From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: Avoid using vmx instruction directly Date: Thu, 09 Nov 2006 15:36:35 +0200 Message-ID: <45532EE3.4000104@qumranet.com> References: <20061109110852.A6B712500F7@cleopatra.q> <200611091429.42040.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, akpm-3NddpPZAyC0@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: To: Arnd Bergmann In-Reply-To: <200611091429.42040.arnd-r2nGTMty4D4@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 Arnd Bergmann wrote: > On Thursday 09 November 2006 12:08, Avi Kivity wrote: > >> Index: linux-2.6/drivers/kvm/kvm_main.c >> =================================================================== >> --- linux-2.6.orig/drivers/kvm/kvm_main.c >> +++ linux-2.6/drivers/kvm/kvm_main.c >> @@ -369,8 +369,8 @@ static void vmcs_clear(struct vmcs *vmcs >> u64 phys_addr = __pa(vmcs); >> u8 error; >> >> - asm volatile ("vmclear %1; setna %0" >> - : "=m"(error) : "m"(phys_addr) : "cc", "memory" ); >> + asm volatile (ASM_VMX_VMCLEAR_RAX "; setna %0" >> + : "=g"(error) : "a"(&phys_addr) : "cc", "memory" ); >> if (error) >> printk(KERN_ERR "kvm: vmclear fail: %p/%llx\n", >> vmcs, phys_addr); >> > > I'm not an expert on inline assembly, but don't you need an extra > '"m" (phys_addr)' to make sure that gcc actually puts the variable > on the stack instead of passing a NULL pointer as '"a"(&phys_addr)'? > > Taking a variable's address should force its contents into memory (like calling an uninlined function with &var). -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642