Re: [PATCH v7 01/30] LoongArch: KVM: Add kvm related header files
From: WANG Xuerui
Date: Wed Apr 19 2023 - 05:29:04 EST
On 2023/4/17 17:46, Tianrui Zhao 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.
Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
arch/loongarch/include/asm/cpu-features.h | 22 ++
arch/loongarch/include/asm/kvm_host.h | 268 ++++++++++++++++++++++
arch/loongarch/include/asm/kvm_types.h | 11 +
arch/loongarch/include/uapi/asm/kvm.h | 107 +++++++++
include/uapi/linux/kvm.h | 9 +
5 files changed, 417 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/cpu-features.h b/arch/loongarch/include/asm/cpu-features.h
index b07974218393..345b7674a15f 100644
--- a/arch/loongarch/include/asm/cpu-features.h
+++ b/arch/loongarch/include/asm/cpu-features.h
@@ -64,5 +64,27 @@
#define cpu_has_guestid cpu_opt(LOONGARCH_CPU_GUESTID)
#define cpu_has_hypervisor cpu_opt(LOONGARCH_CPU_HYPERVISOR)
+#define cpu_has_matc_guest (cpu_data[0].guest_cfg & BIT(0))
+#define cpu_has_matc_root (cpu_data[0].guest_cfg & BIT(1))
+#define cpu_has_matc_nest (cpu_data[0].guest_cfg & BIT(2))
+#define cpu_has_sitp (cpu_data[0].guest_cfg & BIT(6))
+#define cpu_has_titp (cpu_data[0].guest_cfg & BIT(8))
+#define cpu_has_toep (cpu_data[0].guest_cfg & BIT(10))
+#define cpu_has_topp (cpu_data[0].guest_cfg & BIT(12))
+#define cpu_has_torup (cpu_data[0].guest_cfg & BIT(14))
+#define cpu_has_gcip_all (cpu_data[0].guest_cfg & BIT(16))
+#define cpu_has_gcip_hit (cpu_data[0].guest_cfg & BIT(17))
+#define cpu_has_gcip_secure (cpu_data[0].guest_cfg & BIT(18))
We don't have guest_cfg yet in the cpu_data structure. You may have to
re-organize a little bit to avoid referencing things from future commits.
Also you may want to make more use of the definitions already in
<asm/loongarch.h>, e.g. the BIT(6) here is just CSR_GCFG_SITP, and it
seems the matc_{guest,root,nest} definitions here conflict with the
definitions in <asm/loongarch.h> which implies the MATC is a plain value
instead of a bunch of bit flags.
+
+/*
+ * Guest capabilities
+ */
+#define cpu_guest_has_conf1 (cpu_data[0].guest.conf & BIT(1))
+#define cpu_guest_has_conf2 (cpu_data[0].guest.conf & BIT(2))
+#define cpu_guest_has_conf3 (cpu_data[0].guest.conf & BIT(3))
+#define cpu_guest_has_fpu (cpu_data[0].guest.options & LOONGARCH_CPU_FPU)
+#define cpu_guest_has_perf (cpu_data[0].guest.options & LOONGARCH_CPU_PMP)
+#define cpu_guest_has_watch (cpu_data[0].guest.options & LOONGARCH_CPU_WATCH)
+#define cpu_guest_has_lsx (cpu_data[0].guest.ases & LOONGARCH_ASE_LSX)
There is no LOONGARCH_ASE_LSX either.
#endif /* __ASM_CPU_FEATURES_H */
diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
new file mode 100644
index 000000000000..bd239079b36f
--- /dev/null
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -0,0 +1,268 @@
+/* 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/loongarch.h>
+
+/* Loongarch KVM register ids */
+#define LOONGARCH_CSR_32(_R, _S) \
+ (KVM_REG_LOONGARCH_CSR | KVM_REG_SIZE_U32 | (8 * (_R) + (_S)))
+
+#define LOONGARCH_CSR_64(_R, _S) \
+ (KVM_REG_LOONGARCH_CSR | KVM_REG_SIZE_U64 | (8 * (_R) + (_S)))
+
+#define KVM_IOC_CSRID(id) LOONGARCH_CSR_64(id, 0)
+#define KVM_GET_IOC_CSRIDX(id) ((id & KVM_CSR_IDX_MASK) >> 3)
+
+#define KVM_MAX_VCPUS 256
+/* 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;
+};
+
+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;
+};
+
+struct kvm_arch {
+ /* Guest physical mm */
+ struct mm_struct gpa_mm;
+ /* Mask of CPUs needing GPA ASID flush */
+ cpumask_t asid_flush_mask;
+
+ unsigned char online_vcpus;
+ unsigned char is_migrate;
+ s64 time_offset;
+ struct kvm_context __percpu *vmcs;
+ unsigned long gpa_size;
+};
+
+
+#define LOONGARCH_CSRS 0x100
+#define CSR_UCWIN_BASE 0x100
+#define CSR_UCWIN_SIZE 0x10
+#define CSR_DMWIN_BASE 0x180
+#define CSR_DMWIN_SIZE 0x4 > +#define CSR_PERF_BASE 0x200
+#define CSR_PERF_SIZE 0x8
+#define CSR_DEBUG_BASE 0x500
+#define CSR_DEBUG_SIZE 0x3
+#define CSR_ALL_SIZE 0x800
Is the "SIZE"'s actually "numbers"? 16-byte or even 3-byte CSRs make
absolutely no sense in LoongArch. However e.g. there are indeed 4 DMWINs
in total, so I think you may want to say "number of xxx" instead (in
which case you should probably name them "CSR_XXX_NUM").
Also there are duplications here too. CSR_UCWIN_BASE is just
LOONGARCH_CSR_UCAWIN, CSR_DMWIN_BASE is LOONGARCH_CSR_DMWIN0,
CSR_PERF_BASE is LOONGARCH_CSR_PERFCTRL0, and CSR_DEBUG_BASE is
LOONGARCH_CSR_DEBUG. You should at least avoid repeating the magic numbers.
+
+struct loongarch_csrs {
+ unsigned long csrs[CSR_ALL_SIZE];
+};
+
+/* Resume Flags */
+#define RESUME_GUEST 1
+#define RESUME_HOST 0
+
+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_WAIT, /* WAIT instruction */
+ EMULATE_EXCEPT, /* A guest exception has been generated */
+ EMULATE_DO_IOCSR, /* handle IOCSR request */
+};
+
+#define KVM_NR_MEM_OBJS 4
+#define KVM_LARCH_FPU (0x1 << 0)
+#define KVM_LARCH_CSR (0x1 << 1)
+
+struct kvm_vcpu_arch {
+ /*
+ * Switch pointer-to-function type to unsigned long
+ * for loading the value into register directly.
+ */
+ unsigned long guest_eentry;
+ unsigned long host_eentry;
+
+ /* Pointers stored here for easy access from assembly code. */
nit: remove trailing period
+ int (*handle_exit)(struct kvm_run *run, struct kvm_vcpu *vcpu);
+
+ /* Host registers preserved across guest mode execution */
+ unsigned long host_stack;
+ unsigned long host_gp;
+ unsigned long host_pgd;
+ unsigned long host_pgdhi;
+ unsigned long host_entryhi;
+
+ /* Host CSR registers used when handling exits from guest */
nit: "Host CSRs"
+ unsigned long badv;
+ unsigned long host_estat;
+ unsigned long badi;
+ unsigned long host_ecfg;
+ unsigned long host_percpu;
+
+ /* GPRS */
nit: "GPRs"
+ unsigned long gprs[32];
+ unsigned long pc;
+
+ /* FPU State */
nit: "state"
+ struct loongarch_fpu fpu FPU_ALIGN;
+ /* Which auxiliary state is loaded (KVM_LOONGARCH_AUX_*) */
+ unsigned int aux_inuse;
+
+ /* CSR State */
+ struct loongarch_csrs *csr;
+
+ /* GPR used as IO source/target */
+ u32 io_gpr;
+
+ struct hrtimer swtimer;
+ /* Count timer control KVM register */
This doesn't make sense, how can the timer control KVM? Seems something
like "KVM register to control count timer" but I'm not sure.
+ u32 count_ctl;
+
+ /* Bitmask of exceptions that are pending */
+ unsigned long irq_pending;
+ /* Bitmask of pending exceptions to be cleared */
+ unsigned long irq_clear;
+
+ /* Cache some mmu pages needed inside spinlock regions */
"Cache for pages needed inside ..."?
+ struct kvm_mmu_memory_cache mmu_page_cache;
+
+ /* vcpu's vpid */
+ u64 vpid;
+
+ /* Period of stable timer tick in ns */
+ u64 timer_period;
Can you make it "timer_period_ns" or are you following other arches'
conventions?
+ /* Frequency of stable timer in Hz */
+ u64 timer_mhz;
Is it really MHz or Hz?
+ /* Stable bias from the raw time */
+ u64 timer_bias;
+ /* Dynamic nanosecond bias (multiple of timer_period) to avoid overflow */
+ s64 timer_dyn_bias;
+ /* Save ktime */
The comment seems redundant (code is too trivial so the comment doesn't
add any information).
+ ktime_t stable_ktime_saved;
+
+ u64 core_ext_ioisr[4];
+
+ /* Last CPU the VCPU state was loaded on */
Use consistent spelling: "vCPU".
+ int last_sched_cpu;
+ /* Last CPU the VCPU actually executed guest code on */
+ int last_exec_cpu;
+ /* mp state */
+ struct kvm_mp_state mp_state;
+};
+
+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);
+void _kvm_destroy_mm(struct kvm *kvm);
+pgd_t *kvm_pgd_alloc(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)
+{
+ if (arch->pc == arch->badv)
+ return true;
+
+ return false;
return arch->pc == arch->badv;
All other such occurrences should preferably be simplified too.
+}
+
+/* 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_vmid(struct kvm_vcpu *vcpu, int cpu);
+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)
+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 000000000000..060647b5fe2e
--- /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 4
Is there any difference with KVM_NR_MEM_OBJS in <asm/kvm_host.h> in the
same commit? If they are actually the same thing you should avoid
duplicating the "4".
+
+#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 000000000000..074d86ba532c
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -0,0 +1,107 @@
+/* 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
+
+/*
+ * 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;
+ __u32 none;
Is this field an explicit padding? Probably it's better to use a more
descriptive name like __pad0 if it's the case.
+ __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_GP (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)
+#define KVM_REG_LOONGARCH_MASK (KVM_REG_LOONGARCH | 0x30000ULL)
+#define KVM_CSR_IDX_MASK (0x10000 - 1)
+
+/*
+ * 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)
+
+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;
+};
+
+struct kvm_loongarch_interrupt {
+ /* in */
+ __u32 cpu;
+ __u32 irq;
+};
+
+#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 d77aef872a0a..d14fde87ae35 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;
@@ -1354,6 +1362,7 @@ 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
--
WANG "xen0n" Xuerui
Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/