x86/build: Build VSMP support only if selected
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Message ID alpine.DEB.2.21.1811011032190.1642@nanos.tec.linutronix.de
State New
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  • x86/build: Build VSMP support only if selected
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Commit Message

Thomas Gleixner Nov. 1, 2018, 9:36 a.m. UTC
VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build
breakage when CONFIG_PCI is disabled as well.

Build VSMP code only when selected.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---

Comments

Shai Fultheim (Shai@ScaleMP.com) Nov. 1, 2018, 10:39 a.m. UTC | #1
On 01/11/18 11:37, Thomas Gleixner wrote:

> VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build
> breakage when CONFIG_PCI is disabled as well.
> 
> Build VSMP code only when selected.

This patch disables detect_vsmp_box() on systems without CONFIG_X86_VSMP, due to
the recent 6da63eb241a05b0e676d68975e793c0521387141.  This is significant
regression that will affect significant number of deployments.

We will reply shortly with an updated patch that fix the dependency on pv_irq_ops,
and revert to CONFIG_PARAVIRT, with proper protection for CONFIG_PCI.
Eial Czerwacki Nov. 1, 2018, 1:10 p.m. UTC | #2
Greetings,

On 11/01/2018 12:39 PM, Shai Fultheim (Shai@ScaleMP.com) wrote:
> On 01/11/18 11:37, Thomas Gleixner wrote:
> 
>> VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build
>> breakage when CONFIG_PCI is disabled as well.
>>
>> Build VSMP code only when selected.
> 
> This patch disables detect_vsmp_box() on systems without CONFIG_X86_VSMP, due to
> the recent 6da63eb241a05b0e676d68975e793c0521387141.  This is significant
> regression that will affect significant number of deployments.
> 
> We will reply shortly with an updated patch that fix the dependency on pv_irq_ops,
> and revert to CONFIG_PARAVIRT, with proper protection for CONFIG_PCI.
> 

here is the proper patch which fixes the issue on hand:
From ebff534f8cfa55d7c3ab798c44abe879f3fbe2b8 Mon Sep 17 00:00:00 2001
From: Eial Czerwacki <eial@scalemp.com>
Date: Thu, 1 Nov 2018 15:08:32 +0200
Subject: [PATCH] x86/build: Build VSMP support only if CONFIG_PCI is
selected

vsmp dependency of pv_irq_ops removed some years ago, so now let's clean
it up from vsmp_64.c.

In short, "cap & ctl & (1 << 4)" was always returning 0, as such we can
remove all the PARAVIRT/PARAVIRT_XXL code handling that.

However, the rest of the code depends on CONFIG_PCI, so fix it accordingly.

Signed-off-by: Eial Czerwacki <eial@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
---
 arch/x86/Kconfig          |  1 -
 arch/x86/kernel/vsmp_64.c | 80
+++--------------------------------------------
 2 files changed, 5 insertions(+), 76 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c51c989..4b187ca 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -524,7 +524,6 @@ config X86_VSMP
        bool "ScaleMP vSMP"
        select HYPERVISOR_GUEST
        select PARAVIRT
-       select PARAVIRT_XXL
        depends on X86_64 && PCI
        depends on X86_EXTENDED_PLATFORM
        depends on SMP
diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c
index 1eae5af..c6d2b76 100644
--- a/arch/x86/kernel/vsmp_64.c
+++ b/arch/x86/kernel/vsmp_64.c
@@ -26,64 +26,7 @@

 #define TOPOLOGY_REGISTER_OFFSET 0x10

-#if defined CONFIG_PCI && defined CONFIG_PARAVIRT_XXL
-/*
- * Interrupt control on vSMPowered systems:
- * ~AC is a shadow of IF.  If IF is 'on' AC should be 'off'
- * and vice versa.
- */
-
-asmlinkage __visible unsigned long vsmp_save_fl(void)
-{
-       unsigned long flags = native_save_fl();
-
-       if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
-               flags &= ~X86_EFLAGS_IF;
-       return flags;
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
-
-__visible void vsmp_restore_fl(unsigned long flags)
-{
-       if (flags & X86_EFLAGS_IF)
-               flags &= ~X86_EFLAGS_AC;
-       else
-               flags |= X86_EFLAGS_AC;
-       native_restore_fl(flags);
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
-
-asmlinkage __visible void vsmp_irq_disable(void)
-{
-       unsigned long flags = native_save_fl();
-
-       native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
-
-asmlinkage __visible void vsmp_irq_enable(void)
-{
-       unsigned long flags = native_save_fl();
-
-       native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
-
-static unsigned __init vsmp_patch(u8 type, void *ibuf,
-                                 unsigned long addr, unsigned len)
-{
-       switch (type) {
-       case PARAVIRT_PATCH(irq.irq_enable):
-       case PARAVIRT_PATCH(irq.irq_disable):
-       case PARAVIRT_PATCH(irq.save_fl):
-       case PARAVIRT_PATCH(irq.restore_fl):
-               return paravirt_patch_default(type, ibuf, addr, len);
-       default:
-               return native_patch(type, ibuf, addr, len);
-       }
-
-}
-
+#if defined CONFIG_PCI
 static void __init set_vsmp_pv_ops(void)
 {
        void __iomem *address;
@@ -109,28 +52,12 @@ static void __init set_vsmp_pv_ops(void)
        }
 #endif

-       if (cap & ctl & (1 << 4)) {
-               /* Setup irq ops and turn on vSMP  IRQ fastpath handling */
-               pv_ops.irq.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable);
-               pv_ops.irq.irq_enable = PV_CALLEE_SAVE(vsmp_irq_enable);
-               pv_ops.irq.save_fl = PV_CALLEE_SAVE(vsmp_save_fl);
-               pv_ops.irq.restore_fl = PV_CALLEE_SAVE(vsmp_restore_fl);
-               pv_ops.init.patch = vsmp_patch;
-               ctl &= ~(1 << 4);
-       }
        writel(ctl, address + 4);
        ctl = readl(address + 4);
        pr_info("vSMP CTL: control set to:0x%08x\n", ctl);

        early_iounmap(address, 8);
 }
-#else
-static void __init set_vsmp_pv_ops(void)
-{
-}
-#endif
-
-#ifdef CONFIG_PCI
 static int is_vsmp = -1;

 static void __init detect_vsmp_box(void)
@@ -164,11 +91,14 @@ static int is_vsmp_box(void)
 {
        return 0;
 }
+static void __init set_vsmp_pv_ops(void)
+{
+}
 #endif

 static void __init vsmp_cap_cpus(void)
 {
-#if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP)
+#if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
        void __iomem *address;
        unsigned int cfg, topology, node_shift, maxcpus;
Thomas Gleixner Nov. 1, 2018, 1:17 p.m. UTC | #3
On Thu, 1 Nov 2018, Eial Czerwacki wrote:

> Greetings,
> 
> On 11/01/2018 12:39 PM, Shai Fultheim (Shai@ScaleMP.com) wrote:
> > On 01/11/18 11:37, Thomas Gleixner wrote:
> > 
> >> VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build
> >> breakage when CONFIG_PCI is disabled as well.
> >>
> >> Build VSMP code only when selected.
> > 
> > This patch disables detect_vsmp_box() on systems without CONFIG_X86_VSMP, due to
> > the recent 6da63eb241a05b0e676d68975e793c0521387141.  This is significant
> > regression that will affect significant number of deployments.
> > 
> > We will reply shortly with an updated patch that fix the dependency on pv_irq_ops,
> > and revert to CONFIG_PARAVIRT, with proper protection for CONFIG_PCI.
> > 
> 
> here is the proper patch which fixes the issue on hand:
> >From ebff534f8cfa55d7c3ab798c44abe879f3fbe2b8 Mon Sep 17 00:00:00 2001
> From: Eial Czerwacki <eial@scalemp.com>
> Date: Thu, 1 Nov 2018 15:08:32 +0200
> Subject: [PATCH] x86/build: Build VSMP support only if CONFIG_PCI is
> selected
> 
> vsmp dependency of pv_irq_ops removed some years ago, so now let's clean
> it up from vsmp_64.c.
> 
> In short, "cap & ctl & (1 << 4)" was always returning 0, as such we can
> remove all the PARAVIRT/PARAVIRT_XXL code handling that.
> 
> However, the rest of the code depends on CONFIG_PCI, so fix it accordingly.
> 
> Signed-off-by: Eial Czerwacki <eial@scalemp.com>
> Acked-by: Shai Fultheim <shai@scalemp.com>

Nice cleanup!

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Jürgen Groß Nov. 1, 2018, 1:45 p.m. UTC | #4
On 01/11/2018 14:10, Eial Czerwacki wrote:
> Greetings,
> 
> On 11/01/2018 12:39 PM, Shai Fultheim (Shai@ScaleMP.com) wrote:
>> On 01/11/18 11:37, Thomas Gleixner wrote:
>>
>>> VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build
>>> breakage when CONFIG_PCI is disabled as well.
>>>
>>> Build VSMP code only when selected.
>>
>> This patch disables detect_vsmp_box() on systems without CONFIG_X86_VSMP, due to
>> the recent 6da63eb241a05b0e676d68975e793c0521387141.  This is significant
>> regression that will affect significant number of deployments.
>>
>> We will reply shortly with an updated patch that fix the dependency on pv_irq_ops,
>> and revert to CONFIG_PARAVIRT, with proper protection for CONFIG_PCI.
>>
> 
> here is the proper patch which fixes the issue on hand:
> From ebff534f8cfa55d7c3ab798c44abe879f3fbe2b8 Mon Sep 17 00:00:00 2001
> From: Eial Czerwacki <eial@scalemp.com>
> Date: Thu, 1 Nov 2018 15:08:32 +0200
> Subject: [PATCH] x86/build: Build VSMP support only if CONFIG_PCI is
> selected
> 
> vsmp dependency of pv_irq_ops removed some years ago, so now let's clean
> it up from vsmp_64.c.
> 
> In short, "cap & ctl & (1 << 4)" was always returning 0, as such we can
> remove all the PARAVIRT/PARAVIRT_XXL code handling that.
> 
> However, the rest of the code depends on CONFIG_PCI, so fix it accordingly.
> 
> Signed-off-by: Eial Czerwacki <eial@scalemp.com>
> Acked-by: Shai Fultheim <shai@scalemp.com>
> ---
>  arch/x86/Kconfig          |  1 -
>  arch/x86/kernel/vsmp_64.c | 80
> +++--------------------------------------------
>  2 files changed, 5 insertions(+), 76 deletions(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index c51c989..4b187ca 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -524,7 +524,6 @@ config X86_VSMP
>         bool "ScaleMP vSMP"
>         select HYPERVISOR_GUEST
>         select PARAVIRT

Do you really still need PARAVIRT and HYPERVISOR_GUEST?
Maybe you want IRQ_REMAP instead?

> -       select PARAVIRT_XXL
>         depends on X86_64 && PCI
>         depends on X86_EXTENDED_PLATFORM
>         depends on SMP
> diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c
> index 1eae5af..c6d2b76 100644
> --- a/arch/x86/kernel/vsmp_64.c
> +++ b/arch/x86/kernel/vsmp_64.c
> @@ -26,64 +26,7 @@
> 
>  #define TOPOLOGY_REGISTER_OFFSET 0x10
> 
> -#if defined CONFIG_PCI && defined CONFIG_PARAVIRT_XXL
> -/*
> - * Interrupt control on vSMPowered systems:
> - * ~AC is a shadow of IF.  If IF is 'on' AC should be 'off'
> - * and vice versa.
> - */
> -
> -asmlinkage __visible unsigned long vsmp_save_fl(void)
> -{
> -       unsigned long flags = native_save_fl();
> -
> -       if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
> -               flags &= ~X86_EFLAGS_IF;
> -       return flags;
> -}
> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
> -
> -__visible void vsmp_restore_fl(unsigned long flags)
> -{
> -       if (flags & X86_EFLAGS_IF)
> -               flags &= ~X86_EFLAGS_AC;
> -       else
> -               flags |= X86_EFLAGS_AC;
> -       native_restore_fl(flags);
> -}
> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
> -
> -asmlinkage __visible void vsmp_irq_disable(void)
> -{
> -       unsigned long flags = native_save_fl();
> -
> -       native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
> -}
> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
> -
> -asmlinkage __visible void vsmp_irq_enable(void)
> -{
> -       unsigned long flags = native_save_fl();
> -
> -       native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
> -}
> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
> -
> -static unsigned __init vsmp_patch(u8 type, void *ibuf,
> -                                 unsigned long addr, unsigned len)
> -{
> -       switch (type) {
> -       case PARAVIRT_PATCH(irq.irq_enable):
> -       case PARAVIRT_PATCH(irq.irq_disable):
> -       case PARAVIRT_PATCH(irq.save_fl):
> -       case PARAVIRT_PATCH(irq.restore_fl):
> -               return paravirt_patch_default(type, ibuf, addr, len);
> -       default:
> -               return native_patch(type, ibuf, addr, len);
> -       }
> -
> -}
> -
> +#if defined CONFIG_PCI
>  static void __init set_vsmp_pv_ops(void)

Wouldn't be a rename of the function be appropriate now?


Juergen
Eial Czerwacki Nov. 1, 2018, 3:09 p.m. UTC | #5
Greetings,

On 11/01/2018 03:45 PM, Juergen Gross wrote:
> On 01/11/2018 14:10, Eial Czerwacki wrote:
>> Greetings,
>>
>> On 11/01/2018 12:39 PM, Shai Fultheim (Shai@ScaleMP.com) wrote:
>>> On 01/11/18 11:37, Thomas Gleixner wrote:
>>>
>>>> VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build
>>>> breakage when CONFIG_PCI is disabled as well.
>>>>
>>>> Build VSMP code only when selected.
>>>
>>> This patch disables detect_vsmp_box() on systems without CONFIG_X86_VSMP, due to
>>> the recent 6da63eb241a05b0e676d68975e793c0521387141.  This is significant
>>> regression that will affect significant number of deployments.
>>>
>>> We will reply shortly with an updated patch that fix the dependency on pv_irq_ops,
>>> and revert to CONFIG_PARAVIRT, with proper protection for CONFIG_PCI.
>>>
>>
>> here is the proper patch which fixes the issue on hand:
>> From ebff534f8cfa55d7c3ab798c44abe879f3fbe2b8 Mon Sep 17 00:00:00 2001
>> From: Eial Czerwacki <eial@scalemp.com>
>> Date: Thu, 1 Nov 2018 15:08:32 +0200
>> Subject: [PATCH] x86/build: Build VSMP support only if CONFIG_PCI is
>> selected
>>
>> vsmp dependency of pv_irq_ops removed some years ago, so now let's clean
>> it up from vsmp_64.c.
>>
>> In short, "cap & ctl & (1 << 4)" was always returning 0, as such we can
>> remove all the PARAVIRT/PARAVIRT_XXL code handling that.
>>
>> However, the rest of the code depends on CONFIG_PCI, so fix it accordingly.
>>
>> Signed-off-by: Eial Czerwacki <eial@scalemp.com>
>> Acked-by: Shai Fultheim <shai@scalemp.com>
>> ---
>>  arch/x86/Kconfig          |  1 -
>>  arch/x86/kernel/vsmp_64.c | 80
>> +++--------------------------------------------
>>  2 files changed, 5 insertions(+), 76 deletions(-)
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index c51c989..4b187ca 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -524,7 +524,6 @@ config X86_VSMP
>>         bool "ScaleMP vSMP"
>>         select HYPERVISOR_GUEST
>>         select PARAVIRT
> 
> Do you really still need PARAVIRT and HYPERVISOR_GUEST?
> Maybe you want IRQ_REMAP instead?
> 
Better performance is achieved with PARAVIRTed kernel.   Hence we keep
them both in.

>> -       select PARAVIRT_XXL
>>         depends on X86_64 && PCI
>>         depends on X86_EXTENDED_PLATFORM
>>         depends on SMP
>> diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c
>> index 1eae5af..c6d2b76 100644
>> --- a/arch/x86/kernel/vsmp_64.c
>> +++ b/arch/x86/kernel/vsmp_64.c
>> @@ -26,64 +26,7 @@
>>
>>  #define TOPOLOGY_REGISTER_OFFSET 0x10
>>
>> -#if defined CONFIG_PCI && defined CONFIG_PARAVIRT_XXL
>> -/*
>> - * Interrupt control on vSMPowered systems:
>> - * ~AC is a shadow of IF.  If IF is 'on' AC should be 'off'
>> - * and vice versa.
>> - */
>> -
>> -asmlinkage __visible unsigned long vsmp_save_fl(void)
>> -{
>> -       unsigned long flags = native_save_fl();
>> -
>> -       if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
>> -               flags &= ~X86_EFLAGS_IF;
>> -       return flags;
>> -}
>> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
>> -
>> -__visible void vsmp_restore_fl(unsigned long flags)
>> -{
>> -       if (flags & X86_EFLAGS_IF)
>> -               flags &= ~X86_EFLAGS_AC;
>> -       else
>> -               flags |= X86_EFLAGS_AC;
>> -       native_restore_fl(flags);
>> -}
>> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
>> -
>> -asmlinkage __visible void vsmp_irq_disable(void)
>> -{
>> -       unsigned long flags = native_save_fl();
>> -
>> -       native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
>> -}
>> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
>> -
>> -asmlinkage __visible void vsmp_irq_enable(void)
>> -{
>> -       unsigned long flags = native_save_fl();
>> -
>> -       native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
>> -}
>> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
>> -
>> -static unsigned __init vsmp_patch(u8 type, void *ibuf,
>> -                                 unsigned long addr, unsigned len)
>> -{
>> -       switch (type) {
>> -       case PARAVIRT_PATCH(irq.irq_enable):
>> -       case PARAVIRT_PATCH(irq.irq_disable):
>> -       case PARAVIRT_PATCH(irq.save_fl):
>> -       case PARAVIRT_PATCH(irq.restore_fl):
>> -               return paravirt_patch_default(type, ibuf, addr, len);
>> -       default:
>> -               return native_patch(type, ibuf, addr, len);
>> -       }
>> -
>> -}
>> -
>> +#if defined CONFIG_PCI
>>  static void __init set_vsmp_pv_ops(void)
> 
> Wouldn't be a rename of the function be appropriate now?
you are correct, I'll fix and resend the patch.

> 
> 
> Juergen
>
Jürgen Groß Nov. 1, 2018, 3:39 p.m. UTC | #6
On 01/11/2018 16:09, Eial Czerwacki wrote:
> Greetings,
> 
> On 11/01/2018 03:45 PM, Juergen Gross wrote:
>> On 01/11/2018 14:10, Eial Czerwacki wrote:
>>> Greetings,
>>>
>>> On 11/01/2018 12:39 PM, Shai Fultheim (Shai@ScaleMP.com) wrote:
>>>> On 01/11/18 11:37, Thomas Gleixner wrote:
>>>>
>>>>> VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build
>>>>> breakage when CONFIG_PCI is disabled as well.
>>>>>
>>>>> Build VSMP code only when selected.
>>>>
>>>> This patch disables detect_vsmp_box() on systems without CONFIG_X86_VSMP, due to
>>>> the recent 6da63eb241a05b0e676d68975e793c0521387141.  This is significant
>>>> regression that will affect significant number of deployments.
>>>>
>>>> We will reply shortly with an updated patch that fix the dependency on pv_irq_ops,
>>>> and revert to CONFIG_PARAVIRT, with proper protection for CONFIG_PCI.
>>>>
>>>
>>> here is the proper patch which fixes the issue on hand:
>>> From ebff534f8cfa55d7c3ab798c44abe879f3fbe2b8 Mon Sep 17 00:00:00 2001
>>> From: Eial Czerwacki <eial@scalemp.com>
>>> Date: Thu, 1 Nov 2018 15:08:32 +0200
>>> Subject: [PATCH] x86/build: Build VSMP support only if CONFIG_PCI is
>>> selected
>>>
>>> vsmp dependency of pv_irq_ops removed some years ago, so now let's clean
>>> it up from vsmp_64.c.
>>>
>>> In short, "cap & ctl & (1 << 4)" was always returning 0, as such we can
>>> remove all the PARAVIRT/PARAVIRT_XXL code handling that.
>>>
>>> However, the rest of the code depends on CONFIG_PCI, so fix it accordingly.
>>>
>>> Signed-off-by: Eial Czerwacki <eial@scalemp.com>
>>> Acked-by: Shai Fultheim <shai@scalemp.com>
>>> ---
>>>  arch/x86/Kconfig          |  1 -
>>>  arch/x86/kernel/vsmp_64.c | 80
>>> +++--------------------------------------------
>>>  2 files changed, 5 insertions(+), 76 deletions(-)
>>>
>>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>>> index c51c989..4b187ca 100644
>>> --- a/arch/x86/Kconfig
>>> +++ b/arch/x86/Kconfig
>>> @@ -524,7 +524,6 @@ config X86_VSMP
>>>         bool "ScaleMP vSMP"
>>>         select HYPERVISOR_GUEST
>>>         select PARAVIRT
>>
>> Do you really still need PARAVIRT and HYPERVISOR_GUEST?
>> Maybe you want IRQ_REMAP instead?
>>
> Better performance is achieved with PARAVIRTed kernel.   Hence we keep
> them both in.

Do you have an explanation for that? Normally PARAVIRT is expected
to have a small negative impact on performance.


Juergen

Patch
diff mbox series

diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index ae13bc974416..b6b911c4c7f3 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -33,7 +33,7 @@ 
 extern u64 relocated_ramdisk;
 
 /* Interrupt control for vSMPowered x86_64 systems */
-#ifdef CONFIG_X86_64
+#if defined(CONFIG_X86_64) && defined(CONFIG_X86_VSMP)
 void vsmp_init(void);
 #else
 static inline void vsmp_init(void) { }
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 8824d01c0c35..647ce52b17d5 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -148,5 +148,5 @@  ifeq ($(CONFIG_X86_64),y)
 	obj-$(CONFIG_CALGARY_IOMMU)	+= pci-calgary_64.o tce_64.o
 
 	obj-$(CONFIG_MMCONF_FAM10H)	+= mmconf-fam10h_64.o
-	obj-y				+= vsmp_64.o
+	obj-$(CONFIG_X86_VSMP)		+= vsmp_64.o
 endif