On 11/21/2016 8:50 AM, Paolo Bonzini wrote: > > > On 14/11/2016 23:15, Brijesh Singh wrote: >> + /* For size less than 4 we merge, else we zero extend */ >> + val = (size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX) : 0; > > Are you sure it shouldn't always zero extend the high 32-bits? So "val" > should be declared as u32. > > Paolo It should only zero extend when dealing with a 32-bit operation. Any use of 8 or 16 bit registers leaves the upper 56 or 48 bits as is (see section 3.1.2.3 in http://support.amd.com/TechDocs/24592.pdf). Thanks, Tom > >> + ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, port, >> + &val, 1); >> + if (ret) { >> + kvm_register_write(vcpu, VCPU_REGS_RAX, val); >> + return ret; >> + } -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
