > > > > > > > > > > Or did you actually try this code and it worked? > > > > > > > > The one I typed up above - no. The one I had sent - yes. > > > > > > > > But with that above mentioned comment from Daniel I think it is still > > > > worth trying to do dom0_write_console and if the hypercall returns -ENOSYS > > > > then fall back on 0xe9. > > > > > > > > And lastly send an patch to make hypercall_io work under HVM. > > > > > > So you didn't try under PVHVM? That's what I was asking when I asked if > > > you tried it, since that is the point of this patch. > > > > Not the one I typed up above. Just the one I sent. > > And did it work? ecause if the console_io hypercall isn't wired up in > the hypervisor I can't see how it can have done... > > Oh the original patch would buggily never have tried to use console_io, > and you probably didn't notice the lack of output after the hypercall > page was setup. This is a patch below that works for me and also it work with hypervisors that don't have console_io wired in. Pls treat it as RFC >From 5b5faae0038d48aa0169bab8c78d1b47c4f1ac64 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Fri, 16 Aug 2013 15:32:07 -0400 Subject: [PATCH] xen/hvc: Print out to the serial console and pv console irregardless if it is dom0, PV or HVM. *TODO*: BLA BLA BLA Signed-off-by: Konrad Rzeszutek Wilk --- drivers/tty/hvc/hvc_xen.c | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-) diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 682210d..e47c6ae 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -40,6 +40,7 @@ #include #include +#include #include "hvc_console.h" #define HVC_COOKIE 0x58656e /* "Xen" in hex */ @@ -641,7 +642,19 @@ struct console xenboot_console = { void xen_raw_console_write(const char *str) { - dom0_write_console(0, str, strlen(str)); + ssize_t len = strlen(str); + int rc = 0; + + if (xen_domain()) { + rc = dom0_write_console(0, str, len); + if (rc != len && xen_hvm_domain()) /* -ENOSYS */ + goto outb_print; + } else if (xen_cpuid_base()) { + int i; +outb_print: + for (i = 0; i < len; i++) + outb(str[i], 0xe9); + } } void xen_raw_printk(const char *fmt, ...) -- 1.7.7.6 > Ian. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/