From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [Xen-devel] [PATCH] xen/apic: implement io apic read with hypercall Date: Fri, 20 Apr 2012 10:58:24 +0100 Message-ID: <4F913340.4000202@citrix.com> References: <1334913957.2863.1.camel@hp6530s> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1334913957.2863.1.camel@hp6530s> Sender: linux-kernel-owner@vger.kernel.org To: Lin Ming Cc: Konrad Rzeszutek Wilk , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" List-Id: xen-devel@lists.xenproject.org On 20/04/12 10:25, Lin Ming wrote: > Implements xen_io_apic_read with hypercall, so it returns proper IO-APIC > information instead of fabricated one. > > Signed-off-by: Lin Ming > --- > arch/x86/xen/apic.c | 16 +++++++++++----- > 1 files changed, 11 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c > index aee16ab..f1f392d 100644 > --- a/arch/x86/xen/apic.c > +++ b/arch/x86/xen/apic.c > @@ -1,14 +1,20 @@ > #include > #include > +#include > +#include > +#include > > unsigned int xen_io_apic_read(unsigned apic, unsigned reg) > { > - if (reg == 0x1) > - return 0x00170020; > - else if (reg == 0x0) > - return apic << 24; > + struct physdev_apic apic_op; > + int ret; > > - return 0xff; > + apic_op.apic_physbase = mpc_ioapic_addr(apic); > + apic_op.reg = reg; > + ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op); > + if (ret) > + return ret; > + return apic_op.value; Hypercall ret errors are negative, yet this function is unsigned. Given that the previous function had no possible way to fail, perhaps on error you should fake up the values as before. > } > > void __init xen_init_apic(void) -- Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer T: +44 (0)1223 225 900, http://www.citrix.com