diff options
| author | Hou Wenlong <houwenlong.hwl@antgroup.com> | 2022-02-08 17:34:05 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-03-01 08:50:49 -0500 |
| commit | 1e326ad429784a16b2b34ec296ff4ca7ad42c220 (patch) | |
| tree | 329080be832ad360024958c604bee37ee9b2df8c /arch/x86/kvm/emulate.c | |
| parent | 31c66dabaa8a48792469cd2d19a000a0b630aab4 (diff) | |
| download | linux-1e326ad429784a16b2b34ec296ff4ca7ad42c220.tar.bz2 | |
KVM: x86/emulator: Move the unhandled outer privilege level logic of far return into __load_segment_descriptor()
Outer-privilege level return is not implemented in emulator,
move the unhandled logic into __load_segment_descriptor to
make it easier to understand why the checks for RET are
incomplete.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Message-Id: <5b7188e6388ac9f4567d14eab32db9adf3e00119.1644292363.git.houwenlong.hwl@antgroup.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 35e69c2adec2..a60b4d20b309 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1623,9 +1623,14 @@ static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt, if (!(seg_desc.type & 8)) goto exception; - /* RET can never return to an inner privilege level. */ - if (transfer == X86_TRANSFER_RET && rpl < cpl) - goto exception; + if (transfer == X86_TRANSFER_RET) { + /* RET can never return to an inner privilege level. */ + if (rpl < cpl) + goto exception; + /* Outer-privilege level return is not implemented */ + if (rpl > cpl) + return X86EMUL_UNHANDLEABLE; + } if (transfer == X86_TRANSFER_RET || transfer == X86_TRANSFER_TASK_SWITCH) { if (seg_desc.type & 4) { /* conforming */ @@ -2220,9 +2225,6 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt) rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; - /* Outer-privilege level return is not implemented */ - if (ctxt->mode >= X86EMUL_MODE_PROT16 && (cs & 3) > cpl) - return X86EMUL_UNHANDLEABLE; rc = __load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS, cpl, X86_TRANSFER_RET, &new_desc); |