diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_emulate.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 36 |
2 files changed, 19 insertions, 18 deletions
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 0cf4311db0d..777240d4524 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -53,6 +53,7 @@ struct x86_emulate_ctxt; #define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */ #define X86EMUL_RETRY_INSTR 3 /* retry the instruction for some reason */ #define X86EMUL_CMPXCHG_FAILED 4 /* cmpxchg did not see expected value */ +#define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */ struct x86_emulate_ops { /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b976c4c1fa8..4cb65d82abc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3275,7 +3275,7 @@ static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes, } ret = kvm_read_guest(vcpu->kvm, gpa, data, toread); if (ret < 0) { - r = X86EMUL_UNHANDLEABLE; + r = X86EMUL_IO_NEEDED; goto out; } @@ -3331,7 +3331,7 @@ static int kvm_write_guest_virt_system(gva_t addr, void *val, } ret = kvm_write_guest(vcpu->kvm, gpa, data, towrite); if (ret < 0) { - r = X86EMUL_UNHANDLEABLE; + r = X86EMUL_IO_NEEDED; goto out; } @@ -3391,7 +3391,7 @@ mmio: vcpu->run->mmio.len = vcpu->mmio_size = bytes; vcpu->run->mmio.is_write = vcpu->mmio_is_write = 0; - return X86EMUL_UNHANDLEABLE; + return X86EMUL_IO_NEEDED; } int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, @@ -3863,8 +3863,6 @@ int emulate_instruction(struct kvm_vcpu *vcpu, */ cache_all_regs(vcpu); - vcpu->mmio_is_write = 0; - if (!(emulation_type & EMULTYPE_NO_DECODE)) { int cs_db, cs_l; kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l); @@ -3938,24 +3936,26 @@ restart: return EMULATE_DO_MMIO; } - if (r) { - if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) - goto done; - if (!vcpu->mmio_needed) { - ++vcpu->stat.insn_emulation_fail; - trace_kvm_emulate_insn_failed(vcpu); - kvm_report_emulation_failure(vcpu, "mmio"); - return EMULATE_FAIL; - } + if (vcpu->mmio_needed) { + if (vcpu->mmio_is_write) + vcpu->mmio_needed = 0; return EMULATE_DO_MMIO; } - if (vcpu->mmio_is_write) { - vcpu->mmio_needed = 0; - return EMULATE_DO_MMIO; + if (r) { /* emulation failed */ + /* + * if emulation was due to access to shadowed page table + * and it failed try to unshadow page and re-entetr the + * guest to let CPU execute the instruction. + */ + if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) + return EMULATE_DONE; + + trace_kvm_emulate_insn_failed(vcpu); + kvm_report_emulation_failure(vcpu, "mmio"); + return EMULATE_FAIL; } -done: if (vcpu->arch.exception.pending) vcpu->arch.emulate_ctxt.restart = false; |