From: Feng Wu <feng.wu@intel.com>
To: joro@8bytes.org, dwmw2@infradead.org
Cc: tglx@linutronix.de, jiang.liu@linux.intel.com,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
Feng Wu <feng.wu@intel.com>
Subject: [v8 5/9] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts
Date: Wed, 27 May 2015 12:05:40 +0800 [thread overview]
Message-ID: <1432699544-17444-6-git-send-email-feng.wu@intel.com> (raw)
In-Reply-To: <1432699544-17444-1-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 | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 70a1b79..d230edc 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -1003,7 +1003,10 @@ 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);
+
+ /* Update the hardware only if the interrupt is in remapped mode. */
+ if (ir_data->irq_2_iommu.mode == IRQ_REMAPPING)
+ modify_irte(&ir_data->irq_2_iommu, irte);
/*
* After this point, all the interrupts will start arriving
--
2.1.0
next prev parent reply other threads:[~2015-05-27 4:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-27 4:05 [v8 0/9] Add VT-d Posted-Interrupts support - IOMMU part Feng Wu
2015-05-27 4:05 ` [v8 1/9] iommu: Add new member capability to struct irq_remap_ops Feng Wu
2015-05-27 4:05 ` [v8 2/9] iommu: dmar: Extend struct irte for VT-d Posted-Interrupts Feng Wu
2015-05-27 4:05 ` [v8 3/9] iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip Feng Wu
2015-06-02 13:59 ` Thomas Gleixner
2015-06-03 1:05 ` Wu, Feng
2015-05-27 4:05 ` [v8 4/9] iommu, x86: Save the mode (posted or remapped) of an IRTE Feng Wu
2015-05-27 4:05 ` Feng Wu [this message]
2015-05-27 4:05 ` [v8 6/9] iommu, x86: Add cap_pi_support() to detect VT-d PI capability Feng Wu
2015-05-27 4:05 ` [v8 7/9] iommu, x86: Setup Posted-Interrupts capability for Intel iommu Feng Wu
2015-05-27 4:05 ` [v8 8/9] iommu, x86: define irq_remapping_cap() Feng Wu
2015-05-27 4:05 ` [v8 9/9] iommu, x86: Properly handler PI for IOMMU hotplug Feng Wu
2015-06-01 2:18 ` [v8 0/9] Add VT-d Posted-Interrupts support - IOMMU part Wu, Feng
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