Prepare to factor out load/store instruction decoding by using struct
kvm_decode and operate on a separate copy of struct pt_regs.
Signed-off-by: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx>
---
arch/arm/include/asm/kvm_host.h | 12 ++++--
arch/arm/kvm/emulate.c | 84 ++++++++++++++++++++++++---------------
arch/arm/kvm/mmio.c | 22 +++++-----
3 files changed, 70 insertions(+), 48 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 6c1c6fc..439deb0 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -78,6 +78,13 @@ struct kvm_mmu_memory_cache {
void *objects[KVM_NR_MEM_OBJS];
};
+struct kvm_decode {
+ struct pt_regs *regs;
+ unsigned long hxfar;
+ unsigned long rt; /* destination register for loads */
+ bool sign_extend; /* for byte/halfword loads */
+};
+
struct kvm_vcpu_arch {
struct kvm_regs regs;
@@ -115,10 +122,7 @@ struct kvm_vcpu_arch {
bool pause;
/* IO related fields */
- struct {
- bool sign_extend; /* for byte/halfword loads */
- u32 rd;
- } mmio;
+ struct kvm_decode mmio_decode;
/* Interrupt related fields */
u32 irq_lines; /* IRQ and FIQ levels */
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index ca72be9..7cbdc68 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -304,7 +304,7 @@ struct arm_instr {
bool sign_extend;
bool w;
- bool (*decode)(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+ bool (*decode)(struct kvm_decode *decode, struct kvm_exit_mmio *mmio,
unsigned long instr, struct arm_instr *ai);
};
@@ -380,7 +380,7 @@ u32 shift(u32 value, u8 N, enum SRType type, u8 amount, bool carry_in)
return value & mask;
}
-static bool decode_arm_wb(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+static bool decode_arm_wb(struct kvm_decode *decode, struct kvm_exit_mmio *mmio,
unsigned long instr, const struct arm_instr *ai)
{
u8 Rt = (instr >> 12) & 0xf;
@@ -388,7 +388,7 @@ static bool decode_arm_wb(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
u8 W = (instr >> 21) & 1;
u8 U = (instr >> 23) & 1;
u8 P = (instr >> 24) & 1;
- u32 base_addr = *vcpu_reg(vcpu, Rn);
+ u32 base_addr = decode->regs->uregs[Rn];
u32 offset_addr, offset;
/*
@@ -403,14 +403,14 @@ static bool decode_arm_wb(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
return false;
}
- vcpu->arch.mmio.rd = Rt;
+ decode->rt = Rt;
if (ai->register_form) {
/* Register operation */
enum SRType s_type;
u8 shift_n;
- bool c_bit = *vcpu_cpsr(vcpu) & PSR_C_BIT;
- u32 s_reg = *vcpu_reg(vcpu, ai->Rm);
+ bool c_bit = decode->regs->ARM_cpsr & PSR_C_BIT;
+ u32 s_reg = decode->regs->uregs[ai->Rm];
s_type = decode_imm_shift(ai->type, ai->shift_n, &shift_n);
offset = shift(s_reg, 5, s_type, shift_n, c_bit);
@@ -424,18 +424,18 @@ static bool decode_arm_wb(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
offset_addr = base_addr + offset;
else
offset_addr = base_addr - offset;
- *vcpu_reg(vcpu, Rn) = offset_addr;
+ decode->regs->uregs[Rn] = offset_addr;
return true;
}
-static bool decode_arm_ls(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+static bool decode_arm_ls(struct kvm_decode *decode, struct kvm_exit_mmio *mmio,
unsigned long instr, struct arm_instr *ai)
{
u8 A = (instr >> 25) & 1;
mmio->is_write = ai->w;
mmio->len = ai->len;
- vcpu->arch.mmio.sign_extend = false;
+ decode->sign_extend = false;
ai->register_form = A;
ai->imm = instr & 0xfff;
@@ -443,15 +443,16 @@ static bool decode_arm_ls(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
ai->type = (instr >> 5) & 0x3;
ai->shift_n = (instr >> 7) & 0x1f;
- return decode_arm_wb(vcpu, mmio, instr, ai);
+ return decode_arm_wb(decode, mmio, instr, ai);
}
-static bool decode_arm_extra(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+static bool decode_arm_extra(struct kvm_decode *decode,
+ struct kvm_exit_mmio *mmio,
unsigned long instr, struct arm_instr *ai)
{
mmio->is_write = ai->w;
mmio->len = ai->len;
- vcpu->arch.mmio.sign_extend = ai->sign_extend;
+ decode->sign_extend = ai->sign_extend;
ai->register_form = !((instr >> 22) & 1);
ai->imm = ((instr >> 4) & 0xf0) | (instr & 0xf);
@@ -459,7 +460,7 @@ static bool decode_arm_extra(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
ai->type = 0; /* SRType_LSL */
ai->shift_n = 0;
- return decode_arm_wb(vcpu, mmio, instr, ai);
+ return decode_arm_wb(decode, mmio, instr, ai);
}
/*
@@ -526,7 +527,7 @@ static const struct arm_instr arm_instr[] = {
.sign_extend = true , .decode = decode_arm_extra },
};
-static bool kvm_decode_arm_ls(struct kvm_vcpu *vcpu, unsigned long instr,
+static bool kvm_decode_arm_ls(struct kvm_decode *decode, unsigned long instr,
struct kvm_exit_mmio *mmio)
{
int i;
@@ -535,7 +536,7 @@ static bool kvm_decode_arm_ls(struct kvm_vcpu *vcpu, unsigned long instr,
const struct arm_instr *ai = &arm_instr[i];
if ((instr & ai->opc_mask) == ai->opc) {
struct arm_instr ai_copy = *ai;
- return ai->decode(vcpu, mmio, instr, &ai_copy);
+ return ai->decode(decode, mmio, instr, &ai_copy);
}
}
return false;
@@ -557,40 +558,42 @@ struct thumb_instr {
} t32;
};
- bool (*decode)(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+ bool (*decode)(struct kvm_decode *decode, struct kvm_exit_mmio *mmio,
unsigned long instr, const struct thumb_instr *ti);
};
-static bool decode_thumb_wb(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+static bool decode_thumb_wb(struct kvm_decode *decode,
+ struct kvm_exit_mmio *mmio,
unsigned long instr)
{
bool P = (instr >> 10) & 1;
bool U = (instr >> 9) & 1;
u8 imm8 = instr & 0xff;
- u32 offset_addr = vcpu->arch.hxfar;
+ u32 offset_addr = decode->hxfar;
u8 Rn = (instr >> 16) & 0xf;
- vcpu->arch.mmio.rd = (instr >> 12) & 0xf;
+ decode->rt = (instr >> 12) & 0xf;
- if (kvm_vcpu_reg_is_pc(vcpu, Rn))
+ if (Rn == 15)
return false;
/* Handle Writeback */
if (!P && U)
- *vcpu_reg(vcpu, Rn) = offset_addr + imm8;
+ decode->regs->uregs[Rn] = offset_addr + imm8;
else if (!P && !U)
- *vcpu_reg(vcpu, Rn) = offset_addr - imm8;
+ decode->regs->uregs[Rn] = offset_addr - imm8;
return true;
}
-static bool decode_thumb_str(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+static bool decode_thumb_str(struct kvm_decode *decode,
+ struct kvm_exit_mmio *mmio,
unsigned long instr, const struct thumb_instr *ti)
{
u8 op1 = (instr >> (16 + 5)) & 0x7;
u8 op2 = (instr >> 6) & 0x3f;
mmio->is_write = true;
- vcpu->arch.mmio.sign_extend = false;
+ decode->sign_extend = false;
switch (op1) {
case 0x0: mmio->len = 1; break;
@@ -602,13 +605,14 @@ static bool decode_thumb_str(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
if ((op2 & 0x24) == 0x24) {
/* STRB (immediate, thumb, W=1) */
- return decode_thumb_wb(vcpu, mmio, instr);
+ return decode_thumb_wb(decode, mmio, instr);
}
return false;
}
-static bool decode_thumb_ldr(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+static bool decode_thumb_ldr(struct kvm_decode *decode,
+ struct kvm_exit_mmio *mmio,
unsigned long instr, const struct thumb_instr *ti)
{
u8 op1 = (instr >> (16 + 7)) & 0x3;
@@ -623,15 +627,15 @@ static bool decode_thumb_ldr(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
}
if (op1 == 0x0)
- vcpu->arch.mmio.sign_extend = false;
+ decode->sign_extend = false;
else if (op1 == 0x2 && (ti->t32.op2 & 0x7) != 0x5)
- vcpu->arch.mmio.sign_extend = true;
+ decode->sign_extend = true;
else
return false; /* Only register write-back versions! */
if ((op2 & 0x24) == 0x24) {
/* LDR{S}X (immediate, thumb, W=1) */
- return decode_thumb_wb(vcpu, mmio, instr);
+ return decode_thumb_wb(decode, mmio, instr);
}
return false;
@@ -663,7 +667,7 @@ static const struct thumb_instr thumb_instr[] = {
-static bool kvm_decode_thumb_ls(struct kvm_vcpu *vcpu, unsigned long instr,
+static bool kvm_decode_thumb_ls(struct kvm_decode *decode, unsigned long instr,
struct kvm_exit_mmio *mmio)
{
bool is32 = is_wide_instruction(instr);
@@ -693,7 +697,7 @@ static bool kvm_decode_thumb_ls(struct kvm_vcpu *vcpu, unsigned long instr,
continue;
}
- return ti->decode(vcpu, mmio, instr, &tinstr);
+ return ti->decode(decode, mmio, instr, &tinstr);
}
return false;
@@ -720,6 +724,8 @@ int kvm_emulate_mmio_ls(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
{
bool is_thumb;
unsigned long instr = 0;
+ struct pt_regs current_regs;
+ struct kvm_decode *decode = &vcpu->arch.mmio_decode;
trace_kvm_mmio_emulate(*vcpu_pc(vcpu), instr, *vcpu_cpsr(vcpu));
@@ -728,14 +734,22 @@ int kvm_emulate_mmio_ls(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return 1;
mmio->phys_addr = fault_ipa;
+
+ memcpy(¤t_regs, &vcpu->arch.regs.usr_regs, sizeof(current_regs));
+ current_regs.ARM_sp = *vcpu_reg(vcpu, 13);
+ current_regs.ARM_lr = *vcpu_reg(vcpu, 14);
+
+ decode->regs = ¤t_regs;
+ decode->hxfar = vcpu->arch.hxfar;
+
is_thumb = !!(*vcpu_cpsr(vcpu) & PSR_T_BIT);
- if (!is_thumb && !kvm_decode_arm_ls(vcpu, instr, mmio)) {
+ if (!is_thumb && !kvm_decode_arm_ls(decode, instr, mmio)) {
kvm_debug("Unable to decode inst: %#08lx (cpsr: %#08x (T=0)"
"pc: %#08x)\n",
instr, *vcpu_cpsr(vcpu), *vcpu_pc(vcpu));
kvm_inject_dabt(vcpu, vcpu->arch.hxfar);
return 1;
- } else if (is_thumb && !kvm_decode_thumb_ls(vcpu, instr, mmio)) {
+ } else if (is_thumb && !kvm_decode_thumb_ls(decode, instr, mmio)) {
kvm_debug("Unable to decode inst: %#08lx (cpsr: %#08x (T=1)"
"pc: %#08x)\n",
instr, *vcpu_cpsr(vcpu), *vcpu_pc(vcpu));
@@ -743,6 +757,10 @@ int kvm_emulate_mmio_ls(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return 1;
}
+ memcpy(&vcpu->arch.regs.usr_regs, ¤t_regs, sizeof(current_regs));
+ *vcpu_reg(vcpu, 13) = current_regs.ARM_sp;
+ *vcpu_reg(vcpu, 14) = current_regs.ARM_lr;
+
/*
* The MMIO instruction is emulated and should not be re-executed
* in the guest.
diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
index beb7134..eefbead 100644
--- a/arch/arm/kvm/mmio.c
+++ b/arch/arm/kvm/mmio.c
@@ -37,7 +37,7 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
int mask;
if (!run->mmio.is_write) {
- dest = vcpu_reg(vcpu, vcpu->arch.mmio.rd);
+ dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt);
memset(dest, 0, sizeof(int));
len = run->mmio.len;
@@ -49,7 +49,7 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
*((u64 *)run->mmio.data));
- if (vcpu->arch.mmio.sign_extend && len < 4) {
+ if (vcpu->arch.mmio_decode.sign_extend && len < 4) {
mask = 1U << ((len * 8) - 1);
*dest = (*dest ^ mask) - mask;
}
@@ -61,7 +61,7 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_exit_mmio *mmio)
{
- unsigned long rd, len;
+ unsigned long rt, len;
bool is_write, sign_extend;
if ((vcpu->arch.hsr >> 8) & 1) {
@@ -93,9 +93,9 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
is_write = vcpu->arch.hsr & HSR_WNR;
sign_extend = vcpu->arch.hsr & HSR_SSE;
- rd = (vcpu->arch.hsr & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
+ rt = (vcpu->arch.hsr & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
- if (kvm_vcpu_reg_is_pc(vcpu, rd)) {
+ if (kvm_vcpu_reg_is_pc(vcpu, rt)) {
/* IO memory trying to read/write pc */
kvm_inject_pabt(vcpu, vcpu->arch.hxfar);
return 1;
@@ -104,8 +104,8 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
mmio->is_write = is_write;
mmio->phys_addr = fault_ipa;
mmio->len = len;
- vcpu->arch.mmio.sign_extend = sign_extend;
- vcpu->arch.mmio.rd = rd;
+ vcpu->arch.mmio_decode.sign_extend = sign_extend;
+ vcpu->arch.mmio_decode.rt = rt;
/*
* The MMIO instruction is emulated and should not be re-executed
@@ -119,7 +119,7 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
phys_addr_t fault_ipa, struct kvm_memory_slot *memslot)
{
struct kvm_exit_mmio mmio;
- unsigned long rd;
+ unsigned long rt;
int ret;
/*
@@ -137,14 +137,14 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
if (ret != 0)
return ret;
- rd = vcpu->arch.mmio.rd;
+ rt = vcpu->arch.mmio_decode.rt;
trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE :
KVM_TRACE_MMIO_READ_UNSATISFIED,
mmio.len, fault_ipa,
- (mmio.is_write) ? *vcpu_reg(vcpu, rd) : 0);
+ (mmio.is_write) ? *vcpu_reg(vcpu, rt) : 0);
if (mmio.is_write)
- memcpy(mmio.data, vcpu_reg(vcpu, rd), mmio.len);
+ memcpy(mmio.data, vcpu_reg(vcpu, rt), mmio.len);
if (vgic_handle_mmio(vcpu, run, &mmio))
return 1;
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