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linux/arch/mips/kvm/kvm_mips_emul.c
Sanjay Lal e685c689f3 KVM/MIPS32: Privileged instruction/target branch emulation. 
- The Guest kernel is run in UM and privileged instructions cause a trap.
- If the instruction causing the trap is in a branch delay slot, the branch
  needs to be emulated to figure out the PC @ which the guest will resume
  execution.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:35 +02:00

1830 lines
46 KiB
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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* KVM/MIPS: Instruction/Exception emulation
*
* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
* Authors: Sanjay Lal <sanjayl@kymasys.com>
*/
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/bootmem.h>
#include <linux/random.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/cpu-info.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
#include <asm/inst.h>
#undef CONFIG_MIPS_MT
#include <asm/r4kcache.h>
#define CONFIG_MIPS_MT
#include "kvm_mips_opcode.h"
#include "kvm_mips_int.h"
#include "kvm_mips_comm.h"
#include "trace.h"
/*
* Compute the return address and do emulate branch simulation, if required.
* This function should be called only in branch delay slot active.
*/
unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu,
unsigned long instpc)
{
unsigned int dspcontrol;
union mips_instruction insn;
struct kvm_vcpu_arch *arch = &vcpu->arch;
long epc = instpc;
long nextpc = KVM_INVALID_INST;
if (epc & 3)
goto unaligned;
/*
* Read the instruction
*/
insn.word = kvm_get_inst((uint32_t *) epc, vcpu);
if (insn.word == KVM_INVALID_INST)
return KVM_INVALID_INST;
switch (insn.i_format.opcode) {
/*
* jr and jalr are in r_format format.
*/
case spec_op:
switch (insn.r_format.func) {
case jalr_op:
arch->gprs[insn.r_format.rd] = epc + 8;
/* Fall through */
case jr_op:
nextpc = arch->gprs[insn.r_format.rs];
break;
}
break;
/*
* This group contains:
* bltz_op, bgez_op, bltzl_op, bgezl_op,
* bltzal_op, bgezal_op, bltzall_op, bgezall_op.
*/
case bcond_op:
switch (insn.i_format.rt) {
case bltz_op:
case bltzl_op:
if ((long)arch->gprs[insn.i_format.rs] < 0)
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
case bgez_op:
case bgezl_op:
if ((long)arch->gprs[insn.i_format.rs] >= 0)
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
case bltzal_op:
case bltzall_op:
arch->gprs[31] = epc + 8;
if ((long)arch->gprs[insn.i_format.rs] < 0)
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
case bgezal_op:
case bgezall_op:
arch->gprs[31] = epc + 8;
if ((long)arch->gprs[insn.i_format.rs] >= 0)
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
case bposge32_op:
if (!cpu_has_dsp)
goto sigill;
dspcontrol = rddsp(0x01);
if (dspcontrol >= 32) {
epc = epc + 4 + (insn.i_format.simmediate << 2);
} else
epc += 8;
nextpc = epc;
break;
}
break;
/*
* These are unconditional and in j_format.
*/
case jal_op:
arch->gprs[31] = instpc + 8;
case j_op:
epc += 4;
epc >>= 28;
epc <<= 28;
epc |= (insn.j_format.target << 2);
nextpc = epc;
break;
/*
* These are conditional and in i_format.
*/
case beq_op:
case beql_op:
if (arch->gprs[insn.i_format.rs] ==
arch->gprs[insn.i_format.rt])
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
case bne_op:
case bnel_op:
if (arch->gprs[insn.i_format.rs] !=
arch->gprs[insn.i_format.rt])
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
case blez_op: /* not really i_format */
case blezl_op:
/* rt field assumed to be zero */
if ((long)arch->gprs[insn.i_format.rs] <= 0)
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
case bgtz_op:
case bgtzl_op:
/* rt field assumed to be zero */
if ((long)arch->gprs[insn.i_format.rs] > 0)
epc = epc + 4 + (insn.i_format.simmediate << 2);
else
epc += 8;
nextpc = epc;
break;
/*
* And now the FPA/cp1 branch instructions.
*/
case cop1_op:
printk("%s: unsupported cop1_op\n", __func__);
break;
}
return nextpc;
unaligned:
printk("%s: unaligned epc\n", __func__);
return nextpc;
sigill:
printk("%s: DSP branch but not DSP ASE\n", __func__);
return nextpc;
}
enum emulation_result update_pc(struct kvm_vcpu *vcpu, uint32_t cause)
{
unsigned long branch_pc;
enum emulation_result er = EMULATE_DONE;
if (cause & CAUSEF_BD) {
branch_pc = kvm_compute_return_epc(vcpu, vcpu->arch.pc);
if (branch_pc == KVM_INVALID_INST) {
er = EMULATE_FAIL;
} else {
vcpu->arch.pc = branch_pc;
kvm_debug("BD update_pc(): New PC: %#lx\n", vcpu->arch.pc);
}
} else
vcpu->arch.pc += 4;
kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc);
return er;
}
/* Everytime the compare register is written to, we need to decide when to fire
* the timer that represents timer ticks to the GUEST.
*
*/
enum emulation_result kvm_mips_emulate_count(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
enum emulation_result er = EMULATE_DONE;
/* If COUNT is enabled */
if (!(kvm_read_c0_guest_cause(cop0) & CAUSEF_DC)) {
hrtimer_try_to_cancel(&vcpu->arch.comparecount_timer);
hrtimer_start(&vcpu->arch.comparecount_timer,
ktime_set(0, MS_TO_NS(10)), HRTIMER_MODE_REL);
} else {
hrtimer_try_to_cancel(&vcpu->arch.comparecount_timer);
}
return er;
}
enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
enum emulation_result er = EMULATE_DONE;
if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc,
kvm_read_c0_guest_epc(cop0));
kvm_clear_c0_guest_status(cop0, ST0_EXL);
vcpu->arch.pc = kvm_read_c0_guest_epc(cop0);
} else if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
kvm_clear_c0_guest_status(cop0, ST0_ERL);
vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
} else {
printk("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n",
vcpu->arch.pc);
er = EMULATE_FAIL;
}
return er;
}
enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
{
enum emulation_result er = EMULATE_DONE;
kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
vcpu->arch.pending_exceptions);
++vcpu->stat.wait_exits;
trace_kvm_exit(vcpu, WAIT_EXITS);
if (!vcpu->arch.pending_exceptions) {
vcpu->arch.wait = 1;
kvm_vcpu_block(vcpu);
/* We we are runnable, then definitely go off to user space to check if any
* I/O interrupts are pending.
*/
if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
}
}
return er;
}
/* XXXKYMA: Linux doesn't seem to use TLBR, return EMULATE_FAIL for now so that we can catch
* this, if things ever change
*/
enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
enum emulation_result er = EMULATE_FAIL;
uint32_t pc = vcpu->arch.pc;
printk("[%#x] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0));
return er;
}
/* Write Guest TLB Entry @ Index */
enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
int index = kvm_read_c0_guest_index(cop0);
enum emulation_result er = EMULATE_DONE;
struct kvm_mips_tlb *tlb = NULL;
uint32_t pc = vcpu->arch.pc;
if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
printk("%s: illegal index: %d\n", __func__, index);
printk
("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
pc, index, kvm_read_c0_guest_entryhi(cop0),
kvm_read_c0_guest_entrylo0(cop0),
kvm_read_c0_guest_entrylo1(cop0),
kvm_read_c0_guest_pagemask(cop0));
index = (index & ~0x80000000) % KVM_MIPS_GUEST_TLB_SIZE;
}
tlb = &vcpu->arch.guest_tlb[index];
#if 1
/* Probe the shadow host TLB for the entry being overwritten, if one matches, invalidate it */
kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
#endif
tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
kvm_debug
("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
pc, index, kvm_read_c0_guest_entryhi(cop0),
kvm_read_c0_guest_entrylo0(cop0), kvm_read_c0_guest_entrylo1(cop0),
kvm_read_c0_guest_pagemask(cop0));
return er;
}
/* Write Guest TLB Entry @ Random Index */
enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
enum emulation_result er = EMULATE_DONE;
struct kvm_mips_tlb *tlb = NULL;
uint32_t pc = vcpu->arch.pc;
int index;
#if 1
get_random_bytes(&index, sizeof(index));
index &= (KVM_MIPS_GUEST_TLB_SIZE - 1);
#else
index = jiffies % KVM_MIPS_GUEST_TLB_SIZE;
#endif
if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
printk("%s: illegal index: %d\n", __func__, index);
return EMULATE_FAIL;
}
tlb = &vcpu->arch.guest_tlb[index];
#if 1
/* Probe the shadow host TLB for the entry being overwritten, if one matches, invalidate it */
kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
#endif
tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
kvm_debug
("[%#x] COP0_TLBWR[%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx)\n",
pc, index, kvm_read_c0_guest_entryhi(cop0),
kvm_read_c0_guest_entrylo0(cop0),
kvm_read_c0_guest_entrylo1(cop0));
return er;
}
enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
long entryhi = kvm_read_c0_guest_entryhi(cop0);
enum emulation_result er = EMULATE_DONE;
uint32_t pc = vcpu->arch.pc;
int index = -1;
index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
kvm_write_c0_guest_index(cop0, index);
kvm_debug("[%#x] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi,
index);
return er;
}
enum emulation_result
kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc, uint32_t cause,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
enum emulation_result er = EMULATE_DONE;
int32_t rt, rd, copz, sel, co_bit, op;
uint32_t pc = vcpu->arch.pc;
unsigned long curr_pc;
/*
* Update PC and hold onto current PC in case there is
* an error and we want to rollback the PC
*/
curr_pc = vcpu->arch.pc;
er = update_pc(vcpu, cause);
if (er == EMULATE_FAIL) {
return er;
}
copz = (inst >> 21) & 0x1f;
rt = (inst >> 16) & 0x1f;
rd = (inst >> 11) & 0x1f;
sel = inst & 0x7;
co_bit = (inst >> 25) & 1;
/* Verify that the register is valid */
if (rd > MIPS_CP0_DESAVE) {
printk("Invalid rd: %d\n", rd);
er = EMULATE_FAIL;
goto done;
}
if (co_bit) {
op = (inst) & 0xff;
switch (op) {
case tlbr_op: /* Read indexed TLB entry */
er = kvm_mips_emul_tlbr(vcpu);
break;
case tlbwi_op: /* Write indexed */
er = kvm_mips_emul_tlbwi(vcpu);
break;
case tlbwr_op: /* Write random */
er = kvm_mips_emul_tlbwr(vcpu);
break;
case tlbp_op: /* TLB Probe */
er = kvm_mips_emul_tlbp(vcpu);
break;
case rfe_op:
printk("!!!COP0_RFE!!!\n");
break;
case eret_op:
er = kvm_mips_emul_eret(vcpu);
goto dont_update_pc;
break;
case wait_op:
er = kvm_mips_emul_wait(vcpu);
break;
}
} else {
switch (copz) {
case mfc_op:
#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
cop0->stat[rd][sel]++;
#endif
/* Get reg */
if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
/* XXXKYMA: Run the Guest count register @ 1/4 the rate of the host */
vcpu->arch.gprs[rt] = (read_c0_count() >> 2);
} else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
vcpu->arch.gprs[rt] = 0x0;
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
kvm_mips_trans_mfc0(inst, opc, vcpu);
#endif
}
else {
vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
kvm_mips_trans_mfc0(inst, opc, vcpu);
#endif
}
kvm_debug
("[%#x] MFCz[%d][%d], vcpu->arch.gprs[%d]: %#lx\n",
pc, rd, sel, rt, vcpu->arch.gprs[rt]);
break;
case dmfc_op:
vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
break;
case mtc_op:
#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
cop0->stat[rd][sel]++;
#endif
if ((rd == MIPS_CP0_TLB_INDEX)
&& (vcpu->arch.gprs[rt] >=
KVM_MIPS_GUEST_TLB_SIZE)) {
printk("Invalid TLB Index: %ld",
vcpu->arch.gprs[rt]);
er = EMULATE_FAIL;
break;
}
#define C0_EBASE_CORE_MASK 0xff
if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
/* Preserve CORE number */
kvm_change_c0_guest_ebase(cop0,
~(C0_EBASE_CORE_MASK),
vcpu->arch.gprs[rt]);
printk("MTCz, cop0->reg[EBASE]: %#lx\n",
kvm_read_c0_guest_ebase(cop0));
} else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
uint32_t nasid =
vcpu->arch.gprs[rt] & ASID_MASK;
if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0)
&&
((kvm_read_c0_guest_entryhi(cop0) &
ASID_MASK) != nasid)) {
kvm_debug
("MTCz, change ASID from %#lx to %#lx\n",
kvm_read_c0_guest_entryhi(cop0) &
ASID_MASK,
vcpu->arch.gprs[rt] & ASID_MASK);
/* Blow away the shadow host TLBs */
kvm_mips_flush_host_tlb(1);
}
kvm_write_c0_guest_entryhi(cop0,
vcpu->arch.gprs[rt]);
}
/* Are we writing to COUNT */
else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
/* Linux doesn't seem to write into COUNT, we throw an error
* if we notice a write to COUNT
*/
/*er = EMULATE_FAIL; */
goto done;
} else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) {
kvm_debug("[%#x] MTCz, COMPARE %#lx <- %#lx\n",
pc, kvm_read_c0_guest_compare(cop0),
vcpu->arch.gprs[rt]);
/* If we are writing to COMPARE */
/* Clear pending timer interrupt, if any */
kvm_mips_callbacks->dequeue_timer_int(vcpu);
kvm_write_c0_guest_compare(cop0,
vcpu->arch.gprs[rt]);
} else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
kvm_write_c0_guest_status(cop0,
vcpu->arch.gprs[rt]);
/* Make sure that CU1 and NMI bits are never set */
kvm_clear_c0_guest_status(cop0,
(ST0_CU1 | ST0_NMI));
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
kvm_mips_trans_mtc0(inst, opc, vcpu);
#endif
} else {
cop0->reg[rd][sel] = vcpu->arch.gprs[rt];
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
kvm_mips_trans_mtc0(inst, opc, vcpu);
#endif
}
kvm_debug("[%#x] MTCz, cop0->reg[%d][%d]: %#lx\n", pc,
rd, sel, cop0->reg[rd][sel]);
break;
case dmtc_op:
printk
("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n",
vcpu->arch.pc, rt, rd, sel);
er = EMULATE_FAIL;
break;
case mfmcz_op:
#ifdef KVM_MIPS_DEBUG_COP0_COUNTERS
cop0->stat[MIPS_CP0_STATUS][0]++;
#endif
if (rt != 0) {
vcpu->arch.gprs[rt] =
kvm_read_c0_guest_status(cop0);
}
/* EI */
if (inst & 0x20) {
kvm_debug("[%#lx] mfmcz_op: EI\n",
vcpu->arch.pc);
kvm_set_c0_guest_status(cop0, ST0_IE);
} else {
kvm_debug("[%#lx] mfmcz_op: DI\n",
vcpu->arch.pc);
kvm_clear_c0_guest_status(cop0, ST0_IE);
}
break;
case wrpgpr_op:
{
uint32_t css =
cop0->reg[MIPS_CP0_STATUS][2] & 0xf;
uint32_t pss =
(cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf;
/* We don't support any shadow register sets, so SRSCtl[PSS] == SRSCtl[CSS] = 0 */
if (css || pss) {
er = EMULATE_FAIL;
break;
}
kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd,
vcpu->arch.gprs[rt]);
vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt];
}
break;
default:
printk
("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n",
vcpu->arch.pc, copz);
er = EMULATE_FAIL;
break;
}
}
done:
/*
* Rollback PC only if emulation was unsuccessful
*/
if (er == EMULATE_FAIL) {
vcpu->arch.pc = curr_pc;
}
dont_update_pc:
/*
* This is for special instructions whose emulation
* updates the PC, so do not overwrite the PC under
* any circumstances
*/
return er;
}
enum emulation_result
kvm_mips_emulate_store(uint32_t inst, uint32_t cause,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
enum emulation_result er = EMULATE_DO_MMIO;
int32_t op, base, rt, offset;
uint32_t bytes;
void *data = run->mmio.data;
unsigned long curr_pc;
/*
* Update PC and hold onto current PC in case there is
* an error and we want to rollback the PC
*/
curr_pc = vcpu->arch.pc;
er = update_pc(vcpu, cause);
if (er == EMULATE_FAIL)
return er;
rt = (inst >> 16) & 0x1f;
base = (inst >> 21) & 0x1f;
offset = inst & 0xffff;
op = (inst >> 26) & 0x3f;
switch (op) {
case sb_op:
bytes = 1;
if (bytes > sizeof(run->mmio.data)) {
kvm_err("%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr =
kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
er = EMULATE_FAIL;
break;
}
run->mmio.len = bytes;
run->mmio.is_write = 1;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 1;
*(u8 *) data = vcpu->arch.gprs[rt];
kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],
*(uint8_t *) data);
break;
case sw_op:
bytes = 4;
if (bytes > sizeof(run->mmio.data)) {
kvm_err("%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr =
kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
er = EMULATE_FAIL;
break;
}
run->mmio.len = bytes;
run->mmio.is_write = 1;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 1;
*(uint32_t *) data = vcpu->arch.gprs[rt];
kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
vcpu->arch.gprs[rt], *(uint32_t *) data);
break;
case sh_op:
bytes = 2;
if (bytes > sizeof(run->mmio.data)) {
kvm_err("%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr =
kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
er = EMULATE_FAIL;
break;
}
run->mmio.len = bytes;
run->mmio.is_write = 1;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 1;
*(uint16_t *) data = vcpu->arch.gprs[rt];
kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
vcpu->arch.gprs[rt], *(uint32_t *) data);
break;
default:
printk("Store not yet supported");
er = EMULATE_FAIL;
break;
}
/*
* Rollback PC if emulation was unsuccessful
*/
if (er == EMULATE_FAIL) {
vcpu->arch.pc = curr_pc;
}
return er;
}
enum emulation_result
kvm_mips_emulate_load(uint32_t inst, uint32_t cause,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
enum emulation_result er = EMULATE_DO_MMIO;
int32_t op, base, rt, offset;
uint32_t bytes;
rt = (inst >> 16) & 0x1f;
base = (inst >> 21) & 0x1f;
offset = inst & 0xffff;
op = (inst >> 26) & 0x3f;
vcpu->arch.pending_load_cause = cause;
vcpu->arch.io_gpr = rt;
switch (op) {
case lw_op:
bytes = 4;
if (bytes > sizeof(run->mmio.data)) {
kvm_err("%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
er = EMULATE_FAIL;
break;
}
run->mmio.phys_addr =
kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
er = EMULATE_FAIL;
break;
}
run->mmio.len = bytes;
run->mmio.is_write = 0;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 0;
break;
case lh_op:
case lhu_op:
bytes = 2;
if (bytes > sizeof(run->mmio.data)) {
kvm_err("%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
er = EMULATE_FAIL;
break;
}
run->mmio.phys_addr =
kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
er = EMULATE_FAIL;
break;
}
run->mmio.len = bytes;
run->mmio.is_write = 0;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 0;
if (op == lh_op)
vcpu->mmio_needed = 2;
else
vcpu->mmio_needed = 1;
break;
case lbu_op:
case lb_op:
bytes = 1;
if (bytes > sizeof(run->mmio.data)) {
kvm_err("%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
er = EMULATE_FAIL;
break;
}
run->mmio.phys_addr =
kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
er = EMULATE_FAIL;
break;
}
run->mmio.len = bytes;
run->mmio.is_write = 0;
vcpu->mmio_is_write = 0;
if (op == lb_op)
vcpu->mmio_needed = 2;
else
vcpu->mmio_needed = 1;
break;
default:
printk("Load not yet supported");
er = EMULATE_FAIL;
break;
}
return er;
}
int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu)
{
unsigned long offset = (va & ~PAGE_MASK);
struct kvm *kvm = vcpu->kvm;
unsigned long pa;
gfn_t gfn;
pfn_t pfn;
gfn = va >> PAGE_SHIFT;
if (gfn >= kvm->arch.guest_pmap_npages) {
printk("%s: Invalid gfn: %#llx\n", __func__, gfn);
kvm_mips_dump_host_tlbs();
kvm_arch_vcpu_dump_regs(vcpu);
return -1;
}
pfn = kvm->arch.guest_pmap[gfn];
pa = (pfn << PAGE_SHIFT) | offset;
printk("%s: va: %#lx, unmapped: %#x\n", __func__, va, CKSEG0ADDR(pa));
mips32_SyncICache(CKSEG0ADDR(pa), 32);
return 0;
}
#define MIPS_CACHE_OP_INDEX_INV 0x0
#define MIPS_CACHE_OP_INDEX_LD_TAG 0x1
#define MIPS_CACHE_OP_INDEX_ST_TAG 0x2
#define MIPS_CACHE_OP_IMP 0x3
#define MIPS_CACHE_OP_HIT_INV 0x4
#define MIPS_CACHE_OP_FILL_WB_INV 0x5
#define MIPS_CACHE_OP_HIT_HB 0x6
#define MIPS_CACHE_OP_FETCH_LOCK 0x7
#define MIPS_CACHE_ICACHE 0x0
#define MIPS_CACHE_DCACHE 0x1
#define MIPS_CACHE_SEC 0x3
enum emulation_result
kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc, uint32_t cause,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
extern void (*r4k_blast_dcache) (void);
extern void (*r4k_blast_icache) (void);
enum emulation_result er = EMULATE_DONE;
int32_t offset, cache, op_inst, op, base;
struct kvm_vcpu_arch *arch = &vcpu->arch;
unsigned long va;
unsigned long curr_pc;
/*
* Update PC and hold onto current PC in case there is
* an error and we want to rollback the PC
*/
curr_pc = vcpu->arch.pc;
er = update_pc(vcpu, cause);
if (er == EMULATE_FAIL)
return er;
base = (inst >> 21) & 0x1f;
op_inst = (inst >> 16) & 0x1f;
offset = inst & 0xffff;
cache = (inst >> 16) & 0x3;
op = (inst >> 18) & 0x7;
va = arch->gprs[base] + offset;
kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
cache, op, base, arch->gprs[base], offset);
/* Treat INDEX_INV as a nop, basically issued by Linux on startup to invalidate
* the caches entirely by stepping through all the ways/indexes
*/
if (op == MIPS_CACHE_OP_INDEX_INV) {
kvm_debug
("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base,
arch->gprs[base], offset);
if (cache == MIPS_CACHE_DCACHE)
r4k_blast_dcache();
else if (cache == MIPS_CACHE_ICACHE)
r4k_blast_icache();
else {
printk("%s: unsupported CACHE INDEX operation\n",
__func__);
return EMULATE_FAIL;
}
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
kvm_mips_trans_cache_index(inst, opc, vcpu);
#endif
goto done;
}
preempt_disable();
if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
if (kvm_mips_host_tlb_lookup(vcpu, va) < 0) {
kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
}
} else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
int index;
/* If an entry already exists then skip */
if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0) {
goto skip_fault;
}
/* If address not in the guest TLB, then give the guest a fault, the
* resulting handler will do the right thing
*/
index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
(kvm_read_c0_guest_entryhi
(cop0) & ASID_MASK));
if (index < 0) {
vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
vcpu->arch.host_cp0_badvaddr = va;
er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
vcpu);
preempt_enable();
goto dont_update_pc;
} else {
struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
/* Check if the entry is valid, if not then setup a TLB invalid exception to the guest */
if (!TLB_IS_VALID(*tlb, va)) {
er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
run, vcpu);
preempt_enable();
goto dont_update_pc;
} else {
/* We fault an entry from the guest tlb to the shadow host TLB */
kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
NULL,
NULL);
}
}
} else {
printk
("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
cache, op, base, arch->gprs[base], offset);
er = EMULATE_FAIL;
preempt_enable();
goto dont_update_pc;
}
skip_fault:
/* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
if (cache == MIPS_CACHE_DCACHE
&& (op == MIPS_CACHE_OP_FILL_WB_INV
|| op == MIPS_CACHE_OP_HIT_INV)) {
flush_dcache_line(va);
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
/* Replace the CACHE instruction, with a SYNCI, not the same, but avoids a trap */
kvm_mips_trans_cache_va(inst, opc, vcpu);
#endif
} else if (op == MIPS_CACHE_OP_HIT_INV && cache == MIPS_CACHE_ICACHE) {
flush_dcache_line(va);
flush_icache_line(va);
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
/* Replace the CACHE instruction, with a SYNCI */
kvm_mips_trans_cache_va(inst, opc, vcpu);
#endif
} else {
printk
("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
cache, op, base, arch->gprs[base], offset);
er = EMULATE_FAIL;
preempt_enable();
goto dont_update_pc;
}
preempt_enable();
dont_update_pc:
/*
* Rollback PC
*/
vcpu->arch.pc = curr_pc;
done:
return er;
}
enum emulation_result
kvm_mips_emulate_inst(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
enum emulation_result er = EMULATE_DONE;
uint32_t inst;
/*
* Fetch the instruction.
*/
if (cause & CAUSEF_BD) {
opc += 1;
}
inst = kvm_get_inst(opc, vcpu);
switch (((union mips_instruction)inst).r_format.opcode) {
case cop0_op:
er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);
break;
case sb_op:
case sh_op:
case sw_op:
er = kvm_mips_emulate_store(inst, cause, run, vcpu);
break;
case lb_op:
case lbu_op:
case lhu_op:
case lh_op:
case lw_op:
er = kvm_mips_emulate_load(inst, cause, run, vcpu);
break;
case cache_op:
++vcpu->stat.cache_exits;
trace_kvm_exit(vcpu, CACHE_EXITS);
er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu);
break;
default:
printk("Instruction emulation not supported (%p/%#x)\n", opc,
inst);
kvm_arch_vcpu_dump_regs(vcpu);
er = EMULATE_FAIL;
break;
}
return er;
}
enum emulation_result
kvm_mips_emulate_syscall(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc);
kvm_change_c0_guest_cause(cop0, (0xff),
(T_SYSCALL << CAUSEB_EXCCODE));
/* Set PC to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x180;
} else {
printk("Trying to deliver SYSCALL when EXL is already set\n");
er = EMULATE_FAIL;
}
return er;
}
enum emulation_result
kvm_mips_emulate_tlbmiss_ld(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
unsigned long entryhi = (vcpu->arch. host_cp0_badvaddr & VPN2_MASK) |
(kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n",
arch->pc);
/* set pc to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x0;
} else {
kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
arch->pc);
arch->pc = KVM_GUEST_KSEG0 + 0x180;
}
kvm_change_c0_guest_cause(cop0, (0xff),
(T_TLB_LD_MISS << CAUSEB_EXCCODE));
/* setup badvaddr, context and entryhi registers for the guest */
kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
/* XXXKYMA: is the context register used by linux??? */
kvm_write_c0_guest_entryhi(cop0, entryhi);
/* Blow away the shadow host TLBs */
kvm_mips_flush_host_tlb(1);
return er;
}
enum emulation_result
kvm_mips_emulate_tlbinv_ld(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
unsigned long entryhi =
(vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
(kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n",
arch->pc);
/* set pc to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x180;
} else {
kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
arch->pc);
arch->pc = KVM_GUEST_KSEG0 + 0x180;
}
kvm_change_c0_guest_cause(cop0, (0xff),
(T_TLB_LD_MISS << CAUSEB_EXCCODE));
/* setup badvaddr, context and entryhi registers for the guest */
kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
/* XXXKYMA: is the context register used by linux??? */
kvm_write_c0_guest_entryhi(cop0, entryhi);
/* Blow away the shadow host TLBs */
kvm_mips_flush_host_tlb(1);
return er;
}
enum emulation_result
kvm_mips_emulate_tlbmiss_st(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
(kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
arch->pc);
/* Set PC to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x0;
} else {
kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
arch->pc);
arch->pc = KVM_GUEST_KSEG0 + 0x180;
}
kvm_change_c0_guest_cause(cop0, (0xff),
(T_TLB_ST_MISS << CAUSEB_EXCCODE));
/* setup badvaddr, context and entryhi registers for the guest */
kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
/* XXXKYMA: is the context register used by linux??? */
kvm_write_c0_guest_entryhi(cop0, entryhi);
/* Blow away the shadow host TLBs */
kvm_mips_flush_host_tlb(1);
return er;
}
enum emulation_result
kvm_mips_emulate_tlbinv_st(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
(kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
arch->pc);
/* Set PC to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x180;
} else {
kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
arch->pc);
arch->pc = KVM_GUEST_KSEG0 + 0x180;
}
kvm_change_c0_guest_cause(cop0, (0xff),
(T_TLB_ST_MISS << CAUSEB_EXCCODE));
/* setup badvaddr, context and entryhi registers for the guest */
kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
/* XXXKYMA: is the context register used by linux??? */
kvm_write_c0_guest_entryhi(cop0, entryhi);
/* Blow away the shadow host TLBs */
kvm_mips_flush_host_tlb(1);
return er;
}
/* TLBMOD: store into address matching TLB with Dirty bit off */
enum emulation_result
kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
enum emulation_result er = EMULATE_DONE;
#ifdef DEBUG
/*
* If address not in the guest TLB, then we are in trouble
*/
index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
if (index < 0) {
/* XXXKYMA Invalidate and retry */
kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr);
kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n",
__func__, entryhi);
kvm_mips_dump_guest_tlbs(vcpu);
kvm_mips_dump_host_tlbs();
return EMULATE_FAIL;
}
#endif
er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
return er;
}
enum emulation_result
kvm_mips_emulate_tlbmod(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
(kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n",
arch->pc);
arch->pc = KVM_GUEST_KSEG0 + 0x180;
} else {
kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
arch->pc);
arch->pc = KVM_GUEST_KSEG0 + 0x180;
}
kvm_change_c0_guest_cause(cop0, (0xff), (T_TLB_MOD << CAUSEB_EXCCODE));
/* setup badvaddr, context and entryhi registers for the guest */
kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
/* XXXKYMA: is the context register used by linux??? */
kvm_write_c0_guest_entryhi(cop0, entryhi);
/* Blow away the shadow host TLBs */
kvm_mips_flush_host_tlb(1);
return er;
}
enum emulation_result
kvm_mips_emulate_fpu_exc(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
}
arch->pc = KVM_GUEST_KSEG0 + 0x180;
kvm_change_c0_guest_cause(cop0, (0xff),
(T_COP_UNUSABLE << CAUSEB_EXCCODE));
kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE));
return er;
}
enum emulation_result
kvm_mips_emulate_ri_exc(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("Delivering RI @ pc %#lx\n", arch->pc);
kvm_change_c0_guest_cause(cop0, (0xff),
(T_RES_INST << CAUSEB_EXCCODE));
/* Set PC to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x180;
} else {
kvm_err("Trying to deliver RI when EXL is already set\n");
er = EMULATE_FAIL;
}
return er;
}
enum emulation_result
kvm_mips_emulate_bp_exc(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("Delivering BP @ pc %#lx\n", arch->pc);
kvm_change_c0_guest_cause(cop0, (0xff),
(T_BREAK << CAUSEB_EXCCODE));
/* Set PC to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x180;
} else {
printk("Trying to deliver BP when EXL is already set\n");
er = EMULATE_FAIL;
}
return er;
}
/*
* ll/sc, rdhwr, sync emulation
*/
#define OPCODE 0xfc000000
#define BASE 0x03e00000
#define RT 0x001f0000
#define OFFSET 0x0000ffff
#define LL 0xc0000000
#define SC 0xe0000000
#define SPEC0 0x00000000
#define SPEC3 0x7c000000
#define RD 0x0000f800
#define FUNC 0x0000003f
#define SYNC 0x0000000f
#define RDHWR 0x0000003b
enum emulation_result
kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
unsigned long curr_pc;
uint32_t inst;
/*
* Update PC and hold onto current PC in case there is
* an error and we want to rollback the PC
*/
curr_pc = vcpu->arch.pc;
er = update_pc(vcpu, cause);
if (er == EMULATE_FAIL)
return er;
/*
* Fetch the instruction.
*/
if (cause & CAUSEF_BD)
opc += 1;
inst = kvm_get_inst(opc, vcpu);
if (inst == KVM_INVALID_INST) {
printk("%s: Cannot get inst @ %p\n", __func__, opc);
return EMULATE_FAIL;
}
if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) {
int rd = (inst & RD) >> 11;
int rt = (inst & RT) >> 16;
switch (rd) {
case 0: /* CPU number */
arch->gprs[rt] = 0;
break;
case 1: /* SYNCI length */
arch->gprs[rt] = min(current_cpu_data.dcache.linesz,
current_cpu_data.icache.linesz);
break;
case 2: /* Read count register */
printk("RDHWR: Cont register\n");
arch->gprs[rt] = kvm_read_c0_guest_count(cop0);
break;
case 3: /* Count register resolution */
switch (current_cpu_data.cputype) {
case CPU_20KC:
case CPU_25KF:
arch->gprs[rt] = 1;
break;
default:
arch->gprs[rt] = 2;
}
break;
case 29:
#if 1
arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
#else
/* UserLocal not implemented */
er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
#endif
break;
default:
printk("RDHWR not supported\n");
er = EMULATE_FAIL;
break;
}
} else {
printk("Emulate RI not supported @ %p: %#x\n", opc, inst);
er = EMULATE_FAIL;
}
/*
* Rollback PC only if emulation was unsuccessful
*/
if (er == EMULATE_FAIL) {
vcpu->arch.pc = curr_pc;
}
return er;
}
enum emulation_result
kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
enum emulation_result er = EMULATE_DONE;
unsigned long curr_pc;
if (run->mmio.len > sizeof(*gpr)) {
printk("Bad MMIO length: %d", run->mmio.len);
er = EMULATE_FAIL;
goto done;
}
/*
* Update PC and hold onto current PC in case there is
* an error and we want to rollback the PC
*/
curr_pc = vcpu->arch.pc;
er = update_pc(vcpu, vcpu->arch.pending_load_cause);
if (er == EMULATE_FAIL)
return er;
switch (run->mmio.len) {
case 4:
*gpr = *(int32_t *) run->mmio.data;
break;
case 2:
if (vcpu->mmio_needed == 2)
*gpr = *(int16_t *) run->mmio.data;
else
*gpr = *(int16_t *) run->mmio.data;
break;
case 1:
if (vcpu->mmio_needed == 2)
*gpr = *(int8_t *) run->mmio.data;
else
*gpr = *(u8 *) run->mmio.data;
break;
}
if (vcpu->arch.pending_load_cause & CAUSEF_BD)
kvm_debug
("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n",
vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr,
vcpu->mmio_needed);
done:
return er;
}
static enum emulation_result
kvm_mips_emulate_exc(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
enum emulation_result er = EMULATE_DONE;
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_change_c0_guest_cause(cop0, (0xff),
(exccode << CAUSEB_EXCCODE));
/* Set PC to the exception entry point */
arch->pc = KVM_GUEST_KSEG0 + 0x180;
kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n",
exccode, kvm_read_c0_guest_epc(cop0),
kvm_read_c0_guest_badvaddr(cop0));
} else {
printk("Trying to deliver EXC when EXL is already set\n");
er = EMULATE_FAIL;
}
return er;
}
enum emulation_result
kvm_mips_check_privilege(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
enum emulation_result er = EMULATE_DONE;
uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
if (usermode) {
switch (exccode) {
case T_INT:
case T_SYSCALL:
case T_BREAK:
case T_RES_INST:
break;
case T_COP_UNUSABLE:
if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0)
er = EMULATE_PRIV_FAIL;
break;
case T_TLB_MOD:
break;
case T_TLB_LD_MISS:
/* We we are accessing Guest kernel space, then send an address error exception to the guest */
if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
printk("%s: LD MISS @ %#lx\n", __func__,
badvaddr);
cause &= ~0xff;
cause |= (T_ADDR_ERR_LD << CAUSEB_EXCCODE);
er = EMULATE_PRIV_FAIL;
}
break;
case T_TLB_ST_MISS:
/* We we are accessing Guest kernel space, then send an address error exception to the guest */
if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
printk("%s: ST MISS @ %#lx\n", __func__,
badvaddr);
cause &= ~0xff;
cause |= (T_ADDR_ERR_ST << CAUSEB_EXCCODE);
er = EMULATE_PRIV_FAIL;
}
break;
case T_ADDR_ERR_ST:
printk("%s: address error ST @ %#lx\n", __func__,
badvaddr);
if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
cause &= ~0xff;
cause |= (T_TLB_ST_MISS << CAUSEB_EXCCODE);
}
er = EMULATE_PRIV_FAIL;
break;
case T_ADDR_ERR_LD:
printk("%s: address error LD @ %#lx\n", __func__,
badvaddr);
if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
cause &= ~0xff;
cause |= (T_TLB_LD_MISS << CAUSEB_EXCCODE);
}
er = EMULATE_PRIV_FAIL;
break;
default:
er = EMULATE_PRIV_FAIL;
break;
}
}
if (er == EMULATE_PRIV_FAIL) {
kvm_mips_emulate_exc(cause, opc, run, vcpu);
}
return er;
}
/* User Address (UA) fault, this could happen if
* (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
* case we pass on the fault to the guest kernel and let it handle it.
* (2) TLB entry is present in the Guest TLB but not in the shadow, in this
* case we inject the TLB from the Guest TLB into the shadow host TLB
*/
enum emulation_result
kvm_mips_handle_tlbmiss(unsigned long cause, uint32_t *opc,
struct kvm_run *run, struct kvm_vcpu *vcpu)
{
enum emulation_result er = EMULATE_DONE;
uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
unsigned long va = vcpu->arch.host_cp0_badvaddr;
int index;
kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx, entryhi: %#lx\n",
vcpu->arch.host_cp0_badvaddr, vcpu->arch.host_cp0_entryhi);
/* KVM would not have got the exception if this entry was valid in the shadow host TLB
* Check the Guest TLB, if the entry is not there then send the guest an
* exception. The guest exc handler should then inject an entry into the
* guest TLB
*/
index = kvm_mips_guest_tlb_lookup(vcpu,
(va & VPN2_MASK) |
(kvm_read_c0_guest_entryhi
(vcpu->arch.cop0) & ASID_MASK));
if (index < 0) {
if (exccode == T_TLB_LD_MISS) {
er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
} else if (exccode == T_TLB_ST_MISS) {
er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu);
} else {
printk("%s: invalid exc code: %d\n", __func__, exccode);
er = EMULATE_FAIL;
}
} else {
struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
/* Check if the entry is valid, if not then setup a TLB invalid exception to the guest */
if (!TLB_IS_VALID(*tlb, va)) {
if (exccode == T_TLB_LD_MISS) {
er = kvm_mips_emulate_tlbinv_ld(cause, opc, run,
vcpu);
} else if (exccode == T_TLB_ST_MISS) {
er = kvm_mips_emulate_tlbinv_st(cause, opc, run,
vcpu);
} else {
printk("%s: invalid exc code: %d\n", __func__,
exccode);
er = EMULATE_FAIL;
}
} else {
#ifdef DEBUG
kvm_debug
("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
#endif
/* OK we have a Guest TLB entry, now inject it into the shadow host TLB */
kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
NULL);
}
}
return er;
}
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