iommu/amd: Detect and enable guest vAPIC support

This patch introduces a new IOMMU driver parameter, amd_iommu_guest_ir,
which can be used to specify different interrupt remapping mode for
passthrough devices to VM guest:
    * legacy: Legacy interrupt remapping (w/ 32-bit IRTE)
    * vapic : Guest vAPIC interrupt remapping (w/ GA mode 128-bit IRTE)

Note that in vapic mode, it can also supports legacy interrupt remapping
for non-passthrough devices with the 128-bit IRTE.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 46c030a..748ef7b 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -460,6 +460,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        driver will print ACPI tables for AMD IOMMU during
                        IOMMU initialization.
 
+       amd_iommu_intr= [HW,X86-64]
+                       Specifies one of the following AMD IOMMU interrupt
+                       remapping modes:
+                       legacy     - Use legacy interrupt remapping mode.
+                       vapic      - Use virtual APIC mode, which allows IOMMU
+                                    to inject interrupts directly into guest.
+                                    This mode requires kvm-amd.avic=1.
+                                    (Default when IOMMU HW support is present.)
+
        amijoy.map=     [HW,JOY] Amiga joystick support
                        Map of devices attached to JOY0DAT and JOY1DAT
                        Format: <a>,<b>

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 59741ea..c3afd86 100644 (file)
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -145,6 +145,8 @@ struct ivmd_header {
 bool amd_iommu_dump;
 bool amd_iommu_irq_remap __read_mostly;
 
+int amd_iommu_guest_ir;
+
 static bool amd_iommu_detected;
 static bool __initdata amd_iommu_disabled;
 static int amd_iommu_target_ivhd_type;
@@ -1258,6 +1260,8 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
                        iommu->mmio_phys_end = MMIO_REG_END_OFFSET;
                else
                        iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;
+               if (((h->efr_attr & (0x1 << IOMMU_FEAT_GASUP_SHIFT)) == 0))
+                       amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
                break;
        case 0x11:
        case 0x40:
@@ -1265,6 +1269,8 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
                        iommu->mmio_phys_end = MMIO_REG_END_OFFSET;
                else
                        iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;
+               if (((h->efr_reg & (0x1 << IOMMU_EFR_GASUP_SHIFT)) == 0))
+                       amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
                break;
        default:
                return -EINVAL;
@@ -1488,6 +1494,14 @@ static int iommu_init_pci(struct amd_iommu *iommu)
        if (iommu_feature(iommu, FEATURE_PPR) && alloc_ppr_log(iommu))
                return -ENOMEM;
 
+       /* Note: We have already checked GASup from IVRS table.
+        *       Now, we need to make sure that GAMSup is set.
+        */
+       if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
+           !iommu_feature(iommu, FEATURE_GAM_VAPIC))
+               amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY_GA;
+
+
        if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE))
                amd_iommu_np_cache = true;
 
@@ -1545,16 +1559,24 @@ static void print_iommu_info(void)
                        dev_name(&iommu->dev->dev), iommu->cap_ptr);
 
                if (iommu->cap & (1 << IOMMU_CAP_EFR)) {
-                       pr_info("AMD-Vi:  Extended features: ");
+                       pr_info("AMD-Vi: Extended features (%#llx):\n",
+                               iommu->features);
                        for (i = 0; i < ARRAY_SIZE(feat_str); ++i) {
                                if (iommu_feature(iommu, (1ULL << i)))
                                        pr_cont(" %s", feat_str[i]);
                        }
+
+                       if (iommu->features & FEATURE_GAM_VAPIC)
+                               pr_cont(" GA_vAPIC");
+
                        pr_cont("\n");
                }
        }
-       if (irq_remapping_enabled)
+       if (irq_remapping_enabled) {
                pr_info("AMD-Vi: Interrupt remapping enabled\n");
+               if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
+                       pr_info("AMD-Vi: virtual APIC enabled\n");
+       }
 }
 
 static int __init amd_iommu_init_pci(void)
@@ -1862,6 +1884,22 @@ static void iommu_apply_resume_quirks(struct amd_iommu *iommu)
                               iommu->stored_addr_lo | 1);
 }
 
+static void iommu_enable_ga(struct amd_iommu *iommu)
+{
+#ifdef CONFIG_IRQ_REMAP
+       switch (amd_iommu_guest_ir) {
+       case AMD_IOMMU_GUEST_IR_VAPIC:
+               iommu_feature_enable(iommu, CONTROL_GAM_EN);
+               /* Fall through */
+       case AMD_IOMMU_GUEST_IR_LEGACY_GA:
+               iommu_feature_enable(iommu, CONTROL_GA_EN);
+               break;
+       default:
+               break;
+       }
+#endif
+}
+
 /*
  * This function finally enables all IOMMUs found in the system after
  * they have been initialized
@@ -1877,6 +1915,7 @@ static void early_enable_iommus(void)
                iommu_enable_command_buffer(iommu);
                iommu_enable_event_buffer(iommu);
                iommu_set_exclusion_range(iommu);
+               iommu_enable_ga(iommu);
                iommu_enable(iommu);
                iommu_flush_all_caches(iommu);
        }
@@ -2059,7 +2098,7 @@ static int __init early_amd_iommu_init(void)
        struct acpi_table_header *ivrs_base;
        acpi_size ivrs_size;
        acpi_status status;
-       int i, ret = 0;
+       int i, remap_cache_sz, ret = 0;
 
        if (!amd_iommu_detected)
                return -ENODEV;
@@ -2157,10 +2196,14 @@ static int __init early_amd_iommu_init(void)
                 * remapping tables.
                 */
                ret = -ENOMEM;
+               if (!AMD_IOMMU_GUEST_IR_GA(amd_iommu_guest_ir))
+                       remap_cache_sz = MAX_IRQS_PER_TABLE * sizeof(u32);
+               else
+                       remap_cache_sz = MAX_IRQS_PER_TABLE * (sizeof(u64) * 2);
                amd_iommu_irq_cache = kmem_cache_create("irq_remap_cache",
-                               MAX_IRQS_PER_TABLE * sizeof(u32),
-                               IRQ_TABLE_ALIGNMENT,
-                               0, NULL);
+                                                       remap_cache_sz,
+                                                       IRQ_TABLE_ALIGNMENT,
+                                                       0, NULL);
                if (!amd_iommu_irq_cache)
                        goto out;
 
@@ -2413,6 +2456,21 @@ static int __init parse_amd_iommu_dump(char *str)
        return 1;
 }
 
+static int __init parse_amd_iommu_intr(char *str)
+{
+       for (; *str; ++str) {
+               if (strncmp(str, "legacy", 6) == 0) {
+                       amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
+                       break;
+               }
+               if (strncmp(str, "vapic", 5) == 0) {
+                       amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_VAPIC;
+                       break;
+               }
+       }
+       return 1;
+}
+
 static int __init parse_amd_iommu_options(char *str)
 {
        for (; *str; ++str) {
@@ -2521,6 +2579,7 @@ static int __init parse_ivrs_acpihid(char *str)
 
 __setup("amd_iommu_dump",      parse_amd_iommu_dump);
 __setup("amd_iommu=",          parse_amd_iommu_options);
+__setup("amd_iommu_intr=",     parse_amd_iommu_intr);
 __setup("ivrs_ioapic",         parse_ivrs_ioapic);
 __setup("ivrs_hpet",           parse_ivrs_hpet);
 __setup("ivrs_acpihid",                parse_ivrs_acpihid);

diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index 0bd9eb3..faa3b48 100644 (file)
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -38,6 +38,7 @@ extern int amd_iommu_enable(void);
 extern void amd_iommu_disable(void);
 extern int amd_iommu_reenable(int);
 extern int amd_iommu_enable_faulting(void);
+extern int amd_iommu_guest_ir;
 
 /* IOMMUv2 specific functions */
 struct iommu_domain;

diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index caf5e38..3d1fc37 100644 (file)
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -92,6 +92,7 @@
 #define FEATURE_GA             (1ULL<<7)
 #define FEATURE_HE             (1ULL<<8)
 #define FEATURE_PC             (1ULL<<9)
+#define FEATURE_GAM_VAPIC      (1ULL<<21)
 
 #define FEATURE_PASID_SHIFT    32
 #define FEATURE_PASID_MASK     (0x1fULL << FEATURE_PASID_SHIFT)
@@ -146,6 +147,8 @@
 #define CONTROL_PPFINT_EN       0x0eULL
 #define CONTROL_PPR_EN          0x0fULL
 #define CONTROL_GT_EN           0x10ULL
+#define CONTROL_GA_EN           0x11ULL
+#define CONTROL_GAM_EN          0x19ULL
 
 #define CTRL_INV_TO_MASK       (7 << CONTROL_INV_TIMEOUT)
 #define CTRL_INV_TO_NONE       0
@@ -329,6 +332,12 @@
 #define IOMMU_CAP_NPCACHE 26
 #define IOMMU_CAP_EFR     27
 
+/* IOMMU Feature Reporting Field (for IVHD type 10h */
+#define IOMMU_FEAT_GASUP_SHIFT 6
+
+/* IOMMU Extended Feature Register (EFR) */
+#define IOMMU_EFR_GASUP_SHIFT  7
+
 #define MAX_DOMAIN_ID 65536
 
 /* Protection domain flags */
@@ -681,4 +690,19 @@ static inline int get_hpet_devid(int id)
        return -EINVAL;
 }
 
+enum amd_iommu_intr_mode_type {
+       AMD_IOMMU_GUEST_IR_LEGACY,
+
+       /* This mode is not visible to users. It is used when
+        * we cannot fully enable vAPIC and fallback to only support
+        * legacy interrupt remapping via 128-bit IRTE.
+        */
+       AMD_IOMMU_GUEST_IR_LEGACY_GA,
+       AMD_IOMMU_GUEST_IR_VAPIC,
+};
+
+#define AMD_IOMMU_GUEST_IR_GA(x)       (x == AMD_IOMMU_GUEST_IR_VAPIC || \
+                                        x == AMD_IOMMU_GUEST_IR_LEGACY_GA)
+
+#define AMD_IOMMU_GUEST_IR_VAPIC(x)    (x == AMD_IOMMU_GUEST_IR_VAPIC)
 #endif /* _ASM_X86_AMD_IOMMU_TYPES_H */