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| author | Marc Zyngier <maz@kernel.org> | 2022-04-19 19:27:50 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-04-20 13:24:45 +0100 |
| commit | 89f5074c503b6b6f181c0240c931f67bcaf266e9 (patch) | |
| tree | cd4f418e74bc656f9277c17507e245e561bb24a2 /arch/arm64/kvm/handle_exit.c | |
| parent | daf85a5f6be33788e18ff3efad1d7c3ad66a8cb3 (diff) | |
| download | lwn-89f5074c503b6b6f181c0240c931f67bcaf266e9.tar.gz lwn-89f5074c503b6b6f181c0240c931f67bcaf266e9.zip | |
KVM: arm64: Handle blocking WFIT instruction
When trapping a blocking WFIT instruction, take it into account when
computing the deadline of the background timer.
The state is tracked with a new vcpu flag, and is gated by a new
CPU capability, which isn't currently enabled.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-6-maz@kernel.org
Diffstat (limited to 'arch/arm64/kvm/handle_exit.c')
| -rw-r--r-- | arch/arm64/kvm/handle_exit.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 97fe14aab1a3..4260f2cd1971 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -85,16 +85,21 @@ static int handle_no_fpsimd(struct kvm_vcpu *vcpu) * WFI: Simply call kvm_vcpu_halt(), which will halt execution of * world-switches and schedule other host processes until there is an * incoming IRQ or FIQ to the VM. + * WFIT: Same as WFI, with a timed wakeup implemented as a background timer */ static int kvm_handle_wfx(struct kvm_vcpu *vcpu) { - if (kvm_vcpu_get_esr(vcpu) & ESR_ELx_WFx_ISS_WFE) { + u64 esr = kvm_vcpu_get_esr(vcpu); + + if (esr & ESR_ELx_WFx_ISS_WFE) { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu)); } else { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; + if ((esr & (ESR_ELx_WFx_ISS_RV | ESR_ELx_WFx_ISS_WFxT)) == (ESR_ELx_WFx_ISS_RV | ESR_ELx_WFx_ISS_WFxT)) + vcpu->arch.flags |= KVM_ARM64_WFIT; kvm_vcpu_wfi(vcpu); } |