On 2014/11/10 14:26, Feng Wu wrote:
> VT-d Posted-Interrupts is an enhancement to CPU side Posted-Interrupt.
> With VT-d Posted-Interrupts enabled, external interrupts from
> direct-assigned devices can be delivered to guests without VMM
> intervention when guest is running in non-root mode.
>
> This patch adds feature detection logic for VT-d posted-interrupt.
>
> Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
> ---
> drivers/iommu/intel_irq_remapping.c | 13 +++++++++++++
> drivers/iommu/irq_remapping.c | 4 ++++
> drivers/iommu/irq_remapping.h | 5 +++++
> include/linux/intel-iommu.h | 1 +
> 4 files changed, 23 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
> index 7c80661..f99f0f1 100644
> --- a/drivers/iommu/intel_irq_remapping.c
> +++ b/drivers/iommu/intel_irq_remapping.c
> @@ -580,6 +580,19 @@ static int __init intel_irq_remapping_supported(void)
> if (!ecap_ir_support(iommu->ecap))
> return 0;
>
> + /* VT-d posted-interrupt feature detection*/
> + if (disable_irq_post == 0)
> + for_each_drhd_unit(drhd) {
> + struct intel_iommu *iommu = drhd->iommu;
Hi Feng,
You may use for_each_active_iommu() here.
Regards!
Gerry
> +
> + if (!cap_pi_support(iommu->cap)) {
> + irq_post_enabled = 0;
> + disable_irq_post = 1;
> + break;
> + }
> + irq_post_enabled = 1;
> + }
> +
> return 1;
> }
>
> diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
> index 74a1767..2f8ee00 100644
> --- a/drivers/iommu/irq_remapping.c
> +++ b/drivers/iommu/irq_remapping.c
> @@ -23,6 +23,10 @@ int irq_remap_broken;
> int disable_sourceid_checking;
> int no_x2apic_optout;
>
> +int disable_irq_post = 1;
> +int irq_post_enabled = 0;
> +EXPORT_SYMBOL_GPL(irq_post_enabled);
> +
> static struct irq_remap_ops *remap_ops;
>
> static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec);
> diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h
> index fde250f..7bb5913 100644
> --- a/drivers/iommu/irq_remapping.h
> +++ b/drivers/iommu/irq_remapping.h
> @@ -37,6 +37,9 @@ extern int disable_sourceid_checking;
> extern int no_x2apic_optout;
> extern int irq_remapping_enabled;
>
> +extern int disable_irq_post;
> +extern int irq_post_enabled;
> +
> struct irq_remap_ops {
> /* Check whether Interrupt Remapping is supported */
> int (*supported)(void);
> @@ -91,6 +94,8 @@ extern struct irq_remap_ops amd_iommu_irq_ops;
> #define irq_remapping_enabled 0
> #define disable_irq_remap 1
> #define irq_remap_broken 0
> +#define disable_irq_post 1
> +#define irq_post_enabled 0
>
> #endif /* CONFIG_IRQ_REMAP */
>
> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> index a65208a..5b1a124 100644
> --- a/include/linux/intel-iommu.h
> +++ b/include/linux/intel-iommu.h
> @@ -87,6 +87,7 @@ static inline void dmar_writeq(void __iomem *addr, u64 val)
> /*
> * Decoding Capability Register
> */
> +#define cap_pi_support(c) (((c) >> 59) & 1)
> #define cap_read_drain(c) (((c) >> 55) & 1)
> #define cap_write_drain(c) (((c) >> 54) & 1)
> #define cap_max_amask_val(c) (((c) >> 48) & 0x3f)
>
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