On 03/28/2018 08:42 AM, Michael Clark wrote: > This change is a workaround for a bug where mstatus.FS > is not correctly reporting dirty after operations that > modify floating point registers. This a critical bug > or RISC-V in QEMU as it results in floating point > register file corruption when running SMP Linux due to > task migration and possibly uniprocessor Linux if > more than one process is using the FPU. > > This workaround will return dirty if mstatus.FS is > switched from off to initial or clean. According to > the specification it is legal for an implementation > to return only off, or dirty. > > Cc: Palmer Dabbelt <pal...@sifive.com> > Cc: Sagar Karandikar <sag...@eecs.berkeley.edu> > Cc: Bastian Koppelmann <kbast...@mail.uni-paderborn.de> > Cc: Peter Maydell <peter.mayd...@linaro.org> > Cc: Alex Bennée <alex.ben...@linaro.org> > Cc: Richard Henderson <richard.hender...@linaro.org> > Cc: Philippe Mathieu-Daudé <f4...@amsat.org> > Tested-by: Richard W.M. Jones <rjo...@redhat.com> > Signed-off-by: Michael Clark <m...@sifive.com> > --- > target/riscv/op_helper.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-)
In case the more extensive fix waits until 2.13, Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
