From: Feng Wu <feng.wu@intel.com>
To: dwmw2@infradead.org, joro@8bytes.or
Cc: jiang.liu@linux.intel.com, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, Feng Wu <feng.wu@intel.com>
Subject: [v4 4/8] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts
Date: Mon, 2 Feb 2015 16:01:50 +0800 [thread overview]
Message-ID: <1422864114-19324-5-git-send-email-feng.wu@intel.com> (raw)
In-Reply-To: <1422864114-19324-1-git-send-email-feng.wu@intel.com>
We don't need to migrate the irqs for VT-d Posted-Interrupts here.
When 'pst' is set in IRTE, the associated irq will be posted to
guests instead of interrupt remapping. The destination of the
interrupt is set in Posted-Interrupts Descriptor, and the migration
happens during vCPU scheduling.
However, we still update the cached irte here, which can be used
when changing back to remapping mode.
Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Jiang Liu <jiang.liu@linux.intel.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
---
drivers/iommu/intel_irq_remapping.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 48c2051..ab9057a 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -977,6 +977,7 @@ intel_ir_set_affinity(struct irq_data *data, const struct cpumask *mask,
{
struct intel_ir_data *ir_data = data->chip_data;
struct irte *irte = &ir_data->irte_entry;
+ struct irte_pi *irte_pi = (struct irte_pi *)irte;
struct irq_cfg *cfg = irqd_cfg(data);
struct irq_data *parent = data->parent_data;
int ret;
@@ -991,7 +992,10 @@ intel_ir_set_affinity(struct irq_data *data, const struct cpumask *mask,
*/
irte->vector = cfg->vector;
irte->dest_id = IRTE_DEST(cfg->dest_apicid);
- modify_irte(&ir_data->irq_2_iommu, irte);
+
+ /* We don't need to modify irte if the interrupt is for posting. */
+ if (irte_pi->pst != 1)
+ modify_irte(&ir_data->irq_2_iommu, irte);
/*
* After this point, all the interrupts will start arriving
--
1.7.1
next prev parent reply other threads:[~2015-02-02 8:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-02 8:01 [v4 0/8] Add VT-d Posted-Interrupts support - IOMMU part Feng Wu
2015-02-02 8:01 ` [v4 1/8] iommu: Add new member capability to struct irq_remap_ops Feng Wu
2015-02-02 8:01 ` [v4 2/8] iommu, x86: Define new irte structure for VT-d Posted-Interrupts Feng Wu
2015-02-02 8:01 ` [v4 3/8] iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip Feng Wu
2015-02-02 8:01 ` Feng Wu [this message]
2015-02-02 8:01 ` [v4 5/8] iommu, x86: Add cap_pi_support() to detect VT-d PI capability Feng Wu
2015-02-02 8:01 ` [v4 6/8] iommu, x86: Setup Posted-Interrupts capability for Intel iommu Feng Wu
2015-02-02 8:01 ` [v4 7/8] iommu, x86: define irq_remapping_cap() Feng Wu
2015-02-02 8:01 ` [v4 8/8] iommu, x86: Properly handler PI for IOMMU hotplug Feng Wu
2015-02-02 8:17 ` [v4 0/8] Add VT-d Posted-Interrupts support - IOMMU part Wu, Feng
2015-02-02 8:06 Feng Wu
2015-02-02 8:07 ` [v4 4/8] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts Feng Wu
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