On 02.09.14 09:07, Christian Borntraeger wrote: > On 02/09/14 00:39, Alexander Graf wrote: >> >> >> On 29.08.14 15:52, Jens Freimann wrote: >>> From: David Hildenbrand <d...@linux.vnet.ibm.com> >>> >>> When reading/writing the psw mask, the condition code may only be touched if >>> running on tcg. >> >> Why? Shouldn't we be able to set CC from gdb as well? >> > > You can. What this patch does (and the patch description is a bit vague here) > is to not modify the PSW it gets from KVM when passing it to gdb: > The qemu core gets the PSW from KVM. Without this patch, we use cc_op to > calculate the current CC of the PSW (No idea of TCG, I guess its evaluated > lazy - at least this is how valgrind works). This is wrong for the KVM case, > as cc_op does not contain any useful data for the KVM case. With this patch > we simply pass the psw from KVM to gdb and back. > > The symptom was that the cc was always shown as zero.
Ah, I see. I agree with the patch, but the patch description does not actually describe what the patch does. Please rework it. I also wouldn't mind if instead of hard coding this logic in the gdbstub, we'd extract it as helper functions to read and write the PSW.MASK in cpu.h. Alex
