LoongArch: KVM: Allow to access HW timer CSR registers always

Currently HW timer CSR registers are allowed to access before entering
to vm and disabled if switch to SW timer in host mode, instead it is not
necessary to do so. HW timer CSR registers can be accessed always, it
is nothing to do with whether it is in vm mode or host mode. This patch
removes the limitation.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 1c1d5199500eec1ef6ffe44d7e7e1bf059c069c8..86a2f2d0cb27e3d213012d6987abde4ab1dae60e 100644 (file)
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -287,7 +287,6 @@ int kvm_arch_hardware_enable(void)
        if (env & CSR_GCFG_MATC_ROOT)
                gcfg |= CSR_GCFG_MATC_ROOT;
 
-       gcfg |= CSR_GCFG_TIT;
        write_csr_gcfg(gcfg);
 
        kvm_flush_tlb_all();

diff --git a/arch/loongarch/kvm/timer.c b/arch/loongarch/kvm/timer.c
index 12d58040122dd13fbc04c9899b210b28af0bda8d..d6d5bcea349bde3f967c5d32fb7a88016764d1d0 100644 (file)
--- a/arch/loongarch/kvm/timer.c
+++ b/arch/loongarch/kvm/timer.c
@@ -70,15 +70,6 @@ void kvm_init_timer(struct kvm_vcpu *vcpu, unsigned long timer_hz)
  */
 void kvm_acquire_timer(struct kvm_vcpu *vcpu)
 {
-       unsigned long cfg;
-
-       cfg = read_csr_gcfg();
-       if (!(cfg & CSR_GCFG_TIT))
-               return;
-
-       /* Enable guest access to hard timer */
-       write_csr_gcfg(cfg & ~CSR_GCFG_TIT);
-
        /*
         * Freeze the soft-timer and sync the guest stable timer with it. We do
         * this with interrupts disabled to avoid latency.
@@ -174,21 +165,15 @@ static void _kvm_save_timer(struct kvm_vcpu *vcpu)
  */
 void kvm_save_timer(struct kvm_vcpu *vcpu)
 {
-       unsigned long cfg;
        struct loongarch_csrs *csr = vcpu->arch.csr;
 
        preempt_disable();
-       cfg = read_csr_gcfg();
-       if (!(cfg & CSR_GCFG_TIT)) {
-               /* Disable guest use of hard timer */
-               write_csr_gcfg(cfg | CSR_GCFG_TIT);
-
-               /* Save hard timer state */
-               kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TCFG);
-               kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TVAL);
-               if (kvm_read_sw_gcsr(csr, LOONGARCH_CSR_TCFG) & CSR_TCFG_EN)
-                       _kvm_save_timer(vcpu);
-       }
+
+       /* Save hard timer state */
+       kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TCFG);
+       kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TVAL);
+       if (kvm_read_sw_gcsr(csr, LOONGARCH_CSR_TCFG) & CSR_TCFG_EN)
+               _kvm_save_timer(vcpu);
 
        /* Save timer-related state to vCPU context */
        kvm_save_hw_gcsr(csr, LOONGARCH_CSR_ESTAT);