[PATCH v16 02/30] LoongArch: KVM: Implement kvm module related interface

[Tianrui Zhao]

Implement LoongArch kvm module init, module exit interface,
using kvm context to save the vpid info and vcpu world switch
interface pointer.

Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
 arch/loongarch/kvm/main.c | 299 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 299 insertions(+)
 create mode 100644 arch/loongarch/kvm/main.c

diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
new file mode 100644
index 000000000000..c204853b8c44
--- /dev/null
+++ b/arch/loongarch/kvm/main.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/kvm_host.h>
+#include <asm/cacheflush.h>
+#include <asm/kvm_csr.h>
+
+static struct kvm_context __percpu *vmcs;
+struct kvm_world_switch *kvm_loongarch_ops;
+unsigned long vpid_mask;
+static int gcsr_flag[CSR_MAX_NUMS];
+
+int get_gcsr_flag(int csr)
+{
+	if (csr < CSR_MAX_NUMS)
+		return gcsr_flag[csr];
+
+	return INVALID_GCSR;
+}
+
+static inline void set_gcsr_sw_flag(int csr)
+{
+	if (csr < CSR_MAX_NUMS)
+		gcsr_flag[csr] |= SW_GCSR;
+}
+
+static inline void set_gcsr_hw_flag(int csr)
+{
+	if (csr < CSR_MAX_NUMS)
+		gcsr_flag[csr] |= HW_GCSR;
+}
+
+/*
+ * The default value of gcsr_flag[CSR] is 0, and we use this
+ * function to set the flag to 1(SW_GCSR) or 2(HW_GCSR) if the
+ * gcsr is software or hardware. It will be used by get/set_gcsr,
+ * if gcsr_flag is HW we should use gcsrrd/gcsrwr to access it,
+ * else use sw csr to emulate it.
+ */
+static void _kvm_init_gcsr_flag(void)
+{
+	set_gcsr_hw_flag(LOONGARCH_CSR_CRMD);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PRMD);
+	set_gcsr_hw_flag(LOONGARCH_CSR_EUEN);
+	set_gcsr_hw_flag(LOONGARCH_CSR_MISC);
+	set_gcsr_hw_flag(LOONGARCH_CSR_ECFG);
+	set_gcsr_hw_flag(LOONGARCH_CSR_ESTAT);
+	set_gcsr_hw_flag(LOONGARCH_CSR_ERA);
+	set_gcsr_hw_flag(LOONGARCH_CSR_BADV);
+	set_gcsr_hw_flag(LOONGARCH_CSR_BADI);
+	set_gcsr_hw_flag(LOONGARCH_CSR_EENTRY);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBIDX);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBEHI);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO0);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO1);
+	set_gcsr_hw_flag(LOONGARCH_CSR_ASID);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PGDL);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PGDH);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL0);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL1);
+	set_gcsr_hw_flag(LOONGARCH_CSR_STLBPGSIZE);
+	set_gcsr_hw_flag(LOONGARCH_CSR_RVACFG);
+	set_gcsr_hw_flag(LOONGARCH_CSR_CPUID);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG1);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG2);
+	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG3);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS0);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS1);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS2);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS3);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS4);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS5);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS6);
+	set_gcsr_hw_flag(LOONGARCH_CSR_KS7);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TMID);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TCFG);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TVAL);
+	set_gcsr_hw_flag(LOONGARCH_CSR_CNTC);
+	set_gcsr_hw_flag(LOONGARCH_CSR_LLBCTL);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRENTRY);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRBADV);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRERA);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRSAVE);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO0);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO1);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBREHI);
+	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRPRMD);
+	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN0);
+	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN1);
+	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN2);
+	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN3);
+	set_gcsr_hw_flag(LOONGARCH_CSR_MWPS);
+	set_gcsr_hw_flag(LOONGARCH_CSR_FWPS);
+
+	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL1);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL2);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MERRCTL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO1);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO2);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MERRENTRY);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MERRERA);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MERRSAVE);
+	set_gcsr_sw_flag(LOONGARCH_CSR_CTAG);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DEBUG);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DERA);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DESAVE);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PRCFG1);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PRCFG2);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PRCFG3);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PGD);
+	set_gcsr_sw_flag(LOONGARCH_CSR_TINTCLR);
+
+	set_gcsr_sw_flag(LOONGARCH_CSR_FWPS);
+	set_gcsr_sw_flag(LOONGARCH_CSR_FWPC);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MWPS);
+	set_gcsr_sw_flag(LOONGARCH_CSR_MWPC);
+
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB0MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB0CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB1MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB1CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB2MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB2CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB3MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB3CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB4MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB4CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB5MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB5CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB6MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB6CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB7MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB7CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ASID);
+
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB0MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB0CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB1MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB1CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB2MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB2CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB3MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB3CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB4MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB4CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB5MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB5CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB6MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB6CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ASID);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ADDR);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB7MASK);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB7CTRL);
+	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ASID);
+
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL0);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR0);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL1);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR1);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL2);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR2);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL3);
+	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR3);
+}
+
+static int kvm_loongarch_env_init(void)
+{
+	struct kvm_context *context;
+	int cpu, order;
+	void *addr;
+
+	vmcs = alloc_percpu(struct kvm_context);
+	if (!vmcs) {
+		pr_err("kvm: failed to allocate percpu kvm_context\n");
+		return -ENOMEM;
+	}
+
+	kvm_loongarch_ops = kzalloc(sizeof(*kvm_loongarch_ops), GFP_KERNEL);
+	if (!kvm_loongarch_ops) {
+		free_percpu(vmcs);
+		vmcs = NULL;
+		return -ENOMEM;
+	}
+	/*
+	 * There will be problem in world switch code if there
+	 * is page fault reenter, since pgd register is shared
+	 * between root kernel and kvm hypervisor. World switch
+	 * entry need be unmapped area, cannot be tlb mapped area.
+	 * In future if hw pagetable walking is supported, or there
+	 * is separate pgd registers between root kernel and kvm
+	 * hypervisor, copying about world switch code will not be used.
+	 */
+
+	order = get_order(kvm_vector_size + kvm_enter_guest_size);
+	addr = (void *)__get_free_pages(GFP_KERNEL, order);
+	if (!addr) {
+		free_percpu(vmcs);
+		vmcs = NULL;
+		kfree(kvm_loongarch_ops);
+		kvm_loongarch_ops = NULL;
+		return -ENOMEM;
+	}
+
+	memcpy(addr, kvm_vector_entry, kvm_vector_size);
+	memcpy(addr + kvm_vector_size, kvm_enter_guest, kvm_enter_guest_size);
+	flush_icache_range((unsigned long)addr, (unsigned long)addr +
+				kvm_vector_size + kvm_enter_guest_size);
+	kvm_loongarch_ops->guest_eentry = addr;
+	kvm_loongarch_ops->enter_guest = addr + kvm_vector_size;
+	kvm_loongarch_ops->page_order = order;
+
+	vpid_mask = read_csr_gstat();
+	vpid_mask = (vpid_mask & CSR_GSTAT_GIDBIT) >> CSR_GSTAT_GIDBIT_SHIFT;
+	if (vpid_mask)
+		vpid_mask = GENMASK(vpid_mask - 1, 0);
+
+	for_each_possible_cpu(cpu) {
+		context = per_cpu_ptr(vmcs, cpu);
+		context->vpid_cache = vpid_mask + 1;
+		context->last_vcpu = NULL;
+	}
+
+	_kvm_init_fault();
+	_kvm_init_gcsr_flag();
+
+	return 0;
+}
+
+static void kvm_loongarch_env_exit(void)
+{
+	unsigned long addr;
+
+	if (vmcs)
+		free_percpu(vmcs);
+
+	if (kvm_loongarch_ops) {
+		if (kvm_loongarch_ops->guest_eentry) {
+			addr = (unsigned long)kvm_loongarch_ops->guest_eentry;
+			free_pages(addr, kvm_loongarch_ops->page_order);
+		}
+		kfree(kvm_loongarch_ops);
+	}
+}
+
+static int kvm_loongarch_init(void)
+{
+	int r;
+
+	if (!cpu_has_lvz) {
+		kvm_info("hardware virtualization not available\n");
+		return -ENODEV;
+	}
+	r = kvm_loongarch_env_init();
+	if (r)
+		return r;
+
+	return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+}
+
+static void kvm_loongarch_exit(void)
+{
+	kvm_exit();
+	kvm_loongarch_env_exit();
+}
+
+module_init(kvm_loongarch_init);
+module_exit(kvm_loongarch_exit);
-- 
2.39.1