On Wed, Jun 26, 2019 at 03:40:11PM +0200, Auger Eric wrote: > Hi, > > On 6/26/19 3:28 PM, Andrew Jones wrote: > > On Wed, Jun 26, 2019 at 12:01:10PM +0200, Auger Eric wrote: > >> Hi Drew, > >> > >> On 6/21/19 6:34 PM, Andrew Jones wrote: > >>> Suggested-by: Dave Martin <dave.mar...@arm.com> > >>> Signed-off-by: Andrew Jones <drjo...@redhat.com> > >>> --- > >>> target/arm/helper.c | 1 + > >>> 1 file changed, 1 insertion(+) > >>> > >>> diff --git a/target/arm/helper.c b/target/arm/helper.c > >>> index df4276f5f6ca..edba94004e0b 100644 > >>> --- a/target/arm/helper.c > >>> +++ b/target/arm/helper.c > >>> @@ -5319,6 +5319,7 @@ static void zcr_write(CPUARMState *env, const > >>> ARMCPRegInfo *ri, > >>> int new_len; > >>> > >>> /* Bits other than [3:0] are RAZ/WI. */ > >>> + QEMU_BUILD_BUG_ON(ARM_MAX_VQ > 16); > >> Can you document in the commit message why this check is critical? > > > > Sure. I can copy+paste the email subject into the commit message :-) > Well that's not what I asked for. Are you enforcing an architectural > maximum of 2048 bits or is the limitation due to some data structs in > the existing code, ... For a non expert reviewer as I am it is not > totally obvious.
How's this for the commit message The current implementation of ZCR_ELx matches the architecture, only implementing the lower four bits, with the rest RAZ/WI. This puts a strict limit on ARM_MAX_VQ of 16. Make sure we don't let ARM_MAX_VQ grow without a corresponding update here. Thanks, drew > > Thanks > > Eric > > > > drew > > > >> > >> Thanks > >> > >> Eric > >>> raw_write(env, ri, value & 0xf); > >>> > >>> /* > >>> > >>