diff options
| -rw-r--r-- | arch/x86/include/asm/msi.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/x86_init.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 26 | ||||
| -rw-r--r-- | arch/x86/kernel/x86_init.c | 1 |
4 files changed, 29 insertions, 3 deletions
diff --git a/arch/x86/include/asm/msi.h b/arch/x86/include/asm/msi.h index 322fd905da9c..b85147d75626 100644 --- a/arch/x86/include/asm/msi.h +++ b/arch/x86/include/asm/msi.h @@ -29,7 +29,8 @@ typedef struct x86_msi_addr_lo { u32 reserved_0 : 2, dest_mode_logical : 1, redirect_hint : 1, - reserved_1 : 8, + reserved_1 : 1, + virt_destid_8_14 : 7, destid_0_7 : 8, base_address : 12; }; diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index dde5b3f1e7cd..5c69f7eb5d47 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -116,6 +116,7 @@ struct x86_init_pci { * @init_platform: platform setup * @guest_late_init: guest late init * @x2apic_available: X2APIC detection + * @msi_ext_dest_id: MSI supports 15-bit APIC IDs * @init_mem_mapping: setup early mappings during init_mem_mapping() * @init_after_bootmem: guest init after boot allocator is finished */ @@ -123,6 +124,7 @@ struct x86_hyper_init { void (*init_platform)(void); void (*guest_late_init)(void); bool (*x2apic_available)(void); + bool (*msi_ext_dest_id)(void); void (*init_mem_mapping)(void); void (*init_after_bootmem)(void); }; diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index f7196ee0f005..6bd20c0de8bc 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -94,6 +94,11 @@ static unsigned int disabled_cpu_apicid __ro_after_init = BAD_APICID; static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP; /* + * Hypervisor supports 15 bits of APIC ID in MSI Extended Destination ID + */ +static bool virt_ext_dest_id __ro_after_init; + +/* * Map cpu index to physical APIC ID */ DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID); @@ -1841,6 +1846,8 @@ static __init void try_to_enable_x2apic(int remap_mode) return; if (remap_mode != IRQ_REMAP_X2APIC_MODE) { + u32 apic_limit = 255; + /* * Using X2APIC without IR is not architecturally supported * on bare metal but may be supported in guests. @@ -1852,11 +1859,21 @@ static __init void try_to_enable_x2apic(int remap_mode) } /* + * If the hypervisor supports extended destination ID in + * MSI, that increases the maximum APIC ID that can be + * used for non-remapped IRQ domains. + */ + if (x86_init.hyper.msi_ext_dest_id()) { + virt_ext_dest_id = 1; + apic_limit = 32767; + } + + /* * Without IR, all CPUs can be addressed by IOAPIC/MSI only * in physical mode, and CPUs with an APIC ID that cannnot * be addressed must not be brought online. */ - x2apic_set_max_apicid(255); + x2apic_set_max_apicid(apic_limit); x2apic_phys = 1; } x2apic_enable(); @@ -2497,10 +2514,15 @@ void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg, * Only the IOMMU itself can use the trick of putting destination * APIC ID into the high bits of the address. Anything else would * just be writing to memory if it tried that, and needs IR to - * address higher APIC IDs. + * address APICs which can't be addressed in the normal 32-bit + * address range at 0xFFExxxxx. That is typically just 8 bits, but + * some hypervisors allow the extended destination ID field in bits + * 5-11 to be used, giving support for 15 bits of APIC IDs in total. */ if (dmar) msg->arch_addr_hi.destid_8_31 = cfg->dest_apicid >> 8; + else if (virt_ext_dest_id && cfg->dest_apicid < 0x8000) + msg->arch_addr_lo.virt_destid_8_14 = cfg->dest_apicid >> 8; else WARN_ON_ONCE(cfg->dest_apicid > 0xFF); } diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index a3038d8deb6a..8b395821cb8d 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -110,6 +110,7 @@ struct x86_init_ops x86_init __initdata = { .init_platform = x86_init_noop, .guest_late_init = x86_init_noop, .x2apic_available = bool_x86_init_noop, + .msi_ext_dest_id = bool_x86_init_noop, .init_mem_mapping = x86_init_noop, .init_after_bootmem = x86_init_noop, }, |