From b4000606205959e6cfe1fd3a71c490267ff23506 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 27 Aug 2019 14:40:32 -0700 Subject: [PATCH] KVM: x86: Add explicit flag for forced emulation on #UD Add an explicit emulation type for forced #UD emulation and use it to detect that KVM should unconditionally inject a #UD instead of falling into its standard emulation failure handling. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/x86.c | 5 +++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 80071d0..f3c623d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1325,6 +1325,7 @@ enum emulation_result { #define EMULTYPE_TRAP_UD (1 << 1) #define EMULTYPE_SKIP (1 << 2) #define EMULTYPE_ALLOW_RETRY (1 << 3) +#define EMULTYPE_TRAP_UD_FORCED (1 << 4) #define EMULTYPE_VMWARE_GP (1 << 5) int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type); int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 09753b6..eb2ed5c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5449,7 +5449,7 @@ int handle_ud(struct kvm_vcpu *vcpu) sig, sizeof(sig), &e) == 0 && memcmp(sig, "\xf\xbkvm", sizeof(sig)) == 0) { kvm_rip_write(vcpu, kvm_rip_read(vcpu) + sizeof(sig)); - emul_type = 0; + emul_type = EMULTYPE_TRAP_UD_FORCED; } er = kvm_emulate_instruction(vcpu, emul_type); @@ -6629,7 +6629,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, trace_kvm_emulate_insn_start(vcpu); ++vcpu->stat.insn_emulation; if (r != EMULATION_OK) { - if (emulation_type & EMULTYPE_TRAP_UD) + if ((emulation_type & EMULTYPE_TRAP_UD) || + (emulation_type & EMULTYPE_TRAP_UD_FORCED)) return EMULATE_FAIL; if (reexecute_instruction(vcpu, cr2, write_fault_to_spt, emulation_type)) -- 2.7.4