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| author | Mark Brown <broonie@kernel.org> | 2022-01-24 16:57:20 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-02-08 15:42:59 +0100 |
| commit | 01a244decc760b1ae2caa045647d79ff431bf37b (patch) | |
| tree | df422fe96605b6ba6988961c05f8a788ecee7178 /arch/arm64 | |
| parent | KVM: arm64: Add comments for context flush and sync callbacks (diff) | |
| download | linux-01a244decc760b1ae2caa045647d79ff431bf37b.tar.xz linux-01a244decc760b1ae2caa045647d79ff431bf37b.zip | |
KVM: arm64: Add some more comments in kvm_hyp_handle_fpsimd()
The handling for FPSIMD/SVE traps is multi stage and involves some trap
manipulation which isn't quite so immediately obvious as might be desired
so add a few more comments.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220124155720.3943374-3-broonie@kernel.org
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/switch.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 701cfb964905..667654bd3734 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -173,6 +173,8 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) return false; /* Valid trap. Switch the context: */ + + /* First disable enough traps to allow us to update the registers */ if (has_vhe()) { reg = CPACR_EL1_FPEN; if (sve_guest) @@ -188,11 +190,13 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) } isb(); + /* Write out the host state if it's in the registers */ if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { __fpsimd_save_state(vcpu->arch.host_fpsimd_state); vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; } + /* Restore the guest state */ if (sve_guest) __hyp_sve_restore_guest(vcpu); else |