From c60658d1d983641fcdbb16f86bc2f3806d88bab4 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 23 Aug 2018 13:56:53 -0700 Subject: [PATCH] KVM: x86: Unexport x86_emulate_instruction() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Allowing x86_emulate_instruction() to be called directly has led to subtle bugs being introduced, e.g. not setting EMULTYPE_NO_REEXECUTE in the emulation type. While most of the blame lies on re-execute being opt-out, exporting x86_emulate_instruction() also exposes its cr2 parameter, which may have contributed to commit d391f1207067 ("x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested") using x86_emulate_instruction() instead of emulate_instruction() because "hey, I have a cr2!", which in turn introduced its EMULTYPE_NO_REEXECUTE bug. Signed-off-by: Sean Christopherson Signed-off-by: Radim Krčmář --- arch/x86/include/asm/kvm_host.h | 17 +++-------------- arch/x86/kvm/x86.c | 14 +++++++++++++- arch/x86/kvm/x86.h | 2 ++ 3 files changed, 18 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 8c9023661351..e12916e7c2fb 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1240,20 +1240,9 @@ enum emulation_result { #define EMULTYPE_ALLOW_RETRY (1 << 3) #define EMULTYPE_NO_UD_ON_FAIL (1 << 4) #define EMULTYPE_VMWARE (1 << 5) -int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, - int emulation_type, void *insn, int insn_len); - -static inline int kvm_emulate_instruction(struct kvm_vcpu *vcpu, - int emulation_type) -{ - return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0); -} - -static inline int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, - void *insn, int insn_len) -{ - return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len); -} +int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type); +int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, + void *insn, int insn_len); void kvm_enable_efer_bits(u64); bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 915002c7f07e..542f6315444d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6282,7 +6282,19 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, return r; } -EXPORT_SYMBOL_GPL(x86_emulate_instruction); + +int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type) +{ + return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0); +} +EXPORT_SYMBOL_GPL(kvm_emulate_instruction); + +int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, + void *insn, int insn_len) +{ + return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len); +} +EXPORT_SYMBOL_GPL(kvm_emulate_instruction_from_buffer); static int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port) diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 257f27620bc2..67b9568613f3 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -274,6 +274,8 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata); bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, int page_num); bool kvm_vector_hashing_enabled(void); +int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, + int emulation_type, void *insn, int insn_len); #define KVM_SUPPORTED_XCR0 (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \ | XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \ -- GitLab