Anup Patel cea8896bd9 RISC-V: KVM: Fix kvm_riscv_vcpu_timer_pending() for Sstc
The kvm_riscv_vcpu_timer_pending() checks per-VCPU next_cycles
and per-VCPU software injected VS timer interrupt. This function
returns incorrect value when Sstc is available because the per-VCPU
next_cycles are only updated by kvm_riscv_vcpu_timer_save() called
from kvm_arch_vcpu_put(). As a result, when Sstc is available the
VCPU does not block properly upon WFI traps.

To fix the above issue, we introduce kvm_riscv_vcpu_timer_sync()
which will update per-VCPU next_cycles upon every VM exit instead
of kvm_riscv_vcpu_timer_save().

Fixes: 8f5cb44b1bae ("RISC-V: KVM: Support sstc extension")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-21 11:52:45 +05:30
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