diff options
Diffstat (limited to 'arch/riscv/kvm/vcpu_exit.c')
| -rw-r--r-- | arch/riscv/kvm/vcpu_exit.c | 701 |
1 files changed, 701 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c new file mode 100644 index 000000000000..7f2d742ae4c6 --- /dev/null +++ b/arch/riscv/kvm/vcpu_exit.c @@ -0,0 +1,701 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Western Digital Corporation or its affiliates. + * + * Authors: + * Anup Patel <anup.patel@wdc.com> + */ + +#include <linux/bitops.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/kvm_host.h> +#include <asm/csr.h> + +#define INSN_OPCODE_MASK 0x007c +#define INSN_OPCODE_SHIFT 2 +#define INSN_OPCODE_SYSTEM 28 + +#define INSN_MASK_WFI 0xffffffff +#define INSN_MATCH_WFI 0x10500073 + +#define INSN_MATCH_LB 0x3 +#define INSN_MASK_LB 0x707f +#define INSN_MATCH_LH 0x1003 +#define INSN_MASK_LH 0x707f +#define INSN_MATCH_LW 0x2003 +#define INSN_MASK_LW 0x707f +#define INSN_MATCH_LD 0x3003 +#define INSN_MASK_LD 0x707f +#define INSN_MATCH_LBU 0x4003 +#define INSN_MASK_LBU 0x707f +#define INSN_MATCH_LHU 0x5003 +#define INSN_MASK_LHU 0x707f +#define INSN_MATCH_LWU 0x6003 +#define INSN_MASK_LWU 0x707f +#define INSN_MATCH_SB 0x23 +#define INSN_MASK_SB 0x707f +#define INSN_MATCH_SH 0x1023 +#define INSN_MASK_SH 0x707f +#define INSN_MATCH_SW 0x2023 +#define INSN_MASK_SW 0x707f +#define INSN_MATCH_SD 0x3023 +#define INSN_MASK_SD 0x707f + +#define INSN_MATCH_C_LD 0x6000 +#define INSN_MASK_C_LD 0xe003 +#define INSN_MATCH_C_SD 0xe000 +#define INSN_MASK_C_SD 0xe003 +#define INSN_MATCH_C_LW 0x4000 +#define INSN_MASK_C_LW 0xe003 +#define INSN_MATCH_C_SW 0xc000 +#define INSN_MASK_C_SW 0xe003 +#define INSN_MATCH_C_LDSP 0x6002 +#define INSN_MASK_C_LDSP 0xe003 +#define INSN_MATCH_C_SDSP 0xe002 +#define INSN_MASK_C_SDSP 0xe003 +#define INSN_MATCH_C_LWSP 0x4002 +#define INSN_MASK_C_LWSP 0xe003 +#define INSN_MATCH_C_SWSP 0xc002 +#define INSN_MASK_C_SWSP 0xe003 + +#define INSN_16BIT_MASK 0x3 + +#define INSN_IS_16BIT(insn) (((insn) & INSN_16BIT_MASK) != INSN_16BIT_MASK) + +#define INSN_LEN(insn) (INSN_IS_16BIT(insn) ? 2 : 4) + +#ifdef CONFIG_64BIT +#define LOG_REGBYTES 3 +#else +#define LOG_REGBYTES 2 +#endif +#define REGBYTES (1 << LOG_REGBYTES) + +#define SH_RD 7 +#define SH_RS1 15 +#define SH_RS2 20 +#define SH_RS2C 2 + +#define RV_X(x, s, n) (((x) >> (s)) & ((1 << (n)) - 1)) +#define RVC_LW_IMM(x) ((RV_X(x, 6, 1) << 2) | \ + (RV_X(x, 10, 3) << 3) | \ + (RV_X(x, 5, 1) << 6)) +#define RVC_LD_IMM(x) ((RV_X(x, 10, 3) << 3) | \ + (RV_X(x, 5, 2) << 6)) +#define RVC_LWSP_IMM(x) ((RV_X(x, 4, 3) << 2) | \ + (RV_X(x, 12, 1) << 5) | \ + (RV_X(x, 2, 2) << 6)) +#define RVC_LDSP_IMM(x) ((RV_X(x, 5, 2) << 3) | \ + (RV_X(x, 12, 1) << 5) | \ + (RV_X(x, 2, 3) << 6)) +#define RVC_SWSP_IMM(x) ((RV_X(x, 9, 4) << 2) | \ + (RV_X(x, 7, 2) << 6)) +#define RVC_SDSP_IMM(x) ((RV_X(x, 10, 3) << 3) | \ + (RV_X(x, 7, 3) << 6)) +#define RVC_RS1S(insn) (8 + RV_X(insn, SH_RD, 3)) +#define RVC_RS2S(insn) (8 + RV_X(insn, SH_RS2C, 3)) +#define RVC_RS2(insn) RV_X(insn, SH_RS2C, 5) + +#define SHIFT_RIGHT(x, y) \ + ((y) < 0 ? ((x) << -(y)) : ((x) >> (y))) + +#define REG_MASK \ + ((1 << (5 + LOG_REGBYTES)) - (1 << LOG_REGBYTES)) + +#define REG_OFFSET(insn, pos) \ + (SHIFT_RIGHT((insn), (pos) - LOG_REGBYTES) & REG_MASK) + +#define REG_PTR(insn, pos, regs) \ + ((ulong *)((ulong)(regs) + REG_OFFSET(insn, pos))) + +#define GET_RM(insn) (((insn) >> 12) & 7) + +#define GET_RS1(insn, regs) (*REG_PTR(insn, SH_RS1, regs)) +#define GET_RS2(insn, regs) (*REG_PTR(insn, SH_RS2, regs)) +#define GET_RS1S(insn, regs) (*REG_PTR(RVC_RS1S(insn), 0, regs)) +#define GET_RS2S(insn, regs) (*REG_PTR(RVC_RS2S(insn), 0, regs)) +#define GET_RS2C(insn, regs) (*REG_PTR(insn, SH_RS2C, regs)) +#define GET_SP(regs) (*REG_PTR(2, 0, regs)) +#define SET_RD(insn, regs, val) (*REG_PTR(insn, SH_RD, regs) = (val)) +#define IMM_I(insn) ((s32)(insn) >> 20) +#define IMM_S(insn) (((s32)(insn) >> 25 << 5) | \ + (s32)(((insn) >> 7) & 0x1f)) +#define MASK_FUNCT3 0x7000 + +static int truly_illegal_insn(struct kvm_vcpu *vcpu, + struct kvm_run *run, + ulong insn) +{ + struct kvm_cpu_trap utrap = { 0 }; + + /* Redirect trap to Guest VCPU */ + utrap.sepc = vcpu->arch.guest_context.sepc; + utrap.scause = EXC_INST_ILLEGAL; + utrap.stval = insn; + kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); + + return 1; +} + +static int system_opcode_insn(struct kvm_vcpu *vcpu, + struct kvm_run *run, + ulong insn) +{ + if ((insn & INSN_MASK_WFI) == INSN_MATCH_WFI) { + vcpu->stat.wfi_exit_stat++; + if (!kvm_arch_vcpu_runnable(vcpu)) { + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->arch.srcu_idx); + kvm_vcpu_block(vcpu); + vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + kvm_clear_request(KVM_REQ_UNHALT, vcpu); + } + vcpu->arch.guest_context.sepc += INSN_LEN(insn); + return 1; + } + + return truly_illegal_insn(vcpu, run, insn); +} + +static int virtual_inst_fault(struct kvm_vcpu *vcpu, struct kvm_run *run, + struct kvm_cpu_trap *trap) +{ + unsigned long insn = trap->stval; + struct kvm_cpu_trap utrap = { 0 }; + struct kvm_cpu_context *ct; + + if (unlikely(INSN_IS_16BIT(insn))) { + if (insn == 0) { + ct = &vcpu->arch.guest_context; + insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, + ct->sepc, + &utrap); + if (utrap.scause) { + utrap.sepc = ct->sepc; + kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); + return 1; + } + } + if (INSN_IS_16BIT(insn)) + return truly_illegal_insn(vcpu, run, insn); + } + + switch ((insn & INSN_OPCODE_MASK) >> INSN_OPCODE_SHIFT) { + case INSN_OPCODE_SYSTEM: + return system_opcode_insn(vcpu, run, insn); + default: + return truly_illegal_insn(vcpu, run, insn); + } +} + +static int emulate_load(struct kvm_vcpu *vcpu, struct kvm_run *run, + unsigned long fault_addr, unsigned long htinst) +{ + u8 data_buf[8]; + unsigned long insn; + int shift = 0, len = 0, insn_len = 0; + struct kvm_cpu_trap utrap = { 0 }; + struct kvm_cpu_context *ct = &vcpu->arch.guest_context; + + /* Determine trapped instruction */ + if (htinst & 0x1) { + /* + * Bit[0] == 1 implies trapped instruction value is + * transformed instruction or custom instruction. + */ + insn = htinst | INSN_16BIT_MASK; + insn_len = (htinst & BIT(1)) ? INSN_LEN(insn) : 2; + } else { + /* + * Bit[0] == 0 implies trapped instruction value is + * zero or special value. + */ + insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, ct->sepc, + &utrap); + if (utrap.scause) { + /* Redirect trap if we failed to read instruction */ + utrap.sepc = ct->sepc; + kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); + return 1; + } + insn_len = INSN_LEN(insn); + } + + /* Decode length of MMIO and shift */ + if ((insn & INSN_MASK_LW) == INSN_MATCH_LW) { + len = 4; + shift = 8 * (sizeof(ulong) - len); + } else if ((insn & INSN_MASK_LB) == INSN_MATCH_LB) { + len = 1; + shift = 8 * (sizeof(ulong) - len); + } else if ((insn & INSN_MASK_LBU) == INSN_MATCH_LBU) { + len = 1; + shift = 8 * (sizeof(ulong) - len); +#ifdef CONFIG_64BIT + } else if ((insn & INSN_MASK_LD) == INSN_MATCH_LD) { + len = 8; + shift = 8 * (sizeof(ulong) - len); + } else if ((insn & INSN_MASK_LWU) == INSN_MATCH_LWU) { + len = 4; +#endif + } else if ((insn & INSN_MASK_LH) == INSN_MATCH_LH) { + len = 2; + shift = 8 * (sizeof(ulong) - len); + } else if ((insn & INSN_MASK_LHU) == INSN_MATCH_LHU) { + len = 2; +#ifdef CONFIG_64BIT + } else if ((insn & INSN_MASK_C_LD) == INSN_MATCH_C_LD) { + len = 8; + shift = 8 * (sizeof(ulong) - len); + insn = RVC_RS2S(insn) << SH_RD; + } else if ((insn & INSN_MASK_C_LDSP) == INSN_MATCH_C_LDSP && + ((insn >> SH_RD) & 0x1f)) { + len = 8; + shift = 8 * (sizeof(ulong) - len); +#endif + } else if ((insn & INSN_MASK_C_LW) == INSN_MATCH_C_LW) { + len = 4; + shift = 8 * (sizeof(ulong) - len); + insn = RVC_RS2S(insn) << SH_RD; + } else if ((insn & INSN_MASK_C_LWSP) == INSN_MATCH_C_LWSP && + ((insn >> SH_RD) & 0x1f)) { + len = 4; + shift = 8 * (sizeof(ulong) - len); + } else { + return -EOPNOTSUPP; + } + + /* Fault address should be aligned to length of MMIO */ + if (fault_addr & (len - 1)) + return -EIO; + + /* Save instruction decode info */ + vcpu->arch.mmio_decode.insn = insn; + vcpu->arch.mmio_decode.insn_len = insn_len; + vcpu->arch.mmio_decode.shift = shift; + vcpu->arch.mmio_decode.len = len; + vcpu->arch.mmio_decode.return_handled = 0; + + /* Update MMIO details in kvm_run struct */ + run->mmio.is_write = false; + run->mmio.phys_addr = fault_addr; + run->mmio.len = len; + + /* Try to handle MMIO access in the kernel */ + if (!kvm_io_bus_read(vcpu, KVM_MMIO_BUS, fault_addr, len, data_buf)) { + /* Successfully handled MMIO access in the kernel so resume */ + memcpy(run->mmio.data, data_buf, len); + vcpu->stat.mmio_exit_kernel++; + kvm_riscv_vcpu_mmio_return(vcpu, run); + return 1; + } + + /* Exit to userspace for MMIO emulation */ + vcpu->stat.mmio_exit_user++; + run->exit_reason = KVM_EXIT_MMIO; + + return 0; +} + +static int emulate_store(struct kvm_vcpu *vcpu, struct kvm_run *run, + unsigned long fault_addr, unsigned long htinst) +{ + u8 data8; + u16 data16; + u32 data32; + u64 data64; + ulong data; + unsigned long insn; + int len = 0, insn_len = 0; + struct kvm_cpu_trap utrap = { 0 }; + struct kvm_cpu_context *ct = &vcpu->arch.guest_context; + + /* Determine trapped instruction */ + if (htinst & 0x1) { + /* + * Bit[0] == 1 implies trapped instruction value is + * transformed instruction or custom instruction. + */ + insn = htinst | INSN_16BIT_MASK; + insn_len = (htinst & BIT(1)) ? INSN_LEN(insn) : 2; + } else { + /* + * Bit[0] == 0 implies trapped instruction value is + * zero or special value. + */ + insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, ct->sepc, + &utrap); + if (utrap.scause) { + /* Redirect trap if we failed to read instruction */ + utrap.sepc = ct->sepc; + kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); + return 1; + } + insn_len = INSN_LEN(insn); + } + + data = GET_RS2(insn, &vcpu->arch.guest_context); + data8 = data16 = data32 = data64 = data; + + if ((insn & INSN_MASK_SW) == INSN_MATCH_SW) { + len = 4; + } else if ((insn & INSN_MASK_SB) == INSN_MATCH_SB) { + len = 1; +#ifdef CONFIG_64BIT + } else if ((insn & INSN_MASK_SD) == INSN_MATCH_SD) { + len = 8; +#endif + } else if ((insn & INSN_MASK_SH) == INSN_MATCH_SH) { + len = 2; +#ifdef CONFIG_64BIT + } else if ((insn & INSN_MASK_C_SD) == INSN_MATCH_C_SD) { + len = 8; + data64 = GET_RS2S(insn, &vcpu->arch.guest_context); + } else if ((insn & INSN_MASK_C_SDSP) == INSN_MATCH_C_SDSP && + ((insn >> SH_RD) & 0x1f)) { + len = 8; + data64 = GET_RS2C(insn, &vcpu->arch.guest_context); +#endif + } else if ((insn & INSN_MASK_C_SW) == INSN_MATCH_C_SW) { + len = 4; + data32 = GET_RS2S(insn, &vcpu->arch.guest_context); + } else if ((insn & INSN_MASK_C_SWSP) == INSN_MATCH_C_SWSP && + ((insn >> SH_RD) & 0x1f)) { + len = 4; + data32 = GET_RS2C(insn, &vcpu->arch.guest_context); + } else { + return -EOPNOTSUPP; + } + + /* Fault address should be aligned to length of MMIO */ + if (fault_addr & (len - 1)) + return -EIO; + + /* Save instruction decode info */ + vcpu->arch.mmio_decode.insn = insn; + vcpu->arch.mmio_decode.insn_len = insn_len; + vcpu->arch.mmio_decode.shift = 0; + vcpu->arch.mmio_decode.len = len; + vcpu->arch.mmio_decode.return_handled = 0; + + /* Copy data to kvm_run instance */ + switch (len) { + case 1: + *((u8 *)run->mmio.data) = data8; + break; + case 2: + *((u16 *)run->mmio.data) = data16; + break; + case 4: + *((u32 *)run->mmio.data) = data32; + break; + case 8: + *((u64 *)run->mmio.data) = data64; + break; + default: + return -EOPNOTSUPP; + } + + /* Update MMIO details in kvm_run struct */ + run->mmio.is_write = true; + run->mmio.phys_addr = fault_addr; + run->mmio.len = len; + + /* Try to handle MMIO access in the kernel */ + if (!kvm_io_bus_write(vcpu, KVM_MMIO_BUS, + fault_addr, len, run->mmio.data)) { + /* Successfully handled MMIO access in the kernel so resume */ + vcpu->stat.mmio_exit_kernel++; + kvm_riscv_vcpu_mmio_return(vcpu, run); + return 1; + } + + /* Exit to userspace for MMIO emulation */ + vcpu->stat.mmio_exit_user++; + run->exit_reason = KVM_EXIT_MMIO; + + return 0; +} + +static int stage2_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run, + struct kvm_cpu_trap *trap) +{ + struct kvm_memory_slot *memslot; + unsigned long hva, fault_addr; + bool writeable; + gfn_t gfn; + int ret; + + fault_addr = (trap->htval << 2) | (trap->stval & 0x3); + gfn = fault_addr >> PAGE_SHIFT; + memslot = gfn_to_memslot(vcpu->kvm, gfn); + hva = gfn_to_hva_memslot_prot(memslot, gfn, &writeable); + + if (kvm_is_error_hva(hva) || + (trap->scause == EXC_STORE_GUEST_PAGE_FAULT && !writeable)) { + switch (trap->scause) { + case EXC_LOAD_GUEST_PAGE_FAULT: + return emulate_load(vcpu, run, fault_addr, + trap->htinst); + case EXC_STORE_GUEST_PAGE_FAULT: + return emulate_store(vcpu, run, fault_addr, + trap->htinst); + default: + return -EOPNOTSUPP; + }; + } + + ret = kvm_riscv_stage2_map(vcpu, memslot, fault_addr, hva, + (trap->scause == EXC_STORE_GUEST_PAGE_FAULT) ? true : false); + if (ret < 0) + return ret; + + return 1; +} + +/** + * kvm_riscv_vcpu_unpriv_read -- Read machine word from Guest memory + * + * @vcpu: The VCPU pointer + * @read_insn: Flag representing whether we are reading instruction + * @guest_addr: Guest address to read + * @trap: Output pointer to trap details + */ +unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu, + bool read_insn, + unsigned long guest_addr, + struct kvm_cpu_trap *trap) +{ + register unsigned long taddr asm("a0") = (unsigned long)trap; + register unsigned long ttmp asm("a1"); + register unsigned long val asm("t0"); + register unsigned long tmp asm("t1"); + register unsigned long addr asm("t2") = guest_addr; + unsigned long flags; + unsigned long old_stvec, old_hstatus; + + local_irq_save(flags); + + old_hstatus = csr_swap(CSR_HSTATUS, vcpu->arch.guest_context.hstatus); + old_stvec = csr_swap(CSR_STVEC, (ulong)&__kvm_riscv_unpriv_trap); + + if (read_insn) { + /* + * HLVX.HU instruction + * 0110010 00011 rs1 100 rd 1110011 + */ + asm volatile ("\n" + ".option push\n" + ".option norvc\n" + "add %[ttmp], %[taddr], 0\n" + /* + * HLVX.HU %[val], (%[addr]) + * HLVX.HU t0, (t2) + * 0110010 00011 00111 100 00101 1110011 + */ + ".word 0x6433c2f3\n" + "andi %[tmp], %[val], 3\n" + "addi %[tmp], %[tmp], -3\n" + "bne %[tmp], zero, 2f\n" + "addi %[addr], %[addr], 2\n" + /* + * HLVX.HU %[tmp], (%[addr]) + * HLVX.HU t1, (t2) + * 0110010 00011 00111 100 00110 1110011 + */ + ".word 0x6433c373\n" + "sll %[tmp], %[tmp], 16\n" + "add %[val], %[val], %[tmp]\n" + "2:\n" + ".option pop" + : [val] "=&r" (val), [tmp] "=&r" (tmp), + [taddr] "+&r" (taddr), [ttmp] "+&r" (ttmp), + [addr] "+&r" (addr) : : "memory"); + + if (trap->scause == EXC_LOAD_PAGE_FAULT) + trap->scause = EXC_INST_PAGE_FAULT; + } else { + /* + * HLV.D instruction + * 0110110 00000 rs1 100 rd 1110011 + * + * HLV.W instruction + * 0110100 00000 rs1 100 rd 1110011 + */ + asm volatile ("\n" + ".option push\n" + ".option norvc\n" + "add %[ttmp], %[taddr], 0\n" +#ifdef CONFIG_64BIT + /* + * HLV.D %[val], (%[addr]) + * HLV.D t0, (t2) + * 0110110 00000 00111 100 00101 1110011 + */ + ".word 0x6c03c2f3\n" +#else + /* + * HLV.W %[val], (%[addr]) + * HLV.W t0, (t2) + * 0110100 00000 00111 100 00101 1110011 + */ + ".word 0x6803c2f3\n" +#endif + ".option pop" + : [val] "=&r" (val), + [taddr] "+&r" (taddr), [ttmp] "+&r" (ttmp) + : [addr] "r" (addr) : "memory"); + } + + csr_write(CSR_STVEC, old_stvec); + csr_write(CSR_HSTATUS, old_hstatus); + + local_irq_restore(flags); + + return val; +} + +/** + * kvm_riscv_vcpu_trap_redirect -- Redirect trap to Guest + * + * @vcpu: The VCPU pointer + * @trap: Trap details + */ +void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu, + struct kvm_cpu_trap *trap) +{ + unsigned long vsstatus = csr_read(CSR_VSSTATUS); + + /* Change Guest SSTATUS.SPP bit */ + vsstatus &= ~SR_SPP; + if (vcpu->arch.guest_context.sstatus & SR_SPP) + vsstatus |= SR_SPP; + + /* Change Guest SSTATUS.SPIE bit */ + vsstatus &= ~SR_SPIE; + if (vsstatus & SR_SIE) + vsstatus |= SR_SPIE; + + /* Clear Guest SSTATUS.SIE bit */ + vsstatus &= ~SR_SIE; + + /* Update Guest SSTATUS */ + csr_write(CSR_VSSTATUS, vsstatus); + + /* Update Guest SCAUSE, STVAL, and SEPC */ + csr_write(CSR_VSCAUSE, trap->scause); + csr_write(CSR_VSTVAL, trap->stval); + csr_write(CSR_VSEPC, trap->sepc); + + /* Set Guest PC to Guest exception vector */ + vcpu->arch.guest_context.sepc = csr_read(CSR_VSTVEC); +} + +/** + * kvm_riscv_vcpu_mmio_return -- Handle MMIO loads after user space emulation + * or in-kernel IO emulation + * + * @vcpu: The VCPU pointer + * @run: The VCPU run struct containing the mmio data + */ +int kvm_riscv_vcpu_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + u8 data8; + u16 data16; + u32 data32; + u64 data64; + ulong insn; + int len, shift; + + if (vcpu->arch.mmio_decode.return_handled) + return 0; + + vcpu->arch.mmio_decode.return_handled = 1; + insn = vcpu->arch.mmio_decode.insn; + + if (run->mmio.is_write) + goto done; + + len = vcpu->arch.mmio_decode.len; + shift = vcpu->arch.mmio_decode.shift; + + switch (len) { + case 1: + data8 = *((u8 *)run->mmio.data); + SET_RD(insn, &vcpu->arch.guest_context, + (ulong)data8 << shift >> shift); + break; + case 2: + data16 = *((u16 *)run->mmio.data); + SET_RD(insn, &vcpu->arch.guest_context, + (ulong)data16 << shift >> shift); + break; + case 4: + data32 = *((u32 *)run->mmio.data); + SET_RD(insn, &vcpu->arch.guest_context, + (ulong)data32 << shift >> shift); + break; + case 8: + data64 = *((u64 *)run->mmio.data); + SET_RD(insn, &vcpu->arch.guest_context, + (ulong)data64 << shift >> shift); + break; + default: + return -EOPNOTSUPP; + } + +done: + /* Move to next instruction */ + vcpu->arch.guest_context.sepc += vcpu->arch.mmio_decode.insn_len; + + return 0; +} + +/* + * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on + * proper exit to userspace. + */ +int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, + struct kvm_cpu_trap *trap) +{ + int ret; + + /* If we got host interrupt then do nothing */ + if (trap->scause & CAUSE_IRQ_FLAG) + return 1; + + /* Handle guest traps */ + ret = -EFAULT; + run->exit_reason = KVM_EXIT_UNKNOWN; + switch (trap->scause) { + case EXC_VIRTUAL_INST_FAULT: + if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) + ret = virtual_inst_fault(vcpu, run, trap); + break; + case EXC_INST_GUEST_PAGE_FAULT: + case EXC_LOAD_GUEST_PAGE_FAULT: + case EXC_STORE_GUEST_PAGE_FAULT: + if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) + ret = stage2_page_fault(vcpu, run, trap); + break; + case EXC_SUPERVISOR_SYSCALL: + if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) + ret = kvm_riscv_vcpu_sbi_ecall(vcpu, run); + break; + default: + break; + } + + /* Print details in-case of error */ + if (ret < 0) { + kvm_err("VCPU exit error %d\n", ret); + kvm_err("SEPC=0x%lx SSTATUS=0x%lx HSTATUS=0x%lx\n", + vcpu->arch.guest_context.sepc, + vcpu->arch.guest_context.sstatus, + vcpu->arch.guest_context.hstatus); + kvm_err("SCAUSE=0x%lx STVAL=0x%lx HTVAL=0x%lx HTINST=0x%lx\n", + trap->scause, trap->stval, trap->htval, trap->htinst); + } + + return ret; +} |