From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH v11 for-xen-4.5 13/20] x86/VPMU: Save VPMU state for PV guests during context switch Date: Tue, 23 Sep 2014 11:01:31 -0400 Message-ID: <20140923150131.GI3007@laptop.dumpdata.com> References: <1411430281-6132-1-git-send-email-boris.ostrovsky@oracle.com> <1411430281-6132-14-git-send-email-boris.ostrovsky@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1411430281-6132-14-git-send-email-boris.ostrovsky@oracle.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: Boris Ostrovsky Cc: kevin.tian@intel.com, keir@xen.org, jbeulich@suse.com, jun.nakajima@intel.com, andrew.cooper3@citrix.com, tim@xen.org, dietmar.hahn@ts.fujitsu.com, xen-devel@lists.xen.org, Aravind.Gopalakrishnan@amd.com, suravee.suthikulpanit@amd.com List-Id: xen-devel@lists.xenproject.org On Mon, Sep 22, 2014 at 07:57:54PM -0400, Boris Ostrovsky wrote: > Save VPMU state during context switch for both HVM and PV(H) guests. > > A subsequent patch will make it possible for vpmu_switch_to() to call Could you say what is the name of the 'subsequent patch' in the commit description please? > vmx_vmcs_try_enter()->vcpu_pause() which needs is_running to be correctly > set/cleared. To prepare for that, call context_saved() before vpmu_switch_to() > is executed. And what ramifications does that have to the guests if one only applied patches up to this point? > > Signed-off-by: Boris Ostrovsky > --- > xen/arch/x86/domain.c | 20 +++++++++----------- > 1 file changed, 9 insertions(+), 11 deletions(-) > > diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c > index 5e492d8..d7fb99d 100644 > --- a/xen/arch/x86/domain.c > +++ b/xen/arch/x86/domain.c > @@ -1495,16 +1495,13 @@ void context_switch(struct vcpu *prev, struct vcpu *next) > } > > if ( prev != next ) > - _update_runstate_area(prev); > - > - if ( is_hvm_vcpu(prev) ) > { > - if (prev != next) > - vpmu_switch_from(prev, next); > + _update_runstate_area(prev); > + vpmu_switch_from(prev, next); > + } > > - if ( !list_empty(&prev->arch.hvm_vcpu.tm_list) ) > + if ( is_hvm_vcpu(prev) && !list_empty(&prev->arch.hvm_vcpu.tm_list) ) > pt_save_timer(prev); > - } > > local_irq_disable(); > > @@ -1543,15 +1540,16 @@ void context_switch(struct vcpu *prev, struct vcpu *next) > !is_hardware_domain(next->domain)); > } > > - if ( is_hvm_vcpu(prev) && (prev != next) ) > - /* Must be done with interrupts enabled */ > - vpmu_switch_to(prev, next); > - > context_saved(prev); > > if ( prev != next ) > + { > _update_runstate_area(next); > > + /* Must be done with interrupts enabled */ > + vpmu_switch_to(prev, next); > + } > + > /* Ensure that the vcpu has an up-to-date time base. */ > update_vcpu_system_time(next); > > -- > 1.8.1.4 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel