redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

KVM: x86: Unexport x86_emulate_instruction() 

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 d391f12070
("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 <sean.j.christopherson@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
hifive-unleashed-5.1
Sean Christopherson 2018-08-23 13:56:53 -07:00 committed by Radim Krčmář
parent 0ce97a2b62
commit c60658d1d9
3 changed files with 18 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
arch/x86/include/asm/kvm_host.h
View File

@ -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);

14
arch/x86/kvm/x86.c
View File

@ -6282,7 +6282,19 @@ restart:
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)

2
arch/x86/kvm/x86.h
View File

@ -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 \