Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
On Wed, Jul 01, 2015 at 09:26:59AM +0100, Marc Zyngier wrote: > On 30/06/15 21:19, Christoffer Dall wrote: > > On Mon, Jun 08, 2015 at 06:04:05PM +0100, Marc Zyngier wrote: > >> So far, the only use of the HW interrupt facility is the timer, > >> implying that the active state is context-switched for each vcpu, > >> as the device is is shared across all vcpus. > >> > >> This does not work for a device that has been assigned to a VM, > >> as the guest is entierely in control of that device (the HW is > >> not shared). In that case, it makes sense to bypass the whole > >> active state switchint, and only track the deactivation of the > >> interrupt. > >> > > The discinction here between shared and non-shared feels a bit arbitrary > > (it may not be, but just feel that way) and I can't easily convince > > myself that this is the logical/correct/all-encompassing word to > > describe the nature of the two devices. > > Does the idea of global vs private resource feel more correct? > I think shared covers that equally well. This feels like one of those things that just doesn't make intuitive sense on its own but when you think about the cases we are familiar with, then it fits for now. So what you have here is probably as good as it gets and hopefully it does cover all the cases we care about, i.e. shared and non-shared :) -Christoffer ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
On 30/06/15 21:19, Christoffer Dall wrote: > On Mon, Jun 08, 2015 at 06:04:05PM +0100, Marc Zyngier wrote: >> So far, the only use of the HW interrupt facility is the timer, >> implying that the active state is context-switched for each vcpu, >> as the device is is shared across all vcpus. >> >> This does not work for a device that has been assigned to a VM, >> as the guest is entierely in control of that device (the HW is >> not shared). In that case, it makes sense to bypass the whole >> active state switchint, and only track the deactivation of the >> interrupt. >> > The discinction here between shared and non-shared feels a bit arbitrary > (it may not be, but just feel that way) and I can't easily convince > myself that this is the logical/correct/all-encompassing word to > describe the nature of the two devices. Does the idea of global vs private resource feel more correct? M. -- Jazz is not dead. It just smells funny... ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
On Mon, Jun 08, 2015 at 06:04:05PM +0100, Marc Zyngier wrote: > So far, the only use of the HW interrupt facility is the timer, > implying that the active state is context-switched for each vcpu, > as the device is is shared across all vcpus. > > This does not work for a device that has been assigned to a VM, > as the guest is entierely in control of that device (the HW is > not shared). In that case, it makes sense to bypass the whole > active state switchint, and only track the deactivation of the > interrupt. > The discinction here between shared and non-shared feels a bit arbitrary (it may not be, but just feel that way) and I can't easily convince myself that this is the logical/correct/all-encompassing word to describe the nature of the two devices. Meh, not the most productive comment, I know... -Christoffer ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
On 06/18/2015 10:37 AM, Marc Zyngier wrote:
> On 17/06/15 16:50, Eric Auger wrote:
>> On 06/17/2015 05:37 PM, Marc Zyngier wrote:
>>> On 17/06/15 16:11, Eric Auger wrote:
Hi Marc,
On 06/08/2015 07:04 PM, Marc Zyngier wrote:
> So far, the only use of the HW interrupt facility is the timer,
> implying that the active state is context-switched for each vcpu,
> as the device is is shared across all vcpus.
s/is//
>
> This does not work for a device that has been assigned to a VM,
> as the guest is entierely in control of that device (the HW is
entirely?
> not shared). In that case, it makes sense to bypass the whole
> active state srtwitchint, and only track the deactivation of the
switching
>>>
>>> Congratulations, I think you're now ready to try deciphering my
>>> handwriting... ;-)
>> good to see you're not a machine or maybe you do it on purpose some
>> times ;-)
>>>
> interrupt.
>
> Signed-off-by: Marc Zyngier
> ---
> include/kvm/arm_vgic.h| 5 +++--
> virt/kvm/arm/arch_timer.c | 2 +-
> virt/kvm/arm/vgic.c | 37 -
> 3 files changed, 28 insertions(+), 16 deletions(-)
>
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 1c653c1..5d47d60 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -164,7 +164,8 @@ struct irq_phys_map {
> u32 virt_irq;
> u32 phys_irq;
> u32 irq;
> - boolactive;
> + boolshared;
> + boolactive; /* Only valid if shared */
> };
>
> struct vgic_dist {
> @@ -347,7 +348,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64
> reg);
> int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
> int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
> struct irq_phys_map *vgic_map_phys_irq(struct kvm_vcpu *vcpu,
> -int virt_irq, int irq);
> +int virt_irq, int irq, bool shared);
> int vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
> bool vgic_get_phys_irq_active(struct irq_phys_map *map);
> void vgic_set_phys_irq_active(struct irq_phys_map *map, bool active);
> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
> index b9fff78..9544d79 100644
> --- a/virt/kvm/arm/arch_timer.c
> +++ b/virt/kvm/arm/arch_timer.c
> @@ -202,7 +202,7 @@ void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
>* Tell the VGIC that the virtual interrupt is tied to a
>* physical interrupt. We do that once per VCPU.
>*/
> - timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
> + timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq, true);
> WARN_ON(!timer->map);
> }
>
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index f376b56..4223166 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -1125,18 +1125,21 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu
> *vcpu, int irq,
> map = vgic_irq_map_search(vcpu, irq);
>
> if (map) {
> - int ret;
> -
> - BUG_ON(!map->active);
> vlr.hwirq = map->phys_irq;
> vlr.state |= LR_HW;
> vlr.state &= ~LR_EOI_INT;
>
> - ret = irq_set_irqchip_state(map->irq,
> - IRQCHIP_STATE_ACTIVE,
> - true);
> vgic_irq_set_queued(vcpu, irq);
the queued state is set again in vgic_queue_hwirq for level_sensitive
IRQs although not harmful.
>>>
>>> Indeed. We still need it for edge interrupts though. I'll try to find a
>>> nicer way...
>>>
> - WARN_ON(ret);
> +
> + if (map->shared) {
> + int ret;
> +
> + BUG_ON(!map->active);
> + ret = irq_set_irqchip_state(map->irq,
> +
> IRQCHIP_STATE_ACTIVE,
> + true);
> + WARN_ON(ret);
> + }
> }
> }
>
> @@ -1368,21 +1371,28 @@ static bool vgic_process_maintenance(struct
> kvm_vcpu *vcpu)
> static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
> {
> struct irq_phys_map *map;
> + bool active;
> int ret;
>
> if (!(vlr.state & LR_HW))
> return 0;
>
> map = vgic_irq_map_search(vcpu, vlr.irq);
> - BUG_ON(!map || !map->active);
Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
On 17/06/15 16:50, Eric Auger wrote:
> On 06/17/2015 05:37 PM, Marc Zyngier wrote:
>> On 17/06/15 16:11, Eric Auger wrote:
>>> Hi Marc,
>>> On 06/08/2015 07:04 PM, Marc Zyngier wrote:
So far, the only use of the HW interrupt facility is the timer,
implying that the active state is context-switched for each vcpu,
as the device is is shared across all vcpus.
>>> s/is//
This does not work for a device that has been assigned to a VM,
as the guest is entierely in control of that device (the HW is
>>> entirely?
not shared). In that case, it makes sense to bypass the whole
active state srtwitchint, and only track the deactivation of the
>>> switching
>>
>> Congratulations, I think you're now ready to try deciphering my
>> handwriting... ;-)
> good to see you're not a machine or maybe you do it on purpose some
> times ;-)
>>
interrupt.
Signed-off-by: Marc Zyngier
---
include/kvm/arm_vgic.h| 5 +++--
virt/kvm/arm/arch_timer.c | 2 +-
virt/kvm/arm/vgic.c | 37 -
3 files changed, 28 insertions(+), 16 deletions(-)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 1c653c1..5d47d60 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -164,7 +164,8 @@ struct irq_phys_map {
u32 virt_irq;
u32 phys_irq;
u32 irq;
- boolactive;
+ boolshared;
+ boolactive; /* Only valid if shared */
};
struct vgic_dist {
@@ -347,7 +348,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64
reg);
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
struct irq_phys_map *vgic_map_phys_irq(struct kvm_vcpu *vcpu,
- int virt_irq, int irq);
+ int virt_irq, int irq, bool shared);
int vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
bool vgic_get_phys_irq_active(struct irq_phys_map *map);
void vgic_set_phys_irq_active(struct irq_phys_map *map, bool active);
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index b9fff78..9544d79 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -202,7 +202,7 @@ void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
* Tell the VGIC that the virtual interrupt is tied to a
* physical interrupt. We do that once per VCPU.
*/
- timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
+ timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq, true);
WARN_ON(!timer->map);
}
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index f376b56..4223166 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1125,18 +1125,21 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu
*vcpu, int irq,
map = vgic_irq_map_search(vcpu, irq);
if (map) {
- int ret;
-
- BUG_ON(!map->active);
vlr.hwirq = map->phys_irq;
vlr.state |= LR_HW;
vlr.state &= ~LR_EOI_INT;
- ret = irq_set_irqchip_state(map->irq,
- IRQCHIP_STATE_ACTIVE,
- true);
vgic_irq_set_queued(vcpu, irq);
>>>
>>> the queued state is set again in vgic_queue_hwirq for level_sensitive
>>> IRQs although not harmful.
>>
>> Indeed. We still need it for edge interrupts though. I'll try to find a
>> nicer way...
>>
- WARN_ON(ret);
+
+ if (map->shared) {
+ int ret;
+
+ BUG_ON(!map->active);
+ ret = irq_set_irqchip_state(map->irq,
+
IRQCHIP_STATE_ACTIVE,
+ true);
+ WARN_ON(ret);
+ }
}
}
@@ -1368,21 +1371,28 @@ static bool vgic_process_maintenance(struct
kvm_vcpu *vcpu)
static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
{
struct irq_phys_map *map;
+ bool active;
int ret;
if (!(vlr.state & LR_HW))
return 0;
map = vgic_irq_map_search(vcpu, vlr.irq);
- BUG_ON(!map || !map->active);
+ BUG_ON(!map);
+ BUG_ON(map->shared && !map->active);
ret = irq_get_irqchip_state(map->irq,
Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
On 06/17/2015 05:37 PM, Marc Zyngier wrote:
> On 17/06/15 16:11, Eric Auger wrote:
>> Hi Marc,
>> On 06/08/2015 07:04 PM, Marc Zyngier wrote:
>>> So far, the only use of the HW interrupt facility is the timer,
>>> implying that the active state is context-switched for each vcpu,
>>> as the device is is shared across all vcpus.
>> s/is//
>>>
>>> This does not work for a device that has been assigned to a VM,
>>> as the guest is entierely in control of that device (the HW is
>> entirely?
>>> not shared). In that case, it makes sense to bypass the whole
>>> active state srtwitchint, and only track the deactivation of the
>> switching
>
> Congratulations, I think you're now ready to try deciphering my
> handwriting... ;-)
good to see you're not a machine or maybe you do it on purpose some
times ;-)
>
>>> interrupt.
>>>
>>> Signed-off-by: Marc Zyngier
>>> ---
>>> include/kvm/arm_vgic.h| 5 +++--
>>> virt/kvm/arm/arch_timer.c | 2 +-
>>> virt/kvm/arm/vgic.c | 37 -
>>> 3 files changed, 28 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>>> index 1c653c1..5d47d60 100644
>>> --- a/include/kvm/arm_vgic.h
>>> +++ b/include/kvm/arm_vgic.h
>>> @@ -164,7 +164,8 @@ struct irq_phys_map {
>>> u32 virt_irq;
>>> u32 phys_irq;
>>> u32 irq;
>>> - boolactive;
>>> + boolshared;
>>> + boolactive; /* Only valid if shared */
>>> };
>>>
>>> struct vgic_dist {
>>> @@ -347,7 +348,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64
>>> reg);
>>> int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
>>> int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
>>> struct irq_phys_map *vgic_map_phys_irq(struct kvm_vcpu *vcpu,
>>> - int virt_irq, int irq);
>>> + int virt_irq, int irq, bool shared);
>>> int vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
>>> bool vgic_get_phys_irq_active(struct irq_phys_map *map);
>>> void vgic_set_phys_irq_active(struct irq_phys_map *map, bool active);
>>> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
>>> index b9fff78..9544d79 100644
>>> --- a/virt/kvm/arm/arch_timer.c
>>> +++ b/virt/kvm/arm/arch_timer.c
>>> @@ -202,7 +202,7 @@ void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
>>> * Tell the VGIC that the virtual interrupt is tied to a
>>> * physical interrupt. We do that once per VCPU.
>>> */
>>> - timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
>>> + timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq, true);
>>> WARN_ON(!timer->map);
>>> }
>>>
>>> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
>>> index f376b56..4223166 100644
>>> --- a/virt/kvm/arm/vgic.c
>>> +++ b/virt/kvm/arm/vgic.c
>>> @@ -1125,18 +1125,21 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu
>>> *vcpu, int irq,
>>> map = vgic_irq_map_search(vcpu, irq);
>>>
>>> if (map) {
>>> - int ret;
>>> -
>>> - BUG_ON(!map->active);
>>> vlr.hwirq = map->phys_irq;
>>> vlr.state |= LR_HW;
>>> vlr.state &= ~LR_EOI_INT;
>>>
>>> - ret = irq_set_irqchip_state(map->irq,
>>> - IRQCHIP_STATE_ACTIVE,
>>> - true);
>>> vgic_irq_set_queued(vcpu, irq);
>>
>> the queued state is set again in vgic_queue_hwirq for level_sensitive
>> IRQs although not harmful.
>
> Indeed. We still need it for edge interrupts though. I'll try to find a
> nicer way...
>
>>> - WARN_ON(ret);
>>> +
>>> + if (map->shared) {
>>> + int ret;
>>> +
>>> + BUG_ON(!map->active);
>>> + ret = irq_set_irqchip_state(map->irq,
>>> +
>>> IRQCHIP_STATE_ACTIVE,
>>> + true);
>>> + WARN_ON(ret);
>>> + }
>>> }
>>> }
>>>
>>> @@ -1368,21 +1371,28 @@ static bool vgic_process_maintenance(struct
>>> kvm_vcpu *vcpu)
>>> static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
>>> {
>>> struct irq_phys_map *map;
>>> + bool active;
>>> int ret;
>>>
>>> if (!(vlr.state & LR_HW))
>>> return 0;
>>>
>>> map = vgic_irq_map_search(vcpu, vlr.irq);
>>> - BUG_ON(!map || !map->active);
>>> + BUG_ON(!map);
>>> + BUG_ON(map->shared && !map->active);
>>>
>>> ret = irq_get_irqchip_state(map->irq,
>>> IRQCHIP_STATE_ACTIVE,
>>> - &map->active);
>>> +
Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
On 17/06/15 16:11, Eric Auger wrote:
> Hi Marc,
> On 06/08/2015 07:04 PM, Marc Zyngier wrote:
>> So far, the only use of the HW interrupt facility is the timer,
>> implying that the active state is context-switched for each vcpu,
>> as the device is is shared across all vcpus.
> s/is//
>>
>> This does not work for a device that has been assigned to a VM,
>> as the guest is entierely in control of that device (the HW is
> entirely?
>> not shared). In that case, it makes sense to bypass the whole
>> active state srtwitchint, and only track the deactivation of the
> switching
Congratulations, I think you're now ready to try deciphering my
handwriting... ;-)
>> interrupt.
>>
>> Signed-off-by: Marc Zyngier
>> ---
>> include/kvm/arm_vgic.h| 5 +++--
>> virt/kvm/arm/arch_timer.c | 2 +-
>> virt/kvm/arm/vgic.c | 37 -
>> 3 files changed, 28 insertions(+), 16 deletions(-)
>>
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index 1c653c1..5d47d60 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -164,7 +164,8 @@ struct irq_phys_map {
>> u32 virt_irq;
>> u32 phys_irq;
>> u32 irq;
>> -boolactive;
>> +boolshared;
>> +boolactive; /* Only valid if shared */
>> };
>>
>> struct vgic_dist {
>> @@ -347,7 +348,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64
>> reg);
>> int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
>> int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
>> struct irq_phys_map *vgic_map_phys_irq(struct kvm_vcpu *vcpu,
>> - int virt_irq, int irq);
>> + int virt_irq, int irq, bool shared);
>> int vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
>> bool vgic_get_phys_irq_active(struct irq_phys_map *map);
>> void vgic_set_phys_irq_active(struct irq_phys_map *map, bool active);
>> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
>> index b9fff78..9544d79 100644
>> --- a/virt/kvm/arm/arch_timer.c
>> +++ b/virt/kvm/arm/arch_timer.c
>> @@ -202,7 +202,7 @@ void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
>> * Tell the VGIC that the virtual interrupt is tied to a
>> * physical interrupt. We do that once per VCPU.
>> */
>> -timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
>> +timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq, true);
>> WARN_ON(!timer->map);
>> }
>>
>> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
>> index f376b56..4223166 100644
>> --- a/virt/kvm/arm/vgic.c
>> +++ b/virt/kvm/arm/vgic.c
>> @@ -1125,18 +1125,21 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu
>> *vcpu, int irq,
>> map = vgic_irq_map_search(vcpu, irq);
>>
>> if (map) {
>> -int ret;
>> -
>> -BUG_ON(!map->active);
>> vlr.hwirq = map->phys_irq;
>> vlr.state |= LR_HW;
>> vlr.state &= ~LR_EOI_INT;
>>
>> -ret = irq_set_irqchip_state(map->irq,
>> -IRQCHIP_STATE_ACTIVE,
>> -true);
>> vgic_irq_set_queued(vcpu, irq);
>
> the queued state is set again in vgic_queue_hwirq for level_sensitive
> IRQs although not harmful.
Indeed. We still need it for edge interrupts though. I'll try to find a
nicer way...
>> -WARN_ON(ret);
>> +
>> +if (map->shared) {
>> +int ret;
>> +
>> +BUG_ON(!map->active);
>> +ret = irq_set_irqchip_state(map->irq,
>> +
>> IRQCHIP_STATE_ACTIVE,
>> +true);
>> +WARN_ON(ret);
>> +}
>> }
>> }
>>
>> @@ -1368,21 +1371,28 @@ static bool vgic_process_maintenance(struct kvm_vcpu
>> *vcpu)
>> static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
>> {
>> struct irq_phys_map *map;
>> +bool active;
>> int ret;
>>
>> if (!(vlr.state & LR_HW))
>> return 0;
>>
>> map = vgic_irq_map_search(vcpu, vlr.irq);
>> -BUG_ON(!map || !map->active);
>> +BUG_ON(!map);
>> +BUG_ON(map->shared && !map->active);
>>
>> ret = irq_get_irqchip_state(map->irq,
>> IRQCHIP_STATE_ACTIVE,
>> -&map->active);
>> +&active);
>>
> In case of non shared and EOIMode = 1 - I know this is not your current
> interest here though ;-) - , once the guest EOIs its virtual IRQ and GIC
> deactivates the ph
Re: [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
Hi Marc,
On 06/08/2015 07:04 PM, Marc Zyngier wrote:
> So far, the only use of the HW interrupt facility is the timer,
> implying that the active state is context-switched for each vcpu,
> as the device is is shared across all vcpus.
s/is//
>
> This does not work for a device that has been assigned to a VM,
> as the guest is entierely in control of that device (the HW is
entirely?
> not shared). In that case, it makes sense to bypass the whole
> active state srtwitchint, and only track the deactivation of the
switching
> interrupt.
>
> Signed-off-by: Marc Zyngier
> ---
> include/kvm/arm_vgic.h| 5 +++--
> virt/kvm/arm/arch_timer.c | 2 +-
> virt/kvm/arm/vgic.c | 37 -
> 3 files changed, 28 insertions(+), 16 deletions(-)
>
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 1c653c1..5d47d60 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -164,7 +164,8 @@ struct irq_phys_map {
> u32 virt_irq;
> u32 phys_irq;
> u32 irq;
> - boolactive;
> + boolshared;
> + boolactive; /* Only valid if shared */
> };
>
> struct vgic_dist {
> @@ -347,7 +348,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
> int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
> int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
> struct irq_phys_map *vgic_map_phys_irq(struct kvm_vcpu *vcpu,
> -int virt_irq, int irq);
> +int virt_irq, int irq, bool shared);
> int vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
> bool vgic_get_phys_irq_active(struct irq_phys_map *map);
> void vgic_set_phys_irq_active(struct irq_phys_map *map, bool active);
> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
> index b9fff78..9544d79 100644
> --- a/virt/kvm/arm/arch_timer.c
> +++ b/virt/kvm/arm/arch_timer.c
> @@ -202,7 +202,7 @@ void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
>* Tell the VGIC that the virtual interrupt is tied to a
>* physical interrupt. We do that once per VCPU.
>*/
> - timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
> + timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq, true);
> WARN_ON(!timer->map);
> }
>
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index f376b56..4223166 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -1125,18 +1125,21 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu
> *vcpu, int irq,
> map = vgic_irq_map_search(vcpu, irq);
>
> if (map) {
> - int ret;
> -
> - BUG_ON(!map->active);
> vlr.hwirq = map->phys_irq;
> vlr.state |= LR_HW;
> vlr.state &= ~LR_EOI_INT;
>
> - ret = irq_set_irqchip_state(map->irq,
> - IRQCHIP_STATE_ACTIVE,
> - true);
> vgic_irq_set_queued(vcpu, irq);
the queued state is set again in vgic_queue_hwirq for level_sensitive
IRQs although not harmful.
> - WARN_ON(ret);
> +
> + if (map->shared) {
> + int ret;
> +
> + BUG_ON(!map->active);
> + ret = irq_set_irqchip_state(map->irq,
> +
> IRQCHIP_STATE_ACTIVE,
> + true);
> + WARN_ON(ret);
> + }
> }
> }
>
> @@ -1368,21 +1371,28 @@ static bool vgic_process_maintenance(struct kvm_vcpu
> *vcpu)
> static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
> {
> struct irq_phys_map *map;
> + bool active;
> int ret;
>
> if (!(vlr.state & LR_HW))
> return 0;
>
> map = vgic_irq_map_search(vcpu, vlr.irq);
> - BUG_ON(!map || !map->active);
> + BUG_ON(!map);
> + BUG_ON(map->shared && !map->active);
>
> ret = irq_get_irqchip_state(map->irq,
> IRQCHIP_STATE_ACTIVE,
> - &map->active);
> + &active);
>
In case of non shared and EOIMode = 1 - I know this is not your current
interest here though ;-) - , once the guest EOIs its virtual IRQ and GIC
deactivates the physical one, a new phys IRQ can hit immediatly, the
physical handler can be entered and the state is seen as active here.
The queued state is never reset in such a case and the system gets stuck
since the can_sample fails I think. What I mean here is sounds the state
machine as is does not wo
[PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts
So far, the only use of the HW interrupt facility is the timer,
implying that the active state is context-switched for each vcpu,
as the device is is shared across all vcpus.
This does not work for a device that has been assigned to a VM,
as the guest is entierely in control of that device (the HW is
not shared). In that case, it makes sense to bypass the whole
active state switchint, and only track the deactivation of the
interrupt.
Signed-off-by: Marc Zyngier
---
include/kvm/arm_vgic.h| 5 +++--
virt/kvm/arm/arch_timer.c | 2 +-
virt/kvm/arm/vgic.c | 37 -
3 files changed, 28 insertions(+), 16 deletions(-)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 1c653c1..5d47d60 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -164,7 +164,8 @@ struct irq_phys_map {
u32 virt_irq;
u32 phys_irq;
u32 irq;
- boolactive;
+ boolshared;
+ boolactive; /* Only valid if shared */
};
struct vgic_dist {
@@ -347,7 +348,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
struct irq_phys_map *vgic_map_phys_irq(struct kvm_vcpu *vcpu,
- int virt_irq, int irq);
+ int virt_irq, int irq, bool shared);
int vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
bool vgic_get_phys_irq_active(struct irq_phys_map *map);
void vgic_set_phys_irq_active(struct irq_phys_map *map, bool active);
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index b9fff78..9544d79 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -202,7 +202,7 @@ void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
* Tell the VGIC that the virtual interrupt is tied to a
* physical interrupt. We do that once per VCPU.
*/
- timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
+ timer->map = vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq, true);
WARN_ON(!timer->map);
}
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index f376b56..4223166 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1125,18 +1125,21 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu *vcpu,
int irq,
map = vgic_irq_map_search(vcpu, irq);
if (map) {
- int ret;
-
- BUG_ON(!map->active);
vlr.hwirq = map->phys_irq;
vlr.state |= LR_HW;
vlr.state &= ~LR_EOI_INT;
- ret = irq_set_irqchip_state(map->irq,
- IRQCHIP_STATE_ACTIVE,
- true);
vgic_irq_set_queued(vcpu, irq);
- WARN_ON(ret);
+
+ if (map->shared) {
+ int ret;
+
+ BUG_ON(!map->active);
+ ret = irq_set_irqchip_state(map->irq,
+
IRQCHIP_STATE_ACTIVE,
+ true);
+ WARN_ON(ret);
+ }
}
}
@@ -1368,21 +1371,28 @@ static bool vgic_process_maintenance(struct kvm_vcpu
*vcpu)
static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
{
struct irq_phys_map *map;
+ bool active;
int ret;
if (!(vlr.state & LR_HW))
return 0;
map = vgic_irq_map_search(vcpu, vlr.irq);
- BUG_ON(!map || !map->active);
+ BUG_ON(!map);
+ BUG_ON(map->shared && !map->active);
ret = irq_get_irqchip_state(map->irq,
IRQCHIP_STATE_ACTIVE,
- &map->active);
+ &active);
WARN_ON(ret);
- if (map->active) {
+ if (!map->shared)
+ return !active;
+
+ map->active = active;
+
+ if (active) {
ret = irq_set_irqchip_state(map->irq,
IRQCHIP_STATE_ACTIVE,
false);
@@ -1663,7 +1673,7 @@ static struct rb_root *vgic_get_irq_phys_map(struct
kvm_vcpu *vcpu,
}
struct irq_phys_map *vgic_map_phys_irq(struct kvm_vcpu *vcpu,
- int virt_irq, int irq)
+ int virt_irq, int irq, bool shared)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
struct rb_root *root = vgic_get_irq_phys_map(vcpu, vir
