From: Arthur Chunqi Li Date: Mon, 16 Sep 2013 08:11:44 +0000 (+0800) Subject: KVM: nVMX: Fully support nested VMX preemption timer X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7854cbca815562a49d50bbc6f31599312853d1f4;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git KVM: nVMX: Fully support nested VMX preemption timer This patch contains the following two changes: 1. Fix the bug in nested preemption timer support. If vmexit L2->L0 with some reasons not emulated by L1, preemption timer value should be save in such exits. 2. Add support of "Save VMX-preemption timer value" VM-Exit controls to nVMX. With this patch, nested VMX preemption timer features are fully supported. Signed-off-by: Arthur Chunqi Li Reviewed-by: Gleb Natapov Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h index bb0465090ae5..b93e09a0fa21 100644 --- a/arch/x86/include/uapi/asm/msr-index.h +++ b/arch/x86/include/uapi/asm/msr-index.h @@ -536,6 +536,7 @@ /* MSR_IA32_VMX_MISC bits */ #define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29) +#define MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE 0x1F /* AMD-V MSRs */ #define MSR_VM_CR 0xc0010114 diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2db91645a6cc..0156560c68a8 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2200,7 +2200,13 @@ static __init void nested_vmx_setup_ctls_msrs(void) #ifdef CONFIG_X86_64 VM_EXIT_HOST_ADDR_SPACE_SIZE | #endif - VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT; + VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT | + VM_EXIT_SAVE_VMX_PREEMPTION_TIMER; + if (!(nested_vmx_pinbased_ctls_high & PIN_BASED_VMX_PREEMPTION_TIMER) || + !(nested_vmx_exit_ctls_high & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)) { + nested_vmx_exit_ctls_high &= ~VM_EXIT_SAVE_VMX_PREEMPTION_TIMER; + nested_vmx_pinbased_ctls_high &= ~PIN_BASED_VMX_PREEMPTION_TIMER; + } nested_vmx_exit_ctls_high |= (VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR | VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER); @@ -6724,6 +6730,27 @@ static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2) *info2 = vmcs_read32(VM_EXIT_INTR_INFO); } +static void nested_adjust_preemption_timer(struct kvm_vcpu *vcpu) +{ + u64 delta_tsc_l1; + u32 preempt_val_l1, preempt_val_l2, preempt_scale; + + if (!(get_vmcs12(vcpu)->pin_based_vm_exec_control & + PIN_BASED_VMX_PREEMPTION_TIMER)) + return; + preempt_scale = native_read_msr(MSR_IA32_VMX_MISC) & + MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE; + preempt_val_l2 = vmcs_read32(VMX_PREEMPTION_TIMER_VALUE); + delta_tsc_l1 = vmx_read_l1_tsc(vcpu, native_read_tsc()) + - vcpu->arch.last_guest_tsc; + preempt_val_l1 = delta_tsc_l1 >> preempt_scale; + if (preempt_val_l2 <= preempt_val_l1) + preempt_val_l2 = 0; + else + preempt_val_l2 -= preempt_val_l1; + vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, preempt_val_l2); +} + /* * The guest has exited. See if we can fix it or if we need userspace * assistance. @@ -7134,6 +7161,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) atomic_switch_perf_msrs(vmx); debugctlmsr = get_debugctlmsr(); + if (is_guest_mode(vcpu) && !vmx->nested.nested_run_pending) + nested_adjust_preemption_timer(vcpu); vmx->__launched = vmx->loaded_vmcs->launched; asm( /* Store host registers */ @@ -7543,6 +7572,7 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) { struct vcpu_vmx *vmx = to_vmx(vcpu); u32 exec_control; + u32 exit_control; vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector); vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector); @@ -7716,7 +7746,10 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) * we should use its exit controls. Note that VM_EXIT_LOAD_IA32_EFER * bits are further modified by vmx_set_efer() below. */ - vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl); + exit_control = vmcs_config.vmexit_ctrl; + if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER) + exit_control |= VM_EXIT_SAVE_VMX_PREEMPTION_TIMER; + vmcs_write32(VM_EXIT_CONTROLS, exit_control); /* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are * emulated by vmx_set_efer(), below. @@ -8124,6 +8157,11 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmcs12->guest_pending_dbg_exceptions = vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS); + if ((vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER) && + (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)) + vmcs12->vmx_preemption_timer_value = + vmcs_read32(VMX_PREEMPTION_TIMER_VALUE); + /* * In some cases (usually, nested EPT), L2 is allowed to change its * own CR3 without exiting. If it has changed it, we must keep it.