| Message ID | E0A769A898ADB6449596C41F51EF62C6B03226@SZXEMI506-MBX.china.huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Apr 13, 2017 at 02:20:23AM +0000, Xuquan (Quan Xu) wrote: >From 946e7589e5a875574c7567a91943d47c38218a6f Mon Sep 17 00:00:00 2001 >From: Quan Xu <xuquan8@huawei.com> >Date: Fri, 14 Apr 2017 02:11:30 +0800 >Subject: [PATCH v1] vmx: set 'SN' bit for the runstate transition from blocked > to runnable > >set 'SN' bit of posted-interrupt descriptor when the runstate transition >is from blocked to runnable (SN bit of posted-interrupt descriptor is still >set to a blocked vCPU), otherwise PI notification event may be sent to a Currently, we clear 'SN' bit for a blocked vCPU in order to receive a wakeup interrupt to wake up the blocked vCPU. Also note that wakeup interrupt is not a special vector for CPU. >non-running vCPU. > >Signed-off-by: Quan Xu <xuquan8@huawei.com> >--- > xen/arch/x86/hvm/vmx/vmx.c | 3 --- > 1 file changed, 3 deletions(-) > >diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c >index 9c5a388..956f104 100644 >--- a/xen/arch/x86/hvm/vmx/vmx.c >+++ b/xen/arch/x86/hvm/vmx/vmx.c >@@ -142,9 +142,6 @@ static void vmx_pi_switch_from(struct vcpu *v) > { > struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc; > >- if ( test_bit(_VPF_blocked, &v->pause_flags) ) >- return; >- I wander whether vmx_pi_switch_from() will be called in the transition blocked -> runnable. In my mind, the function is called during context switch and consumes the vcpu that is to be blocked or runnable. I think this if() statement is to distinguish 'block' case and doesn't set 'SN' for this case. Thanks Chao > pi_set_sn(pi_desc); > } > >-- >1.8.3.1 >_______________________________________________ >Xen-devel mailing list >Xen-devel@lists.xen.org >https://lists.xen.org/xen-devel
On April 13, 2017 3:35 AM, Chao Gao wrote: >On Thu, Apr 13, 2017 at 02:20:23AM +0000, Xuquan (Quan Xu) wrote: >>From 946e7589e5a875574c7567a91943d47c38218a6f Mon Sep 17 >00:00:00 2001 >>From: Quan Xu <xuquan8@huawei.com> >>Date: Fri, 14 Apr 2017 02:11:30 +0800 >>Subject: [PATCH v1] vmx: set 'SN' bit for the runstate transition from >>blocked to runnable >> >>set 'SN' bit of posted-interrupt descriptor when the runstate >>transition is from blocked to runnable (SN bit of posted-interrupt >>descriptor is still set to a blocked vCPU), otherwise PI notification >>event may be sent to a > >Currently, we clear 'SN' bit for a blocked vCPU in order to receive a wakeup >interrupt to wake up the blocked vCPU. Also note that wakeup interrupt is not >a special vector for CPU. > Sorry, a typo 's/set/clear/'.... You are right. It is clear. that's why I want to set it. >>non-running vCPU. >> >>Signed-off-by: Quan Xu <xuquan8@huawei.com> >>--- >> xen/arch/x86/hvm/vmx/vmx.c | 3 --- >> 1 file changed, 3 deletions(-) >> >>diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c >>index 9c5a388..956f104 100644 >>--- a/xen/arch/x86/hvm/vmx/vmx.c >>+++ b/xen/arch/x86/hvm/vmx/vmx.c >>@@ -142,9 +142,6 @@ static void vmx_pi_switch_from(struct vcpu *v) { >> struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc; >> >>- if ( test_bit(_VPF_blocked, &v->pause_flags) ) >>- return; >>- > >I wander whether vmx_pi_switch_from() will be called in the transition >blocked -> runnable. >In my mind, the function is called during context switch and consumes the >vcpu that is to be blocked or runnable. If you are right, my patch is wrong.. Chao, thank you. I will check it again.. Quan >I think this if() statement is to >distinguish 'block' case and doesn't set 'SN' for this case. > >Thanks >Chao > >> pi_set_sn(pi_desc); >> } >> >>-- >>1.8.3.1 > > >>_______________________________________________ >>Xen-devel mailing list >>Xen-devel@lists.xen.org >>https://lists.xen.org/xen-devel
__sorry for the noise, please ignore this patch__ On April 13, 2017 11:45 AM, Quan Xu wrote: >On April 13, 2017 3:35 AM, Chao Gao wrote: >>On Thu, Apr 13, 2017 at 02:20:23AM +0000, Xuquan (Quan Xu) wrote: >>>From 946e7589e5a875574c7567a91943d47c38218a6f Mon Sep 17 >>00:00:00 2001 >>>From: Quan Xu <xuquan8@huawei.com> >>>Date: Fri, 14 Apr 2017 02:11:30 +0800 >>>Subject: [PATCH v1] vmx: set 'SN' bit for the runstate transition from >>>blocked to runnable >>> >>>set 'SN' bit of posted-interrupt descriptor when the runstate >>>transition is from blocked to runnable (SN bit of posted-interrupt >>>descriptor is still set to a blocked vCPU), otherwise PI notification >>>event may be sent to a >> >>Currently, we clear 'SN' bit for a blocked vCPU in order to receive a >>wakeup interrupt to wake up the blocked vCPU. Also note that wakeup >>interrupt is not a special vector for CPU. >> >Sorry, a typo 's/set/clear/'.... >You are right. It is clear. that's why I want to set it. > > >>>non-running vCPU. >>> >>>Signed-off-by: Quan Xu <xuquan8@huawei.com> >>>--- >>> xen/arch/x86/hvm/vmx/vmx.c | 3 --- >>> 1 file changed, 3 deletions(-) >>> >>>diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c >>>index 9c5a388..956f104 100644 >>>--- a/xen/arch/x86/hvm/vmx/vmx.c >>>+++ b/xen/arch/x86/hvm/vmx/vmx.c >>>@@ -142,9 +142,6 @@ static void vmx_pi_switch_from(struct vcpu *v) { >>> struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc; >>> >>>- if ( test_bit(_VPF_blocked, &v->pause_flags) ) >>>- return; >>>- >> >>I wander whether vmx_pi_switch_from() will be called in the transition >>blocked -> runnable. >>In my mind, the function is called during context switch and consumes >>the vcpu that is to be blocked or runnable. > >If you are right, my patch is wrong.. > >Chao, thank you. I will check it again.. Chao, checked the code, I think you are right.. For example, HLT: vmx_vmexit_handler(... case EXIT_REASON_HLT ... ) | hvm_hlt() | do_sched_op(... SCHEDOP_block ...) | vcpu_block_enable_events() | vcpu_block() | arch_vcpu_block() raise_softirq(SCHEDULE_SOFTIRQ) if the vcpu is blocked, the vcpu is de-scheduled.. sorry for the noise, please ignore this patch .. Quan > >Quan > >>I think this if() statement is to >>distinguish 'block' case and doesn't set 'SN' for this case. >> > > > > > >>Thanks >>Chao >> >>> pi_set_sn(pi_desc); >>> } >>> >>>-- >>>1.8.3.1 >> >> >>>_______________________________________________ >>>Xen-devel mailing list >>>Xen-devel@lists.xen.org >>>https://lists.xen.org/xen-devel
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 9c5a388..956f104 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -142,9 +142,6 @@ static void vmx_pi_switch_from(struct vcpu *v) { struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc; - if ( test_bit(_VPF_blocked, &v->pause_flags) ) - return; - pi_set_sn(pi_desc); }