diff options
Diffstat (limited to 'drivers/iommu/intr_remapping.c')
| -rw-r--r-- | drivers/iommu/intr_remapping.c | 44 |
1 files changed, 36 insertions, 8 deletions
diff --git a/drivers/iommu/intr_remapping.c b/drivers/iommu/intr_remapping.c index 1a89d4a2cad..51a2ce9b878 100644 --- a/drivers/iommu/intr_remapping.c +++ b/drivers/iommu/intr_remapping.c @@ -21,6 +21,7 @@ int intr_remapping_enabled; static int disable_intremap; static int disable_sourceid_checking; +static int no_x2apic_optout; static __init int setup_nointremap(char *str) { @@ -34,12 +35,20 @@ static __init int setup_intremap(char *str) if (!str) return -EINVAL; - if (!strncmp(str, "on", 2)) - disable_intremap = 0; - else if (!strncmp(str, "off", 3)) - disable_intremap = 1; - else if (!strncmp(str, "nosid", 5)) - disable_sourceid_checking = 1; + while (*str) { + if (!strncmp(str, "on", 2)) + disable_intremap = 0; + else if (!strncmp(str, "off", 3)) + disable_intremap = 1; + else if (!strncmp(str, "nosid", 5)) + disable_sourceid_checking = 1; + else if (!strncmp(str, "no_x2apic_optout", 16)) + no_x2apic_optout = 1; + + str += strcspn(str, ","); + while (*str == ',') + str++; + } return 0; } @@ -501,6 +510,15 @@ end: spin_unlock_irqrestore(&iommu->register_lock, flags); } +static int __init dmar_x2apic_optout(void) +{ + struct acpi_table_dmar *dmar; + dmar = (struct acpi_table_dmar *)dmar_tbl; + if (!dmar || no_x2apic_optout) + return 0; + return dmar->flags & DMAR_X2APIC_OPT_OUT; +} + int __init intr_remapping_supported(void) { struct dmar_drhd_unit *drhd; @@ -521,16 +539,25 @@ int __init intr_remapping_supported(void) return 1; } -int __init enable_intr_remapping(int eim) +int __init enable_intr_remapping(void) { struct dmar_drhd_unit *drhd; int setup = 0; + int eim = 0; if (parse_ioapics_under_ir() != 1) { printk(KERN_INFO "Not enable interrupt remapping\n"); return -1; } + if (x2apic_supported()) { + eim = !dmar_x2apic_optout(); + WARN(!eim, KERN_WARNING + "Your BIOS is broken and requested that x2apic be disabled\n" + "This will leave your machine vulnerable to irq-injection attacks\n" + "Use 'intremap=no_x2apic_optout' to override BIOS request\n"); + } + for_each_drhd_unit(drhd) { struct intel_iommu *iommu = drhd->iommu; @@ -606,8 +633,9 @@ int __init enable_intr_remapping(int eim) goto error; intr_remapping_enabled = 1; + pr_info("Enabled IRQ remapping in %s mode\n", eim ? "x2apic" : "xapic"); - return 0; + return eim ? IRQ_REMAP_X2APIC_MODE : IRQ_REMAP_XAPIC_MODE; error: /* |