On 22 November 2011 15:05, Alexander Graf agraf@suse.de wrote:
On 22.11.2011, at 15:44, Peter Maydell peter.maydell@linaro.org wrote:
We're aiming for a reasonable working prototype of A15 guest on an A15 Fast Model host here; we need to fix at least some of the bugs which currently mean upstream QEMU doesn't work on ARM hosts,
I thought there was upstream tcg support for arm now? What specifically doesn't work?
* coroutine implementation doesn't cope if libc provides a makecontext() that returns ENOSYS (so we abort on startup) * the MAP_FIXED static codegen buffer is put at an address which overlaps the glibc heap so we crash about 50% of the time * if you try to start a standard i386 debian image which works fine on x86 host, the guest reboots just before displaying the blue-background grub image -- clearly something wrong here, not tracked down what yet * if the C code was compiled -mthumb, our choice of TCG_AREG0 clashes with the frame pointer (trivial fix but could do with a quick benchmark run to see whether making AREG0 r6 or r10 (ie thumb lowreg or high) has any effect on performance)
Those are just the ones I know about... The coroutine one is the only one that KVM specifically will require a fix for, but being able to cross-compare "run with KVM" vs "run with TCG" will be handy for debugging I suspect.
ARM host support is documented as "known not to work" in the 1.0 release notes (see earlier mail to qemu-devel).
-- PMM