[PATCH v16 14/30] LoongArch: KVM: Implement vcpu load and vcpu put operations

From: Tianrui Zhao
Date: Thu Jun 29 2023 - 04:00:56 EST


Implement LoongArch vcpu load and vcpu put operations, including
load csr value into hardware and save csr value into vcpu structure.

Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
arch/loongarch/kvm/vcpu.c | 198 ++++++++++++++++++++++++++++++++++++++
1 file changed, 198 insertions(+)

diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 634836ead8bd..de76b4349098 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -602,6 +602,204 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
}
}

+static int _kvm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+ struct kvm_context *context;
+ struct loongarch_csrs *csr = vcpu->arch.csr;
+ bool migrated, all;
+
+ /*
+ * Have we migrated to a different CPU?
+ * If so, any old guest TLB state may be stale.
+ */
+ migrated = (vcpu->arch.last_sched_cpu != cpu);
+
+ /*
+ * Was this the last vCPU to run on this CPU?
+ * If not, any old guest state from this vCPU will have been clobbered.
+ */
+ context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
+ all = migrated || (context->last_vcpu != vcpu);
+ context->last_vcpu = vcpu;
+
+ /*
+ * Restore timer state regardless
+ */
+ kvm_restore_timer(vcpu);
+
+ /* Control guest page CCA attribute */
+ change_csr_gcfg(CSR_GCFG_MATC_MASK, CSR_GCFG_MATC_ROOT);
+ /* Don't bother restoring registers multiple times unless necessary */
+ if (!all)
+ return 0;
+
+ write_csr_gcntc((ulong)vcpu->kvm->arch.time_offset);
+ /*
+ * Restore guest CSR registers
+ */
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_CRMD);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PRMD);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_EUEN);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_MISC);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_ECFG);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_ERA);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_BADV);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_BADI);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_EENTRY);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBIDX);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBEHI);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBELO0);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBELO1);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_ASID);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PGDL);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PGDH);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PWCTL0);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_PWCTL1);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_STLBPGSIZE);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_RVACFG);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_CPUID);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS0);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS1);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS2);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS3);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS4);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS5);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS6);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_KS7);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TMID);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_CNTC);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRENTRY);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRBADV);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRERA);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRSAVE);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO0);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO1);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBREHI);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_TLBRPRMD);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN0);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN1);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN2);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_DMWIN3);
+ kvm_restore_hw_gcsr(csr, LOONGARCH_CSR_LLBCTL);
+
+ /* restore Root.Guestexcept from unused Guest guestexcept register */
+ write_csr_gintc(csr->csrs[LOONGARCH_CSR_GINTC]);
+
+ /*
+ * We should clear linked load bit to break interrupted atomics. This
+ * prevents a SC on the next vCPU from succeeding by matching a LL on
+ * the previous vCPU.
+ */
+ if (vcpu->kvm->created_vcpus > 1)
+ set_gcsr_llbctl(CSR_LLBCTL_WCLLB);
+
+ return 0;
+}
+
+void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ vcpu->cpu = cpu;
+ if (vcpu->arch.last_sched_cpu != cpu) {
+ kvm_debug("[%d->%d]KVM vCPU[%d] switch\n",
+ vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id);
+ /*
+ * Migrate the timer interrupt to the current CPU so that it
+ * always interrupts the guest and synchronously triggers a
+ * guest timer interrupt.
+ */
+ kvm_migrate_count(vcpu);
+ }
+
+ /* restore guest state to registers */
+ _kvm_vcpu_load(vcpu, cpu);
+ local_irq_restore(flags);
+}
+
+static int _kvm_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
+{
+ struct loongarch_csrs *csr = vcpu->arch.csr;
+
+ kvm_lose_fpu(vcpu);
+ /*
+ * update csr state from hardware if software csr state is stale,
+ * most csr registers are kept unchanged during process context
+ * switch except csr registers like remaining timer tick value and
+ * injected interrupt state.
+ */
+ if (!(vcpu->arch.aux_inuse & KVM_LARCH_CSR)) {
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_CRMD);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRMD);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_EUEN);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_MISC);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_ECFG);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_ERA);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_BADV);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_BADI);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_EENTRY);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBIDX);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBEHI);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBELO0);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBELO1);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_ASID);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PGDL);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PGDH);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PWCTL0);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PWCTL1);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_STLBPGSIZE);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_RVACFG);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_CPUID);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRCFG1);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRCFG2);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_PRCFG3);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS0);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS1);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS2);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS3);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS4);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS5);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS6);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_KS7);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TMID);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_CNTC);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_LLBCTL);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRENTRY);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRBADV);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRERA);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRSAVE);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO0);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRELO1);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBREHI);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_TLBRPRMD);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN0);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN1);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN2);
+ kvm_save_hw_gcsr(csr, LOONGARCH_CSR_DMWIN3);
+ vcpu->arch.aux_inuse |= KVM_LARCH_CSR;
+ }
+ /* save Root.Guestexcept in unused Guest guestexcept register */
+ kvm_save_timer(vcpu);
+ csr->csrs[LOONGARCH_CSR_GINTC] = read_csr_gintc();
+ return 0;
+}
+
+void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
+{
+ unsigned long flags;
+ int cpu;
+
+ local_irq_save(flags);
+ cpu = smp_processor_id();
+ vcpu->arch.last_sched_cpu = cpu;
+ vcpu->cpu = -1;
+
+ /* save guest state in registers */
+ _kvm_vcpu_put(vcpu, cpu);
+ local_irq_restore(flags);
+}
+
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
{
int r = -EINTR;
--
2.39.1