Re: [PATCH v21 01/29] LoongArch: KVM: Add kvm related header files

From: zhaotianrui
Date: Sun Sep 17 2023 - 21:33:23 EST


在 2023/9/16 下午4:48, Huacai Chen 写道:
Hi, Tianrui,

On Fri, Sep 15, 2023 at 9:50 AM Tianrui Zhao <zhaotianrui@xxxxxxxxxxx> wrote:
Add LoongArch KVM related header files, including kvm.h,
kvm_host.h, kvm_types.h. All of those are about LoongArch
virtualization features and kvm interfaces.

Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
arch/loongarch/include/asm/kvm_host.h | 245 +++++++++++++++++++++++++
arch/loongarch/include/asm/kvm_types.h | 11 ++
arch/loongarch/include/uapi/asm/kvm.h | 108 +++++++++++
include/uapi/linux/kvm.h | 9 +
4 files changed, 373 insertions(+)
create mode 100644 arch/loongarch/include/asm/kvm_host.h
create mode 100644 arch/loongarch/include/asm/kvm_types.h
create mode 100644 arch/loongarch/include/uapi/asm/kvm.h

diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
new file mode 100644
index 0000000000..00e0c1876b
--- /dev/null
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -0,0 +1,245 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_LOONGARCH_KVM_HOST_H__
+#define __ASM_LOONGARCH_KVM_HOST_H__
+
+#include <linux/cpumask.h>
+#include <linux/mutex.h>
+#include <linux/hrtimer.h>
+#include <linux/interrupt.h>
+#include <linux/types.h>
+#include <linux/kvm.h>
+#include <linux/kvm_types.h>
+#include <linux/threads.h>
+#include <linux/spinlock.h>
+
+#include <asm/inst.h>
+#include <asm/kvm_mmu.h>
+#include <asm/loongarch.h>
+
+/* Loongarch KVM register ids */
+#define KVM_GET_IOC_CSRIDX(id) ((id & KVM_CSR_IDX_MASK) >> LOONGARCH_REG_SHIFT)
+#define KVM_GET_IOC_CPUCFG_IDX(id) ((id & KVM_CPUCFG_IDX_MASK) >> LOONGARCH_REG_SHIFT)
+
+#define KVM_MAX_VCPUS 256
+#define KVM_MAX_CPUCFG_REGS 21
+/* memory slots that does not exposed to userspace */
+#define KVM_PRIVATE_MEM_SLOTS 0
+
+#define KVM_HALT_POLL_NS_DEFAULT 500000
+
+struct kvm_vm_stat {
+ struct kvm_vm_stat_generic generic;
+ u64 pages;
+ u64 hugepages;
+};
+
+struct kvm_vcpu_stat {
+ struct kvm_vcpu_stat_generic generic;
+ u64 idle_exits;
+ u64 signal_exits;
+ u64 int_exits;
+ u64 cpucfg_exits;
+};
+
+struct kvm_arch_memory_slot {
+};
+
+struct kvm_context {
+ unsigned long vpid_cache;
+ struct kvm_vcpu *last_vcpu;
+};
+
+struct kvm_world_switch {
+ int (*guest_eentry)(void);
+ int (*enter_guest)(struct kvm_run *run, struct kvm_vcpu *vcpu);
+ unsigned long page_order;
+};
+
+#define MAX_PGTABLE_LEVELS 4
+struct kvm_arch {
+ /* Guest physical mm */
+ kvm_pte_t *pgd;
+ unsigned long gpa_size;
+ unsigned long invalid_ptes[MAX_PGTABLE_LEVELS];
+ unsigned int pte_shifts[MAX_PGTABLE_LEVELS];
+ unsigned int root_level;
+
+ s64 time_offset;
+ struct kvm_context __percpu *vmcs;
+};
+
+#define CSR_MAX_NUMS 0x800
+
+struct loongarch_csrs {
+ unsigned long csrs[CSR_MAX_NUMS];
+};
+
+/* Resume Flags */
+#define RESUME_HOST 0
+#define RESUME_GUEST 1
+
+enum emulation_result {
+ EMULATE_DONE, /* no further processing */
+ EMULATE_DO_MMIO, /* kvm_run filled with MMIO request */
+ EMULATE_FAIL, /* can't emulate this instruction */
+ EMULATE_EXCEPT, /* A guest exception has been generated */
+ EMULATE_DO_IOCSR, /* handle IOCSR request */
+};
+
+#define KVM_LARCH_FPU (0x1 << 0)
+#define KVM_LARCH_CSR (0x1 << 1)
+#define KVM_LARCH_HWCSR_USABLE (0x1 << 2)
+
+struct kvm_vcpu_arch {
+ /*
+ * Switch pointer-to-function type to unsigned long
+ * for loading the value into register directly.
+ */
+ unsigned long host_eentry;
+ unsigned long guest_eentry;
+
+ /* Pointers stored here for easy accessing from assembly code */
+ int (*handle_exit)(struct kvm_run *run, struct kvm_vcpu *vcpu);
+
+ /* Host registers preserved across guest mode execution */
+ unsigned long host_sp;
+ unsigned long host_tp;
+ unsigned long host_pgd;
+
+ /* Host CSRs are used when handling exits from guest */
+ unsigned long badi;
+ unsigned long badv;
+ unsigned long host_ecfg;
+ unsigned long host_estat;
+ unsigned long host_percpu;
+
+ /* GPRs */
+ unsigned long gprs[32];
+ unsigned long pc;
+
+ /* Which auxiliary state is loaded (KVM_LARCH_*) */
+ unsigned int aux_inuse;
+ /* FPU state */
+ struct loongarch_fpu fpu FPU_ALIGN;
+
+ /* CSR state */
+ struct loongarch_csrs *csr;
+
+ /* GPR used as IO source/target */
+ u32 io_gpr;
+
+ struct hrtimer swtimer;
+ /* KVM register to control count timer */
+ u32 count_ctl;
+
+ /* Bitmask of intr that are pending */
+ unsigned long irq_pending;
+ /* Bitmask of pending intr to be cleared */
+ unsigned long irq_clear;
+
+ /* Bitmask of exceptions that are pending */
+ unsigned long exception_pending;
+ unsigned int subcode;
+
+ /* Cache for pages needed inside spinlock regions */
+ struct kvm_mmu_memory_cache mmu_page_cache;
+
+ /* vcpu's vpid */
+ u64 vpid;
+
+ /* Frequency of stable timer in Hz */
+ u64 timer_mhz;
+ ktime_t expire;
+
+ u64 core_ext_ioisr[4];
+
+ /* Last CPU the vCPU state was loaded on */
+ int last_sched_cpu;
+ /* mp state */
+ struct kvm_mp_state mp_state;
+ /* cpucfg */
+ u32 cpucfg[KVM_MAX_CPUCFG_REGS];
+};
+
+static inline unsigned long readl_sw_gcsr(struct loongarch_csrs *csr, int reg)
+{
+ return csr->csrs[reg];
+}
+
+static inline void writel_sw_gcsr(struct loongarch_csrs *csr, int reg, unsigned long val)
+{
+ csr->csrs[reg] = val;
+}
+
+/* Helpers */
+static inline bool kvm_guest_has_fpu(struct kvm_vcpu_arch *arch)
+{
+ return cpu_has_fpu;
+}
+
+void kvm_init_fault(void);
+
+/* Debug: dump vcpu state */
+int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
+
+/* MMU handling */
+int kvm_handle_mm_fault(struct kvm_vcpu *vcpu, unsigned long badv, bool write);
+void kvm_flush_tlb_all(void);
+
+#define KVM_ARCH_WANT_MMU_NOTIFIER
+int kvm_unmap_hva_range(struct kvm *kvm,
+ unsigned long start, unsigned long end, bool blockable);
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
+int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
+int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
+
+static inline void update_pc(struct kvm_vcpu_arch *arch)
+{
+ arch->pc += 4;
+}
+
+/**
+ * kvm_is_ifetch_fault() - Find whether a TLBL exception is due to ifetch fault.
+ * @vcpu: Virtual CPU.
+ *
+ * Returns: Whether the TLBL exception was likely due to an instruction
+ * fetch fault rather than a data load fault.
+ */
+static inline bool kvm_is_ifetch_fault(struct kvm_vcpu_arch *arch)
+{
+ return arch->pc == arch->badv;
+}
+
+/* Misc */
+static inline void kvm_arch_hardware_unsetup(void) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_free_memslot(struct kvm *kvm,
+ struct kvm_memory_slot *slot) {}
+void kvm_check_vpid(struct kvm_vcpu *vcpu);
+enum hrtimer_restart kvm_swtimer_wakeup(struct hrtimer *timer);
+int kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa);
+void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
+ const struct kvm_memory_slot *memslot);
+void kvm_init_vmcs(struct kvm *kvm);
+void kvm_vector_entry(void);
+int kvm_enter_guest(struct kvm_run *run, struct kvm_vcpu *vcpu);
+extern const unsigned long kvm_vector_size;
+extern const unsigned long kvm_enter_guest_size;
+extern unsigned long vpid_mask;
+extern struct kvm_world_switch *kvm_loongarch_ops;
+
+#define SW_GCSR (1 << 0)
+#define HW_GCSR (1 << 1)
+#define INVALID_GCSR (1 << 2)
+int get_gcsr_flag(int csr);
+extern void set_hw_gcsr(int csr_id, unsigned long val);
+#endif /* __ASM_LOONGARCH_KVM_HOST_H__ */
diff --git a/arch/loongarch/include/asm/kvm_types.h b/arch/loongarch/include/asm/kvm_types.h
new file mode 100644
index 0000000000..2fe1d4bdff
--- /dev/null
+++ b/arch/loongarch/include/asm/kvm_types.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#ifndef _ASM_LOONGARCH_KVM_TYPES_H
+#define _ASM_LOONGARCH_KVM_TYPES_H
+
+#define KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE 40
+
+#endif /* _ASM_LOONGARCH_KVM_TYPES_H */
diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h
new file mode 100644
index 0000000000..fafda487d6
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#ifndef __UAPI_ASM_LOONGARCH_KVM_H
+#define __UAPI_ASM_LOONGARCH_KVM_H
+
+#include <linux/types.h>
+
+/*
+ * KVM Loongarch specific structures and definitions.
+ *
+ * Some parts derived from the x86 version of this file.
+ */
+
+#define __KVM_HAVE_READONLY_MEM
+
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+#define KVM_DIRTY_LOG_PAGE_OFFSET 64
+
+/*
+ * for KVM_GET_REGS and KVM_SET_REGS
+ */
+struct kvm_regs {
+ /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
+ __u64 gpr[32];
+ __u64 pc;
+};
+
+/*
+ * for KVM_GET_FPU and KVM_SET_FPU
+ */
+struct kvm_fpu {
+ __u32 fcsr;
+ __u64 fcc; /* 8x8 */
+ struct kvm_fpureg {
+ __u64 val64[4];
+ } fpr[32];
+};
+
+/*
+ * For LoongArch, we use KVM_SET_ONE_REG and KVM_GET_ONE_REG to access various
+ * registers. The id field is broken down as follows:
+ *
+ * bits[63..52] - As per linux/kvm.h
+ * bits[51..32] - Must be zero.
+ * bits[31..16] - Register set.
+ *
+ * Register set = 0: GP registers from kvm_regs (see definitions below).
+ *
+ * Register set = 1: CSR registers.
+ *
+ * Register set = 2: KVM specific registers (see definitions below).
+ *
+ * Register set = 3: FPU / SIMD registers (see definitions below).
+ *
+ * Other sets registers may be added in the future. Each set would
+ * have its own identifier in bits[31..16].
+ */
+
+#define KVM_REG_LOONGARCH_GPR (KVM_REG_LOONGARCH | 0x00000ULL)
+#define KVM_REG_LOONGARCH_CSR (KVM_REG_LOONGARCH | 0x10000ULL)
+#define KVM_REG_LOONGARCH_KVM (KVM_REG_LOONGARCH | 0x20000ULL)
+#define KVM_REG_LOONGARCH_FPU (KVM_REG_LOONGARCH | 0x30000ULL)
How about rename to KVM_REG_LOONGARCH_FPSIMD？

Huacai
It will broke uapi used by user space software, it may cause incompatible issue, so I think it is better to keep the original name.

Thanks
Tianrui Zhao

+#define KVM_REG_LOONGARCH_CPUCFG (KVM_REG_LOONGARCH | 0x40000ULL)
+#define KVM_REG_LOONGARCH_MASK (KVM_REG_LOONGARCH | 0x70000ULL)
+#define KVM_CSR_IDX_MASK 0x7fff
+#define KVM_CPUCFG_IDX_MASK 0x7fff
+
+/*
+ * KVM_REG_LOONGARCH_KVM - KVM specific control registers.
+ */
+
+#define KVM_REG_LOONGARCH_COUNTER (KVM_REG_LOONGARCH_KVM | KVM_REG_SIZE_U64 | 3)
+#define KVM_REG_LOONGARCH_VCPU_RESET (KVM_REG_LOONGARCH_KVM | KVM_REG_SIZE_U64 | 4)
+
+#define LOONGARCH_REG_SHIFT 3
+#define LOONGARCH_REG_64(TYPE, REG) (TYPE | KVM_REG_SIZE_U64 | (REG << LOONGARCH_REG_SHIFT))
+#define KVM_IOC_CSRID(REG) LOONGARCH_REG_64(KVM_REG_LOONGARCH_CSR, REG)
+#define KVM_IOC_CPUCFG(REG) LOONGARCH_REG_64(KVM_REG_LOONGARCH_CPUCFG, REG)
+
+struct kvm_debug_exit_arch {
+};
+
+/* for KVM_SET_GUEST_DEBUG */
+struct kvm_guest_debug_arch {
+};
+
+/* definition of registers in kvm_run */
+struct kvm_sync_regs {
+};
+
+/* dummy definition */
+struct kvm_sregs {
+};
+
+struct kvm_iocsr_entry {
+ __u32 addr;
+ __u32 pad;
+ __u64 data;
+};
+
+#define KVM_NR_IRQCHIPS 1
+#define KVM_IRQCHIP_NUM_PINS 64
+#define KVM_MAX_CORES 256
+
+#endif /* __UAPI_ASM_LOONGARCH_KVM_H */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 13065dd961..863f84619a 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -264,6 +264,7 @@ struct kvm_xen_exit {
#define KVM_EXIT_RISCV_SBI 35
#define KVM_EXIT_RISCV_CSR 36
#define KVM_EXIT_NOTIFY 37
+#define KVM_EXIT_LOONGARCH_IOCSR 38

/* For KVM_EXIT_INTERNAL_ERROR */
/* Emulate instruction failed. */
@@ -336,6 +337,13 @@ struct kvm_run {
__u32 len;
__u8 is_write;
} mmio;
+ /* KVM_EXIT_LOONGARCH_IOCSR */
+ struct {
+ __u64 phys_addr;
+ __u8 data[8];
+ __u32 len;
+ __u8 is_write;
+ } iocsr_io;
/* KVM_EXIT_HYPERCALL */
struct {
__u64 nr;
@@ -1362,6 +1370,7 @@ struct kvm_dirty_tlb {
#define KVM_REG_ARM64 0x6000000000000000ULL
#define KVM_REG_MIPS 0x7000000000000000ULL
#define KVM_REG_RISCV 0x8000000000000000ULL
+#define KVM_REG_LOONGARCH 0x9000000000000000ULL

#define KVM_REG_SIZE_SHIFT 52
#define KVM_REG_SIZE_MASK 0x00f0000000000000ULL
--
2.39.1