From: Wei Yongjun <[email protected]> If the destination is a memory operand and the memory cannot map to a valid page, the xchg instruction emulation and locked instruction will not work on io regions and stuck in endless loop. We should emulate exchange as write to fix it.
Signed-off-by: Wei Yongjun <[email protected]> Acked-by: Gleb Natapov <[email protected]> Signed-off-by: Marcelo Tosatti <[email protected]> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 86c8102..84bfb51 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3562,6 +3562,10 @@ static int emulator_cmpxchg_emulated(unsigned long addr, goto emul_write; page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT); + if (is_error_page(page)) { + kvm_release_page_clean(page); + goto emul_write; + } kaddr = kmap_atomic(page, KM_USER0); kaddr += offset_in_page(gpa); -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
