[PATCH v3 17/23] arm64: KVM: VHE: Add fpsimd enabling on guest access
From: Marc Zyngier <hidden>
Date: 2016-02-03 18:00:52
Also in:
kvm, kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Despite the fact that a VHE enabled kernel runs at EL2, it uses CPACR_EL1 to trap FPSIMD access. Add the required alternative code to re-enable guest FPSIMD access when it has trapped to EL2. Reviewed-by: Christoffer Dall <redacted> Signed-off-by: Marc Zyngier <redacted> --- arch/arm64/kvm/hyp/entry.S | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index fd0fbe9..ce9e5e5 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S@@ -130,9 +130,15 @@ ENDPROC(__guest_exit) ENTRY(__fpsimd_guest_restore) stp x4, lr, [sp, #-16]! +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN mrs x2, cptr_el2 bic x2, x2, #CPTR_EL2_TFP msr cptr_el2, x2 +alternative_else + mrs x2, cpacr_el1 + orr x2, x2, #CPACR_EL1_FPEN + msr cpacr_el1, x2 +alternative_endif isb mrs x3, tpidr_el2
--
2.1.4