[PATCH v2 1/3] RISC-V: KVM: Factor-out instruction emulation into separate sources
Anup Patel
apatel at ventanamicro.com
Wed Jun 15 03:40:23 PDT 2022
The instruction and CSR emulation for VCPU is going to grow over time
due to upcoming AIA, PMU, Nested and other virtualization features.
Let us factor-out VCPU instruction emulation from vcpu_exit.c to a
separate source dedicated for this purpose.
Signed-off-by: Anup Patel <apatel at ventanamicro.com>
---
arch/riscv/include/asm/kvm_host.h | 11 +-
arch/riscv/include/asm/kvm_vcpu_insn.h | 33 ++
arch/riscv/kvm/Makefile | 1 +
arch/riscv/kvm/vcpu_exit.c | 490 +-------------------
arch/riscv/kvm/{vcpu_exit.c => vcpu_insn.c} | 309 +++---------
5 files changed, 101 insertions(+), 743 deletions(-)
create mode 100644 arch/riscv/include/asm/kvm_vcpu_insn.h
copy arch/riscv/kvm/{vcpu_exit.c => vcpu_insn.c} (67%)
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 319c8aeb42af..03103b86dd86 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -15,6 +15,7 @@
#include <linux/spinlock.h>
#include <asm/csr.h>
#include <asm/kvm_vcpu_fp.h>
+#include <asm/kvm_vcpu_insn.h>
#include <asm/kvm_vcpu_timer.h>
#define KVM_MAX_VCPUS 1024
@@ -90,14 +91,6 @@ struct kvm_arch {
struct kvm_guest_timer timer;
};
-struct kvm_mmio_decode {
- unsigned long insn;
- int insn_len;
- int len;
- int shift;
- int return_handled;
-};
-
struct kvm_sbi_context {
int return_handled;
};
@@ -303,14 +296,12 @@ void kvm_riscv_gstage_vmid_update(struct kvm_vcpu *vcpu);
void __kvm_riscv_unpriv_trap(void);
-void kvm_riscv_vcpu_wfi(struct kvm_vcpu *vcpu);
unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
bool read_insn,
unsigned long guest_addr,
struct kvm_cpu_trap *trap);
void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
struct kvm_cpu_trap *trap);
-int kvm_riscv_vcpu_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_cpu_trap *trap);
diff --git a/arch/riscv/include/asm/kvm_vcpu_insn.h b/arch/riscv/include/asm/kvm_vcpu_insn.h
new file mode 100644
index 000000000000..4e3ba4e84d0f
--- /dev/null
+++ b/arch/riscv/include/asm/kvm_vcpu_insn.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef __KVM_VCPU_RISCV_INSN_H
+#define __KVM_VCPU_RISCV_INSN_H
+
+struct kvm_vcpu;
+struct kvm_run;
+struct kvm_cpu_trap;
+
+struct kvm_mmio_decode {
+ unsigned long insn;
+ int insn_len;
+ int len;
+ int shift;
+ int return_handled;
+};
+
+void kvm_riscv_vcpu_wfi(struct kvm_vcpu *vcpu);
+int kvm_riscv_vcpu_virtual_insn(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ struct kvm_cpu_trap *trap);
+
+int kvm_riscv_vcpu_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ unsigned long fault_addr,
+ unsigned long htinst);
+int kvm_riscv_vcpu_mmio_store(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ unsigned long fault_addr,
+ unsigned long htinst);
+int kvm_riscv_vcpu_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
+
+#endif
diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
index e5c56182f48f..019df9208bdd 100644
--- a/arch/riscv/kvm/Makefile
+++ b/arch/riscv/kvm/Makefile
@@ -17,6 +17,7 @@ kvm-y += mmu.o
kvm-y += vcpu.o
kvm-y += vcpu_exit.o
kvm-y += vcpu_fp.o
+kvm-y += vcpu_insn.o
kvm-y += vcpu_switch.o
kvm-y += vcpu_sbi.o
kvm-$(CONFIG_RISCV_SBI_V01) += vcpu_sbi_v01.o
diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
index dbb09afd7546..c364128787be 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -6,412 +6,9 @@
* Anup Patel <anup.patel at 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++;
- kvm_riscv_vcpu_wfi(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 gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_cpu_trap *trap)
{
@@ -430,11 +27,13 @@ static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
(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);
+ return kvm_riscv_vcpu_mmio_load(vcpu, run,
+ fault_addr,
+ trap->htinst);
case EXC_STORE_GUEST_PAGE_FAULT:
- return emulate_store(vcpu, run, fault_addr,
- trap->htinst);
+ return kvm_riscv_vcpu_mmio_store(vcpu, run,
+ fault_addr,
+ trap->htinst);
default:
return -EOPNOTSUPP;
};
@@ -448,21 +47,6 @@ static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
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);
- }
-}
-
/**
* kvm_riscv_vcpu_unpriv_read -- Read machine word from Guest memory
*
@@ -601,66 +185,6 @@ void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
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.
@@ -680,7 +204,7 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
switch (trap->scause) {
case EXC_VIRTUAL_INST_FAULT:
if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)
- ret = virtual_inst_fault(vcpu, run, trap);
+ ret = kvm_riscv_vcpu_virtual_insn(vcpu, run, trap);
break;
case EXC_INST_GUEST_PAGE_FAULT:
case EXC_LOAD_GUEST_PAGE_FAULT:
diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_insn.c
similarity index 67%
copy from arch/riscv/kvm/vcpu_exit.c
copy to arch/riscv/kvm/vcpu_insn.c
index dbb09afd7546..be756879c2ee 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_insn.c
@@ -1,16 +1,11 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
- *
- * Authors:
- * Anup Patel <anup.patel at wdc.com>
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
*/
#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
@@ -138,6 +133,21 @@ static int truly_illegal_insn(struct kvm_vcpu *vcpu,
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 system_opcode_insn(struct kvm_vcpu *vcpu,
struct kvm_run *run,
ulong insn)
@@ -152,8 +162,19 @@ static int system_opcode_insn(struct kvm_vcpu *vcpu,
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)
+/**
+ * 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 };
@@ -183,8 +204,21 @@ static int virtual_inst_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
}
}
-static int emulate_load(struct kvm_vcpu *vcpu, struct kvm_run *run,
- unsigned long fault_addr, unsigned long htinst)
+/**
+ * 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;
@@ -292,8 +326,21 @@ static int emulate_load(struct kvm_vcpu *vcpu, struct kvm_run *run,
return 0;
}
-static int emulate_store(struct kvm_vcpu *vcpu, struct kvm_run *run,
- unsigned long fault_addr, unsigned long htinst)
+/**
+ * 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;
@@ -412,195 +459,6 @@ static int emulate_store(struct kvm_vcpu *vcpu, struct kvm_run *run,
return 0;
}
-static int gstage_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_gstage_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_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);
- }
-}
-
-/**
- * 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
@@ -660,52 +518,3 @@ int kvm_riscv_vcpu_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
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 = gstage_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;
-}
--
2.34.1
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