From: Mayuresh Chitale <mchitale@xxxxxxxxxxxxxxxx> commit de1d7b6a51dab546160d252e47baa54adf104d4a upstream. Those applications that run in VU mode and access the time CSR cause a virtual instruction trap as Guest kernel currently does not initialize the scounteren CSR. To fix this, we should make CY, TM, and IR counters accessibile by default in VU mode (similar to OpenSBI). Fixes: a33c72faf2d73 ("RISC-V: KVM: Implement VCPU create, init and destroy functions") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Mayuresh Chitale <mchitale@xxxxxxxxxxxxxxxx> Signed-off-by: Anup Patel <anup@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/riscv/kvm/vcpu.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -74,6 +74,7 @@ int kvm_arch_vcpu_precreate(struct kvm * int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *cntx; + struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; /* Mark this VCPU never ran */ vcpu->arch.ran_atleast_once = false; @@ -89,6 +90,9 @@ int kvm_arch_vcpu_create(struct kvm_vcpu cntx->hstatus |= HSTATUS_SPVP; cntx->hstatus |= HSTATUS_SPV; + /* By default, make CY, TM, and IR counters accessible in VU mode */ + reset_csr->scounteren = 0x7; + /* Setup VCPU timer */ kvm_riscv_vcpu_timer_init(vcpu);