On Tue, Aug 15, 2017 at 05:33:15PM +0100, Marc Zyngier wrote: > On 09/08/17 13:05, Dave Martin wrote: > > Until KVM has full SVE support, guests must not be allowed to > > execute SVE instructions. > > > > This patch enables the necessary traps, and also ensures that the > > traps are disabled again on exit from the guest so that the host > > can still use SVE if it wants to. > > > > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> > > --- > > arch/arm64/include/asm/kvm_arm.h | 3 ++- > > arch/arm64/kvm/hyp/switch.c | 6 +++--- > > 2 files changed, 5 insertions(+), 4 deletions(-) > > > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > > index dbf0537..8a19651 100644 > > --- a/arch/arm64/include/asm/kvm_arm.h > > +++ b/arch/arm64/include/asm/kvm_arm.h > > @@ -186,7 +186,7 @@ > > #define CPTR_EL2_TTA (1 << 20) > > #define CPTR_EL2_TFP (1 << CPTR_EL2_TFP_SHIFT) > > #define CPTR_EL2_TZ (1 << 8) > > -#define CPTR_EL2_DEFAULT 0x000033ff > > +#define CPTR_EL2_DEFAULT (0x000033ff & ~CPTR_EL2_TZ) > > I must say I'm not overly fond of this construct. I'd rather introduce a > RES1 field that matches the v8.2 description, instead of this ugly > constant and something that clears it. Sorry, I don't get your meaning here. v8.2 neither immediately predates or postdates SVE. What are you propsing? I guess we could just write 0x000032ff now that the only meaning the architecture can ever assign to bit 8 is known. [...] Cheers ---Dave
