From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v2 09/12] x86/altp2m: add remaining support routines. Date: Wed, 24 Jun 2015 19:19:01 +0100 Message-ID: <558AF495.7010101@citrix.com> References: <1434999372-3688-1-git-send-email-edmund.h.white@intel.com> <1434999372-3688-10-git-send-email-edmund.h.white@intel.com> <558AB4D3.4030805@citrix.com> <558AED2B.6030409@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <558AED2B.6030409@intel.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: Ed White , xen-devel@lists.xen.org Cc: Ravi Sahita , Wei Liu , Tim Deegan , Ian Jackson , Jan Beulich , tlengyel@novetta.com, Daniel De Graaf List-Id: xen-devel@lists.xenproject.org On 24/06/15 18:47, Ed White wrote: >> > This looks like some hoop jumping around the assertions in >> > domain_pause() and vcpu_pause(). >> > >> > We should probably have some new helpers where the domain needs to be >> > paused, possibly while in context. The current domain/vcpu_pause() are >> > almost always used where it is definitely not safe to pause in context, >> > hence the assertions. >> > > It is. I'd be happy to use new helpers, I don't feel qualified to > write them. > > Ed Something like this? Only compile tested. In the meantime, I have an optimisation in mind for domain_pause() on domains with large numbers of vcpus, but that will have to wait a while. From: Andrew Cooper Date: Wed, 24 Jun 2015 19:06:14 +0100 Subject: [PATCH] common/domain: Helpers to pause a domain while in context For use on codepaths which would need to use domain_pause() but might be in the target domain's context. In the case that the target domain is in context, all other vcpus are paused. Signed-off-by: Andrew Cooper --- xen/common/domain.c | 28 ++++++++++++++++++++++++++++ xen/include/xen/sched.h | 5 +++++ 2 files changed, 33 insertions(+) diff --git a/xen/common/domain.c b/xen/common/domain.c index 3bc52e6..a1d27e3 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -1010,6 +1010,34 @@ int domain_unpause_by_systemcontroller(struct domain *d) return 0; } +void domain_pause_except_self(struct domain *d) +{ + struct vcpu *v, *curr = current; + + if ( curr->domain == d ) + { + for_each_vcpu( d, v ) + if ( likely(v != curr) ) + vcpu_pause(v); + } + else + domain_pause(d); +} + +void domain_unpause_except_self(struct domain *d) +{ + struct vcpu *v, *curr = current; + + if ( curr->domain == d ) + { + for_each_vcpu( d, v ) + if ( likely(v != curr) ) + vcpu_unpause(v); + } + else + domain_unpause(d); +} + int vcpu_reset(struct vcpu *v) { struct domain *d = v->domain; diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index b29d9e7..8e1345a 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -804,6 +804,11 @@ static inline int domain_pause_by_systemcontroller_nosync(struct domain *d) { return __domain_pause_by_systemcontroller(d, domain_pause_nosync); } + +/* domain_pause() but safe against trying to pause current. */ +void domain_pause_except_self(struct domain *d); +void domain_unpause_except_self(struct domain *d); + void cpu_init(void); struct scheduler;