xen: PV on HVM: support PV spinlocks
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 6f53453..5643c43 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1290,6 +1290,8 @@ static int __cpuinit xen_hvm_cpu_notify(struct
notifier_block *self,
switch (action) {
case CPU_UP_PREPARE:
per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+ if (xen_have_vector_callback)
+ xen_init_lock_cpu(cpu);
break;
default:
break;
@@ -1301,6 +1303,20 @@ static struct notifier_block __cpuinitdata
xen_hvm_cpu_notifier = {
.notifier_call = xen_hvm_cpu_notify,
};
+static void xen_hvm_spinlock_init(void)
+{
+ if (!xen_have_vector_callback)
+ return
+ xen_init_lock_cpu(0);
+ xen_init_spinlocks();
+}
+
+static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
+{
+ xen_hvm_spinlock_init();
+ native_smp_prepare_cpus(max_cpus);
+}
+
static void __init xen_hvm_guest_init(void)
{
int r;
@@ -1320,6 +1336,7 @@ static void __init xen_hvm_guest_init(void)
x86_init.irqs.intr_init = xen_init_IRQ;
xen_hvm_init_time_ops();
xen_hvm_init_mmu_ops();
+ smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
}
static bool __init xen_hvm_platform(void)
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Jeremy Fitzhardinge
2010-Aug-13 21:17 UTC
Re: [Xen-devel] xen: PV on HVM: support PV spinlocks
On 08/13/2010 12:06 PM, Stefano Stabellini wrote:> xen: PV on HVM: support PV spinlocks > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > index 6f53453..5643c43 100644 > --- a/arch/x86/xen/enlighten.c > +++ b/arch/x86/xen/enlighten.c > @@ -1290,6 +1290,8 @@ static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self, > switch (action) { > case CPU_UP_PREPARE: > per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; > + if (xen_have_vector_callback) > + xen_init_lock_cpu(cpu);Why does this depend on vector_callback? pv spinlocks never have events actually delivered. Nice and simple otherwise. J> break; > default: > break; > @@ -1301,6 +1303,20 @@ static struct notifier_block __cpuinitdata xen_hvm_cpu_notifier = { > .notifier_call = xen_hvm_cpu_notify, > }; > > +static void xen_hvm_spinlock_init(void) > +{ > + if (!xen_have_vector_callback) > + return > + xen_init_lock_cpu(0); > + xen_init_spinlocks(); > +} > + > +static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus) > +{ > + xen_hvm_spinlock_init(); > + native_smp_prepare_cpus(max_cpus); > +} > + > static void __init xen_hvm_guest_init(void) > { > int r; > @@ -1320,6 +1336,7 @@ static void __init xen_hvm_guest_init(void) > x86_init.irqs.intr_init = xen_init_IRQ; > xen_hvm_init_time_ops(); > xen_hvm_init_mmu_ops(); > + smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus; > } > > static bool __init xen_hvm_platform(void) > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Stefano Stabellini
2010-Aug-16 11:56 UTC
Re: [Xen-devel] xen: PV on HVM: support PV spinlocks
On Fri, 13 Aug 2010, Jeremy Fitzhardinge wrote:> On 08/13/2010 12:06 PM, Stefano Stabellini wrote: > > xen: PV on HVM: support PV spinlocks > > > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > > index 6f53453..5643c43 100644 > > --- a/arch/x86/xen/enlighten.c > > +++ b/arch/x86/xen/enlighten.c > > @@ -1290,6 +1290,8 @@ static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self, > > switch (action) { > > case CPU_UP_PREPARE: > > per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; > > + if (xen_have_vector_callback) > > + xen_init_lock_cpu(cpu); > > Why does this depend on vector_callback? pv spinlocks never have events > actually delivered. >HVM guests cannot receive events on vcpus other than 0 without vector_callback, this means they wouldn''t receive even a vcpu_kick and would get stuck. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Jeremy Fitzhardinge
2010-Aug-16 19:43 UTC
Re: [Xen-devel] xen: PV on HVM: support PV spinlocks
On 08/16/2010 04:56 AM, Stefano Stabellini wrote:> On Fri, 13 Aug 2010, Jeremy Fitzhardinge wrote: >> On 08/13/2010 12:06 PM, Stefano Stabellini wrote: >>> xen: PV on HVM: support PV spinlocks >>> >>> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> >>> >>> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c >>> index 6f53453..5643c43 100644 >>> --- a/arch/x86/xen/enlighten.c >>> +++ b/arch/x86/xen/enlighten.c >>> @@ -1290,6 +1290,8 @@ static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self, >>> switch (action) { >>> case CPU_UP_PREPARE: >>> per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; >>> + if (xen_have_vector_callback) >>> + xen_init_lock_cpu(cpu); >> Why does this depend on vector_callback? pv spinlocks never have events >> actually delivered. >> > HVM guests cannot receive events on vcpus other than 0 without > vector_callback, this means they wouldn''t receive even a vcpu_kick and > would get stuck.Huh, really. So if a vcpu is blocked in a poll hypercall on a masked event channel and you send that vcpu an IPI, the poll won''t unblock unless you have a delivery vector? OK, I guess. J _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel