From mboxrd@z Thu Jan 1 00:00:00 1970 From: Razvan Cojocaru Subject: Re: [PATCH V4] xen/vm_event: Clean up control-register-write vm_events Date: Fri, 22 May 2015 15:15:59 +0300 Message-ID: <555F1DFF.6080700@bitdefender.com> References: <1432213223-5211-1-git-send-email-rcojocaru@bitdefender.com> <555EF8AA020000780007D0A9@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <555EF8AA020000780007D0A9@mail.emea.novell.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: Jan Beulich Cc: tim@xen.org, kevin.tian@intel.com, wei.liu2@citrix.com, eddie.dong@intel.com, stefano.stabellini@eu.citrix.com, andrew.cooper3@citrix.com, ian.jackson@eu.citrix.com, xen-devel@lists.xen.org, jun.nakajima@intel.com, keir@xen.org, ian.campbell@citrix.com List-Id: xen-devel@lists.xenproject.org On 05/22/2015 10:36 AM, Jan Beulich wrote: >> @@ -1050,6 +1048,8 @@ struct xen_domctl_monitor_op { >> */ >> union { >> struct { >> + /* Which control register */ >> + uint8_t index; > > Okay, 8 bits here (which is reasonable), but ... > >> @@ -156,7 +158,8 @@ struct vm_event_mem_access { >> uint32_t _pad; >> }; >> >> -struct vm_event_mov_to_cr { >> +struct vm_event_write_ctrlreg { >> + uint64_t index; >> uint64_t new_value; >> uint64_t old_value; >> }; > > ... a full 64 bits here? 32 bits surely would do (with 32 bits of padding), > allowing slightly better accessing code on both the consumer and > producer sides. While working on this I found the following in the vm_event.h header: 168 struct vm_event_debug { 169 uint64_t gfn; 170 uint32_t _pad; 171 }; Is this supposed to be 64 + 32 bits padding? Thanks, Razvan