Re: [Xen-devel] [PATCH v2 02/30] xen/x86: remove XENFEAT_hvm_pirqs for PVHv2 guests

2016-09-29 Thread Jan Beulich 
>>> On 29.09.16 at 16:17,  wrote:
> On Wed, Sep 28, 2016 at 10:03:21AM -0600, Jan Beulich wrote:
>> >>> On 27.09.16 at 17:56,  wrote:
>> > On PVHv2 guests we explicitly want to use native methods for routing
>> > interrupts.
>> > 
>> > Introduce a new XEN_X86_EMU_USE_PIRQ to notify Xen whether a HVM guest can
>> > route physical interrupts (even from emulated devices) over event channels.
>> 
>> So you specifically want this new flag off for PVHv2 guests? Based on
>> just this description I did get the opposite impression...
> 
> Yes, that's right, I don't want PVHv2 guests to know anything about PIRQs. I 
> 
> don't really know how to reword this, what about:
> 
> "PVHv2 guests, unlike HVM guests, won't have the option to route interrupts 
> from physical or emulated devices over event channels using PIRQs. This 
> applies to both DomU and Dom0 PVHv2 guests.
> 
> Introduce a new XEN_X86_EMU_USE_PIRQ to notify Xen whether a HVM guest can
> route physical interrupts (even from emulated devices) over event channels, 
> and is thus allowed to use some of the PHYSDEV ops."

SGTM

Jan


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Re: [Xen-devel] [PATCH v2 02/30] xen/x86: remove XENFEAT_hvm_pirqs for PVHv2 guests

2016-09-29 Thread Roger Pau Monne 
On Wed, Sep 28, 2016 at 10:03:21AM -0600, Jan Beulich wrote:
> >>> On 27.09.16 at 17:56,  wrote:
> > On PVHv2 guests we explicitly want to use native methods for routing
> > interrupts.
> > 
> > Introduce a new XEN_X86_EMU_USE_PIRQ to notify Xen whether a HVM guest can
> > route physical interrupts (even from emulated devices) over event channels.
> 
> So you specifically want this new flag off for PVHv2 guests? Based on
> just this description I did get the opposite impression...

Yes, that's right, I don't want PVHv2 guests to know anything about PIRQs. I 
don't really know how to reword this, what about:

"PVHv2 guests, unlike HVM guests, won't have the option to route interrupts 
from physical or emulated devices over event channels using PIRQs. This 
applies to both DomU and Dom0 PVHv2 guests.

Introduce a new XEN_X86_EMU_USE_PIRQ to notify Xen whether a HVM guest can
route physical interrupts (even from emulated devices) over event channels, 
and is thus allowed to use some of the PHYSDEV ops."

> > --- a/xen/arch/x86/hvm/hvm.c
> > +++ b/xen/arch/x86/hvm/hvm.c
> > @@ -4117,6 +4117,8 @@ static long hvm_memory_op(int cmd, 
> > XEN_GUEST_HANDLE_PARAM(void) arg)
> >  
> >  static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
> >  {
> > +struct domain *d = current->domain;
> 
> currd please.
> 
> > @@ -4128,7 +4130,9 @@ static long hvm_physdev_op(int cmd, 
> > XEN_GUEST_HANDLE_PARAM(void) arg)
> >  case PHYSDEVOP_eoi:
> >  case PHYSDEVOP_irq_status_query:
> >  case PHYSDEVOP_get_free_pirq:
> > -return do_physdev_op(cmd, arg);
> > +return ((d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) ||
> > +   is_pvh_vcpu(current)) ?
> 
> is_pvh_domain(currd)

Thanks, it's fixed now. I've also taken the opportunity to fixing two other 
instances of current and current->domain.

Roger.

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Re: [Xen-devel] [PATCH v2 02/30] xen/x86: remove XENFEAT_hvm_pirqs for PVHv2 guests

2016-09-28 Thread Jan Beulich 
>>> On 27.09.16 at 17:56,  wrote:
> On PVHv2 guests we explicitly want to use native methods for routing
> interrupts.
> 
> Introduce a new XEN_X86_EMU_USE_PIRQ to notify Xen whether a HVM guest can
> route physical interrupts (even from emulated devices) over event channels.

So you specifically want this new flag off for PVHv2 guests? Based on
just this description I did get the opposite impression...

> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -4117,6 +4117,8 @@ static long hvm_memory_op(int cmd, 
> XEN_GUEST_HANDLE_PARAM(void) arg)
>  
>  static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>  {
> +struct domain *d = current->domain;

currd please.

> @@ -4128,7 +4130,9 @@ static long hvm_physdev_op(int cmd, 
> XEN_GUEST_HANDLE_PARAM(void) arg)
>  case PHYSDEVOP_eoi:
>  case PHYSDEVOP_irq_status_query:
>  case PHYSDEVOP_get_free_pirq:
> -return do_physdev_op(cmd, arg);
> +return ((d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) ||
> +   is_pvh_vcpu(current)) ?

is_pvh_domain(currd)

Jan


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[Xen-devel] [PATCH v2 02/30] xen/x86: remove XENFEAT_hvm_pirqs for PVHv2 guests

2016-09-27 Thread Roger Pau Monne 
On PVHv2 guests we explicitly want to use native methods for routing
interrupts.

Introduce a new XEN_X86_EMU_USE_PIRQ to notify Xen whether a HVM guest can
route physical interrupts (even from emulated devices) over event channels.

Signed-off-by: Roger Pau Monné 
---
Cc: Jan Beulich 
Cc: Andrew Cooper 
---
 xen/arch/x86/hvm/hvm.c| 23 +++
 xen/arch/x86/physdev.c|  5 +++--
 xen/common/kernel.c   |  3 ++-
 xen/include/public/arch-x86/xen.h |  4 +++-
 4 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 7bad845..a291f82 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4117,6 +4117,8 @@ static long hvm_memory_op(int cmd, 
XEN_GUEST_HANDLE_PARAM(void) arg)
 
 static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
+struct domain *d = current->domain;
+
 switch ( cmd )
 {
 default:
@@ -4128,7 +4130,9 @@ static long hvm_physdev_op(int cmd, 
XEN_GUEST_HANDLE_PARAM(void) arg)
 case PHYSDEVOP_eoi:
 case PHYSDEVOP_irq_status_query:
 case PHYSDEVOP_get_free_pirq:
-return do_physdev_op(cmd, arg);
+return ((d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) ||
+   is_pvh_vcpu(current)) ?
+do_physdev_op(cmd, arg) : -ENOSYS;
 }
 }
 
@@ -4161,17 +4165,20 @@ static long hvm_memory_op_compat32(int cmd, 
XEN_GUEST_HANDLE_PARAM(void) arg)
 static long hvm_physdev_op_compat32(
 int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
+struct domain *d = current->domain;
+
 switch ( cmd )
 {
-case PHYSDEVOP_map_pirq:
-case PHYSDEVOP_unmap_pirq:
-case PHYSDEVOP_eoi:
-case PHYSDEVOP_irq_status_query:
-case PHYSDEVOP_get_free_pirq:
-return compat_physdev_op(cmd, arg);
+case PHYSDEVOP_map_pirq:
+case PHYSDEVOP_unmap_pirq:
+case PHYSDEVOP_eoi:
+case PHYSDEVOP_irq_status_query:
+case PHYSDEVOP_get_free_pirq:
+return (d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) ?
+compat_physdev_op(cmd, arg) : -ENOSYS;
 break;
 default:
-return -ENOSYS;
+return -ENOSYS;
 break;
 }
 }
diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
index 5a49796..0bea6e1 100644
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -94,7 +94,8 @@ int physdev_map_pirq(domid_t domid, int type, int *index, int 
*pirq_p,
 int pirq, irq, ret = 0;
 void *map_data = NULL;
 
-if ( domid == DOMID_SELF && is_hvm_domain(d) )
+if ( domid == DOMID_SELF && is_hvm_domain(d) &&
+ (d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) )
 {
 /*
  * Only makes sense for vector-based callback, else HVM-IRQ logic
@@ -265,7 +266,7 @@ int physdev_unmap_pirq(domid_t domid, int pirq)
 if ( ret )
 goto free_domain;
 
-if ( is_hvm_domain(d) )
+if ( is_hvm_domain(d) && (d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) )
 {
 spin_lock(>event_lock);
 if ( domain_pirq_to_emuirq(d, pirq) != IRQ_UNBOUND )
diff --git a/xen/common/kernel.c b/xen/common/kernel.c
index d0edb13..a82f55f 100644
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -332,7 +332,8 @@ DO(xen_version)(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 case guest_type_hvm:
 fi.submap |= (1U << XENFEAT_hvm_safe_pvclock) |
  (1U << XENFEAT_hvm_callback_vector) |
- (1U << XENFEAT_hvm_pirqs);
+ ((d->arch.emulation_flags & XEN_X86_EMU_USE_PIRQ) 
?
+ (1U << XENFEAT_hvm_pirqs) : 0);
 break;
 }
 #endif
diff --git a/xen/include/public/arch-x86/xen.h 
b/xen/include/public/arch-x86/xen.h
index cdd93c1..da6f4f2 100644
--- a/xen/include/public/arch-x86/xen.h
+++ b/xen/include/public/arch-x86/xen.h
@@ -283,12 +283,14 @@ struct xen_arch_domainconfig {
 #define XEN_X86_EMU_IOMMU   (1U<<_XEN_X86_EMU_IOMMU)
 #define _XEN_X86_EMU_PIT8
 #define XEN_X86_EMU_PIT (1U<<_XEN_X86_EMU_PIT)
+#define _XEN_X86_EMU_USE_PIRQ   9
+#define XEN_X86_EMU_USE_PIRQ(1U<<_XEN_X86_EMU_USE_PIRQ)
 
 #define XEN_X86_EMU_ALL (XEN_X86_EMU_LAPIC | XEN_X86_EMU_HPET |  \
  XEN_X86_EMU_PM | XEN_X86_EMU_RTC |  \
  XEN_X86_EMU_IOAPIC | XEN_X86_EMU_PIC |  \
  XEN_X86_EMU_VGA | XEN_X86_EMU_IOMMU |   \
- XEN_X86_EMU_PIT)
+ XEN_X86_EMU_PIT | XEN_X86_EMU_USE_PIRQ)
 uint32_t emulation_flags;
 };
 #endif
-- 
2.7.4 (Apple Git-66)


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