Re: [PATCH v21 02/29] LoongArch: KVM: Implement kvm module related interface
From: zhaotianrui
Date: Tue Sep 19 2023 - 01:07:42 EST
在 2023/9/19 上午10:41, Huacai Chen 写道:
On Tue, Sep 19, 2023 at 10:38 AM zhaotianrui <zhaotianrui@xxxxxxxxxxx> wrote:
在 2023/9/17 下午12:21, Huacai Chen 写道:
Hi, Tianrui,
On Fri, Sep 15, 2023 at 9:50 AM Tianrui Zhao <zhaotianrui@xxxxxxxxxxx> wrote:
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 | 367 ++++++++++++++++++++++++++++++++++++++
1 file changed, 367 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 0000000000..0deb9273d8
--- /dev/null
+++ b/arch/loongarch/kvm/main.c
@@ -0,0 +1,367 @@
+// 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/cpufeature.h>
+#include <asm/kvm_csr.h>
+#include "trace.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 void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
+{
+ struct kvm_context *context;
+ unsigned long vpid;
+
+ context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
+ vpid = context->vpid_cache + 1;
+ if (!(vpid & vpid_mask)) {
+ /* finish round of 64 bit loop */
+ if (unlikely(!vpid))
+ vpid = vpid_mask + 1;
+
+ /* vpid 0 reserved for root */
+ ++vpid;
+
+ /* start new vpid cycle */
+ kvm_flush_tlb_all();
+ }
+
+ context->vpid_cache = vpid;
+ vcpu->arch.vpid = vpid;
+}
+
+void kvm_check_vpid(struct kvm_vcpu *vcpu)
+{
+ struct kvm_context *context;
+ bool migrated;
+ unsigned long ver, old, vpid;
+ int cpu;
+
+ cpu = smp_processor_id();
+ /*
+ * Are we entering guest context on a different CPU to last time?
+ * If so, the vCPU's guest TLB state on this CPU may be stale.
+ */
+ context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
+ migrated = (vcpu->cpu != cpu);
+
+ /*
+ * Check if our vpid is of an older version
+ *
+ * We also discard the stored vpid if we've executed on
+ * another CPU, as the guest mappings may have changed without
+ * hypervisor knowledge.
+ */
+ ver = vcpu->arch.vpid & ~vpid_mask;
+ old = context->vpid_cache & ~vpid_mask;
+ if (migrated || (ver != old)) {
+ kvm_update_vpid(vcpu, cpu);
+ trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
+ vcpu->cpu = cpu;
+ }
+
+ /* Restore GSTAT(0x50).vpid */
+ vpid = (vcpu->arch.vpid & vpid_mask) << CSR_GSTAT_GID_SHIFT;
+ change_csr_gstat(vpid_mask << CSR_GSTAT_GID_SHIFT, vpid);
+}
+
+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);
Why memcpy? In our internal repo, we use kvm_vector_entry and
kvm_enter_guest directly. The long comments above make me nervous
because Loongson-3A6000 already supports hardware pagetable walker.
Huacai
As mentioned in the comments, it need not this memcpy if hardware page
walk is supported in 3A6000.
But why in our internal repo we don't use memcpy() but kvm can still
work on Loongson-3A5000?
Huacai
Because in our internal repo, the KVM is build along with the linux
kernel, however, this KVM patch series is build in module.
Thanks
Tianrui Zhao
Thanks
Tianrui Zhao
+ 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);
+
+#ifdef MODULE
+static const struct cpu_feature loongarch_kvm_feature[] = {
+ { .feature = cpu_feature(LOONGARCH_LVZ) },
+ {},
+};
+MODULE_DEVICE_TABLE(cpu, loongarch_kvm_feature);
+#endif
--
2.39.1