Merge tag 'loongarch-kvm-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD

LoongArch KVM changes for v6.7

Add LoongArch's KVM support. Loongson 3A5000/3A6000 supports hardware
assisted virtualization. With cpu virtualization, there are separate
hw-supported user mode and kernel mode in guest mode. With memory
virtualization, there are two-level hw mmu table for guest mode and host
mode. Also there is separate hw cpu timer with consant frequency in
guest mode, so that vm can migrate between hosts with different freq.
Currently, we are able to boot LoongArch Linux Guests.

Few key aspects of KVM LoongArch added by this series are:
1. Enable kvm hardware function when kvm module is loaded.
2. Implement VM and vcpu related ioctl interface such as vcpu create,
   vcpu run etc. GET_ONE_REG/SET_ONE_REG ioctl commands are use to
   get general registers one by one.
3. Hardware access about MMU, timer and csr are emulated in kernel.
4. Hardwares such as mmio and iocsr device are emulated in user space
   such as IPI, irqchips, pci devices etc.

1 files changed, 108 insertions, 0 deletions

diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h
new file mode 100644
index 000000000000..c6ad2ee6106c
--- /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_FPSIMD	(KVM_REG_LOONGARCH | 0x30000ULL)
+#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 | 1)
+#define KVM_REG_LOONGARCH_VCPU_RESET	(KVM_REG_LOONGARCH_KVM | KVM_REG_SIZE_U64 | 2)
+
+#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 */