Commit be9be07b authored by Jacob Pan's avatar Jacob Pan Committed by Thomas Gleixner
Browse files

iommu/vt-d: Make posted MSI an opt-in command line option 



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: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240423174114.526704-12-jacob.jun.pan@linux.intel.com
parent ce0a9287

Documentation/admin-guide/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -2251,6 +2251,8 @@ 
			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.

arch/x86/include/asm/irq_remapping.h

+7 −0
Original line number Diff line number Diff line
@@ -50,6 +50,13 @@ static inline struct irq_domain *arch_get_ir_parent_domain(void) 
	return x86_vector_domain;

}



extern bool enable_posted_msi;



static inline bool posted_msi_supported(void)

{

	return enable_posted_msi && irq_remapping_cap(IRQ_POSTING_CAP);

}



#else  /* CONFIG_IRQ_REMAP */



static inline bool irq_remapping_cap(enum irq_remap_cap cap) { return 0; }

drivers/iommu/irq_remapping.c

+4 −1
Original line number Diff line number Diff line
@@ -24,6 +24,8 @@ int no_x2apic_optout; 


int disable_irq_post = 0;



bool enable_posted_msi __ro_after_init;



static int disable_irq_remap;

static struct irq_remap_ops *remap_ops;
@@ -70,7 +72,8 @@ static __init int setup_irqremap(char *str) 
			no_x2apic_optout = 1;

		else if (!strncmp(str, "nopost", 6))

			disable_irq_post = 1;



		else if (IS_ENABLED(CONFIG_X86_POSTED_MSI) && !strncmp(str, "posted_msi", 10))

			enable_posted_msi = true;

		str += strcspn(str, ",");

		while (*str == ',')

			str++;