Add a command line opt-in option for posted MSI if CONFIG_X86_POSTED_MSI=y. Also introduce a helper function for testing if posted MSI is supported on the platform. Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> --- Documentation/admin-guide/kernel-parameters.txt | 1 + arch/x86/include/asm/irq_remapping.h | 11 +++++++++++ drivers/iommu/irq_remapping.c | 13 ++++++++++++- 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 31b3a25680d0..35feefc0bdb0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2212,6 +2212,7 @@ no_x2apic_optout BIOS x2APIC opt-out request will be ignored nopost disable Interrupt Posting + posted_msi enable MSIs delivered as posted interrupts iomem= Disable strict checking of access to MMIO memory strict regions from userspace. diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h index 7a2ed154a5e1..e46bde61029b 100644 --- a/arch/x86/include/asm/irq_remapping.h +++ b/arch/x86/include/asm/irq_remapping.h @@ -50,6 +50,17 @@ static inline struct irq_domain *arch_get_ir_parent_domain(void) return x86_vector_domain; } +#ifdef CONFIG_X86_POSTED_MSI +extern int enable_posted_msi; + +static inline bool posted_msi_supported(void) +{ + return enable_posted_msi && irq_remapping_cap(IRQ_POSTING_CAP); +} +#else +static inline bool posted_msi_supported(void) { return false; }; +#endif + #else /* CONFIG_IRQ_REMAP */ static inline bool irq_remapping_cap(enum irq_remap_cap cap) { return 0; } diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c index 83314b9d8f38..4047ac396728 100644 --- a/drivers/iommu/irq_remapping.c +++ b/drivers/iommu/irq_remapping.c @@ -24,6 +24,10 @@ int no_x2apic_optout; int disable_irq_post = 0; +#ifdef CONFIG_X86_POSTED_MSI +int enable_posted_msi; +#endif + static int disable_irq_remap; static struct irq_remap_ops *remap_ops; @@ -70,7 +74,14 @@ static __init int setup_irqremap(char *str) no_x2apic_optout = 1; else if (!strncmp(str, "nopost", 6)) disable_irq_post = 1; - +#ifdef CONFIG_X86_POSTED_MSI + else if (!strncmp(str, "posted_msi", 10)) { + if (disable_irq_post || disable_irq_remap) + pr_warn("Posted MSI not enabled due to conflicting options!"); + else + enable_posted_msi = 1; + } +#endif str += strcspn(str, ","); while (*str == ',') str++; -- 2.25.1