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>
diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c
new file mode 100644
index 0000000..4b6274b
--- /dev/null
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -0,0 +1,1829 @@
+/*
+* 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;
+}
diff --git a/arch/mips/kvm/kvm_mips_opcode.h b/arch/mips/kvm/kvm_mips_opcode.h
new file mode 100644
index 0000000..86d3b4c
--- /dev/null
+++ b/arch/mips/kvm/kvm_mips_opcode.h
@@ -0,0 +1,24 @@
+/*
+* 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.
+*
+* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
+* Authors: Sanjay Lal <sanjayl@kymasys.com>
+*/
+
+/*
+ * Define opcode values not defined in <asm/isnt.h>
+ */
+
+#ifndef __KVM_MIPS_OPCODE_H__
+#define __KVM_MIPS_OPCODE_H__
+
+/* COP0 Ops */
+#define mfmcz_op 0x0b /* 01011 */
+#define wrpgpr_op 0x0e /* 01110 */
+
+/* COP0 opcodes (only if COP0 and CO=1): */
+#define wait_op 0x20 /* 100000 */
+
+#endif /* __KVM_MIPS_OPCODE_H__ */