Abstract the handling of bad guest loads and stores which may need to
trigger an MMIO, so that the same code can be used in a later patch for
guest KSeg0 addresses (TLB exception handling) as well as for host KSeg1
addresses (existing address error exception and TLB exception handling).
We now use kvm_mips_emulate_store() and kvm_mips_emulate_load() directly
rather than the more generic kvm_mips_emulate_inst(), as there is no
need to expose emulation of any other instructions.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
---
arch/mips/kvm/trap_emul.c | 119 +++++++++++++++++++++++----------------
1 file changed, 72 insertions(+), 47 deletions(-)
diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
index 33888f1a89f4..79c30a0baad1 100644
--- a/arch/mips/kvm/trap_emul.c
+++ b/arch/mips/kvm/trap_emul.c
@@ -85,6 +85,75 @@ static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
return ret;
}
+static int kvm_mips_bad_load(u32 cause, u32 *opc, struct kvm_run *run,
+ struct kvm_vcpu *vcpu)
+{
+ enum emulation_result er;
+ union mips_instruction inst;
+ int err;
+
+ /* A code fetch fault doesn't count as an MMIO */
+ if (kvm_is_ifetch_fault(&vcpu->arch)) {
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ return RESUME_HOST;
+ }
+
+ /* Fetch the instruction. */
+ if (cause & CAUSEF_BD)
+ opc += 1;
+ err = kvm_get_badinstr(opc, vcpu, &inst.word);
+ if (err) {
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ return RESUME_HOST;
+ }
+
+ /* Emulate the load */
+ er = kvm_mips_emulate_load(inst, cause, run, vcpu);
+ if (er == EMULATE_FAIL) {
+ kvm_err("Emulate load from MMIO space failed\n");
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ } else {
+ run->exit_reason = KVM_EXIT_MMIO;
+ }
+ return RESUME_HOST;
+}
+
+static int kvm_mips_bad_store(u32 cause, u32 *opc, struct kvm_run *run,
+ struct kvm_vcpu *vcpu)
+{
+ enum emulation_result er;
+ union mips_instruction inst;
+ int err;
+
+ /* Fetch the instruction. */
+ if (cause & CAUSEF_BD)
+ opc += 1;
+ err = kvm_get_badinstr(opc, vcpu, &inst.word);
+ if (err) {
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ return RESUME_HOST;
+ }
+
+ /* Emulate the store */
+ er = kvm_mips_emulate_store(inst, cause, run, vcpu);
+ if (er == EMULATE_FAIL) {
+ kvm_err("Emulate store to MMIO space failed\n");
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ } else {
+ run->exit_reason = KVM_EXIT_MMIO;
+ }
+ return RESUME_HOST;
+}
+
+static int kvm_mips_bad_access(u32 cause, u32 *opc, struct kvm_run *run,
+ struct kvm_vcpu *vcpu, bool store)
+{
+ if (store)
+ return kvm_mips_bad_store(cause, opc, run, vcpu);
+ else
+ return kvm_mips_bad_load(cause, opc, run, vcpu);
+}
+
static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
@@ -178,28 +247,11 @@ static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store)
}
} else if (KVM_GUEST_KERNEL_MODE(vcpu)
&& (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
- /* A code fetch fault doesn't count as an MMIO */
- if (!store && kvm_is_ifetch_fault(&vcpu->arch)) {
- run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- return RESUME_HOST;
- }
-
/*
* With EVA we may get a TLB exception instead of an address
* error when the guest performs MMIO to KSeg1 addresses.
*/
- kvm_debug("Emulate %s MMIO space\n",
- store ? "Store to" : "Load from");
- er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
- if (er == EMULATE_FAIL) {
- kvm_err("Emulate %s MMIO space failed\n",
- store ? "Store to" : "Load from");
- run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- ret = RESUME_HOST;
- } else {
- run->exit_reason = KVM_EXIT_MMIO;
- ret = RESUME_HOST;
- }
+ ret = kvm_mips_bad_access(cause, opc, run, vcpu, store);
} else {
kvm_err("Illegal TLB %s fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
store ? "ST" : "LD", cause, opc, badvaddr);
@@ -227,21 +279,11 @@ static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
u32 __user *opc = (u32 __user *) vcpu->arch.pc;
unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
u32 cause = vcpu->arch.host_cp0_cause;
- enum emulation_result er = EMULATE_DONE;
int ret = RESUME_GUEST;
if (KVM_GUEST_KERNEL_MODE(vcpu)
&& (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
- kvm_debug("Emulate Store to MMIO space\n");
- er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
- if (er == EMULATE_FAIL) {
- kvm_err("Emulate Store to MMIO space failed\n");
- run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- ret = RESUME_HOST;
- } else {
- run->exit_reason = KVM_EXIT_MMIO;
- ret = RESUME_HOST;
- }
+ ret = kvm_mips_bad_store(cause, opc, run, vcpu);
} else {
kvm_err("Address Error (STORE): cause %#x, PC: %p, BadVaddr: %#lx\n",
cause, opc, badvaddr);
@@ -257,32 +299,15 @@ static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
u32 __user *opc = (u32 __user *) vcpu->arch.pc;
unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
u32 cause = vcpu->arch.host_cp0_cause;
- enum emulation_result er = EMULATE_DONE;
int ret = RESUME_GUEST;
if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
- /* A code fetch fault doesn't count as an MMIO */
- if (kvm_is_ifetch_fault(&vcpu->arch)) {
- run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- return RESUME_HOST;
- }
-
- kvm_debug("Emulate Load from MMIO space @ %#lx\n", badvaddr);
- er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
- if (er == EMULATE_FAIL) {
- kvm_err("Emulate Load from MMIO space failed\n");
- run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- ret = RESUME_HOST;
- } else {
- run->exit_reason = KVM_EXIT_MMIO;
- ret = RESUME_HOST;
- }
+ ret = kvm_mips_bad_load(cause, opc, run, vcpu);
} else {
kvm_err("Address Error (LOAD): cause %#x, PC: %p, BadVaddr: %#lx\n",
cause, opc, badvaddr);
run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
ret = RESUME_HOST;
- er = EMULATE_FAIL;
}
return ret;
}
--
git-series 0.8.10
