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-rw-r--r--arch/mips/include/asm/kvm_host.h8
-rw-r--r--arch/mips/kvm/emulate.c36
-rw-r--r--arch/mips/kvm/mips.c7
-rw-r--r--arch/mips/kvm/stats.c1
-rw-r--r--arch/mips/kvm/trap_emul.c39
5 files changed, 88 insertions, 3 deletions
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 866edf330e53..fb264d8695e4 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -123,6 +123,7 @@ struct kvm_vcpu_stat {
u32 resvd_inst_exits;
u32 break_inst_exits;
u32 trap_inst_exits;
+ u32 fpe_exits;
u32 flush_dcache_exits;
u32 halt_successful_poll;
u32 halt_wakeup;
@@ -143,6 +144,7 @@ enum kvm_mips_exit_types {
RESVD_INST_EXITS,
BREAK_INST_EXITS,
TRAP_INST_EXITS,
+ FPE_EXITS,
FLUSH_DCACHE_EXITS,
MAX_KVM_MIPS_EXIT_TYPES
};
@@ -585,6 +587,7 @@ struct kvm_mips_callbacks {
int (*handle_res_inst)(struct kvm_vcpu *vcpu);
int (*handle_break)(struct kvm_vcpu *vcpu);
int (*handle_trap)(struct kvm_vcpu *vcpu);
+ int (*handle_fpe)(struct kvm_vcpu *vcpu);
int (*handle_msa_disabled)(struct kvm_vcpu *vcpu);
int (*vm_init)(struct kvm *kvm);
int (*vcpu_init)(struct kvm_vcpu *vcpu);
@@ -734,6 +737,11 @@ extern enum emulation_result kvm_mips_emulate_trap_exc(unsigned long cause,
struct kvm_run *run,
struct kvm_vcpu *vcpu);
+extern enum emulation_result kvm_mips_emulate_fpe_exc(unsigned long cause,
+ uint32_t *opc,
+ struct kvm_run *run,
+ struct kvm_vcpu *vcpu);
+
extern enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
struct kvm_run *run);
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 3511bb20fe0e..fbf169fb63df 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -2146,6 +2146,41 @@ enum emulation_result kvm_mips_emulate_trap_exc(unsigned long cause,
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;
+}
+
/* ll/sc, rdhwr, sync emulation */
#define OPCODE 0xfc000000
@@ -2353,6 +2388,7 @@ enum emulation_result kvm_mips_check_privilege(unsigned long cause,
case T_BREAK:
case T_RES_INST:
case T_TRAP:
+ case T_FPE:
case T_MSADIS:
break;
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index b26a48d81467..dd0833833bea 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -50,6 +50,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "resvd_inst", VCPU_STAT(resvd_inst_exits), KVM_STAT_VCPU },
{ "break_inst", VCPU_STAT(break_inst_exits), KVM_STAT_VCPU },
{ "trap_inst", VCPU_STAT(trap_inst_exits), KVM_STAT_VCPU },
+ { "fpe", VCPU_STAT(fpe_exits), KVM_STAT_VCPU },
{ "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU },
{ "halt_wakeup", VCPU_STAT(halt_wakeup), KVM_STAT_VCPU },
@@ -1148,6 +1149,12 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
ret = kvm_mips_callbacks->handle_trap(vcpu);
break;
+ case T_FPE:
+ ++vcpu->stat.fpe_exits;
+ trace_kvm_exit(vcpu, FPE_EXITS);
+ ret = kvm_mips_callbacks->handle_fpe(vcpu);
+ break;
+
case T_MSADIS:
ret = kvm_mips_callbacks->handle_msa_disabled(vcpu);
break;
diff --git a/arch/mips/kvm/stats.c b/arch/mips/kvm/stats.c
index dd90b0a92181..3843828f3b91 100644
--- a/arch/mips/kvm/stats.c
+++ b/arch/mips/kvm/stats.c
@@ -26,6 +26,7 @@ char *kvm_mips_exit_types_str[MAX_KVM_MIPS_EXIT_TYPES] = {
"Reserved Inst",
"Break Inst",
"Trap Inst",
+ "FPE",
"D-Cache Flushes",
};
diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
index 408af244aed2..421d5b815f24 100644
--- a/arch/mips/kvm/trap_emul.c
+++ b/arch/mips/kvm/trap_emul.c
@@ -39,16 +39,30 @@ static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
{
+ struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_run *run = vcpu->run;
uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
unsigned long cause = vcpu->arch.host_cp0_cause;
enum emulation_result er = EMULATE_DONE;
int ret = RESUME_GUEST;
- if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1)
- er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
- else
+ if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
+ /* FPU Unusable */
+ if (!kvm_mips_guest_has_fpu(&vcpu->arch) ||
+ (kvm_read_c0_guest_status(cop0) & ST0_CU1) == 0) {
+ /*
+ * Unusable/no FPU in guest:
+ * deliver guest COP1 Unusable Exception
+ */
+ er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
+ } else {
+ /* Restore FPU state */
+ kvm_own_fpu(vcpu);
+ er = EMULATE_DONE;
+ }
+ } else {
er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
+ }
switch (er) {
case EMULATE_DONE:
@@ -348,6 +362,24 @@ static int kvm_trap_emul_handle_trap(struct kvm_vcpu *vcpu)
return ret;
}
+static int kvm_trap_emul_handle_fpe(struct kvm_vcpu *vcpu)
+{
+ struct kvm_run *run = vcpu->run;
+ uint32_t __user *opc = (uint32_t __user *)vcpu->arch.pc;
+ unsigned long cause = vcpu->arch.host_cp0_cause;
+ enum emulation_result er = EMULATE_DONE;
+ int ret = RESUME_GUEST;
+
+ er = kvm_mips_emulate_fpe_exc(cause, opc, run, vcpu);
+ if (er == EMULATE_DONE) {
+ ret = RESUME_GUEST;
+ } else {
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ ret = RESUME_HOST;
+ }
+ return ret;
+}
+
static int kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
@@ -576,6 +608,7 @@ static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
.handle_res_inst = kvm_trap_emul_handle_res_inst,
.handle_break = kvm_trap_emul_handle_break,
.handle_trap = kvm_trap_emul_handle_trap,
+ .handle_fpe = kvm_trap_emul_handle_fpe,
.handle_msa_disabled = kvm_trap_emul_handle_msa_disabled,
.vm_init = kvm_trap_emul_vm_init,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.