On 26/09/2019 15.46, Christian Borntraeger wrote: > > > On 26.09.19 14:58, Daniel P. Berrangé wrote: >> On Thu, Sep 26, 2019 at 08:50:36AM +0100, Peter Maydell wrote: >>> On Thu, 26 Sep 2019 at 00:31, Alex Bennée <alex.ben...@linaro.org> wrote: >>>> >>>> The 32 bit hosts are already a second class citizen especially with >>>> support for running 64 bit guests under TCG. We are also limited by >>>> testing as actual working 32 bit machines are getting quite rare in >>>> developers personal menageries. For TCG supporting newer types like >>>> Int128 is a lot harder with 32 bit calling conventions compared to >>>> their larger bit sized cousins. Fundamentally address space is the >>>> most useful thing for the translator to have even for a 32 bit guest a >>>> 32 bit host is quite constrained. >>>> >>>> As far as I'm aware 32 bit KVM users are even less numerous. Even >>>> ILP32 doesn't make much sense given the address space QEMU needs to >>>> manage. >>> >>> For KVM we should wait until the kernel chooses to drop support, >>> I think. >> >> What if the kernel is waiting for QEMU to drop support too ;-P > > For what its worth on kvm/s390 we never cared about implementing > 32 bit.
Looking at tcg/s390/tcg-target.inc.c : ... /* We only support generating code for 64-bit mode. */ #if TCG_TARGET_REG_BITS != 64 #error "unsupported code generation mode" #endif ... ... it seems to me that TCG does not support 32-bit on s390 either. I think we can remove s390 (32-bit) from the list completely? Thomas
