From: Marc Zyngier <marc.zyngier@arm.com>
To: Christoffer Dall <cdall@linaro.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Cc: kvm@vger.kernel.org
Subject: Re: [RFC PATCH v2 05/19] KVM: arm/arm64: Check that system supports split eoi/deactivate
Date: Tue, 1 Aug 2017 12:35:23 +0100 [thread overview]
Message-ID: <3ca8bc15-b5e7-abf7-78cc-9bbc5332c267@arm.com> (raw)
In-Reply-To: <20170717142718.13853-6-cdall@linaro.org>
On 17/07/17 15:27, Christoffer Dall wrote:
> Some systems without proper firmware and/or hardware description data
> don't support the split EOI and deactivate operation.
>
> On such systems, we cannot leave the physical interrupt active after the
> timer handler on the host has run, so we cannot support KVM with an
> in-kernel GIC with the timer changes we about to introduce.
>
> This patch makes sure that trying to initialize the KVM GIC code will
> fail on such systems.
>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Signed-off-by: Christoffer Dall <cdall@linaro.org>
> ---
> drivers/irqchip/irq-gic.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index 090991f..b7e4fed 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -1391,7 +1391,8 @@ int gic_of_init_child(struct device *dev, struct gic_chip_data **gic, int irq)
> return 0;
> }
>
> -static void __init gic_of_setup_kvm_info(struct device_node *node)
> +static void __init gic_of_setup_kvm_info(struct device_node *node,
> + bool supports_deactivate)
Ouch, nasty. This shadows the static key which is also called
supports_deactivate...
> {
> int ret;
> struct resource *vctrl_res = &gic_v2_kvm_info.vctrl;
> @@ -1411,6 +1412,9 @@ static void __init gic_of_setup_kvm_info(struct device_node *node)
> if (ret)
> return;
>
> + if (!supports_deactivate)
> + return;
> +
> gic_set_kvm_info(&gic_v2_kvm_info);
Speaking of which, the static key should already be initialized, so this
could actually read:
if (static_key_true(&supports_deactivate))
gic_set_kvm_info(&gic_v2_kvm_info);
> }
>
> @@ -1419,6 +1423,7 @@ gic_of_init(struct device_node *node, struct device_node *parent)
> {
> struct gic_chip_data *gic;
> int irq, ret;
> + bool has_eoimode;
>
> if (WARN_ON(!node))
> return -ENODEV;
> @@ -1436,7 +1441,8 @@ gic_of_init(struct device_node *node, struct device_node *parent)
> * Disable split EOI/Deactivate if either HYP is not available
> * or the CPU interface is too small.
> */
> - if (gic_cnt == 0 && !gic_check_eoimode(node, &gic->raw_cpu_base))
> + has_eoimode = gic_check_eoimode(node, &gic->raw_cpu_base);
> + if (gic_cnt == 0 && !has_eoimode)
> static_key_slow_dec(&supports_deactivate);
>
> ret = __gic_init_bases(gic, -1, &node->fwnode);
> @@ -1447,7 +1453,7 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>
> if (!gic_cnt) {
> gic_init_physaddr(node);
> - gic_of_setup_kvm_info(node);
> + gic_of_setup_kvm_info(node, has_eoimode);
> }
>
> if (parent) {
>
and we shouldn't need any of this. What do you think?
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2017-08-01 11:35 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-17 14:26 [RFC PATCH v2 00/19] KVM: arm/arm64: Optimize arch timer register handling Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 01/19] arm64: Use physical counter for in-kernel reads Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 02/19] arm64: Use the physical counter when available for read_cycles Christoffer Dall
2017-07-25 9:43 ` Will Deacon
2017-07-25 14:36 ` Christoffer Dall
2017-07-26 17:17 ` Will Deacon
2017-07-27 7:14 ` Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 03/19] KVM: arm/arm64: Guard kvm_vgic_map_is_active against !vgic_initialized Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 04/19] KVM: arm/arm64: Support calling vgic_update_irq_pending from irq context Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 05/19] KVM: arm/arm64: Check that system supports split eoi/deactivate Christoffer Dall
2017-08-01 11:35 ` Marc Zyngier [this message]
2017-08-01 12:26 ` Christoffer Dall
2017-08-01 12:37 ` Marc Zyngier
2017-08-01 12:54 ` Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 06/19] KVM: arm/arm64: Make timer_arm and timer_disarm helpers more generic Christoffer Dall
2017-08-01 14:10 ` Marc Zyngier
2017-08-01 14:57 ` Christoffer Dall
2017-08-01 15:41 ` Marc Zyngier
2017-07-17 14:27 ` [RFC PATCH v2 07/19] KVM: arm/arm64: Rename soft timer to bg_timer Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 08/19] KVM: arm/arm64: Use separate timer for phys timer emulation Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 09/19] KVM: arm/arm64: Move timer/vgic flush/sync under disabled irq Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 10/19] KVM: arm/arm64: Move timer save/restore out of the hyp code Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 11/19] genirq: Document vcpu_info usage for per-CPU interrupts Christoffer Dall
2017-08-01 16:15 ` Marc Zyngier
2017-08-01 16:57 ` Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 12/19] KVM: arm/arm64: Set VCPU affinity for virt timer irq Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 13/19] KVM: arm/arm64: Avoid timer save/restore in vcpu entry/exit Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 14/19] KVM: arm/arm64: Support EL1 phys timer register access in set/get reg Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 15/19] KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 16/19] KVM: arm/arm64: Move phys_timer_emulate function Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 17/19] KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 18/19] KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate Christoffer Dall
2017-07-17 14:27 ` [RFC PATCH v2 19/19] KVM: arm/arm64: Rework kvm_timer_should_fire Christoffer Dall
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