From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 1/2] kvm: Insist on a reason when injecting a #GP into a guest Date: Tue, 24 Jul 2007 13:15:47 +0300 Message-ID: <46A5D153.9020302@qumranet.com> References: <1185259677.1803.239.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Rusty Russell Return-path: In-Reply-To: <1185259677.1803.239.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Rusty Russell wrote: > Insist on a reason when injecting a #GP into a guest > > All places but one already do a printk before injecting a #GP: just > formalize it a little. > > Signed-off-by: Rusty Russell > > diff -r f75b0a5fc387 drivers/kvm/kvm_main.c > --- a/drivers/kvm/kvm_main.c Mon Jul 23 11:16:12 2007 +1000 > +++ b/drivers/kvm/kvm_main.c Mon Jul 23 16:59:56 2007 +1000 > @@ -419,8 +419,15 @@ static int kvm_vm_release(struct inode * > return 0; > } > > -static void inject_gp(struct kvm_vcpu *vcpu) > -{ > +static void __attribute__((format(printf, 2, 3))) > +inject_gp(struct kvm_vcpu *vcpu, const char *why_fmt, ...) > +{ > + va_list args; > + > + va_start(args, why_fmt); > + printk(KERN_DEBUG "kvm: #GP "); > + vprintk(why_fmt, args); > + va_end(args); > kvm_arch_ops->inject_gp(vcpu, 0); > } > Some guests (non hardware accelerated hypervisors, mostly) will generate #gp. We'll want to inject exceptions without noise then. I don't think we have such an exception today, but it's an excuse to have a clean __inject_gp() and a varargs-infested inject_gp(). > > @@ -464,22 +471,21 @@ void set_cr0(struct kvm_vcpu *vcpu, unsi > void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) > { > if (cr0 & CR0_RESERVED_BITS) { > - printk(KERN_DEBUG "set_cr0: 0x%lx #GP, reserved bits 0x%lx\n", > - cr0, vcpu->cr0); > - inject_gp(vcpu); > + inject_gp(vcpu, > + "set_cr0: 0x%lx reserved bits 0x%lx\n", > + cr0, vcpu->cr0); > Why three lines? > return; > } > > if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD)) { > - printk(KERN_DEBUG "set_cr0: #GP, CD == 0 && NW == 1\n"); > - inject_gp(vcpu); > + inject_gp(vcpu, > + "set_cr0: CD == 0 && NW == 1\n"); > return; > Are you deliberately ignoring an opportunity to reduce our line count?! > @@ -1843,8 +1834,7 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, > /* > * String I/O in reverse. Yuck. Kill the guest, fix later. > */ > - printk(KERN_ERR "kvm: guest string pio down\n"); > - inject_gp(vcpu); > + inject_gp(vcpu, "guest string pio down\n"); > return 1; > } > vcpu->run->io.count = now; > This one really wants to be a KERN_ERR. It's not a guest exception, it's a kvm unimplemented feature for which the guest pays the price. I guess a good place for __inject_gp(). -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/