[PATCH v3 14/23] arm64: KVM: VHE: Make __fpsimd_enabled VHE aware

Marc Zyngier
2016-02-03T18:00:07Z

As non-VHE and VHE have different ways to express the trapping of
FPSIMD registers to EL2, make __fpsimd_enabled a patchable predicate
and provide a VHE implementation.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/include/asm/kvm_arm.h | 3 +++
arch/arm64/kvm/hyp/hyp.h | 5 +----
arch/arm64/kvm/hyp/switch.c | 19 +++++++++++++++++++
3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 738a95f..498335e 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -217,4 +217,7 @@
ECN(SOFTSTP_CUR), ECN(WATCHPT_LOW), ECN(WATCHPT_CUR), \
ECN(BKPT32), ECN(VECTOR32), ECN(BRK64)

+#define CPACR_EL1_FPEN (3 << 20)
+#define CPACR_EL1_TTA (1 << 28)
+
#endif /* __ARM64_KVM_ARM_H__ */
diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h
index 5dfa883..44eaff7 100644
--- a/arch/arm64/kvm/hyp/hyp.h
+++ b/arch/arm64/kvm/hyp/hyp.h
@@ -171,10 +171,7 @@ void __debug_cond_restore_host_state(struct kvm_vcpu *vcpu);

void __fpsimd_save_state(struct user_fpsimd_state *fp_regs);
void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs);
-static inline bool __fpsimd_enabled(void)
-{
- return !(read_sysreg(cptr_el2) & CPTR_EL2_TFP);
-}
+bool __fpsimd_enabled(void);

u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt);
void __noreturn __hyp_do_panic(unsigned long, ...);
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 9071dee..0db161e 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -17,6 +17,25 @@

#include "hyp.h"

+static bool __hyp_text __fpsimd_enabled_nvhe(void)
+{
+ return !(read_sysreg(cptr_el2) & CPTR_EL2_TFP);
+}
+
+static bool __hyp_text __fpsimd_enabled_vhe(void)
+{
+ return !!(read_sysreg(cpacr_el1) & CPACR_EL1_FPEN);
+}
+
+static hyp_alternate_select(__fpsimd_is_enabled,
+ __fpsimd_enabled_nvhe, __fpsimd_enabled_vhe,
+ ARM64_HAS_VIRT_HOST_EXTN);
+
+bool __hyp_text __fpsimd_enabled(void)
+{
+ return __fpsimd_is_enabled()();
+}
+
static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
{
u64 val;
--
2.1.4