From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: [PATCH] x86/HVM: replace open-coded non-local cache flushing Date: Fri, 25 Apr 2014 10:19:55 -0400 Message-ID: <535A6F0B.2040109@oracle.com> References: <535A5A5C020000780000C400@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Wdgvg-0004u0-St for xen-devel@lists.xenproject.org; Fri, 25 Apr 2014 14:16:41 +0000 In-Reply-To: <535A5A5C020000780000C400@nat28.tlf.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: Kevin Tian , Keir Fraser , suravee.suthikulpanit@amd.com, Eddie Dong , Jun Nakajima , xen-devel List-Id: xen-devel@lists.xenproject.org On 04/25/2014 06:51 AM, Jan Beulich wrote: > We accumulated quite a number of these, despite having a pre-canned > interface for it. > > Signed-off-by: Jan Beulich Reviewed-by: Boris Ostrovsky Somewhat related: I also noticed that in on_selected_cpus() (that this patch is replacing for flushing) we take a global lock. I wonder whether this may cause scaling issues on big systems. (The same would be true for flush_all/mask but to a lesser extent since at least that's a lock dedicated to a particular operation) -boris > > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -1823,11 +1823,6 @@ static bool_t domain_exit_uc_mode(struct > return 1; > } > > -static void local_flush_cache(void *info) > -{ > - wbinvd(); > -} > - > static void hvm_set_uc_mode(struct vcpu *v, bool_t is_in_uc_mode) > { > v->domain->arch.hvm_domain.is_in_uc_mode = is_in_uc_mode; > @@ -1927,7 +1922,7 @@ void hvm_shadow_handle_cd(struct vcpu *v > domain_pause_nosync(v->domain); > > /* Flush physical caches. */ > - on_each_cpu(local_flush_cache, NULL, 1); > + flush_all(FLUSH_CACHE); > hvm_set_uc_mode(v, 1); > > domain_unpause(v->domain); > --- a/xen/arch/x86/hvm/svm/svm.c > +++ b/xen/arch/x86/hvm/svm/svm.c > @@ -2106,15 +2106,10 @@ static void svm_vmexit_mce_intercept( > } > } > > -static void wbinvd_ipi(void *info) > -{ > - wbinvd(); > -} > - > static void svm_wbinvd_intercept(void) > { > if ( cache_flush_permitted(current->domain) ) > - on_each_cpu(wbinvd_ipi, NULL, 1); > + flush_all(FLUSH_CACHE); > } > > static void svm_vmexit_do_invalidate_cache(struct cpu_user_regs *regs) > --- a/xen/arch/x86/hvm/vmx/vmcs.c > +++ b/xen/arch/x86/hvm/vmx/vmcs.c > @@ -1301,11 +1301,6 @@ void vm_resume_fail(void) > domain_crash_synchronous(); > } > > -static void wbinvd_ipi(void *info) > -{ > - wbinvd(); > -} > - > void vmx_do_resume(struct vcpu *v) > { > bool_t debug_state; > @@ -1332,7 +1327,7 @@ void vmx_do_resume(struct vcpu *v) > { > int cpu = v->arch.hvm_vmx.active_cpu; > if ( cpu != -1 ) > - on_selected_cpus(cpumask_of(cpu), wbinvd_ipi, NULL, 1); > + flush_mask(cpumask_of(cpu), FLUSH_CACHE); > } > > vmx_clear_vmcs(v); > --- a/xen/arch/x86/hvm/vmx/vmx.c > +++ b/xen/arch/x86/hvm/vmx/vmx.c > @@ -2307,18 +2307,13 @@ static void vmx_do_extint(struct cpu_use > do_IRQ(regs); > } > > -static void wbinvd_ipi(void *info) > -{ > - wbinvd(); > -} > - > static void vmx_wbinvd_intercept(void) > { > if ( !cache_flush_permitted(current->domain) || iommu_snoop ) > return; > > if ( cpu_has_wbinvd_exiting ) > - on_each_cpu(wbinvd_ipi, NULL, 1); > + flush_all(FLUSH_CACHE); > else > wbinvd(); > } > > >