+ Mark
On Tue, 20 Dec 2022 10:50:24 +0000,
Dong Bo <dongbo4@xxxxxxxxxx> wrote:
>
> From: Nianyao Tang <tangnianyao@xxxxxxxxxx>
>
> If we have VHE and need to reenable SME for host in
> kvm_arch_vcpu_put_fp, CPACR.SMEN is modified from 0 to 1. Trap
> control for reading SVCR is modified from enable to disable.
> Synchronization is needed before reading SVCR later in
> fpsimd_save, or it may cause sync exception which can not be
> handled by host.
>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: James Morse <james.morse@xxxxxxx>
> Cc: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> Cc: Oliver Upton <oliver.upton@xxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Signed-off-by: Nianyao Tang <tangnianyao@xxxxxxxxxx>
> ---
> arch/arm64/kvm/fpsimd.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
> index 02dd7e9ebd39..f5799f571317 100644
> --- a/arch/arm64/kvm/fpsimd.c
> +++ b/arch/arm64/kvm/fpsimd.c
> @@ -184,6 +184,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
> sysreg_clear_set(CPACR_EL1,
> CPACR_EL1_SMEN_EL0EN,
> CPACR_EL1_SMEN_EL1EN);
> + isb();
> }
>
> if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) {
> --
> 1.8.3.1
>
>
--
Without deviation from the norm, progress is not possible.
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