Upstream commit 5d6c7de6446e9ab3fb41d6f7d82770e50998f3de. Exit to userspace when emulating an atomic guest access if the CMPXCHG on the userspace address faults. Emulating the access as a write and thus likely treating it as emulated MMIO is wrong, as KVM has already confirmed there is a valid, writable memslot. Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Message-Id: <20220202004945.2540433-6-seanjc@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index aa6f700f8c5f..a9c26397dcfd 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7105,7 +7105,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt, } if (r < 0) - goto emul_write; + return X86EMUL_UNHANDLEABLE; if (r) return X86EMUL_CMPXCHG_FAILED; -- 2.44.0.478.gd926399ef9-goog
