[v2,1/3] KVM: x86: add support for user wait instructions

Message ID	20190524075637.29496-2-tao3.xu@intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> From: Tao Xu <tao3.xu@intel.com> To: pbonzini@redhat.com, rkrcmar@redhat.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, sean.j.christopherson@intel.com Cc: x86@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, tao3.xu@intel.com, jingqi.liu@intel.com Subject: [PATCH v2 1/3] KVM: x86: add support for user wait instructions Date: Fri, 24 May 2019 15:56:35 +0800 Message-Id: <20190524075637.29496-2-tao3.xu@intel.com> In-Reply-To: <20190524075637.29496-1-tao3.xu@intel.com> References: <20190524075637.29496-1-tao3.xu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk
Series	KVM: x86: Enable user wait instructions \| expand [v2,0/3] KVM: x86: Enable user wait instructions [v2,1/3] KVM: x86: add support for user wait instructions [v2,2/3] KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL [v2,3/3] KVM: vmx: handle vm-exit for UMWAIT and TPAUSE

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index ba6c42c576dd..3d0196220486 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4997,6 +4997,18 @@ it hard or impossible to use it correctly. The availability of KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. +7.19 KVM_CAP_ENABLE_USR_WAIT_PAUSE + +Architectures: x86 +Parameters: args[0] whether feature should be enabled or not + +With this capability enabled, a VM can use UMONITOR, UMWAIT and TPAUSE +instructions. If the instruction causes a delay, the amount of +time delayed is called here the physical delay. The physical delay is +first computed by determining the virtual delay (the time to delay +relative to the VM’s timestamp counter). Otherwise, UMONITOR, UMWAIT +and TPAUSE cause an invalid-opcode exception(#UD). + 8. Other capabilities. ---------------------- diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 450d69a1e6fa..0da87c2e1c4d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -882,6 +882,7 @@ struct kvm_arch { bool mwait_in_guest; bool hlt_in_guest; bool pause_in_guest; + bool enable_usr_wait_pause; unsigned long irq_sources_bitmap; s64 kvmclock_offset; diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index 4e4133e86484..1c94b1009288 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -82,6 +82,7 @@ #define SECONDARY_EXEC_PT_USE_GPA 0x01000000 #define SECONDARY_EXEC_MODE_BASED_EPT_EXEC 0x00400000 #define SECONDARY_EXEC_TSC_SCALING 0x02000000 +#define SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE 0x04000000 #define PIN_BASED_EXT_INTR_MASK 0x00000001 #define PIN_BASED_NMI_EXITING 0x00000008 diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 80a642a0143d..1cc001870a9d 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -405,7 +405,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) | - F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B); + F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/; /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 1ac167614032..a65ee7ea47b4 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2247,6 +2247,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf, SECONDARY_EXEC_RDRAND_EXITING | SECONDARY_EXEC_ENABLE_PML | SECONDARY_EXEC_TSC_SCALING | + SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE | SECONDARY_EXEC_PT_USE_GPA | SECONDARY_EXEC_PT_CONCEAL_VMX | SECONDARY_EXEC_ENABLE_VMFUNC | @@ -3880,6 +3881,9 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx) exec_control &= ~SECONDARY_EXEC_UNRESTRICTED_GUEST; if (kvm_pause_in_guest(vmx->vcpu.kvm)) exec_control &= ~SECONDARY_EXEC_PAUSE_LOOP_EXITING; + if (!kvm_enable_usr_wait_pause(vmx->vcpu.kvm) || + (vmcs_config.cpu_based_exec_ctrl & CPU_BASED_RDTSC_EXITING)) + exec_control &= ~SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE; if (!kvm_vcpu_apicv_active(vcpu)) exec_control &= ~(SECONDARY_EXEC_APIC_REGISTER_VIRT | SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 536b78c4af6e..38a89c878c5d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3141,6 +3141,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = kvm_x86_ops->get_nested_state ? kvm_x86_ops->get_nested_state(NULL, NULL, 0) : 0; break; + case KVM_CAP_ENABLE_USR_WAIT_PAUSE: + r = boot_cpu_has(X86_FEATURE_WAITPKG); + break; default: break; } @@ -4622,6 +4625,10 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, kvm->arch.exception_payload_enabled = cap->args[0]; r = 0; break; + case KVM_CAP_ENABLE_USR_WAIT_PAUSE: + kvm->arch.enable_usr_wait_pause = true; + r = 0; + break; default: r = -EINVAL; break; diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index a470ff0868c5..37685e6679f3 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -333,6 +333,11 @@ static inline bool kvm_pause_in_guest(struct kvm *kvm) return kvm->arch.pause_in_guest; } +static inline bool kvm_enable_usr_wait_pause(struct kvm *kvm) +{ + return kvm->arch.enable_usr_wait_pause; +} + DECLARE_PER_CPU(struct kvm_vcpu *, current_vcpu); static inline void kvm_before_interrupt(struct kvm_vcpu *vcpu) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 2fe12b40d503..5a19a5984c57 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -993,6 +993,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_ARM_SVE 170 #define KVM_CAP_ARM_PTRAUTH_ADDRESS 171 #define KVM_CAP_ARM_PTRAUTH_GENERIC 172 +#define KVM_CAP_ENABLE_USR_WAIT_PAUSE 173 #ifdef KVM_CAP_IRQ_ROUTING

[v2,1/3] KVM: x86: add support for user wait instructions

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