Hi Peter, Thanks for the prompt patches!
On Tue, Sep 14, 2021 at 2:08 PM Peter Maydell <peter.mayd...@linaro.org> wrote: > This patchset fixes https://gitlab.com/qemu-project/qemu/-/issues/613 > which is a bug where we weren't setting FPSCR.LTPSIZE correctly > out of reset for the user-mode emulator. The effect is that > when using an M-profile CPU with the low-overhead-branch or MVE > extensions (ie the Cortex-M55) with the linux-user QEMU the 'LE' > instruction would take a UserFault and MVE instructions would > be incorrectly predicated. > > This is the result of some over-exuberant ifdeffery in the > arm_cpu_reset() function. Patch 1 fixes that so that most of > the M-profile-specific reset handling is not ifdeffed, and > when we're in user mode we specifically set the FPU state up > cleanly. Patches 2 and 3 are just follow-on tidyup. > > Christophe, if you are in a position to test this series with: > M55 (has Security, MVE and LOB) > M33 (has Security extension but not MVE/LOB) > M7 or M4 (no Security, but does have FPU) > that would be ideal. I don't really have much in the way of > test cases for usermode to hand, so it's possible that I > forgot something in the init of the FPU state that might break > one of those combinations. (It does fix the test case attached > to the bug report.) > I ran the GCC testsuite with these configurations, and found no regression compared to qemu-6.0, thanks. In the M55 case, this also enabled many more tests, which is great! Christophe > thanks > -- PMM > > Peter Maydell (3): > target/arm: Don't skip M-profile reset entirely in user mode > target/arm: Always clear exclusive monitor on reset > target/arm: Consolidate ifdef blocks in reset > > target/arm/cpu.c | 39 ++++++++++++++++++++++++++++----------- > 1 file changed, 28 insertions(+), 11 deletions(-) > > -- > 2.20.1 > > >
