On 16/08/17 12:20, Marc Zyngier wrote:

On 16/08/17 11:50, Dave Martin wrote:

quoted

On Tue, Aug 15, 2017 at 05:33:15PM +0100, Marc Zyngier wrote:

quoted

On 09/08/17 13:05, Dave Martin wrote:

quoted

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@arm.com>
---
 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.  

The ARMv8 ARM (DDI406B_a, D7.2.19) says otherwise. This bit is only

Of course, the days of the ARMv7 ARM are still haunting me. This should
read DDI487B_a.

Apologies for the confusion.

	M.
-- 
Jazz is not dead. It just smells funny...