MIPS: KVM: Factor writing of translated guest instructions

The code in kvm_mips_dyntrans.c to write a translated guest instruction
to guest memory depending on the segment is duplicated between each of
the functions. Additionally the cache op translation functions assume
the instruction is in the KSEG0/1 segment rather than KSEG2/3, which is
generally true but isn't guaranteed.

Factor that code into a new kvm_mips_trans_replace() which handles both
KSEG0/1 and KSEG2/3.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c
index 79b134c..eb6e0d1 100644 (file)
--- a/arch/mips/kvm/dyntrans.c
+++ b/arch/mips/kvm/dyntrans.c
@@ -28,21 +28,41 @@
 #define CLEAR_TEMPLATE  0x00000020
 #define SW_TEMPLATE     0xac000000
 
+/**
+ * kvm_mips_trans_replace() - Replace trapping instruction in guest memory.
+ * @vcpu:      Virtual CPU.
+ * @opc:       PC of instruction to replace.
+ * @replace:   Instruction to write
+ */
+static int kvm_mips_trans_replace(struct kvm_vcpu *vcpu, u32 *opc, u32 replace)
+{
+       unsigned long kseg0_opc, flags;
+
+       if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
+               kseg0_opc =
+                   CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
+                              (vcpu, (unsigned long) opc));
+               memcpy((void *)kseg0_opc, (void *)&replace, sizeof(u32));
+               local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
+       } else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
+               local_irq_save(flags);
+               memcpy((void *)opc, (void *)&replace, sizeof(u32));
+               local_flush_icache_range((unsigned long)opc,
+                                        (unsigned long)opc + 32);
+               local_irq_restore(flags);
+       } else {
+               kvm_err("%s: Invalid address: %p\n", __func__, opc);
+               return -EFAULT;
+       }
+
+       return 0;
+}
+
 int kvm_mips_trans_cache_index(u32 inst, u32 *opc,
                               struct kvm_vcpu *vcpu)
 {
-       int result = 0;
-       unsigned long kseg0_opc;
-       u32 synci_inst = 0x0;
-
        /* Replace the CACHE instruction, with a NOP */
-       kseg0_opc =
-           CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
-                      (vcpu, (unsigned long) opc));
-       memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(u32));
-       local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
-
-       return result;
+       return kvm_mips_trans_replace(vcpu, opc, 0x00000000);
 }
 
 /*
@@ -52,8 +72,6 @@ int kvm_mips_trans_cache_index(u32 inst, u32 *opc,
 int kvm_mips_trans_cache_va(u32 inst, u32 *opc,
                            struct kvm_vcpu *vcpu)
 {
-       int result = 0;
-       unsigned long kseg0_opc;
        u32 synci_inst = SYNCI_TEMPLATE, base, offset;
 
        base = (inst >> 21) & 0x1f;
@@ -61,20 +79,13 @@ int kvm_mips_trans_cache_va(u32 inst, u32 *opc,
        synci_inst |= (base << 21);
        synci_inst |= offset;
 
-       kseg0_opc =
-           CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
-                      (vcpu, (unsigned long) opc));
-       memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(u32));
-       local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
-
-       return result;
+       return kvm_mips_trans_replace(vcpu, opc, synci_inst);
 }
 
 int kvm_mips_trans_mfc0(u32 inst, u32 *opc, struct kvm_vcpu *vcpu)
 {
        u32 rt, rd, sel;
        u32 mfc0_inst;
-       unsigned long kseg0_opc, flags;
 
        rt = (inst >> 16) & 0x1f;
        rd = (inst >> 11) & 0x1f;
@@ -90,31 +101,13 @@ int kvm_mips_trans_mfc0(u32 inst, u32 *opc, struct kvm_vcpu *vcpu)
                                      cop0.reg[rd][sel]);
        }
 
-       if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
-               kseg0_opc =
-                   CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
-                              (vcpu, (unsigned long) opc));
-               memcpy((void *)kseg0_opc, (void *)&mfc0_inst, sizeof(u32));
-               local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
-       } else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
-               local_irq_save(flags);
-               memcpy((void *)opc, (void *)&mfc0_inst, sizeof(u32));
-               local_flush_icache_range((unsigned long)opc,
-                                        (unsigned long)opc + 32);
-               local_irq_restore(flags);
-       } else {
-               kvm_err("%s: Invalid address: %p\n", __func__, opc);
-               return -EFAULT;
-       }
-
-       return 0;
+       return kvm_mips_trans_replace(vcpu, opc, mfc0_inst);
 }
 
 int kvm_mips_trans_mtc0(u32 inst, u32 *opc, struct kvm_vcpu *vcpu)
 {
        u32 rt, rd, sel;
        u32 mtc0_inst = SW_TEMPLATE;
-       unsigned long kseg0_opc, flags;
 
        rt = (inst >> 16) & 0x1f;
        rd = (inst >> 11) & 0x1f;
@@ -123,22 +116,5 @@ int kvm_mips_trans_mtc0(u32 inst, u32 *opc, struct kvm_vcpu *vcpu)
        mtc0_inst |= ((rt & 0x1f) << 16);
        mtc0_inst |= offsetof(struct kvm_mips_commpage, cop0.reg[rd][sel]);
 
-       if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
-               kseg0_opc =
-                   CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
-                              (vcpu, (unsigned long) opc));
-               memcpy((void *)kseg0_opc, (void *)&mtc0_inst, sizeof(u32));
-               local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
-       } else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
-               local_irq_save(flags);
-               memcpy((void *)opc, (void *)&mtc0_inst, sizeof(u32));
-               local_flush_icache_range((unsigned long)opc,
-                                        (unsigned long)opc + 32);
-               local_irq_restore(flags);
-       } else {
-               kvm_err("%s: Invalid address: %p\n", __func__, opc);
-               return -EFAULT;
-       }
-
-       return 0;
+       return kvm_mips_trans_replace(vcpu, opc, mtc0_inst);
 }