summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--Documentation/kernel-parameters.txt3
-rw-r--r--arch/x86/kernel/apic/apic.c31
-rw-r--r--drivers/iommu/dmar.c2
-rw-r--r--drivers/iommu/intr_remapping.c44
-rw-r--r--include/linux/dmar.h14
5 files changed, 66 insertions, 28 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 854ed5ca7e3f..13865568809e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1014,10 +1014,11 @@ 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= [IA-64]
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 52fa56399a50..6b9874a5c7af 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1440,24 +1440,18 @@ 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)
@@ -1481,11 +1475,11 @@ 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
*/
@@ -1499,6 +1493,9 @@ 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) {
@@ -1508,19 +1505,21 @@ 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/iommu/dmar.c b/drivers/iommu/dmar.c
index 6dcc7e2d54de..c4a0235a4fdb 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/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/iommu/intr_remapping.c b/drivers/iommu/intr_remapping.c
index 1a89d4a2cadf..51a2ce9b8789 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:
/*
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 7b776d71d36d..2dc810e35dd0 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -26,8 +26,13 @@
#include <linux/msi.h>
#include <linux/irqreturn.h>
+/* 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
*/