From: Chao Gao Date: Tue, 19 Apr 2022 15:45:10 +0000 (+0800) Subject: KVM: VMX: enable IPI virtualization X-Git-Tag: baikal/mips/sdk6.1~5143^2~6^2~389^2~47 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=6a0023f052d55b3a020b7a8296e4d757f8535e21;p=kernel.git KVM: VMX: enable IPI virtualization With IPI virtualization enabled, the processor emulates writes to APIC registers that would send IPIs. The processor sets the bit corresponding to the vector in target vCPU's PIR and may send a notification (IPI) specified by NDST and NV fields in target vCPU's Posted-Interrupt Descriptor (PID). It is similar to what IOMMU engine does when dealing with posted interrupt from devices. A PID-pointer table is used by the processor to locate the PID of a vCPU with the vCPU's APIC ID. The table size depends on maximum APIC ID assigned for current VM session from userspace. Allocating memory for PID-pointer table is deferred to vCPU creation, because irqchip mode and VM-scope maximum APIC ID is settled at that point. KVM can skip PID-pointer table allocation if !irqchip_in_kernel(). Like VT-d PI, if a vCPU goes to blocked state, VMM needs to switch its notification vector to wakeup vector. This can ensure that when an IPI for blocked vCPUs arrives, VMM can get control and wake up blocked vCPUs. And if a VCPU is preempted, its posted interrupt notification is suppressed. Note that IPI virtualization can only virualize physical-addressing, flat mode, unicast IPIs. Sending other IPIs would still cause a trap-like APIC-write VM-exit and need to be handled by VMM. Signed-off-by: Chao Gao Signed-off-by: Zeng Guang Message-Id: <20220419154510.11938-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index da47f60a46509..6f2f1affbb782 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -21,6 +21,7 @@ KVM_X86_OP(has_emulated_msr) KVM_X86_OP(vcpu_after_set_cpuid) KVM_X86_OP(vm_init) KVM_X86_OP_OPTIONAL(vm_destroy) +KVM_X86_OP_OPTIONAL_RET0(vcpu_precreate) KVM_X86_OP(vcpu_create) KVM_X86_OP(vcpu_free) KVM_X86_OP(vcpu_reset) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 9dc8d6d0a67db..8118c52e3feca 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1347,6 +1347,7 @@ struct kvm_x86_ops { void (*vm_destroy)(struct kvm *kvm); /* Create, but do not attach this VCPU */ + int (*vcpu_precreate)(struct kvm *kvm); int (*vcpu_create)(struct kvm_vcpu *vcpu); void (*vcpu_free)(struct kvm_vcpu *vcpu); void (*vcpu_reset)(struct kvm_vcpu *vcpu, bool init_event); diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index 34ca428fefeda..89d2172787c55 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -76,6 +76,11 @@ #define SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE VMCS_CONTROL_BIT(USR_WAIT_PAUSE) #define SECONDARY_EXEC_BUS_LOCK_DETECTION VMCS_CONTROL_BIT(BUS_LOCK_DETECTION) +/* + * Definitions of Tertiary Processor-Based VM-Execution Controls. + */ +#define TERTIARY_EXEC_IPI_VIRT VMCS_CONTROL_BIT(IPI_VIRT) + #define PIN_BASED_EXT_INTR_MASK VMCS_CONTROL_BIT(INTR_EXITING) #define PIN_BASED_NMI_EXITING VMCS_CONTROL_BIT(NMI_EXITING) #define PIN_BASED_VIRTUAL_NMIS VMCS_CONTROL_BIT(VIRTUAL_NMIS) @@ -159,6 +164,7 @@ static inline int vmx_misc_mseg_revid(u64 vmx_misc) enum vmcs_field { VIRTUAL_PROCESSOR_ID = 0x00000000, POSTED_INTR_NV = 0x00000002, + LAST_PID_POINTER_INDEX = 0x00000008, GUEST_ES_SELECTOR = 0x00000800, GUEST_CS_SELECTOR = 0x00000802, GUEST_SS_SELECTOR = 0x00000804, @@ -224,6 +230,8 @@ enum vmcs_field { TSC_MULTIPLIER_HIGH = 0x00002033, TERTIARY_VM_EXEC_CONTROL = 0x00002034, TERTIARY_VM_EXEC_CONTROL_HIGH = 0x00002035, + PID_POINTER_TABLE = 0x00002042, + PID_POINTER_TABLE_HIGH = 0x00002043, GUEST_PHYSICAL_ADDRESS = 0x00002400, GUEST_PHYSICAL_ADDRESS_HIGH = 0x00002401, VMCS_LINK_POINTER = 0x00002800, diff --git a/arch/x86/include/asm/vmxfeatures.h b/arch/x86/include/asm/vmxfeatures.h index ff20776dc83b2..589608c157bf4 100644 --- a/arch/x86/include/asm/vmxfeatures.h +++ b/arch/x86/include/asm/vmxfeatures.h @@ -86,4 +86,6 @@ #define VMX_FEATURE_ENCLV_EXITING ( 2*32+ 28) /* "" VM-Exit on ENCLV (leaf dependent) */ #define VMX_FEATURE_BUS_LOCK_DETECTION ( 2*32+ 30) /* "" VM-Exit when bus lock caused */ +/* Tertiary Processor-Based VM-Execution Controls, word 3 */ +#define VMX_FEATURE_IPI_VIRT ( 3*32+ 4) /* Enable IPI virtualization */ #endif /* _ASM_X86_VMXFEATURES_H */ diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h index 31f3d88b3e4df..5f656c9e33be1 100644 --- a/arch/x86/kvm/vmx/capabilities.h +++ b/arch/x86/kvm/vmx/capabilities.h @@ -13,6 +13,7 @@ extern bool __read_mostly enable_ept; extern bool __read_mostly enable_unrestricted_guest; extern bool __read_mostly enable_ept_ad_bits; extern bool __read_mostly enable_pml; +extern bool __read_mostly enable_ipiv; extern int __read_mostly pt_mode; #define PT_MODE_SYSTEM 0 @@ -283,6 +284,11 @@ static inline bool cpu_has_vmx_apicv(void) cpu_has_vmx_posted_intr(); } +static inline bool cpu_has_vmx_ipiv(void) +{ + return vmcs_config.cpu_based_3rd_exec_ctrl & TERTIARY_EXEC_IPI_VIRT; +} + static inline bool cpu_has_vmx_flexpriority(void) { return cpu_has_vmx_tpr_shadow() && diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c index 07e5fcf5a5aaa..237a1f40f9391 100644 --- a/arch/x86/kvm/vmx/posted_intr.c +++ b/arch/x86/kvm/vmx/posted_intr.c @@ -177,11 +177,24 @@ static void pi_enable_wakeup_handler(struct kvm_vcpu *vcpu) local_irq_restore(flags); } +static bool vmx_needs_pi_wakeup(struct kvm_vcpu *vcpu) +{ + /* + * The default posted interrupt vector does nothing when + * invoked outside guest mode. Return whether a blocked vCPU + * can be the target of posted interrupts, as is the case when + * using either IPI virtualization or VT-d PI, so that the + * notification vector is switched to the one that calls + * back to the pi_wakeup_handler() function. + */ + return vmx_can_use_ipiv(vcpu) || vmx_can_use_vtd_pi(vcpu->kvm); +} + void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu) { struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); - if (!vmx_can_use_vtd_pi(vcpu->kvm)) + if (!vmx_needs_pi_wakeup(vcpu)) return; if (kvm_vcpu_is_blocking(vcpu) && !vmx_interrupt_blocked(vcpu)) diff --git a/arch/x86/kvm/vmx/posted_intr.h b/arch/x86/kvm/vmx/posted_intr.h index 9a45d5c9f116e..26992076552ef 100644 --- a/arch/x86/kvm/vmx/posted_intr.h +++ b/arch/x86/kvm/vmx/posted_intr.h @@ -5,6 +5,8 @@ #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 */ diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3cbe3a38b3563..f3175dae25aac 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -105,6 +105,9 @@ module_param(fasteoi, bool, S_IRUGO); module_param(enable_apicv, bool, S_IRUGO); +bool __read_mostly enable_ipiv = true; +module_param(enable_ipiv, bool, 0444); + /* * If nested=1, nested virtualization is supported, i.e., guests may use * VMX and be a hypervisor for its own guests. If nested=0, guests may not @@ -2527,7 +2530,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf, } if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_TERTIARY_CONTROLS) { - u64 opt3 = 0; + u64 opt3 = TERTIARY_EXEC_IPI_VIRT; _cpu_based_3rd_exec_control = adjust_vmx_controls64(opt3, MSR_IA32_VMX_PROCBASED_CTLS3); @@ -3874,6 +3877,8 @@ static void vmx_update_msr_bitmap_x2apic(struct kvm_vcpu *vcpu) vmx_enable_intercept_for_msr(vcpu, X2APIC_MSR(APIC_TMCCT), MSR_TYPE_RW); vmx_disable_intercept_for_msr(vcpu, X2APIC_MSR(APIC_EOI), MSR_TYPE_W); vmx_disable_intercept_for_msr(vcpu, X2APIC_MSR(APIC_SELF_IPI), MSR_TYPE_W); + if (enable_ipiv) + vmx_disable_intercept_for_msr(vcpu, X2APIC_MSR(APIC_ICR), MSR_TYPE_RW); } } @@ -4202,14 +4207,19 @@ static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx)); - if (kvm_vcpu_apicv_active(vcpu)) + if (kvm_vcpu_apicv_active(vcpu)) { secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_APIC_REGISTER_VIRT | SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY); - else + if (enable_ipiv) + tertiary_exec_controls_setbit(vmx, TERTIARY_EXEC_IPI_VIRT); + } else { secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_APIC_REGISTER_VIRT | SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY); + if (enable_ipiv) + tertiary_exec_controls_clearbit(vmx, TERTIARY_EXEC_IPI_VIRT); + } vmx_update_msr_bitmap_x2apic(vcpu); } @@ -4242,7 +4252,16 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx) static u64 vmx_tertiary_exec_control(struct vcpu_vmx *vmx) { - return vmcs_config.cpu_based_3rd_exec_ctrl; + u64 exec_control = vmcs_config.cpu_based_3rd_exec_ctrl; + + /* + * IPI virtualization relies on APICv. Disable IPI virtualization if + * APICv is inhibited. + */ + if (!enable_ipiv || !kvm_vcpu_apicv_active(&vmx->vcpu)) + exec_control &= ~TERTIARY_EXEC_IPI_VIRT; + + return exec_control; } /* @@ -4390,10 +4409,42 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) return exec_control; } +static inline int vmx_get_pid_table_order(struct kvm *kvm) +{ + return get_order(kvm->arch.max_vcpu_ids * sizeof(*to_kvm_vmx(kvm)->pid_table)); +} + +static int vmx_alloc_ipiv_pid_table(struct kvm *kvm) +{ + struct page *pages; + struct kvm_vmx *kvm_vmx = to_kvm_vmx(kvm); + + if (!irqchip_in_kernel(kvm) || !enable_ipiv) + return 0; + + if (kvm_vmx->pid_table) + return 0; + + pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, vmx_get_pid_table_order(kvm)); + if (!pages) + return -ENOMEM; + + kvm_vmx->pid_table = (void *)page_address(pages); + return 0; +} + +static int vmx_vcpu_precreate(struct kvm *kvm) +{ + return vmx_alloc_ipiv_pid_table(kvm); +} + #define VMX_XSS_EXIT_BITMAP 0 static void init_vmcs(struct vcpu_vmx *vmx) { + struct kvm *kvm = vmx->vcpu.kvm; + struct kvm_vmx *kvm_vmx = to_kvm_vmx(kvm); + if (nested) nested_vmx_set_vmcs_shadowing_bitmap(); @@ -4425,7 +4476,12 @@ static void init_vmcs(struct vcpu_vmx *vmx) vmcs_write64(POSTED_INTR_DESC_ADDR, __pa((&vmx->pi_desc))); } - if (!kvm_pause_in_guest(vmx->vcpu.kvm)) { + if (vmx_can_use_ipiv(&vmx->vcpu)) { + vmcs_write64(PID_POINTER_TABLE, __pa(kvm_vmx->pid_table)); + vmcs_write16(LAST_PID_POINTER_INDEX, kvm->arch.max_vcpu_ids - 1); + } + + if (!kvm_pause_in_guest(kvm)) { vmcs_write32(PLE_GAP, ple_gap); vmx->ple_window = ple_window; vmx->ple_window_dirty = true; @@ -7116,6 +7172,10 @@ static int vmx_vcpu_create(struct kvm_vcpu *vcpu) goto free_vmcs; } + if (vmx_can_use_ipiv(vcpu)) + WRITE_ONCE(to_kvm_vmx(vcpu->kvm)->pid_table[vcpu->vcpu_id], + __pa(&vmx->pi_desc) | PID_TABLE_ENTRY_VALID); + return 0; free_vmcs: @@ -7750,6 +7810,13 @@ static bool vmx_check_apicv_inhibit_reasons(enum kvm_apicv_inhibit reason) return supported & BIT(reason); } +static void vmx_vm_destroy(struct kvm *kvm) +{ + struct kvm_vmx *kvm_vmx = to_kvm_vmx(kvm); + + free_pages((unsigned long)kvm_vmx->pid_table, vmx_get_pid_table_order(kvm)); +} + static struct kvm_x86_ops vmx_x86_ops __initdata = { .name = "kvm_intel", @@ -7761,7 +7828,9 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = { .vm_size = sizeof(struct kvm_vmx), .vm_init = vmx_vm_init, + .vm_destroy = vmx_vm_destroy, + .vcpu_precreate = vmx_vcpu_precreate, .vcpu_create = vmx_vcpu_create, .vcpu_free = vmx_vcpu_free, .vcpu_reset = vmx_vcpu_reset, @@ -8039,6 +8108,9 @@ static __init int hardware_setup(void) if (!enable_apicv) vmx_x86_ops.sync_pir_to_irr = NULL; + if (!enable_apicv || !cpu_has_vmx_ipiv()) + enable_ipiv = false; + if (cpu_has_vmx_tsc_scaling()) kvm_has_tsc_control = true; diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index c37befcea2c04..d7baedda79e54 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -366,6 +366,8 @@ struct kvm_vmx { unsigned int tss_addr; bool ept_identity_pagetable_done; gpa_t ept_identity_map_addr; + /* Posted Interrupt Descriptor (PID) table for IPI virtualization */ + u64 *pid_table; }; bool nested_vmx_allowed(struct kvm_vcpu *vcpu); @@ -581,4 +583,9 @@ static inline int vmx_get_instr_info_reg2(u32 vmx_instr_info) return (vmx_instr_info >> 28) & 0xf; } +static inline bool vmx_can_use_ipiv(struct kvm_vcpu *vcpu) +{ + return lapic_in_kernel(vcpu) && enable_ipiv; +} + #endif /* __KVM_X86_VMX_H */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 25fbb90c7c933..37fb301f52af0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11266,7 +11266,7 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) if (id >= kvm->arch.max_vcpu_ids) return -EINVAL; - return 0; + return static_call(kvm_x86_vcpu_precreate)(kvm); } int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)