From 4e47c7a6d714cf352b719db92a924b6ec487acc5 Mon Sep 17 00:00:00 2001 From: Sheng Yang Date: Fri, 18 Dec 2009 16:48:47 +0800 Subject: [PATCH] KVM: VMX: Add instruction rdtscp support for guest Before enabling, execution of "rdtscp" in guest would result in #UD. Signed-off-by: Sheng Yang Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/asm/vmx.h | 1 + arch/x86/kvm/svm.c | 7 ++++ arch/x86/kvm/vmx.c | 60 +++++++++++++++++++++++++++++++-- arch/x86/kvm/x86.c | 3 +- 5 files changed, 68 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7ff0ea371e3..fe4df464fb3 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -521,6 +521,7 @@ struct kvm_x86_ops { int (*get_tdp_level)(void); u64 (*get_mt_mask)(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio); bool (*gb_page_enable)(void); + bool (*rdtscp_supported)(void); const struct trace_print_flags *exit_reasons_str; }; diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index 8f6b0111446..713ed9a5b1d 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -53,6 +53,7 @@ */ #define SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES 0x00000001 #define SECONDARY_EXEC_ENABLE_EPT 0x00000002 +#define SECONDARY_EXEC_RDTSCP 0x00000008 #define SECONDARY_EXEC_ENABLE_VPID 0x00000020 #define SECONDARY_EXEC_WBINVD_EXITING 0x00000040 #define SECONDARY_EXEC_UNRESTRICTED_GUEST 0x00000080 diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 41777e6d976..7f4e225feeb 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2914,6 +2914,11 @@ static bool svm_gb_page_enable(void) return true; } +static bool svm_rdtscp_supported(void) +{ + return false; +} + static struct kvm_x86_ops svm_x86_ops = { .cpu_has_kvm_support = has_svm, .disabled_by_bios = is_disabled, @@ -2982,6 +2987,8 @@ static struct kvm_x86_ops svm_x86_ops = { .gb_page_enable = svm_gb_page_enable, .cpuid_update = svm_cpuid_update, + + .rdtscp_supported = svm_rdtscp_supported, }; static int __init svm_init(void) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 75e8931e96c..74a66f0c00b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -151,6 +151,8 @@ struct vcpu_vmx { ktime_t entry_time; s64 vnmi_blocked_time; u32 exit_reason; + + bool rdtscp_enabled; }; static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu) @@ -225,7 +227,7 @@ static const u32 vmx_msr_index[] = { #ifdef CONFIG_X86_64 MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR, #endif - MSR_EFER, MSR_K6_STAR, + MSR_EFER, MSR_TSC_AUX, MSR_K6_STAR, }; #define NR_VMX_MSR ARRAY_SIZE(vmx_msr_index) @@ -362,6 +364,12 @@ static inline int cpu_has_vmx_vpid(void) SECONDARY_EXEC_ENABLE_VPID; } +static inline int cpu_has_vmx_rdtscp(void) +{ + return vmcs_config.cpu_based_2nd_exec_ctrl & + SECONDARY_EXEC_RDTSCP; +} + static inline int cpu_has_virtual_nmis(void) { return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS; @@ -893,6 +901,11 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr, vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info); } +static bool vmx_rdtscp_supported(void) +{ + return cpu_has_vmx_rdtscp(); +} + /* * Swap MSR entry in host/guest MSR entry array. */ @@ -928,6 +941,9 @@ static void setup_msrs(struct vcpu_vmx *vmx) index = __find_msr_index(vmx, MSR_CSTAR); if (index >= 0) move_msr_up(vmx, index, save_nmsrs++); + index = __find_msr_index(vmx, MSR_TSC_AUX); + if (index >= 0 && vmx->rdtscp_enabled) + move_msr_up(vmx, index, save_nmsrs++); /* * MSR_K6_STAR is only needed on long mode guests, and only * if efer.sce is enabled. @@ -1017,6 +1033,10 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) case MSR_IA32_SYSENTER_ESP: data = vmcs_readl(GUEST_SYSENTER_ESP); break; + case MSR_TSC_AUX: + if (!to_vmx(vcpu)->rdtscp_enabled) + return 1; + /* Otherwise falls through */ default: vmx_load_host_state(to_vmx(vcpu)); msr = find_msr_entry(to_vmx(vcpu), msr_index); @@ -1080,7 +1100,15 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) vcpu->arch.pat = data; break; } - /* Otherwise falls through to kvm_set_msr_common */ + ret = kvm_set_msr_common(vcpu, msr_index, data); + break; + case MSR_TSC_AUX: + if (!vmx->rdtscp_enabled) + return 1; + /* Check reserved bit, higher 32 bits should be zero */ + if ((data >> 32) != 0) + return 1; + /* Otherwise falls through */ default: msr = find_msr_entry(vmx, msr_index); if (msr) { @@ -1260,7 +1288,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf) SECONDARY_EXEC_ENABLE_VPID | SECONDARY_EXEC_ENABLE_EPT | SECONDARY_EXEC_UNRESTRICTED_GUEST | - SECONDARY_EXEC_PAUSE_LOOP_EXITING; + SECONDARY_EXEC_PAUSE_LOOP_EXITING | + SECONDARY_EXEC_RDTSCP; if (adjust_vmx_controls(min2, opt2, MSR_IA32_VMX_PROCBASED_CTLS2, &_cpu_based_2nd_exec_control) < 0) @@ -3988,8 +4017,31 @@ static bool vmx_gb_page_enable(void) return false; } +static inline u32 bit(int bitno) +{ + return 1 << (bitno & 31); +} + static void vmx_cpuid_update(struct kvm_vcpu *vcpu) { + struct kvm_cpuid_entry2 *best; + struct vcpu_vmx *vmx = to_vmx(vcpu); + u32 exec_control; + + vmx->rdtscp_enabled = false; + if (vmx_rdtscp_supported()) { + exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); + if (exec_control & SECONDARY_EXEC_RDTSCP) { + best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0); + if (best && (best->edx & bit(X86_FEATURE_RDTSCP))) + vmx->rdtscp_enabled = true; + else { + exec_control &= ~SECONDARY_EXEC_RDTSCP; + vmcs_write32(SECONDARY_VM_EXEC_CONTROL, + exec_control); + } + } + } } static struct kvm_x86_ops vmx_x86_ops = { @@ -4058,6 +4110,8 @@ static struct kvm_x86_ops vmx_x86_ops = { .gb_page_enable = vmx_gb_page_enable, .cpuid_update = vmx_cpuid_update, + + .rdtscp_supported = vmx_rdtscp_supported, }; static int __init vmx_init(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e5ac21f992f..8798504ace1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1646,6 +1646,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, #else unsigned f_lm = 0; #endif + unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; /* cpuid 1.edx */ const u32 kvm_supported_word0_x86_features = @@ -1665,7 +1666,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | F(PAT) | F(PSE36) | 0 /* Reserved */ | f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | - F(FXSR) | F(FXSR_OPT) | f_gbpages | 0 /* RDTSCP */ | + F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); /* cpuid 1.ecx */ const u32 kvm_supported_word4_x86_features =