diff options
| -rw-r--r-- | include/linux/msi.h | 13 | ||||
| -rw-r--r-- | kernel/irq/msi.c | 27 |
2 files changed, 40 insertions, 0 deletions
diff --git a/include/linux/msi.h b/include/linux/msi.h index a112b913fff9..e8a3f3a8a7f4 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -649,6 +649,19 @@ int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int vir void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq, unsigned int nvec); void *platform_msi_get_host_data(struct irq_domain *domain); + +bool msi_device_has_isolated_msi(struct device *dev); +#else /* CONFIG_GENERIC_MSI_IRQ */ +static inline bool msi_device_has_isolated_msi(struct device *dev) +{ + /* + * Arguably if the platform does not enable MSI support then it has + * "isolated MSI", as an interrupt controller that cannot receive MSIs + * is inherently isolated by our definition. As nobody seems to needs + * this be conservative and return false anyhow. + */ + return false; +} #endif /* CONFIG_GENERIC_MSI_IRQ */ /* PCI specific interfaces */ diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 955267bbc2be..dfb5d40abac9 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -1623,3 +1623,30 @@ struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain) { return (struct msi_domain_info *)domain->host_data; } + +/** + * msi_device_has_isolated_msi - True if the device has isolated MSI + * @dev: The device to check + * + * Isolated MSI means that HW modeled by an irq_domain on the path from the + * initiating device to the CPU will validate that the MSI message specifies an + * interrupt number that the device is authorized to trigger. This must block + * devices from triggering interrupts they are not authorized to trigger. + * Currently authorization means the MSI vector is one assigned to the device. + * + * This is interesting for securing VFIO use cases where a rouge MSI (eg created + * by abusing a normal PCI MemWr DMA) must not allow the VFIO userspace to + * impact outside its security domain, eg userspace triggering interrupts on + * kernel drivers, a VM triggering interrupts on the hypervisor, or a VM + * triggering interrupts on another VM. + */ +bool msi_device_has_isolated_msi(struct device *dev) +{ + struct irq_domain *domain = dev_get_msi_domain(dev); + + for (; domain; domain = domain->parent) + if (domain->flags & IRQ_DOMAIN_FLAG_MSI_REMAP) + return true; + return false; +} +EXPORT_SYMBOL_GPL(msi_device_has_isolated_msi); |