From e911eb3b3414e62cbd9853e0a91c124f4a545c0f Mon Sep 17 00:00:00 2001 From: Yu Zhang Date: Thu, 24 Aug 2017 20:27:52 +0800 Subject: [PATCH] KVM: x86: Add return value to kvm_cpuid(). Return false in kvm_cpuid() when it fails to find the cpuid entry. Also, this routine(and its caller) is optimized with a new argument - check_limit, so that the check_cpuid_limit() fall back can be avoided. Signed-off-by: Yu Zhang Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_emulate.h | 4 ++-- arch/x86/kvm/cpuid.c | 17 +++++++++++++---- arch/x86/kvm/cpuid.h | 3 ++- arch/x86/kvm/emulate.c | 12 ++++++------ arch/x86/kvm/svm.c | 2 +- arch/x86/kvm/trace.h | 11 +++++++---- arch/x86/kvm/x86.c | 6 +++--- 7 files changed, 34 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index fde36f189836..fa2558e12024 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -219,8 +219,8 @@ struct x86_emulate_ops { struct x86_instruction_info *info, enum x86_intercept_stage stage); - void (*get_cpuid)(struct x86_emulate_ctxt *ctxt, - u32 *eax, u32 *ebx, u32 *ecx, u32 *edx); + bool (*get_cpuid)(struct x86_emulate_ctxt *ctxt, u32 *eax, u32 *ebx, + u32 *ecx, u32 *edx, bool check_limit); void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked); unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt); diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 59ca2eea522c..14505473fb21 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -853,16 +853,24 @@ static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); } -void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) +bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, + u32 *ecx, u32 *edx, bool check_limit) { u32 function = *eax, index = *ecx; struct kvm_cpuid_entry2 *best; + bool entry_found = true; best = kvm_find_cpuid_entry(vcpu, function, index); - if (!best) + if (!best) { + entry_found = false; + if (!check_limit) + goto out; + best = check_cpuid_limit(vcpu, function, index); + } +out: if (best) { *eax = best->eax; *ebx = best->ebx; @@ -870,7 +878,8 @@ void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) *edx = best->edx; } else *eax = *ebx = *ecx = *edx = 0; - trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); + trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); + return entry_found; } EXPORT_SYMBOL_GPL(kvm_cpuid); @@ -883,7 +892,7 @@ int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) eax = kvm_register_read(vcpu, VCPU_REGS_RAX); ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); - kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); + kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); kvm_register_write(vcpu, VCPU_REGS_RAX, eax); kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index ac15193e5e52..1ea3c0e1e3a9 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -21,7 +21,8 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries); -void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx); +bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, + u32 *ecx, u32 *edx, bool check_limit); int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index fb0055953fbc..319d91f6f3c4 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2333,7 +2333,7 @@ static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt) eax = 0x80000001; ecx = 0; - ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); return edx & bit(X86_FEATURE_LM); } @@ -2636,7 +2636,7 @@ static bool vendor_intel(struct x86_emulate_ctxt *ctxt) u32 eax, ebx, ecx, edx; eax = ecx = 0; - ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx; @@ -2656,7 +2656,7 @@ static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt) eax = 0x00000000; ecx = 0x00000000; - ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); + ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); /* * Intel ("GenuineIntel") * remark: Intel CPUs only support "syscall" in 64bit @@ -3551,7 +3551,7 @@ static int em_movbe(struct x86_emulate_ctxt *ctxt) /* * Check MOVBE is set in the guest-visible CPUID leaf. */ - ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); if (!(ecx & FFL(MOVBE))) return emulate_ud(ctxt); @@ -3865,7 +3865,7 @@ static int em_cpuid(struct x86_emulate_ctxt *ctxt) eax = reg_read(ctxt, VCPU_REGS_RAX); ecx = reg_read(ctxt, VCPU_REGS_RCX); - ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, true); *reg_write(ctxt, VCPU_REGS_RAX) = eax; *reg_write(ctxt, VCPU_REGS_RBX) = ebx; *reg_write(ctxt, VCPU_REGS_RCX) = ecx; @@ -3924,7 +3924,7 @@ static int check_fxsr(struct x86_emulate_ctxt *ctxt) { u32 eax = 1, ebx, ecx = 0, edx; - ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); if (!(edx & FFL(FXSR))) return emulate_ud(ctxt); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 7e190b21a30b..c5b9705186d6 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1593,7 +1593,7 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) } init_vmcb(svm); - kvm_cpuid(vcpu, &eax, &dummy, &dummy, &dummy); + kvm_cpuid(vcpu, &eax, &dummy, &dummy, &dummy, true); kvm_register_write(vcpu, VCPU_REGS_RDX, eax); if (kvm_vcpu_apicv_active(vcpu) && !init_event) diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index 0a6cc6754ec5..8a202c49e2a0 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -151,8 +151,8 @@ TRACE_EVENT(kvm_fast_mmio, */ TRACE_EVENT(kvm_cpuid, TP_PROTO(unsigned int function, unsigned long rax, unsigned long rbx, - unsigned long rcx, unsigned long rdx), - TP_ARGS(function, rax, rbx, rcx, rdx), + unsigned long rcx, unsigned long rdx, bool found), + TP_ARGS(function, rax, rbx, rcx, rdx, found), TP_STRUCT__entry( __field( unsigned int, function ) @@ -160,6 +160,7 @@ TRACE_EVENT(kvm_cpuid, __field( unsigned long, rbx ) __field( unsigned long, rcx ) __field( unsigned long, rdx ) + __field( bool, found ) ), TP_fast_assign( @@ -168,11 +169,13 @@ TRACE_EVENT(kvm_cpuid, __entry->rbx = rbx; __entry->rcx = rcx; __entry->rdx = rdx; + __entry->found = found; ), - TP_printk("func %x rax %lx rbx %lx rcx %lx rdx %lx", + TP_printk("func %x rax %lx rbx %lx rcx %lx rdx %lx, cpuid entry %s", __entry->function, __entry->rax, - __entry->rbx, __entry->rcx, __entry->rdx) + __entry->rbx, __entry->rcx, __entry->rdx, + __entry->found ? "found" : "not found") ); #define AREG(x) { APIC_##x, "APIC_" #x } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4e699238a113..cc2c7e413e9c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5206,10 +5206,10 @@ static int emulator_intercept(struct x86_emulate_ctxt *ctxt, return kvm_x86_ops->check_intercept(emul_to_vcpu(ctxt), info, stage); } -static void emulator_get_cpuid(struct x86_emulate_ctxt *ctxt, - u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) +static bool emulator_get_cpuid(struct x86_emulate_ctxt *ctxt, + u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, bool check_limit) { - kvm_cpuid(emul_to_vcpu(ctxt), eax, ebx, ecx, edx); + return kvm_cpuid(emul_to_vcpu(ctxt), eax, ebx, ecx, edx, check_limit); } static ulong emulator_read_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg) -- 2.20.1