KVM: arm64: Document check for TIF_FOREIGN_FPSTATE
authorMark Brown <broonie@kernel.org>
Tue, 7 Mar 2023 17:37:14 +0000 (17:37 +0000)
committerMarc Zyngier <maz@kernel.org>
Fri, 21 Apr 2023 12:46:20 +0000 (13:46 +0100)
commit4c181e3d352e9280c84fb4b4c7a8940ce005374e
treea6b4102317e80bc45c1447383897aa09201784a1
parent3d1793562858f2bc42cc722fe00ec9b2ff0618e1
KVM: arm64: Document check for TIF_FOREIGN_FPSTATE

In kvm_arch_vcpu_load_fp() we unconditionally set the current FP state
to FP_STATE_HOST_OWNED, this will be overridden to FP_STATE_NONE if
TIF_FOREIGN_FPSTATE is set but the check is deferred until
kvm_arch_vcpu_ctxflush_fp() where we are no longer preemptable. Add a
comment to this effect to help avoid people being concerned about the
lack of a check and discover where the check is done.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221214-kvm-arm64-sme-context-switch-v2-1-57ba0082e9ff@kernel.org
arch/arm64/kvm/fpsimd.c