diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 11 | ||||
| -rw-r--r-- | arch/x86/entry/entry_fred.c | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/apic.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/hardirq.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/idtentry.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/irq_remapping.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/irq_vectors.h | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/posted_intr.h | 118 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/vector.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/idt.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/irq.c | 172 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/posted_intr.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/posted_intr.h | 93 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.h | 2 | ||||
| -rw-r--r-- | drivers/iommu/intel/irq_remapping.c | 113 | ||||
| -rw-r--r-- | drivers/iommu/irq_remapping.c | 5 |
19 files changed, 450 insertions, 119 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fe39954ca058..8e006cdb1399 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2251,6 +2251,8 @@ no_x2apic_optout BIOS x2APIC opt-out request will be ignored nopost disable Interrupt Posting + posted_msi + enable MSIs delivered as posted interrupts iomem= Disable strict checking of access to MMIO memory strict regions from userspace. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 07e8817278a4..9d16fee6bdb8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -466,6 +466,17 @@ config X86_X2APIC If you don't know what to do here, say N. +config X86_POSTED_MSI + bool "Enable MSI and MSI-x delivery by posted interrupts" + depends on X86_64 && IRQ_REMAP + help + This enables MSIs that are under interrupt remapping to be delivered as + posted interrupts to the host kernel. Interrupt throughput can + potentially be improved by coalescing CPU notifications during high + frequency bursts. + + If you don't know what to do here, say N. + config X86_MPPARSE bool "Enable MPS table" if ACPI default y diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c index 89c1476fcdd9..f004a4dc74c2 100644 --- a/arch/x86/entry/entry_fred.c +++ b/arch/x86/entry/entry_fred.c @@ -117,6 +117,8 @@ static idtentry_t sysvec_table[NR_SYSTEM_VECTORS] __ro_after_init = { SYSVEC(POSTED_INTR_VECTOR, kvm_posted_intr_ipi), SYSVEC(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi), SYSVEC(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi), + + SYSVEC(POSTED_MSI_NOTIFICATION_VECTOR, posted_msi_notification), }; static bool fred_setup_done __initdata; diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 839c58f95114..9327eb00e96d 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -14,6 +14,7 @@ #include <asm/msr.h> #include <asm/hardirq.h> #include <asm/io.h> +#include <asm/posted_intr.h> #define ARCH_APICTIMER_STOPS_ON_C3 1 @@ -500,6 +501,11 @@ static inline bool lapic_vector_set_in_irr(unsigned int vector) return !!(irr & (1U << (vector % 32))); } +static inline bool is_vector_pending(unsigned int vector) +{ + return lapic_vector_set_in_irr(vector) || pi_pending_this_cpu(vector); +} + /* * Warm reset vector position: */ diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h index fbc7722b87d1..c67fa6ad098a 100644 --- a/arch/x86/include/asm/hardirq.h +++ b/arch/x86/include/asm/hardirq.h @@ -44,10 +44,16 @@ typedef struct { unsigned int irq_hv_reenlightenment_count; unsigned int hyperv_stimer0_count; #endif +#ifdef CONFIG_X86_POSTED_MSI + unsigned int posted_msi_notification_count; +#endif } ____cacheline_aligned irq_cpustat_t; DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); +#ifdef CONFIG_X86_POSTED_MSI +DECLARE_PER_CPU_ALIGNED(struct pi_desc, posted_msi_pi_desc); +#endif #define __ARCH_IRQ_STAT #define inc_irq_stat(member) this_cpu_inc(irq_stat.member) diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h index 749c7411d2f1..d4f24499b256 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -751,6 +751,12 @@ DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR, sysvec_kvm_posted_intr_nested # define fred_sysvec_kvm_posted_intr_nested_ipi NULL #endif +# ifdef CONFIG_X86_POSTED_MSI +DECLARE_IDTENTRY_SYSVEC(POSTED_MSI_NOTIFICATION_VECTOR, sysvec_posted_msi_notification); +#else +# define fred_sysvec_posted_msi_notification NULL +# endif + #if IS_ENABLED(CONFIG_HYPERV) DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR, sysvec_hyperv_callback); DECLARE_IDTENTRY_SYSVEC(HYPERV_REENLIGHTENMENT_VECTOR, sysvec_hyperv_reenlightenment); diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h index 7a2ed154a5e1..5036f13ab69f 100644 --- a/arch/x86/include/asm/irq_remapping.h +++ b/arch/x86/include/asm/irq_remapping.h @@ -50,6 +50,13 @@ static inline struct irq_domain *arch_get_ir_parent_domain(void) return x86_vector_domain; } +extern bool enable_posted_msi; + +static inline bool posted_msi_supported(void) +{ + return enable_posted_msi && irq_remapping_cap(IRQ_POSTING_CAP); +} + #else /* CONFIG_IRQ_REMAP */ static inline bool irq_remapping_cap(enum irq_remap_cap cap) { return 0; } diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index d18bfb238f66..13aea8fc3d45 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -97,10 +97,16 @@ #define LOCAL_TIMER_VECTOR 0xec +/* + * Posted interrupt notification vector for all device MSIs delivered to + * the host kernel. + */ +#define POSTED_MSI_NOTIFICATION_VECTOR 0xeb + #define NR_VECTORS 256 #ifdef CONFIG_X86_LOCAL_APIC -#define FIRST_SYSTEM_VECTOR LOCAL_TIMER_VECTOR +#define FIRST_SYSTEM_VECTOR POSTED_MSI_NOTIFICATION_VECTOR #else #define FIRST_SYSTEM_VECTOR NR_VECTORS #endif diff --git a/arch/x86/include/asm/posted_intr.h b/arch/x86/include/asm/posted_intr.h new file mode 100644 index 000000000000..de788b400fba --- /dev/null +++ b/arch/x86/include/asm/posted_intr.h @@ -0,0 +1,118 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _X86_POSTED_INTR_H +#define _X86_POSTED_INTR_H +#include <asm/irq_vectors.h> + +#define POSTED_INTR_ON 0 +#define POSTED_INTR_SN 1 + +#define PID_TABLE_ENTRY_VALID 1 + +/* Posted-Interrupt Descriptor */ +struct pi_desc { + union { + u32 pir[8]; /* Posted interrupt requested */ + u64 pir64[4]; + }; + union { + struct { + u16 notifications; /* Suppress and outstanding bits */ + u8 nv; + u8 rsvd_2; + u32 ndst; + }; + u64 control; + }; + u32 rsvd[6]; +} __aligned(64); + +static inline bool pi_test_and_set_on(struct pi_desc *pi_desc) +{ + return test_and_set_bit(POSTED_INTR_ON, (unsigned long *)&pi_desc->control); +} + +static inline bool pi_test_and_clear_on(struct pi_desc *pi_desc) +{ + return test_and_clear_bit(POSTED_INTR_ON, (unsigned long *)&pi_desc->control); +} + +static inline bool pi_test_and_clear_sn(struct pi_desc *pi_desc) +{ + return test_and_clear_bit(POSTED_INTR_SN, (unsigned long *)&pi_desc->control); +} + +static inline bool pi_test_and_set_pir(int vector, struct pi_desc *pi_desc) +{ + return test_and_set_bit(vector, (unsigned long *)pi_desc->pir); +} + +static inline bool pi_is_pir_empty(struct pi_desc *pi_desc) +{ + return bitmap_empty((unsigned long *)pi_desc->pir, NR_VECTORS); +} + +static inline void pi_set_sn(struct pi_desc *pi_desc) +{ + set_bit(POSTED_INTR_SN, (unsigned long *)&pi_desc->control); +} + +static inline void pi_set_on(struct pi_desc *pi_desc) +{ + set_bit(POSTED_INTR_ON, (unsigned long *)&pi_desc->control); +} + +static inline void pi_clear_on(struct pi_desc *pi_desc) +{ + clear_bit(POSTED_INTR_ON, (unsigned long *)&pi_desc->control); +} + +static inline void pi_clear_sn(struct pi_desc *pi_desc) +{ + clear_bit(POSTED_INTR_SN, (unsigned long *)&pi_desc->control); +} + +static inline bool pi_test_on(struct pi_desc *pi_desc) +{ + return test_bit(POSTED_INTR_ON, (unsigned long *)&pi_desc->control); +} + +static inline bool pi_test_sn(struct pi_desc *pi_desc) +{ + return test_bit(POSTED_INTR_SN, (unsigned long *)&pi_desc->control); +} + +/* Non-atomic helpers */ +static inline void __pi_set_sn(struct pi_desc *pi_desc) +{ + pi_desc->notifications |= BIT(POSTED_INTR_SN); +} + +static inline void __pi_clear_sn(struct pi_desc *pi_desc) +{ + pi_desc->notifications &= ~BIT(POSTED_INTR_SN); +} + +#ifdef CONFIG_X86_POSTED_MSI +/* + * Not all external vectors are subject to interrupt remapping, e.g. IOMMU's + * own interrupts. Here we do not distinguish them since those vector bits in + * PIR will always be zero. + */ +static inline bool pi_pending_this_cpu(unsigned int vector) +{ + struct pi_desc *pid = this_cpu_ptr(&posted_msi_pi_desc); + + if (WARN_ON_ONCE(vector > NR_VECTORS || vector < FIRST_EXTERNAL_VECTOR)) + return false; + + return test_bit(vector, (unsigned long *)pid->pir); +} + +extern void intel_posted_msi_init(void); +#else +static inline bool pi_pending_this_cpu(unsigned int vector) { return false; } + +static inline void intel_posted_msi_init(void) {}; +#endif /* X86_POSTED_MSI */ + +#endif /* _X86_POSTED_INTR_H */ diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index 185738c72766..9eec52925fa3 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -965,7 +965,7 @@ static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr) lockdep_assert_held(&vector_lock); hlist_for_each_entry_safe(apicd, tmp, &cl->head, clist) { - unsigned int irr, vector = apicd->prev_vector; + unsigned int vector = apicd->prev_vector; /* * Paranoia: Check if the vector that needs to be cleaned @@ -979,8 +979,7 @@ static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr) * fixup_irqs() was just called to scan IRR for set bits and * forward them to new destination CPUs via IPIs. */ - irr = check_irr ? apic_read(APIC_IRR + (vector / 32 * 0x10)) : 0; - if (irr & (1U << (vector % 32))) { + if (check_irr && is_vector_pending(vector)) { pr_warn_once("Moved interrupt pending in old target APIC %u\n", apicd->irq); rearm = true; continue; diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index cdaa795a9371..2b170da84f97 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -68,6 +68,7 @@ #include <asm/traps.h> #include <asm/sev.h> #include <asm/tdx.h> +#include <asm/posted_intr.h> #include "cpu.h" @@ -2222,6 +2223,8 @@ void cpu_init(void) barrier(); x2apic_setup(); + + intel_posted_msi_init(); } mmgrab(&init_mm); diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index fc37c8d83daf..f445bec516a0 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -163,6 +163,9 @@ static const __initconst struct idt_data apic_idts[] = { # endif INTG(SPURIOUS_APIC_VECTOR, asm_sysvec_spurious_apic_interrupt), INTG(ERROR_APIC_VECTOR, asm_sysvec_error_interrupt), +# ifdef CONFIG_X86_POSTED_MSI + INTG(POSTED_MSI_NOTIFICATION_VECTOR, asm_sysvec_posted_msi_notification), +# endif #endif }; diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 35fde0107901..385e3a5fc304 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -22,6 +22,8 @@ #include <asm/desc.h> #include <asm/traps.h> #include <asm/thermal.h> +#include <asm/posted_intr.h> +#include <asm/irq_remapping.h> #define CREATE_TRACE_POINTS #include <asm/trace/irq_vectors.h> @@ -182,6 +184,13 @@ int arch_show_interrupts(struct seq_file *p, int prec) irq_stats(j)->kvm_posted_intr_wakeup_ipis); seq_puts(p, " Posted-interrupt wakeup event\n"); #endif +#ifdef CONFIG_X86_POSTED_MSI + seq_printf(p, "%*s: ", prec, "PMN"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", + irq_stats(j)->posted_msi_notification_count); + seq_puts(p, " Posted MSI notification event\n"); +#endif return 0; } @@ -240,24 +249,16 @@ static __always_inline void handle_irq(struct irq_desc *desc, __handle_irq(desc, regs); } -/* - * common_interrupt() handles all normal device IRQ's (the special SMP - * cross-CPU interrupts have their own entry points). - */ -DEFINE_IDTENTRY_IRQ(common_interrupt) +static __always_inline int call_irq_handler(int vector, struct pt_regs *regs) { - struct pt_regs *old_regs = set_irq_regs(regs); struct irq_desc *desc; - - /* entry code tells RCU that we're not quiescent. Check it. */ - RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU"); + int ret = 0; desc = __this_cpu_read(vector_irq[vector]); if (likely(!IS_ERR_OR_NULL(desc))) { handle_irq(desc, regs); } else { - apic_eoi(); - + ret = -EINVAL; if (desc == VECTOR_UNUSED) { pr_emerg_ratelimited("%s: %d.%u No irq handler for vector\n", __func__, smp_processor_id(), @@ -267,6 +268,23 @@ DEFINE_IDTENTRY_IRQ(common_interrupt) } } + return ret; +} + +/* + * common_interrupt() handles all normal device IRQ's (the special SMP + * cross-CPU interrupts have their own entry points). + */ +DEFINE_IDTENTRY_IRQ(common_interrupt) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + /* entry code tells RCU that we're not quiescent. Check it. */ + RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU"); + + if (unlikely(call_irq_handler(vector, regs))) + apic_eoi(); + set_irq_regs(old_regs); } @@ -334,12 +352,139 @@ DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_nested_ipi) } #endif +#ifdef CONFIG_X86_POSTED_MSI + +/* Posted Interrupt Descriptors for coalesced MSIs to be posted */ +DEFINE_PER_CPU_ALIGNED(struct pi_desc, posted_msi_pi_desc); + +void intel_posted_msi_init(void) +{ + u32 destination; + u32 apic_id; + + this_cpu_write(posted_msi_pi_desc.nv, POSTED_MSI_NOTIFICATION_VECTOR); + + /* + * APIC destination ID is stored in bit 8:15 while in XAPIC mode. + * VT-d spec. CH 9.11 + */ + apic_id = this_cpu_read(x86_cpu_to_apicid); + destination = x2apic_enabled() ? apic_id : apic_id << 8; + this_cpu_write(posted_msi_pi_desc.ndst, destination); +} + +/* + * De-multiplexing posted interrupts is on the performance path, the code + * below is written to optimize the cache performance based on the following + * considerations: + * 1.Posted interrupt descriptor (PID) fits in a cache line that is frequently + * accessed by both CPU and IOMMU. + * 2.During posted MSI processing, the CPU needs to do 64-bit read and xchg + * for checking and clearing posted interrupt request (PIR), a 256 bit field + * within the PID. + * 3.On the other side, the IOMMU does atomic swaps of the entire PID cache + * line when posting interrupts and setting control bits. + * 4.The CPU can access the cache line a magnitude faster than the IOMMU. + * 5.Each time the IOMMU does interrupt posting to the PIR will evict the PID + * cache line. The cache line states after each operation are as follows: + * CPU IOMMU PID Cache line state + * --------------------------------------------------------------- + *...read64 exclusive + *...lock xchg64 modified + *... post/atomic swap invalid + *...------------------------------------------------------------- + * + * To reduce L1 data cache miss, it is important to avoid contention with + * IOMMU's interrupt posting/atomic swap. Therefore, a copy of PIR is used + * to dispatch interrupt handlers. + * + * In addition, the code is trying to keep the cache line state consistent + * as much as possible. e.g. when making a copy and clearing the PIR + * (assuming non-zero PIR bits are present in the entire PIR), it does: + * read, read, read, read, xchg, xchg, xchg, xchg + * instead of: + * read, xchg, read, xchg, read, xchg, read, xchg + */ +static __always_inline bool handle_pending_pir(u64 *pir, struct pt_regs *regs) +{ + int i, vec = FIRST_EXTERNAL_VECTOR; + unsigned long pir_copy[4]; + bool handled = false; + + for (i = 0; i < 4; i++) + pir_copy[i] = pir[i]; + + for (i = 0; i < 4; i++) { + if (!pir_copy[i]) + continue; + + pir_copy[i] = arch_xchg(&pir[i], 0); + handled = true; + } + + if (handled) { + for_each_set_bit_from(vec, pir_copy, FIRST_SYSTEM_VECTOR) + call_irq_handler(vec, regs); + } + + return handled; +} + +/* + * Performance data shows that 3 is good enough to harvest 90+% of the benefit + * on high IRQ rate workload. + */ +#define MAX_POSTED_MSI_COALESCING_LOOP 3 + +/* + * For MSIs that are delivered as posted interrupts, the CPU notifications + * can be coalesced if the MSIs arrive in high frequency bursts. + */ +DEFINE_IDTENTRY_SYSVEC(sysvec_posted_msi_notification) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + struct pi_desc *pid; + int i = 0; + + pid = this_cpu_ptr(&posted_msi_pi_desc); + + inc_irq_stat(posted_msi_notification_count); + irq_enter(); + + /* + * Max coalescing count includes the extra round of handle_pending_pir + * after clearing the outstanding notification bit. Hence, at most + * MAX_POSTED_MSI_COALESCING_LOOP - 1 loops are executed here. + */ + while (++i < MAX_POSTED_MSI_COALESCING_LOOP) { + if (!handle_pending_pir(pid->pir64, regs)) + break; + } + + /* + * Clear outstanding notification bit to allow new IRQ notifications, + * do this last to maximize the window of interrupt coalescing. + */ + pi_clear_on(pid); + + /* + * There could be a race of PI notification and the clearing of ON bit, + * process PIR bits one last time such that handling the new interrupts + * are not delayed until the next IRQ. + */ + handle_pending_pir(pid->pir64, regs); + + apic_eoi(); + irq_exit(); + set_irq_regs(old_regs); +} +#endif /* X86_POSTED_MSI */ #ifdef CONFIG_HOTPLUG_CPU /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */ void fixup_irqs(void) { - unsigned int irr, vector; + unsigned int vector; struct irq_desc *desc; struct irq_data *data; struct irq_chip *chip; @@ -366,8 +511,7 @@ void fixup_irqs(void) if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector]))) continue; - irr = apic_read(APIC_IRR + (vector / 32 * 0x10)); - if (irr & (1 << (vector % 32))) { + if (is_vector_pending(vector)) { desc = __this_cpu_read(vector_irq[vector]); raw_spin_lock(&desc->lock); diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c index af662312fd07..ec08fa3caf43 100644 --- a/arch/x86/kvm/vmx/posted_intr.c +++ b/arch/x86/kvm/vmx/posted_intr.c @@ -107,7 +107,7 @@ void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu) * handle task migration (@cpu != vcpu->cpu). */ new.ndst = dest; - new.sn = 0; + __pi_clear_sn(&new); /* * Restore the notification vector; in the blocking case, the @@ -157,7 +157,7 @@ static void pi_enable_wakeup_handler(struct kvm_vcpu *vcpu) &per_cpu(wakeup_vcpus_on_cpu, vcpu->cpu)); raw_spin_unlock(&per_cpu(wakeup_vcpus_on_cpu_lock, vcpu->cpu)); - WARN(pi_desc->sn, "PI descriptor SN field set before blocking"); + WARN(pi_test_sn(pi_desc), "PI descriptor SN field set before blocking"); old.control = READ_ONCE(pi_desc->control); do { diff --git a/arch/x86/kvm/vmx/posted_intr.h b/arch/x86/kvm/vmx/posted_intr.h index 26992076552e..6b2a0226257e 100644 --- a/arch/x86/kvm/vmx/posted_intr.h +++ b/arch/x86/kvm/vmx/posted_intr.h @@ -1,98 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __KVM_X86_VMX_POSTED_INTR_H #define __KVM_X86_VMX_POSTED_INTR_H - -#define POSTED_INTR_ON 0 -#define POSTED_INTR_SN 1 - -#define PID_TABLE_ENTRY_VALID 1 - -/* Posted-Interrupt Descriptor */ -struct pi_desc { - u32 pir[8]; /* Posted interrupt requested */ - union { - struct { - /* bit 256 - Outstanding Notification */ - u16 on : 1, - /* bit 257 - Suppress Notification */ - sn : 1, - /* bit 271:258 - Reserved */ - rsvd_1 : 14; - /* bit 279:272 - Notification Vector */ - u8 nv; - /* bit 287:280 - Reserved */ - u8 rsvd_2; - /* bit 319:288 - Notification Destination */ - u32 ndst; - }; - u64 control; - }; - u32 rsvd[6]; -} __aligned(64); - -static inline bool pi_test_and_set_on(struct pi_desc *pi_desc) -{ - return test_and_set_bit(POSTED_INTR_ON, - (unsigned long *)&pi_desc->control); -} - -static inline bool pi_test_and_clear_on(struct pi_desc *pi_desc) -{ - return test_and_clear_bit(POSTED_INTR_ON, - (unsigned long *)&pi_desc->control); -} - -static inline bool pi_test_and_clear_sn(struct pi_desc *pi_desc) -{ - return test_and_clear_bit(POSTED_INTR_SN, - (unsigned long *)&pi_desc->control); -} - -static inline bool pi_test_and_set_pir(int vector, struct pi_desc *pi_desc) -{ - return test_and_set_bit(vector, (unsigned long *)pi_desc->pir); -} - -static inline bool pi_is_pir_empty(struct pi_desc *pi_desc) -{ - return bitmap_empty((unsigned long *)pi_desc->pir, NR_VECTORS); -} - -static inline void pi_set_sn(struct pi_desc *pi_desc) -{ - set_bit(POSTED_INTR_SN, - (unsigned long *)&pi_desc->control); -} - -static inline void pi_set_on(struct pi_desc *pi_desc) -{ - set_bit(POSTED_INTR_ON, - (unsigned long *)&pi_desc->control); -} - -static inline void pi_clear_on(struct pi_desc *pi_desc) -{ - clear_bit(POSTED_INTR_ON, - (unsigned long *)&pi_desc->control); -} - -static inline void pi_clear_sn(struct pi_desc *pi_desc) -{ - clear_bit(POSTED_INTR_SN, - (unsigned long *)&pi_desc->control); -} - -static inline bool pi_test_on(struct pi_desc *pi_desc) -{ - return test_bit(POSTED_INTR_ON, - (unsigned long *)&pi_desc->control); -} - -static inline bool pi_test_sn(struct pi_desc *pi_desc) -{ - return test_bit(POSTED_INTR_SN, - (unsigned long *)&pi_desc->control); -} +#include <asm/posted_intr.h> void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu); void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 22411f4aff53..becefaf95cab 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -70,6 +70,7 @@ #include "x86.h" #include "smm.h" #include "vmx_onhyperv.h" +#include "posted_intr.h" MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); @@ -4844,7 +4845,7 @@ static void __vmx_vcpu_reset(struct kvm_vcpu *vcpu) * or POSTED_INTR_WAKEUP_VECTOR. */ vmx->pi_desc.nv = POSTED_INTR_VECTOR; - vmx->pi_desc.sn = 1; + __pi_set_sn(&vmx->pi_desc); } static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 90f9e4434646..7e483366b31e 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -7,10 +7,10 @@ #include <asm/kvm.h> #include <asm/intel_pt.h> #include <asm/perf_event.h> +#include <asm/posted_intr.h> #include "capabilities.h" #include "../kvm_cache_regs.h" -#include "posted_intr.h" #include "vmcs.h" #include "vmx_ops.h" #include "../cpuid.h" diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c index 566297bc87dd..712ebfc9870c 100644 --- a/drivers/iommu/intel/irq_remapping.c +++ b/drivers/iommu/intel/irq_remapping.c @@ -19,6 +19,7 @@ #include <asm/cpu.h> #include <asm/irq_remapping.h> #include <asm/pci-direct.h> +#include <asm/posted_intr.h> #include "iommu.h" #include "../irq_remapping.h" @@ -49,6 +50,7 @@ struct irq_2_iommu { u16 sub_handle; u8 irte_mask; enum irq_mode mode; + bool posted_msi; }; struct intel_ir_data { @@ -1118,6 +1120,14 @@ static void prepare_irte(struct irte *irte, int vector, unsigned int dest) irte->redir_hint = 1; } +static void prepare_irte_posted(struct irte *irte) +{ + memset(irte, 0, sizeof(*irte)); + + irte->present = 1; + irte->p_pst = 1; +} + struct irq_remap_ops intel_irq_remap_ops = { .prepare = intel_prepare_irq_remapping, .enable = intel_enable_irq_remapping, @@ -1126,6 +1136,47 @@ struct irq_remap_ops intel_irq_remap_ops = { .enable_faulting = enable_drhd_fault_handling, }; +#ifdef CONFIG_X86_POSTED_MSI + +static phys_addr_t get_pi_desc_addr(struct irq_data *irqd) +{ + int cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd)); + + if (WARN_ON(cpu >= nr_cpu_ids)) + return 0; + + return __pa(per_cpu_ptr(&posted_msi_pi_desc, cpu)); +} + +static void intel_ir_reconfigure_irte_posted(struct irq_data *irqd) +{ + struct intel_ir_data *ir_data = irqd->chip_data; + struct irte *irte = &ir_data->irte_entry; + struct irte irte_pi; + u64 pid_addr; + + pid_addr = get_pi_desc_addr(irqd); + + if (!pid_addr) { + pr_warn("Failed to setup IRQ %d for posted mode", irqd->irq); + return; + } + + memset(&irte_pi, 0, sizeof(irte_pi)); + + /* The shared IRTE already be set up as posted during alloc_irte */ + dmar_copy_shared_irte(&irte_pi, irte); + + irte_pi.pda_l = (pid_addr >> (32 - PDA_LOW_BIT)) & ~(-1UL << PDA_LOW_BIT); + irte_pi.pda_h = (pid_addr >> 32) & ~(-1UL << PDA_HIGH_BIT); + + modify_irte(&ir_data->irq_2_iommu, &irte_pi); +} + +#else +static inline void intel_ir_reconfigure_irte_posted(struct irq_data *irqd) {} +#endif + static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force) { struct intel_ir_data *ir_data = irqd->chip_data; @@ -1139,8 +1190,9 @@ static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force) irte->vector = cfg->vector; irte->dest_id = IRTE_DEST(cfg->dest_apicid); - /* Update the hardware only if the interrupt is in remapped mode. */ - if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) + if (ir_data->irq_2_iommu.posted_msi) + intel_ir_reconfigure_irte_posted(irqd); + else if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) modify_irte(&ir_data->irq_2_iommu, irte); } @@ -1194,7 +1246,7 @@ static int intel_ir_set_vcpu_affinity(struct irq_data *data, void *info) struct intel_ir_data *ir_data = data->chip_data; struct vcpu_data *vcpu_pi_info = info; - /* stop posting interrupts, back to remapping mode */ + /* stop posting interrupts, back to the default mode */ if (!vcpu_pi_info) { modify_irte(&ir_data->irq_2_iommu, &ir_data->irte_entry); } else { @@ -1233,6 +1285,49 @@ static struct irq_chip intel_ir_chip = { .irq_set_vcpu_affinity = intel_ir_set_vcpu_affinity, }; +/* + * With posted MSIs, all vectors are multiplexed into a single notification + * vector. Devices MSIs are then dispatched in a demux loop where + * EOIs can be coalesced as well. + * + * "INTEL-IR-POST" IRQ chip does not do EOI on ACK, thus the dummy irq_ack() + * function. Instead EOI is performed by the posted interrupt notification + * handler. + * + * For the example below, 3 MSIs are coalesced into one CPU notification. Only + * one apic_eoi() is needed. + * + * __sysvec_posted_msi_notification() + * irq_enter(); + * handle_edge_irq() + * irq_chip_ack_parent() + * dummy(); // No EOI + * handle_irq_event() + * driver_handler() + * handle_edge_irq() + * irq_chip_ack_parent() + * dummy(); // No EOI + * handle_irq_event() + * driver_handler() + * handle_edge_irq() + * irq_chip_ack_parent() + * dummy(); // No EOI + * handle_irq_event() + * driver_handler() + * apic_eoi() + * irq_exit() + */ + +static void dummy_ack(struct irq_data *d) { } + +static struct irq_chip intel_ir_chip_post_msi = { + .name = "INTEL-IR-POST", + .irq_ack = dummy_ack, + .irq_set_affinity = intel_ir_set_affinity, + .irq_compose_msi_msg = intel_ir_compose_msi_msg, + .irq_set_vcpu_affinity = intel_ir_set_vcpu_affinity, +}; + static void fill_msi_msg(struct msi_msg *msg, u32 index, u32 subhandle) { memset(msg, 0, sizeof(*msg)); @@ -1274,6 +1369,11 @@ static void intel_irq_remapping_prepare_irte(struct intel_ir_data *data, break; case X86_IRQ_ALLOC_TYPE_PCI_MSI: case X86_IRQ_ALLOC_TYPE_PCI_MSIX: + if (posted_msi_supported()) { + prepare_irte_posted(irte); + data->irq_2_iommu.posted_msi = 1; + } + set_msi_sid(irte, pci_real_dma_dev(msi_desc_to_pci_dev(info->desc))); break; @@ -1361,7 +1461,12 @@ static int intel_irq_remapping_alloc(struct irq_domain *domain, irq_data->hwirq = (index << 16) + i; irq_data->chip_data = ird; - irq_data->chip = &intel_ir_chip; + if (posted_msi_supported() && + ((info->type == X86_IRQ_ALLOC_TYPE_PCI_MSI) || + (info->type == X86_IRQ_ALLOC_TYPE_PCI_MSIX))) + irq_data->chip = &intel_ir_chip_post_msi; + else + irq_data->chip = &intel_ir_chip; intel_irq_remapping_prepare_irte(ird, irq_cfg, info, index, i); irq_set_status_flags(virq + i, IRQ_MOVE_PCNTXT); } diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c index ee59647c2050..056fec6991bc 100644 --- a/drivers/iommu/irq_remapping.c +++ b/drivers/iommu/irq_remapping.c @@ -24,6 +24,8 @@ int no_x2apic_optout; int disable_irq_post = 0; +bool enable_posted_msi __ro_after_init; + static int disable_irq_remap; static struct irq_remap_ops *remap_ops; @@ -70,7 +72,8 @@ static __init int setup_irqremap(char *str) no_x2apic_optout = 1; else if (!strncmp(str, "nopost", 6)) disable_irq_post = 1; - + else if (IS_ENABLED(CONFIG_X86_POSTED_MSI) && !strncmp(str, "posted_msi", 10)) + enable_posted_msi = true; str += strcspn(str, ","); while (*str == ',') str++; |