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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-05 00:59:54 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-05 00:59:54 +0300 |
commit | 7c5c3a6177fa9646884114fc7f2e970b0bc50dc9 (patch) | |
tree | 956857522574ae7cb07d2227dc16e53d7e9e00e7 /arch/riscv/kvm/vcpu_insn.c | |
parent | f0a892f599c46af673e47418c47c15e69a7b67f4 (diff) | |
parent | 281106f938d3daaea6f8b6723a8217a2a1ef6936 (diff) | |
download | linux-7c5c3a6177fa9646884114fc7f2e970b0bc50dc9.tar.xz |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"Quite a large pull request due to a selftest API overhaul and some
patches that had come in too late for 5.19.
ARM:
- Unwinder implementations for both nVHE modes (classic and
protected), complete with an overflow stack
- Rework of the sysreg access from userspace, with a complete rewrite
of the vgic-v3 view to allign with the rest of the infrastructure
- Disagregation of the vcpu flags in separate sets to better track
their use model.
- A fix for the GICv2-on-v3 selftest
- A small set of cosmetic fixes
RISC-V:
- Track ISA extensions used by Guest using bitmap
- Added system instruction emulation framework
- Added CSR emulation framework
- Added gfp_custom flag in struct kvm_mmu_memory_cache
- Added G-stage ioremap() and iounmap() functions
- Added support for Svpbmt inside Guest
s390:
- add an interface to provide a hypervisor dump for secure guests
- improve selftests to use TAP interface
- enable interpretive execution of zPCI instructions (for PCI
passthrough)
- First part of deferred teardown
- CPU Topology
- PV attestation
- Minor fixes
x86:
- Permit guests to ignore single-bit ECC errors
- Intel IPI virtualization
- Allow getting/setting pending triple fault with
KVM_GET/SET_VCPU_EVENTS
- PEBS virtualization
- Simplify PMU emulation by just using PERF_TYPE_RAW events
- More accurate event reinjection on SVM (avoid retrying
instructions)
- Allow getting/setting the state of the speaker port data bit
- Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls
are inconsistent
- "Notify" VM exit (detect microarchitectural hangs) for Intel
- Use try_cmpxchg64 instead of cmpxchg64
- Ignore benign host accesses to PMU MSRs when PMU is disabled
- Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior
- Allow NX huge page mitigation to be disabled on a per-vm basis
- Port eager page splitting to shadow MMU as well
- Enable CMCI capability by default and handle injected UCNA errors
- Expose pid of vcpu threads in debugfs
- x2AVIC support for AMD
- cleanup PIO emulation
- Fixes for LLDT/LTR emulation
- Don't require refcounted "struct page" to create huge SPTEs
- Miscellaneous cleanups:
- MCE MSR emulation
- Use separate namespaces for guest PTEs and shadow PTEs bitmasks
- PIO emulation
- Reorganize rmap API, mostly around rmap destruction
- Do not workaround very old KVM bugs for L0 that runs with nesting enabled
- new selftests API for CPUID
Generic:
- Fix races in gfn->pfn cache refresh; do not pin pages tracked by
the cache
- new selftests API using struct kvm_vcpu instead of a (vm, id)
tuple"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (606 commits)
selftests: kvm: set rax before vmcall
selftests: KVM: Add exponent check for boolean stats
selftests: KVM: Provide descriptive assertions in kvm_binary_stats_test
selftests: KVM: Check stat name before other fields
KVM: x86/mmu: remove unused variable
RISC-V: KVM: Add support for Svpbmt inside Guest/VM
RISC-V: KVM: Use PAGE_KERNEL_IO in kvm_riscv_gstage_ioremap()
RISC-V: KVM: Add G-stage ioremap() and iounmap() functions
KVM: Add gfp_custom flag in struct kvm_mmu_memory_cache
RISC-V: KVM: Add extensible CSR emulation framework
RISC-V: KVM: Add extensible system instruction emulation framework
RISC-V: KVM: Factor-out instruction emulation into separate sources
RISC-V: KVM: move preempt_disable() call in kvm_arch_vcpu_ioctl_run
RISC-V: KVM: Make kvm_riscv_guest_timer_init a void function
RISC-V: KVM: Fix variable spelling mistake
RISC-V: KVM: Improve ISA extension by using a bitmap
KVM, x86/mmu: Fix the comment around kvm_tdp_mmu_zap_leafs()
KVM: SVM: Dump Virtual Machine Save Area (VMSA) to klog
KVM: x86/mmu: Treat NX as a valid SPTE bit for NPT
KVM: x86: Do not block APIC write for non ICR registers
...
Diffstat (limited to 'arch/riscv/kvm/vcpu_insn.c')
-rw-r--r-- | arch/riscv/kvm/vcpu_insn.c | 752 |
1 files changed, 752 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_insn.c b/arch/riscv/kvm/vcpu_insn.c new file mode 100644 index 000000000000..7eb90a47b571 --- /dev/null +++ b/arch/riscv/kvm/vcpu_insn.c @@ -0,0 +1,752 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Western Digital Corporation or its affiliates. + * Copyright (c) 2022 Ventana Micro Systems Inc. + */ + +#include <linux/bitops.h> +#include <linux/kvm_host.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_CSRRW 0x1073 +#define INSN_MASK_CSRRW 0x707f +#define INSN_MATCH_CSRRS 0x2073 +#define INSN_MASK_CSRRS 0x707f +#define INSN_MATCH_CSRRC 0x3073 +#define INSN_MASK_CSRRC 0x707f +#define INSN_MATCH_CSRRWI 0x5073 +#define INSN_MASK_CSRRWI 0x707f +#define INSN_MATCH_CSRRSI 0x6073 +#define INSN_MASK_CSRRSI 0x707f +#define INSN_MATCH_CSRRCI 0x7073 +#define INSN_MASK_CSRRCI 0x707f + +#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 MASK_RX 0x1f + +#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_FUNCT3(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)) + +struct insn_func { + unsigned long mask; + unsigned long match; + /* + * Possible return values are as follows: + * 1) Returns < 0 for error case + * 2) Returns 0 for exit to user-space + * 3) Returns 1 to continue with next sepc + * 4) Returns 2 to continue with same sepc + * 5) Returns 3 to inject illegal instruction trap and continue + * 6) Returns 4 to inject virtual instruction trap and continue + * + * Use enum kvm_insn_return for return values + */ + int (*func)(struct kvm_vcpu *vcpu, struct kvm_run *run, ulong insn); +}; + +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; + utrap.htval = 0; + utrap.htinst = 0; + kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); + + return 1; +} + +static int truly_virtual_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_VIRTUAL_INST_FAULT; + utrap.stval = insn; + utrap.htval = 0; + utrap.htinst = 0; + kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); + + return 1; +} + +/** + * kvm_riscv_vcpu_wfi -- Emulate wait for interrupt (WFI) behaviour + * + * @vcpu: The VCPU pointer + */ +void kvm_riscv_vcpu_wfi(struct kvm_vcpu *vcpu) +{ + if (!kvm_arch_vcpu_runnable(vcpu)) { + kvm_vcpu_srcu_read_unlock(vcpu); + kvm_vcpu_halt(vcpu); + kvm_vcpu_srcu_read_lock(vcpu); + kvm_clear_request(KVM_REQ_UNHALT, vcpu); + } +} + +static int wfi_insn(struct kvm_vcpu *vcpu, struct kvm_run *run, ulong insn) +{ + vcpu->stat.wfi_exit_stat++; + kvm_riscv_vcpu_wfi(vcpu); + return KVM_INSN_CONTINUE_NEXT_SEPC; +} + +struct csr_func { + unsigned int base; + unsigned int count; + /* + * Possible return values are as same as "func" callback in + * "struct insn_func". + */ + int (*func)(struct kvm_vcpu *vcpu, unsigned int csr_num, + unsigned long *val, unsigned long new_val, + unsigned long wr_mask); +}; + +static const struct csr_func csr_funcs[] = { }; + +/** + * kvm_riscv_vcpu_csr_return -- Handle CSR read/write after user space + * emulation or in-kernel emulation + * + * @vcpu: The VCPU pointer + * @run: The VCPU run struct containing the CSR data + * + * Returns > 0 upon failure and 0 upon success + */ +int kvm_riscv_vcpu_csr_return(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + ulong insn; + + if (vcpu->arch.csr_decode.return_handled) + return 0; + vcpu->arch.csr_decode.return_handled = 1; + + /* Update destination register for CSR reads */ + insn = vcpu->arch.csr_decode.insn; + if ((insn >> SH_RD) & MASK_RX) + SET_RD(insn, &vcpu->arch.guest_context, + run->riscv_csr.ret_value); + + /* Move to next instruction */ + vcpu->arch.guest_context.sepc += INSN_LEN(insn); + + return 0; +} + +static int csr_insn(struct kvm_vcpu *vcpu, struct kvm_run *run, ulong insn) +{ + int i, rc = KVM_INSN_ILLEGAL_TRAP; + unsigned int csr_num = insn >> SH_RS2; + unsigned int rs1_num = (insn >> SH_RS1) & MASK_RX; + ulong rs1_val = GET_RS1(insn, &vcpu->arch.guest_context); + const struct csr_func *tcfn, *cfn = NULL; + ulong val = 0, wr_mask = 0, new_val = 0; + + /* Decode the CSR instruction */ + switch (GET_FUNCT3(insn)) { + case GET_FUNCT3(INSN_MATCH_CSRRW): + wr_mask = -1UL; + new_val = rs1_val; + break; + case GET_FUNCT3(INSN_MATCH_CSRRS): + wr_mask = rs1_val; + new_val = -1UL; + break; + case GET_FUNCT3(INSN_MATCH_CSRRC): + wr_mask = rs1_val; + new_val = 0; + break; + case GET_FUNCT3(INSN_MATCH_CSRRWI): + wr_mask = -1UL; + new_val = rs1_num; + break; + case GET_FUNCT3(INSN_MATCH_CSRRSI): + wr_mask = rs1_num; + new_val = -1UL; + break; + case GET_FUNCT3(INSN_MATCH_CSRRCI): + wr_mask = rs1_num; + new_val = 0; + break; + default: + return rc; + } + + /* Save instruction decode info */ + vcpu->arch.csr_decode.insn = insn; + vcpu->arch.csr_decode.return_handled = 0; + + /* Update CSR details in kvm_run struct */ + run->riscv_csr.csr_num = csr_num; + run->riscv_csr.new_value = new_val; + run->riscv_csr.write_mask = wr_mask; + run->riscv_csr.ret_value = 0; + + /* Find in-kernel CSR function */ + for (i = 0; i < ARRAY_SIZE(csr_funcs); i++) { + tcfn = &csr_funcs[i]; + if ((tcfn->base <= csr_num) && + (csr_num < (tcfn->base + tcfn->count))) { + cfn = tcfn; + break; + } + } + + /* First try in-kernel CSR emulation */ + if (cfn && cfn->func) { + rc = cfn->func(vcpu, csr_num, &val, new_val, wr_mask); + if (rc > KVM_INSN_EXIT_TO_USER_SPACE) { + if (rc == KVM_INSN_CONTINUE_NEXT_SEPC) { + run->riscv_csr.ret_value = val; + vcpu->stat.csr_exit_kernel++; + kvm_riscv_vcpu_csr_return(vcpu, run); + rc = KVM_INSN_CONTINUE_SAME_SEPC; + } + return rc; + } + } + + /* Exit to user-space for CSR emulation */ + if (rc <= KVM_INSN_EXIT_TO_USER_SPACE) { + vcpu->stat.csr_exit_user++; + run->exit_reason = KVM_EXIT_RISCV_CSR; + } + + return rc; +} + +static const struct insn_func system_opcode_funcs[] = { + { + .mask = INSN_MASK_CSRRW, + .match = INSN_MATCH_CSRRW, + .func = csr_insn, + }, + { + .mask = INSN_MASK_CSRRS, + .match = INSN_MATCH_CSRRS, + .func = csr_insn, + }, + { + .mask = INSN_MASK_CSRRC, + .match = INSN_MATCH_CSRRC, + .func = csr_insn, + }, + { + .mask = INSN_MASK_CSRRWI, + .match = INSN_MATCH_CSRRWI, + .func = csr_insn, + }, + { + .mask = INSN_MASK_CSRRSI, + .match = INSN_MATCH_CSRRSI, + .func = csr_insn, + }, + { + .mask = INSN_MASK_CSRRCI, + .match = INSN_MATCH_CSRRCI, + .func = csr_insn, + }, + { + .mask = INSN_MASK_WFI, + .match = INSN_MATCH_WFI, + .func = wfi_insn, + }, +}; + +static int system_opcode_insn(struct kvm_vcpu *vcpu, struct kvm_run *run, + ulong insn) +{ + int i, rc = KVM_INSN_ILLEGAL_TRAP; + const struct insn_func *ifn; + + for (i = 0; i < ARRAY_SIZE(system_opcode_funcs); i++) { + ifn = &system_opcode_funcs[i]; + if ((insn & ifn->mask) == ifn->match) { + rc = ifn->func(vcpu, run, insn); + break; + } + } + + switch (rc) { + case KVM_INSN_ILLEGAL_TRAP: + return truly_illegal_insn(vcpu, run, insn); + case KVM_INSN_VIRTUAL_TRAP: + return truly_virtual_insn(vcpu, run, insn); + case KVM_INSN_CONTINUE_NEXT_SEPC: + vcpu->arch.guest_context.sepc += INSN_LEN(insn); + break; + default: + break; + } + + return (rc <= 0) ? rc : 1; +} + +/** + * kvm_riscv_vcpu_virtual_insn -- Handle virtual instruction trap + * + * @vcpu: The VCPU pointer + * @run: The VCPU run struct containing the mmio data + * @trap: Trap details + * + * Returns > 0 to continue run-loop + * Returns 0 to exit run-loop and handle in user-space. + * Returns < 0 to report failure and exit run-loop + */ +int kvm_riscv_vcpu_virtual_insn(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); + } +} + +/** + * kvm_riscv_vcpu_mmio_load -- Emulate MMIO load instruction + * + * @vcpu: The VCPU pointer + * @run: The VCPU run struct containing the mmio data + * @fault_addr: Guest physical address to load + * @htinst: Transformed encoding of the load instruction + * + * Returns > 0 to continue run-loop + * Returns 0 to exit run-loop and handle in user-space. + * Returns < 0 to report failure and exit run-loop + */ +int kvm_riscv_vcpu_mmio_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; +} + +/** + * kvm_riscv_vcpu_mmio_store -- Emulate MMIO store instruction + * + * @vcpu: The VCPU pointer + * @run: The VCPU run struct containing the mmio data + * @fault_addr: Guest physical address to store + * @htinst: Transformed encoding of the store instruction + * + * Returns > 0 to continue run-loop + * Returns 0 to exit run-loop and handle in user-space. + * Returns < 0 to report failure and exit run-loop + */ +int kvm_riscv_vcpu_mmio_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; +} + +/** + * 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; +} |