* [PATCH 1/2] xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op
[not found] <1458219805-13197-1-git-send-email-boris.ostrovsky@oracle.com>
@ 2016-03-17 13:03 ` Boris Ostrovsky
2016-03-17 13:03 ` [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead() Boris Ostrovsky
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Boris Ostrovsky @ 2016-03-17 13:03 UTC (permalink / raw)
To: david.vrabel, konrad.wilk; +Cc: xen-devel, Boris Ostrovsky, linux-kernel
Currently Xen uses default_cpu_present_to_apicid() which will always
report BAD_APICID for PV guests since x86_bios_cpu_apic_id is initialised
to that value and is never updated.
With commit 1f12e32f4cd5 ("x86/topology: Create logical package id"), this
op is now called by smp_init_package_map() when deciding whether to call
topology_update_package_map() which sets cpu_data(cpu).logical_proc_id.
The latter (as topology_logical_package_id(cpu)) may be used, for example,
by cpu_to_rapl_pmu() as an array index. Since uninitialized
logical_package_id is set to -1, the index will become 64K which is
obviously problematic.
While RAPL code (and any other users of logical_package_id) should be
careful in their assumptions about id's validity, Xen's
cpu_present_to_apicid op should still provide value consistent with its
own xen_apic_read(APIC_ID).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
arch/x86/xen/apic.c | 12 ++++++++++--
1 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index abf4901..db52a7f 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -66,7 +66,7 @@ static u32 xen_apic_read(u32 reg)
ret = HYPERVISOR_platform_op(&op);
if (ret)
- return 0;
+ op.u.pcpu_info.apic_id = BAD_APICID;
return op.u.pcpu_info.apic_id << 24;
}
@@ -142,6 +142,14 @@ static void xen_silent_inquire(int apicid)
{
}
+static int xen_cpu_present_to_apicid(int cpu)
+{
+ if (cpu_present(cpu))
+ return xen_get_apic_id(xen_apic_read(APIC_ID));
+ else
+ return BAD_APICID;
+}
+
static struct apic xen_pv_apic = {
.name = "Xen PV",
.probe = xen_apic_probe_pv,
@@ -162,7 +170,7 @@ static struct apic xen_pv_apic = {
.ioapic_phys_id_map = default_ioapic_phys_id_map, /* Used on 32-bit */
.setup_apic_routing = NULL,
- .cpu_present_to_apicid = default_cpu_present_to_apicid,
+ .cpu_present_to_apicid = xen_cpu_present_to_apicid,
.apicid_to_cpu_present = physid_set_mask_of_physid, /* Used on 32-bit */
.check_phys_apicid_present = default_check_phys_apicid_present, /* smp_sanity_check needs it */
.phys_pkg_id = xen_phys_pkg_id, /* detect_ht */
--
1.7.1
_______________________________________________
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http://lists.xen.org/xen-devel
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()
[not found] <1458219805-13197-1-git-send-email-boris.ostrovsky@oracle.com>
2016-03-17 13:03 ` [PATCH 1/2] xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op Boris Ostrovsky
@ 2016-03-17 13:03 ` Boris Ostrovsky
[not found] ` <1458219805-13197-2-git-send-email-boris.ostrovsky@oracle.com>
[not found] ` <1458219805-13197-3-git-send-email-boris.ostrovsky@oracle.com>
3 siblings, 0 replies; 6+ messages in thread
From: Boris Ostrovsky @ 2016-03-17 13:03 UTC (permalink / raw)
To: david.vrabel, konrad.wilk; +Cc: xen-devel, Boris Ostrovsky, linux-kernel
This call has always been missing from xen_play dead() but until
recently this was rather benign. With new cpu hotplug framework
however this call is required, otherwise a hot-plugged CPU will not
be properly brough up (by never calling cpuhp_online_idle())
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
arch/x86/xen/smp.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 3c6d17f..719cf29 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -545,6 +545,8 @@ static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
* data back is to call:
*/
tick_nohz_idle_enter();
+
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}
#else /* !CONFIG_HOTPLUG_CPU */
--
1.7.1
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op
[not found] ` <1458219805-13197-2-git-send-email-boris.ostrovsky@oracle.com>
@ 2016-03-25 14:52 ` Konrad Rzeszutek Wilk
0 siblings, 0 replies; 6+ messages in thread
From: Konrad Rzeszutek Wilk @ 2016-03-25 14:52 UTC (permalink / raw)
To: Boris Ostrovsky; +Cc: xen-devel, david.vrabel, linux-kernel
On Thu, Mar 17, 2016 at 09:03:24AM -0400, Boris Ostrovsky wrote:
> Currently Xen uses default_cpu_present_to_apicid() which will always
> report BAD_APICID for PV guests since x86_bios_cpu_apic_id is initialised
> to that value and is never updated.
>
> With commit 1f12e32f4cd5 ("x86/topology: Create logical package id"), this
> op is now called by smp_init_package_map() when deciding whether to call
> topology_update_package_map() which sets cpu_data(cpu).logical_proc_id.
> The latter (as topology_logical_package_id(cpu)) may be used, for example,
> by cpu_to_rapl_pmu() as an array index. Since uninitialized
> logical_package_id is set to -1, the index will become 64K which is
> obviously problematic.
>
> While RAPL code (and any other users of logical_package_id) should be
> careful in their assumptions about id's validity, Xen's
> cpu_present_to_apicid op should still provide value consistent with its
> own xen_apic_read(APIC_ID).
>
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---
> arch/x86/xen/apic.c | 12 ++++++++++--
> 1 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
> index abf4901..db52a7f 100644
> --- a/arch/x86/xen/apic.c
> +++ b/arch/x86/xen/apic.c
> @@ -66,7 +66,7 @@ static u32 xen_apic_read(u32 reg)
>
> ret = HYPERVISOR_platform_op(&op);
> if (ret)
> - return 0;
> + op.u.pcpu_info.apic_id = BAD_APICID;
>
> return op.u.pcpu_info.apic_id << 24;
> }
> @@ -142,6 +142,14 @@ static void xen_silent_inquire(int apicid)
> {
> }
>
> +static int xen_cpu_present_to_apicid(int cpu)
> +{
> + if (cpu_present(cpu))
> + return xen_get_apic_id(xen_apic_read(APIC_ID));
> + else
> + return BAD_APICID;
> +}
> +
> static struct apic xen_pv_apic = {
> .name = "Xen PV",
> .probe = xen_apic_probe_pv,
> @@ -162,7 +170,7 @@ static struct apic xen_pv_apic = {
>
> .ioapic_phys_id_map = default_ioapic_phys_id_map, /* Used on 32-bit */
> .setup_apic_routing = NULL,
> - .cpu_present_to_apicid = default_cpu_present_to_apicid,
> + .cpu_present_to_apicid = xen_cpu_present_to_apicid,
> .apicid_to_cpu_present = physid_set_mask_of_physid, /* Used on 32-bit */
> .check_phys_apicid_present = default_check_phys_apicid_present, /* smp_sanity_check needs it */
> .phys_pkg_id = xen_phys_pkg_id, /* detect_ht */
> --
> 1.7.1
>
_______________________________________________
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Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()
[not found] ` <1458219805-13197-3-git-send-email-boris.ostrovsky@oracle.com>
@ 2016-03-25 14:53 ` Konrad Rzeszutek Wilk
2016-03-25 15:08 ` Boris Ostrovsky
0 siblings, 1 reply; 6+ messages in thread
From: Konrad Rzeszutek Wilk @ 2016-03-25 14:53 UTC (permalink / raw)
To: Boris Ostrovsky; +Cc: xen-devel, david.vrabel, linux-kernel
On Thu, Mar 17, 2016 at 09:03:25AM -0400, Boris Ostrovsky wrote:
> This call has always been missing from xen_play dead() but until
> recently this was rather benign. With new cpu hotplug framework
> however this call is required, otherwise a hot-plugged CPU will not
Could you include the commit id of the 'new cpu hotplug' in case
anybody wants to backport this?
Thanks!
> be properly brough up (by never calling cpuhp_online_idle())
>
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> ---
> arch/x86/xen/smp.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
> index 3c6d17f..719cf29 100644
> --- a/arch/x86/xen/smp.c
> +++ b/arch/x86/xen/smp.c
> @@ -545,6 +545,8 @@ static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
> * data back is to call:
> */
> tick_nohz_idle_enter();
> +
> + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
> }
>
> #else /* !CONFIG_HOTPLUG_CPU */
> --
> 1.7.1
>
_______________________________________________
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Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()
2016-03-25 14:53 ` [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead() Konrad Rzeszutek Wilk
@ 2016-03-25 15:08 ` Boris Ostrovsky
2016-03-25 15:45 ` Konrad Rzeszutek Wilk
0 siblings, 1 reply; 6+ messages in thread
From: Boris Ostrovsky @ 2016-03-25 15:08 UTC (permalink / raw)
To: Konrad Rzeszutek Wilk; +Cc: xen-devel, david.vrabel, linux-kernel
On 03/25/2016 10:53 AM, Konrad Rzeszutek Wilk wrote:
> On Thu, Mar 17, 2016 at 09:03:25AM -0400, Boris Ostrovsky wrote:
>> This call has always been missing from xen_play dead() but until
>> recently this was rather benign. With new cpu hotplug framework
>> however this call is required, otherwise a hot-plugged CPU will not
> Could you include the commit id of the 'new cpu hotplug' in case
> anybody wants to backport this?
Sure.
It's commit 8df3e07e7f21 ("cpu/hotplug: Let upcoming cpu bring itself
fully up").
Do you (or David) want me to re-send it?
-boris
>
> Thanks!
>> be properly brough up (by never calling cpuhp_online_idle())
>>
>> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>> ---
>> arch/x86/xen/smp.c | 2 ++
>> 1 files changed, 2 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
>> index 3c6d17f..719cf29 100644
>> --- a/arch/x86/xen/smp.c
>> +++ b/arch/x86/xen/smp.c
>> @@ -545,6 +545,8 @@ static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
>> * data back is to call:
>> */
>> tick_nohz_idle_enter();
>> +
>> + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
>> }
>>
>> #else /* !CONFIG_HOTPLUG_CPU */
>> --
>> 1.7.1
>>
_______________________________________________
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http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()
2016-03-25 15:08 ` Boris Ostrovsky
@ 2016-03-25 15:45 ` Konrad Rzeszutek Wilk
0 siblings, 0 replies; 6+ messages in thread
From: Konrad Rzeszutek Wilk @ 2016-03-25 15:45 UTC (permalink / raw)
To: Boris Ostrovsky; +Cc: xen-devel, david.vrabel, linux-kernel
On Fri, Mar 25, 2016 at 11:08:32AM -0400, Boris Ostrovsky wrote:
> On 03/25/2016 10:53 AM, Konrad Rzeszutek Wilk wrote:
> >On Thu, Mar 17, 2016 at 09:03:25AM -0400, Boris Ostrovsky wrote:
> >>This call has always been missing from xen_play dead() but until
> >>recently this was rather benign. With new cpu hotplug framework
> >>however this call is required, otherwise a hot-plugged CPU will not
> >Could you include the commit id of the 'new cpu hotplug' in case
> >anybody wants to backport this?
>
> Sure.
>
> It's commit 8df3e07e7f21 ("cpu/hotplug: Let upcoming cpu bring itself fully
> up").
>
> Do you (or David) want me to re-send it?
That is OK. I've updated the patch and committed both of them in for-linus-4.6.
Thanks!
>
> -boris
>
>
>
> >
> >Thanks!
> >>be properly brough up (by never calling cpuhp_online_idle())
> >>
> >>Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> >>---
> >> arch/x86/xen/smp.c | 2 ++
> >> 1 files changed, 2 insertions(+), 0 deletions(-)
> >>
> >>diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
> >>index 3c6d17f..719cf29 100644
> >>--- a/arch/x86/xen/smp.c
> >>+++ b/arch/x86/xen/smp.c
> >>@@ -545,6 +545,8 @@ static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
> >> * data back is to call:
> >> */
> >> tick_nohz_idle_enter();
> >>+
> >>+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
> >> }
> >> #else /* !CONFIG_HOTPLUG_CPU */
> >>--
> >>1.7.1
> >>
>
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[not found] <1458219805-13197-1-git-send-email-boris.ostrovsky@oracle.com>
2016-03-17 13:03 ` [PATCH 1/2] xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op Boris Ostrovsky
2016-03-17 13:03 ` [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead() Boris Ostrovsky
[not found] ` <1458219805-13197-2-git-send-email-boris.ostrovsky@oracle.com>
2016-03-25 14:52 ` [PATCH 1/2] xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op Konrad Rzeszutek Wilk
[not found] ` <1458219805-13197-3-git-send-email-boris.ostrovsky@oracle.com>
2016-03-25 14:53 ` [PATCH 2/2] xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead() Konrad Rzeszutek Wilk
2016-03-25 15:08 ` Boris Ostrovsky
2016-03-25 15:45 ` Konrad Rzeszutek Wilk
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