summaryrefslogtreecommitdiffstats
path: root/arch/mips/kvm/emulate.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/kvm/emulate.c')
-rw-r--r--arch/mips/kvm/emulate.c332
1 files changed, 325 insertions, 7 deletions
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index fb3e8dfd1ff6..6230f376a44e 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -884,6 +884,84 @@ enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu)
return EMULATE_DONE;
}
+/**
+ * kvm_mips_config1_wrmask() - Find mask of writable bits in guest Config1
+ * @vcpu: Virtual CPU.
+ *
+ * Finds the mask of bits which are writable in the guest's Config1 CP0
+ * register, by userland (currently read-only to the guest).
+ */
+unsigned int kvm_mips_config1_wrmask(struct kvm_vcpu *vcpu)
+{
+ unsigned int mask = 0;
+
+ /* Permit FPU to be present if FPU is supported */
+ if (kvm_mips_guest_can_have_fpu(&vcpu->arch))
+ mask |= MIPS_CONF1_FP;
+
+ return mask;
+}
+
+/**
+ * kvm_mips_config3_wrmask() - Find mask of writable bits in guest Config3
+ * @vcpu: Virtual CPU.
+ *
+ * Finds the mask of bits which are writable in the guest's Config3 CP0
+ * register, by userland (currently read-only to the guest).
+ */
+unsigned int kvm_mips_config3_wrmask(struct kvm_vcpu *vcpu)
+{
+ /* Config4 is optional */
+ unsigned int mask = MIPS_CONF_M;
+
+ /* Permit MSA to be present if MSA is supported */
+ if (kvm_mips_guest_can_have_msa(&vcpu->arch))
+ mask |= MIPS_CONF3_MSA;
+
+ return mask;
+}
+
+/**
+ * kvm_mips_config4_wrmask() - Find mask of writable bits in guest Config4
+ * @vcpu: Virtual CPU.
+ *
+ * Finds the mask of bits which are writable in the guest's Config4 CP0
+ * register, by userland (currently read-only to the guest).
+ */
+unsigned int kvm_mips_config4_wrmask(struct kvm_vcpu *vcpu)
+{
+ /* Config5 is optional */
+ return MIPS_CONF_M;
+}
+
+/**
+ * kvm_mips_config5_wrmask() - Find mask of writable bits in guest Config5
+ * @vcpu: Virtual CPU.
+ *
+ * Finds the mask of bits which are writable in the guest's Config5 CP0
+ * register, by the guest itself.
+ */
+unsigned int kvm_mips_config5_wrmask(struct kvm_vcpu *vcpu)
+{
+ unsigned int mask = 0;
+
+ /* Permit MSAEn changes if MSA supported and enabled */
+ if (kvm_mips_guest_has_msa(&vcpu->arch))
+ mask |= MIPS_CONF5_MSAEN;
+
+ /*
+ * Permit guest FPU mode changes if FPU is enabled and the relevant
+ * feature exists according to FIR register.
+ */
+ if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
+ if (cpu_has_fre)
+ mask |= MIPS_CONF5_FRE;
+ /* We don't support UFR or UFE */
+ }
+
+ return mask;
+}
+
enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
uint32_t cause, struct kvm_run *run,
struct kvm_vcpu *vcpu)
@@ -1021,18 +1099,114 @@ enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
kvm_mips_write_compare(vcpu,
vcpu->arch.gprs[rt]);
} else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
- kvm_write_c0_guest_status(cop0,
- vcpu->arch.gprs[rt]);
+ unsigned int old_val, val, change;
+
+ old_val = kvm_read_c0_guest_status(cop0);
+ val = vcpu->arch.gprs[rt];
+ change = val ^ old_val;
+
+ /* Make sure that the NMI bit is never set */
+ val &= ~ST0_NMI;
+
+ /*
+ * Don't allow CU1 or FR to be set unless FPU
+ * capability enabled and exists in guest
+ * configuration.
+ */
+ if (!kvm_mips_guest_has_fpu(&vcpu->arch))
+ val &= ~(ST0_CU1 | ST0_FR);
+
+ /*
+ * Also don't allow FR to be set if host doesn't
+ * support it.
+ */
+ if (!(current_cpu_data.fpu_id & MIPS_FPIR_F64))
+ val &= ~ST0_FR;
+
+
+ /* Handle changes in FPU mode */
+ preempt_disable();
+
+ /*
+ * FPU and Vector register state is made
+ * UNPREDICTABLE by a change of FR, so don't
+ * even bother saving it.
+ */
+ if (change & ST0_FR)
+ kvm_drop_fpu(vcpu);
+
+ /*
+ * If MSA state is already live, it is undefined
+ * how it interacts with FR=0 FPU state, and we
+ * don't want to hit reserved instruction
+ * exceptions trying to save the MSA state later
+ * when CU=1 && FR=1, so play it safe and save
+ * it first.
+ */
+ if (change & ST0_CU1 && !(val & ST0_FR) &&
+ vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
+ kvm_lose_fpu(vcpu);
+
/*
- * Make sure that CU1 and NMI bits are
- * never set
+ * Propagate CU1 (FPU enable) changes
+ * immediately if the FPU context is already
+ * loaded. When disabling we leave the context
+ * loaded so it can be quickly enabled again in
+ * the near future.
*/
- kvm_clear_c0_guest_status(cop0,
- (ST0_CU1 | ST0_NMI));
+ if (change & ST0_CU1 &&
+ vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
+ change_c0_status(ST0_CU1, val);
+
+ preempt_enable();
+
+ kvm_write_c0_guest_status(cop0, val);
#ifdef CONFIG_KVM_MIPS_DYN_TRANS
- kvm_mips_trans_mtc0(inst, opc, vcpu);
+ /*
+ * If FPU present, we need CU1/FR bits to take
+ * effect fairly soon.
+ */
+ if (!kvm_mips_guest_has_fpu(&vcpu->arch))
+ kvm_mips_trans_mtc0(inst, opc, vcpu);
#endif
+ } else if ((rd == MIPS_CP0_CONFIG) && (sel == 5)) {
+ unsigned int old_val, val, change, wrmask;
+
+ old_val = kvm_read_c0_guest_config5(cop0);
+ val = vcpu->arch.gprs[rt];
+
+ /* Only a few bits are writable in Config5 */
+ wrmask = kvm_mips_config5_wrmask(vcpu);
+ change = (val ^ old_val) & wrmask;
+ val = old_val ^ change;
+
+
+ /* Handle changes in FPU/MSA modes */
+ preempt_disable();
+
+ /*
+ * Propagate FRE changes immediately if the FPU
+ * context is already loaded.
+ */
+ if (change & MIPS_CONF5_FRE &&
+ vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
+ change_c0_config5(MIPS_CONF5_FRE, val);
+
+ /*
+ * Propagate MSAEn changes immediately if the
+ * MSA context is already loaded. When disabling
+ * we leave the context loaded so it can be
+ * quickly enabled again in the near future.
+ */
+ if (change & MIPS_CONF5_MSAEN &&
+ vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
+ change_c0_config5(MIPS_CONF5_MSAEN,
+ val);
+
+ preempt_enable();
+
+ kvm_write_c0_guest_config5(cop0, val);
} else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) {
uint32_t old_cause, new_cause;
@@ -1970,6 +2144,146 @@ enum emulation_result kvm_mips_emulate_bp_exc(unsigned long cause,
return er;
}
+enum emulation_result kvm_mips_emulate_trap_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 TRAP @ pc %#lx\n", arch->pc);
+
+ kvm_change_c0_guest_cause(cop0, (0xff),
+ (T_TRAP << CAUSEB_EXCCODE));
+
+ /* Set PC to the exception entry point */
+ arch->pc = KVM_GUEST_KSEG0 + 0x180;
+
+ } else {
+ kvm_err("Trying to deliver TRAP when EXL is already set\n");
+ er = EMULATE_FAIL;
+ }
+
+ return er;
+}
+
+enum emulation_result kvm_mips_emulate_msafpe_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 MSAFPE @ pc %#lx\n", arch->pc);
+
+ kvm_change_c0_guest_cause(cop0, (0xff),
+ (T_MSAFPE << CAUSEB_EXCCODE));
+
+ /* Set PC to the exception entry point */
+ arch->pc = KVM_GUEST_KSEG0 + 0x180;
+
+ } else {
+ kvm_err("Trying to deliver MSAFPE when EXL is already set\n");
+ er = EMULATE_FAIL;
+ }
+
+ return er;
+}
+
+enum emulation_result kvm_mips_emulate_fpe_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 FPE @ pc %#lx\n", arch->pc);
+
+ kvm_change_c0_guest_cause(cop0, (0xff),
+ (T_FPE << CAUSEB_EXCCODE));
+
+ /* Set PC to the exception entry point */
+ arch->pc = KVM_GUEST_KSEG0 + 0x180;
+
+ } else {
+ kvm_err("Trying to deliver FPE when EXL is already set\n");
+ er = EMULATE_FAIL;
+ }
+
+ return er;
+}
+
+enum emulation_result kvm_mips_emulate_msadis_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 MSADIS @ pc %#lx\n", arch->pc);
+
+ kvm_change_c0_guest_cause(cop0, (0xff),
+ (T_MSADIS << CAUSEB_EXCCODE));
+
+ /* Set PC to the exception entry point */
+ arch->pc = KVM_GUEST_KSEG0 + 0x180;
+
+ } else {
+ kvm_err("Trying to deliver MSADIS when EXL is already set\n");
+ er = EMULATE_FAIL;
+ }
+
+ return er;
+}
+
/* ll/sc, rdhwr, sync emulation */
#define OPCODE 0xfc000000
@@ -2176,6 +2490,10 @@ enum emulation_result kvm_mips_check_privilege(unsigned long cause,
case T_SYSCALL:
case T_BREAK:
case T_RES_INST:
+ case T_TRAP:
+ case T_MSAFPE:
+ case T_FPE:
+ case T_MSADIS:
break;
case T_COP_UNUSABLE:
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 12:56:48 +0100