From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH V1 18/29] xen/arm: Don't map disabled device in DOM0 Date: Mon, 09 Sep 2013 22:59:29 +0100 Message-ID: <522E44C1.3020808@linaro.org> References: <1377701263-3319-1-git-send-email-julien.grall@linaro.org> <1377701263-3319-19-git-send-email-julien.grall@linaro.org> <1378726800.19967.73.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1378726800.19967.73.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: stefano.stabellini@eu.citrix.com, andre.przywara@linaro.org, patches@linaro.org, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 09/09/2013 12:40 PM, Ian Campbell wrote: > On Wed, 2013-08-28 at 15:47 +0100, Julien Grall wrote: >> Linux should cope with 'status = "disabled"' in the Device Tree. > > This is devices which were disabled in the DT passed to Xen, rather than > ones which we have disabled ourselves (e.g. the previous patch)? Yes. >> This solution can be used later to pass-through device to a specific guest. > > How? I thought disabled meant "not present/wired-up on this variant of > the platform"? A user cannot be expected to edit the host DTB to enable > passthrough. We might want a dtb_hide cmdline option, or to do it > dynamically like pciback is capable of. Disabled also means "the device is not presently operational, but it might become operational in the future". > Or maybe I'm wrong above and this is indeed devices we have disabled > ourselves? I'm not sure it's usefull. But I don't see any reason to map disabled device in dom0. >> >> Signed-off-by: Julien Grall >> >> --- >> Changes in v2: >> - Add a comment >> --- >> xen/arch/arm/domain_build.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c >> index d56bc70a..11f247b 100644 >> --- a/xen/arch/arm/domain_build.c >> +++ b/xen/arch/arm/domain_build.c >> @@ -416,9 +416,13 @@ static int handle_node(struct domain *d, struct kernel_info *kinfo, >> * - Device used by Xen: Obviously dom0 can't use them >> * - Memory: the guest will see a different view of memory. It will >> * be allocated later. >> + * - Disabled device: Linux is able to cope with status="disabled" >> + * property. Therefore these device doesn't need to be mapped. This >> + * solution can be use later for pass through. >> */ >> if ( dt_device_used_by(np) != DOMID_XEN && >> - !dt_device_type_is_equal(np, "memory") ) >> + !dt_device_type_is_equal(np, "memory") && >> + dt_device_is_available(np) ) >> { >> res = map_device(d, np); >> > > -- Julien Grall