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| author | Mark Brown <broonie@kernel.org> | 2022-04-19 14:22:21 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2022-04-22 20:50:58 +0300 |
| commit | b40c559b45bec736f588c57dd5be967fe573058b (patch) | |
| tree | 3db88580a158e081a31efcea398857d19099d351 /arch/arm64/kvm/fpsimd.c | |
| parent | a9d69158595017d260ab37bf88b8f125e5e8144c (diff) | |
| download | linux-b40c559b45bec736f588c57dd5be967fe573058b.tar.xz | |
arm64/sme: Implement SVCR context switching
In SME the use of both streaming SVE mode and ZA are tracked through
PSTATE.SM and PSTATE.ZA, visible through the system register SVCR. In
order to context switch the floating point state for SME we need to
context switch the contents of this register as part of context
switching the floating point state.
Since changing the vector length exits streaming SVE mode and disables
ZA we also make sure we update SVCR appropriately when setting vector
length, and similarly ensure that new threads have streaming SVE mode
and ZA disabled.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-14-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 397fdac75cb1..ac09f1f682ff 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -109,9 +109,14 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) WARN_ON_ONCE(!irqs_disabled()); if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { + /* + * Currently we do not support SME guests so SVCR is + * always 0 and we just need a variable to point to. + */ fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.fp_regs, vcpu->arch.sve_state, - vcpu->arch.sve_max_vl); + vcpu->arch.sve_max_vl, + NULL); clear_thread_flag(TIF_FOREIGN_FPSTATE); update_thread_flag(TIF_SVE, vcpu_has_sve(vcpu)); |