diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f2d3824..670694f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1007,10 +1007,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. has the capability. With this option, super page will not be supported. intremap= [X86-64, Intel-IOMMU] - Format: { on (default) | off | nosid } on enable Interrupt Remapping (default) off disable Interrupt Remapping nosid disable Source ID checking + no_x2apic_optout + BIOS x2APIC opt-out request will be ignored inttest= [IA64] diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index b9338b8..9802bdf 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1439,24 +1439,18 @@ int __init enable_IR(void) #ifdef CONFIG_INTR_REMAP if (!intr_remapping_supported()) { pr_debug("intr-remapping not supported\n"); - return 0; + return -1; } if (!x2apic_preenabled && skip_ioapic_setup) { pr_info("Skipped enabling intr-remap because of skipping " "io-apic setup\n"); - return 0; + return -1; } - if (enable_intr_remapping(x2apic_supported())) - return 0; - - pr_info("Enabled Interrupt-remapping\n"); - - return 1; - + return enable_intr_remapping(); #endif - return 0; + return -1; } void __init enable_IR_x2apic(void) @@ -1480,11 +1474,11 @@ void __init enable_IR_x2apic(void) mask_ioapic_entries(); if (dmar_table_init_ret) - ret = 0; + ret = -1; else ret = enable_IR(); - if (!ret) { + if (ret < 0) { /* IR is required if there is APIC ID > 255 even when running * under KVM */ @@ -1498,6 +1492,9 @@ void __init enable_IR_x2apic(void) x2apic_force_phys(); } + if (ret == IRQ_REMAP_XAPIC_MODE) + goto nox2apic; + x2apic_enabled = 1; if (x2apic_supported() && !x2apic_mode) { @@ -1507,19 +1504,21 @@ void __init enable_IR_x2apic(void) } nox2apic: - if (!ret) /* IR enabling failed */ + if (ret < 0) /* IR enabling failed */ restore_ioapic_entries(); legacy_pic->restore_mask(); local_irq_restore(flags); out: - if (x2apic_enabled) + if (x2apic_enabled || !x2apic_supported()) return; if (x2apic_preenabled) panic("x2apic: enabled by BIOS but kernel init failed."); - else if (cpu_has_x2apic) - pr_info("Not enabling x2apic, Intr-remapping init failed.\n"); + else if (ret == IRQ_REMAP_XAPIC_MODE) + pr_info("x2apic not enabled, IRQ remapping is in xapic mode\n"); + else if (ret < 0) + pr_info("x2apic not enabled, IRQ remapping init failed\n"); } #ifdef CONFIG_X86_64 diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 3dc9bef..d633f28 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -46,7 +46,7 @@ */ LIST_HEAD(dmar_drhd_units); -static struct acpi_table_header * __initdata dmar_tbl; +struct acpi_table_header * __initdata dmar_tbl; static acpi_size dmar_tbl_size; static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd) diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c index 3607faf..3df0752 100644 --- a/drivers/pci/intr_remapping.c +++ b/drivers/pci/intr_remapping.c @@ -22,6 +22,7 @@ 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) { @@ -35,12 +36,20 @@ 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; } @@ -502,6 +511,15 @@ 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; @@ -522,16 +540,25 @@ 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; @@ -607,8 +634,9 @@ 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: /* diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 7b776d7..2dc810e 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -26,8 +26,13 @@ #include #include +/* DMAR Flags */ +#define DMAR_INTR_REMAP 0x1 +#define DMAR_X2APIC_OPT_OUT 0x2 + struct intel_iommu; #if defined(CONFIG_DMAR) || defined(CONFIG_INTR_REMAP) +extern struct acpi_table_header *dmar_tbl; struct dmar_drhd_unit { struct list_head list; /* list of drhd units */ struct acpi_dmar_header *hdr; /* ACPI header */ @@ -110,7 +115,7 @@ struct irte { #ifdef CONFIG_INTR_REMAP extern int intr_remapping_enabled; extern int intr_remapping_supported(void); -extern int enable_intr_remapping(int); +extern int enable_intr_remapping(void); extern void disable_intr_remapping(void); extern int reenable_intr_remapping(int); @@ -177,7 +182,7 @@ static inline int set_msi_sid(struct irte *irte, struct pci_dev *dev) #define intr_remapping_enabled (0) -static inline int enable_intr_remapping(int eim) +static inline int enable_intr_remapping(void) { return -1; } @@ -192,6 +197,11 @@ static inline int reenable_intr_remapping(int eim) } #endif +enum { + IRQ_REMAP_XAPIC_MODE, + IRQ_REMAP_X2APIC_MODE, +}; + /* Can't use the common MSI interrupt functions * since DMAR is not a pci device */