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ARM: KVM: Add VFP lazy save/restore handler

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Similar to the arm64 version, add the code that deals with VFP traps,
re-enabling VFP, save/restoring the registers and resuming the guest.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Marc Zyngier 2016-01-06 13:53:51 +00:00
parent 89ef2b21ed
commit 96e5e670cc
1 changed files with 31 additions and 0 deletions
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31
arch/arm/kvm/hyp/entry.S
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@ -66,5 +66,36 @@ ENTRY(__guest_exit)
bx lr
ENDPROC(__guest_exit)
/*
* If VFPv3 support is not available, then we will not switch the VFP
* registers; however cp10 and cp11 accesses will still trap and fallback
* to the regular coprocessor emulation code, which currently will
* inject an undefined exception to the guest.
*/
#ifdef CONFIG_VFPv3
ENTRY(__vfp_guest_restore)
push {r3, r4, lr}
@ NEON/VFP used. Turn on VFP access.
mrc p15, 4, r1, c1, c1, 2 @ HCPTR
bic r1, r1, #(HCPTR_TCP(10) | HCPTR_TCP(11))
mcr p15, 4, r1, c1, c1, 2 @ HCPTR
isb
@ Switch VFP/NEON hardware state to the guest's
mov r4, r0
ldr r0, [r0, #VCPU_HOST_CTXT]
add r0, r0, #CPU_CTXT_VFP
bl __vfp_save_state
add r0, r4, #(VCPU_GUEST_CTXT + CPU_CTXT_VFP)
bl __vfp_restore_state
pop {r3, r4, lr}
pop {r0, r1, r2}
clrex
eret
ENDPROC(__vfp_guest_restore)
#endif
.popsection