From a209260781bec2fa050c0ed9f38171373e8d81a2 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Mon, 26 Nov 2007 16:57:57 +0000 Subject: [PATCH] x86 emulate: Emulate atomic read-modify-write instructions as a straightforward write. Hopefully multiprocessor synchronisation is not relied upon in real mode! Signed-off-by: Keir Fraser --- xen/arch/x86/hvm/vmx/realmode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/hvm/vmx/realmode.c b/xen/arch/x86/hvm/vmx/realmode.c index 2f31d8fbcd..d26725ba00 100644 --- a/xen/arch/x86/hvm/vmx/realmode.c +++ b/xen/arch/x86/hvm/vmx/realmode.c @@ -237,7 +237,8 @@ realmode_emulate_cmpxchg( unsigned int bytes, struct x86_emulate_ctxt *ctxt) { - return X86EMUL_UNHANDLEABLE; + /* Fix this in case the guest is really relying on r-m-w atomicity. */ + return realmode_emulate_write(seg, offset, new, bytes, ctxt); } static int -- 2.30.2