From 843e4330573cc5261ae260ce0b83dc570d8cdc05 Mon Sep 17 00:00:00 2001 From: Kai Huang Date: Wed, 28 Jan 2015 10:54:28 +0800 Subject: [PATCH] KVM: VMX: Add PML support in VMX This patch adds PML support in VMX. A new module parameter 'enable_pml' is added to allow user to enable/disable it manually. Signed-off-by: Kai Huang Reviewed-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/vmx.h | 4 + arch/x86/include/uapi/asm/vmx.h | 1 + arch/x86/kvm/trace.h | 18 ++++ arch/x86/kvm/vmx.c | 195 +++++++++++++++++++++++++++++++++++++++- arch/x86/kvm/x86.c | 1 + 5 files changed, 218 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index 45afaee..da772ed 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -69,6 +69,7 @@ #define SECONDARY_EXEC_PAUSE_LOOP_EXITING 0x00000400 #define SECONDARY_EXEC_ENABLE_INVPCID 0x00001000 #define SECONDARY_EXEC_SHADOW_VMCS 0x00004000 +#define SECONDARY_EXEC_ENABLE_PML 0x00020000 #define SECONDARY_EXEC_XSAVES 0x00100000 @@ -121,6 +122,7 @@ enum vmcs_field { GUEST_LDTR_SELECTOR = 0x0000080c, GUEST_TR_SELECTOR = 0x0000080e, GUEST_INTR_STATUS = 0x00000810, + GUEST_PML_INDEX = 0x00000812, HOST_ES_SELECTOR = 0x00000c00, HOST_CS_SELECTOR = 0x00000c02, HOST_SS_SELECTOR = 0x00000c04, @@ -140,6 +142,8 @@ enum vmcs_field { VM_EXIT_MSR_LOAD_ADDR_HIGH = 0x00002009, VM_ENTRY_MSR_LOAD_ADDR = 0x0000200a, VM_ENTRY_MSR_LOAD_ADDR_HIGH = 0x0000200b, + PML_ADDRESS = 0x0000200e, + PML_ADDRESS_HIGH = 0x0000200f, TSC_OFFSET = 0x00002010, TSC_OFFSET_HIGH = 0x00002011, VIRTUAL_APIC_PAGE_ADDR = 0x00002012, diff --git a/arch/x86/include/uapi/asm/vmx.h b/arch/x86/include/uapi/asm/vmx.h index ff2b8e2..c5f1a1d 100644 --- a/arch/x86/include/uapi/asm/vmx.h +++ b/arch/x86/include/uapi/asm/vmx.h @@ -73,6 +73,7 @@ #define EXIT_REASON_XSETBV 55 #define EXIT_REASON_APIC_WRITE 56 #define EXIT_REASON_INVPCID 58 +#define EXIT_REASON_PML_FULL 62 #define EXIT_REASON_XSAVES 63 #define EXIT_REASON_XRSTORS 64 diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index 587149b..7c7bc8b 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -848,6 +848,24 @@ TRACE_EVENT(kvm_track_tsc, #endif /* CONFIG_X86_64 */ +/* + * Tracepoint for PML full VMEXIT. + */ +TRACE_EVENT(kvm_pml_full, + TP_PROTO(unsigned int vcpu_id), + TP_ARGS(vcpu_id), + + TP_STRUCT__entry( + __field( unsigned int, vcpu_id ) + ), + + TP_fast_assign( + __entry->vcpu_id = vcpu_id; + ), + + TP_printk("vcpu %d: PML full", __entry->vcpu_id) +); + TRACE_EVENT(kvm_ple_window, TP_PROTO(bool grow, unsigned int vcpu_id, int new, int old), TP_ARGS(grow, vcpu_id, new, old), diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c987374..de5ce82 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -101,6 +101,9 @@ module_param(nested, bool, S_IRUGO); static u64 __read_mostly host_xss; +static bool __read_mostly enable_pml = 1; +module_param_named(pml, enable_pml, bool, S_IRUGO); + #define KVM_GUEST_CR0_MASK (X86_CR0_NW | X86_CR0_CD) #define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST (X86_CR0_WP | X86_CR0_NE) #define KVM_VM_CR0_ALWAYS_ON \ @@ -516,6 +519,10 @@ struct vcpu_vmx { /* Dynamic PLE window. */ int ple_window; bool ple_window_dirty; + + /* Support for PML */ +#define PML_ENTITY_NUM 512 + struct page *pml_pg; }; enum segment_cache_field { @@ -1068,6 +1075,11 @@ static inline bool cpu_has_vmx_shadow_vmcs(void) SECONDARY_EXEC_SHADOW_VMCS; } +static inline bool cpu_has_vmx_pml(void) +{ + return vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_ENABLE_PML; +} + static inline bool report_flexpriority(void) { return flexpriority_enabled; @@ -2924,7 +2936,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf) SECONDARY_EXEC_APIC_REGISTER_VIRT | SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY | SECONDARY_EXEC_SHADOW_VMCS | - SECONDARY_EXEC_XSAVES; + SECONDARY_EXEC_XSAVES | + SECONDARY_EXEC_ENABLE_PML; if (adjust_vmx_controls(min2, opt2, MSR_IA32_VMX_PROCBASED_CTLS2, &_cpu_based_2nd_exec_control) < 0) @@ -4355,6 +4368,9 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) a current VMCS12 */ exec_control &= ~SECONDARY_EXEC_SHADOW_VMCS; + /* PML is enabled/disabled in creating/destorying vcpu */ + exec_control &= ~SECONDARY_EXEC_ENABLE_PML; + return exec_control; } @@ -5942,6 +5958,20 @@ static __init int hardware_setup(void) update_ple_window_actual_max(); + /* + * Only enable PML when hardware supports PML feature, and both EPT + * and EPT A/D bit features are enabled -- PML depends on them to work. + */ + if (!enable_ept || !enable_ept_ad_bits || !cpu_has_vmx_pml()) + enable_pml = 0; + + if (!enable_pml) { + kvm_x86_ops->slot_enable_log_dirty = NULL; + kvm_x86_ops->slot_disable_log_dirty = NULL; + kvm_x86_ops->flush_log_dirty = NULL; + kvm_x86_ops->enable_log_dirty_pt_masked = NULL; + } + return alloc_kvm_area(); out7: @@ -6971,6 +7001,31 @@ static bool vmx_test_pir(struct kvm_vcpu *vcpu, int vector) return pi_test_pir(vector, &vmx->pi_desc); } +static int handle_pml_full(struct kvm_vcpu *vcpu) +{ + unsigned long exit_qualification; + + trace_kvm_pml_full(vcpu->vcpu_id); + + exit_qualification = vmcs_readl(EXIT_QUALIFICATION); + + /* + * PML buffer FULL happened while executing iret from NMI, + * "blocked by NMI" bit has to be set before next VM entry. + */ + if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) && + cpu_has_virtual_nmis() && + (exit_qualification & INTR_INFO_UNBLOCK_NMI)) + vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, + GUEST_INTR_STATE_NMI); + + /* + * PML buffer already flushed at beginning of VMEXIT. Nothing to do + * here.., and there's no userspace involvement needed for PML. + */ + return 1; +} + /* * The exit handlers return 1 if the exit was handled fully and guest execution * may resume. Otherwise they set the kvm_run parameter to indicate what needs @@ -7019,6 +7074,7 @@ static int (*const kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = { [EXIT_REASON_INVVPID] = handle_invvpid, [EXIT_REASON_XSAVES] = handle_xsaves, [EXIT_REASON_XRSTORS] = handle_xrstors, + [EXIT_REASON_PML_FULL] = handle_pml_full, }; static const int kvm_vmx_max_exit_handlers = @@ -7325,6 +7381,89 @@ static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2) *info2 = vmcs_read32(VM_EXIT_INTR_INFO); } +static int vmx_enable_pml(struct vcpu_vmx *vmx) +{ + struct page *pml_pg; + u32 exec_control; + + pml_pg = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!pml_pg) + return -ENOMEM; + + vmx->pml_pg = pml_pg; + + vmcs_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg)); + vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1); + + exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); + exec_control |= SECONDARY_EXEC_ENABLE_PML; + vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control); + + return 0; +} + +static void vmx_disable_pml(struct vcpu_vmx *vmx) +{ + u32 exec_control; + + ASSERT(vmx->pml_pg); + __free_page(vmx->pml_pg); + vmx->pml_pg = NULL; + + exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); + exec_control &= ~SECONDARY_EXEC_ENABLE_PML; + vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control); +} + +static void vmx_flush_pml_buffer(struct vcpu_vmx *vmx) +{ + struct kvm *kvm = vmx->vcpu.kvm; + u64 *pml_buf; + u16 pml_idx; + + pml_idx = vmcs_read16(GUEST_PML_INDEX); + + /* Do nothing if PML buffer is empty */ + if (pml_idx == (PML_ENTITY_NUM - 1)) + return; + + /* PML index always points to next available PML buffer entity */ + if (pml_idx >= PML_ENTITY_NUM) + pml_idx = 0; + else + pml_idx++; + + pml_buf = page_address(vmx->pml_pg); + for (; pml_idx < PML_ENTITY_NUM; pml_idx++) { + u64 gpa; + + gpa = pml_buf[pml_idx]; + WARN_ON(gpa & (PAGE_SIZE - 1)); + mark_page_dirty(kvm, gpa >> PAGE_SHIFT); + } + + /* reset PML index */ + vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1); +} + +/* + * Flush all vcpus' PML buffer and update logged GPAs to dirty_bitmap. + * Called before reporting dirty_bitmap to userspace. + */ +static void kvm_flush_pml_buffers(struct kvm *kvm) +{ + int i; + struct kvm_vcpu *vcpu; + /* + * We only need to kick vcpu out of guest mode here, as PML buffer + * is flushed at beginning of all VMEXITs, and it's obvious that only + * vcpus running in guest are possible to have unflushed GPAs in PML + * buffer. + */ + kvm_for_each_vcpu(i, vcpu, kvm) + kvm_vcpu_kick(vcpu); +} + /* * The guest has exited. See if we can fix it or if we need userspace * assistance. @@ -7335,6 +7474,16 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu) u32 exit_reason = vmx->exit_reason; u32 vectoring_info = vmx->idt_vectoring_info; + /* + * Flush logged GPAs PML buffer, this will make dirty_bitmap more + * updated. Another good is, in kvm_vm_ioctl_get_dirty_log, before + * querying dirty_bitmap, we only need to kick all vcpus out of guest + * mode as if vcpus is in root mode, the PML buffer must has been + * flushed already. + */ + if (enable_pml) + vmx_flush_pml_buffer(vmx); + /* If guest state is invalid, start emulating */ if (vmx->emulation_required) return handle_invalid_guest_state(vcpu); @@ -7981,6 +8130,8 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); + if (enable_pml) + vmx_disable_pml(vmx); free_vpid(vmx); leave_guest_mode(vcpu); vmx_load_vmcs01(vcpu); @@ -8051,6 +8202,18 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) vmx->nested.current_vmptr = -1ull; vmx->nested.current_vmcs12 = NULL; + /* + * If PML is turned on, failure on enabling PML just results in failure + * of creating the vcpu, therefore we can simplify PML logic (by + * avoiding dealing with cases, such as enabling PML partially on vcpus + * for the guest, etc. + */ + if (enable_pml) { + err = vmx_enable_pml(vmx); + if (err) + goto free_vmcs; + } + return &vmx->vcpu; free_vmcs: @@ -9492,6 +9655,31 @@ static void vmx_sched_in(struct kvm_vcpu *vcpu, int cpu) shrink_ple_window(vcpu); } +static void vmx_slot_enable_log_dirty(struct kvm *kvm, + struct kvm_memory_slot *slot) +{ + kvm_mmu_slot_leaf_clear_dirty(kvm, slot); + kvm_mmu_slot_largepage_remove_write_access(kvm, slot); +} + +static void vmx_slot_disable_log_dirty(struct kvm *kvm, + struct kvm_memory_slot *slot) +{ + kvm_mmu_slot_set_dirty(kvm, slot); +} + +static void vmx_flush_log_dirty(struct kvm *kvm) +{ + kvm_flush_pml_buffers(kvm); +} + +static void vmx_enable_log_dirty_pt_masked(struct kvm *kvm, + struct kvm_memory_slot *memslot, + gfn_t offset, unsigned long mask) +{ + kvm_mmu_clear_dirty_pt_masked(kvm, memslot, offset, mask); +} + static struct kvm_x86_ops vmx_x86_ops = { .cpu_has_kvm_support = cpu_has_kvm_support, .disabled_by_bios = vmx_disabled_by_bios, @@ -9601,6 +9789,11 @@ static struct kvm_x86_ops vmx_x86_ops = { .check_nested_events = vmx_check_nested_events, .sched_in = vmx_sched_in, + + .slot_enable_log_dirty = vmx_slot_enable_log_dirty, + .slot_disable_log_dirty = vmx_slot_disable_log_dirty, + .flush_log_dirty = vmx_flush_log_dirty, + .enable_log_dirty_pt_masked = vmx_enable_log_dirty_pt_masked, }; static int __init vmx_init(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 442ee7d..1373e04 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7880,3 +7880,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window); +EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pml_full); -- 2.7.4