Messages in this thread Patch in this message | | | Date | Sat, 6 Apr 2024 12:31:14 +0800 | Subject | Re: [PATCH v2 11/13] iommu/vt-d: Make posted MSI an opt-in cmdline option | From | Robert Hoo <> |
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On 4/6/2024 6:31 AM, Jacob Pan wrote: > 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@linux.intel.com> > --- > 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 bb884c14b2f6..e5fd02423c4c 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -2251,6 +2251,7 @@ > 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); > +}
Out of this patch set's scope, but, dropping into irq_remappping_cap(), I'd like to bring this change for discussion:
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c index 4047ac396728..ef2de9034897 100644 --- a/drivers/iommu/irq_remapping.c +++ b/drivers/iommu/irq_remapping.c @@ -98,7 +98,7 @@ void set_irq_remapping_broken(void)
bool irq_remapping_cap(enum irq_remap_cap cap) { - if (!remap_ops || disable_irq_post) + if (!remap_ops || disable_irq_remap) return false;
return (remap_ops->capability & (1 << cap));
1. irq_remapping_cap() is to exam some cap, though at present it has only 1 cap, i.e. IRQ_POSTING_CAP, simply return false just because of disable_irq_post isn't good. Instead, IRQ_REMAP is the foundation of all remapping caps. 2. disable_irq_post is used by Intel iommu code only, here irq_remapping_cap() is common code. e.g. AMD iommu code doesn't use it to judge set cap of irq_post or not.
> +#else > +static inline bool posted_msi_supported(void) { return false; }; > +#endif
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