MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase

[karo-tx-linux.git] / arch / mips / kvm / mips.c

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 5a2b9034a05ce1fa7f4772e9c58a097c315bcca2..a6ea084b4d9d5fe500d219cc3d03901f143b4388 100644 (file)
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -245,10 +245,27 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
        }
 }
 
+static inline void dump_handler(const char *symbol, void *start, void *end)
+{
+       u32 *p;
+
+       pr_debug("LEAF(%s)\n", symbol);
+
+       pr_debug("\t.set push\n");
+       pr_debug("\t.set noreorder\n");
+
+       for (p = start; p < (u32 *)end; ++p)
+               pr_debug("\t.word\t0x%08x\t\t# %p\n", *p, p);
+
+       pr_debug("\t.set\tpop\n");
+
+       pr_debug("\tEND(%s)\n", symbol);
+}
+
 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 {
-       int err, size, offset;
-       void *gebase;
+       int err, size;
+       void *gebase, *p, *handler;
        int i;
 
        struct kvm_vcpu *vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
@@ -283,44 +300,53 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
        kvm_debug("Allocated %d bytes for KVM Exception Handlers @ %p\n",
                  ALIGN(size, PAGE_SIZE), gebase);
 
+       /*
+        * Check new ebase actually fits in CP0_EBase. The lack of a write gate
+        * limits us to the low 512MB of physical address space. If the memory
+        * we allocate is out of range, just give up now.
+        */
+       if (!cpu_has_ebase_wg && virt_to_phys(gebase) >= 0x20000000) {
+               kvm_err("CP0_EBase.WG required for guest exception base %pK\n",
+                       gebase);
+               err = -ENOMEM;
+               goto out_free_gebase;
+       }
+
        /* Save new ebase */
        vcpu->arch.guest_ebase = gebase;
 
-       /* Copy L1 Guest Exception handler to correct offset */
+       /* Build guest exception vectors dynamically in unmapped memory */
+       handler = gebase + 0x2000;
 
        /* TLB Refill, EXL = 0 */
-       memcpy(gebase, mips32_exception,
-              mips32_exceptionEnd - mips32_exception);
+       kvm_mips_build_exception(gebase, handler);
 
        /* General Exception Entry point */
-       memcpy(gebase + 0x180, mips32_exception,
-              mips32_exceptionEnd - mips32_exception);
+       kvm_mips_build_exception(gebase + 0x180, handler);
 
        /* For vectored interrupts poke the exception code @ all offsets 0-7 */
        for (i = 0; i < 8; i++) {
                kvm_debug("L1 Vectored handler @ %p\n",
                          gebase + 0x200 + (i * VECTORSPACING));
-               memcpy(gebase + 0x200 + (i * VECTORSPACING), mips32_exception,
-                      mips32_exceptionEnd - mips32_exception);
+               kvm_mips_build_exception(gebase + 0x200 + i * VECTORSPACING,
+                                        handler);
        }
 
-       /* General handler, relocate to unmapped space for sanity's sake */
-       offset = 0x2000;
-       kvm_debug("Installing KVM Exception handlers @ %p, %#x bytes\n",
-                 gebase + offset,
-                 mips32_GuestExceptionEnd - mips32_GuestException);
+       /* General exit handler */
+       p = handler;
+       p = kvm_mips_build_exit(p);
 
-       memcpy(gebase + offset, mips32_GuestException,
-              mips32_GuestExceptionEnd - mips32_GuestException);
+       /* Guest entry routine */
+       vcpu->arch.vcpu_run = p;
+       p = kvm_mips_build_vcpu_run(p);
 
-#ifdef MODULE
-       offset += mips32_GuestExceptionEnd - mips32_GuestException;
-       memcpy(gebase + offset, (char *)__kvm_mips_vcpu_run,
-              __kvm_mips_vcpu_run_end - (char *)__kvm_mips_vcpu_run);
-       vcpu->arch.vcpu_run = gebase + offset;
-#else
-       vcpu->arch.vcpu_run = __kvm_mips_vcpu_run;
-#endif
+       /* Dump the generated code */
+       pr_debug("#include <asm/asm.h>\n");
+       pr_debug("#include <asm/regdef.h>\n");
+       pr_debug("\n");
+       dump_handler("kvm_vcpu_run", vcpu->arch.vcpu_run, p);
+       dump_handler("kvm_gen_exc", gebase + 0x180, gebase + 0x200);
+       dump_handler("kvm_exit", gebase + 0x2000, vcpu->arch.vcpu_run);
 
        /* Invalidate the icache for these ranges */
        local_flush_icache_range((unsigned long)gebase,
@@ -406,7 +432,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
        kvm_mips_deliver_interrupts(vcpu,
                                    kvm_read_c0_guest_cause(vcpu->arch.cop0));
 
-       __kvm_guest_enter();
+       guest_enter_irqoff();
 
        /* Disable hardware page table walking while in guest */
        htw_stop();
@@ -418,7 +444,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
        /* Re-enable HTW before enabling interrupts */
        htw_start();
 
-       __kvm_guest_exit();
+       guest_exit_irqoff();
        local_irq_enable();
 
        if (vcpu->sigset_active)
@@ -507,8 +533,10 @@ static u64 kvm_mips_get_one_regs[] = {
        KVM_REG_MIPS_R30,
        KVM_REG_MIPS_R31,
 
+#ifndef CONFIG_CPU_MIPSR6
        KVM_REG_MIPS_HI,
        KVM_REG_MIPS_LO,
+#endif
        KVM_REG_MIPS_PC,
 
        KVM_REG_MIPS_CP0_INDEX,
@@ -652,12 +680,14 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
        case KVM_REG_MIPS_R0 ... KVM_REG_MIPS_R31:
                v = (long)vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0];
                break;
+#ifndef CONFIG_CPU_MIPSR6
        case KVM_REG_MIPS_HI:
                v = (long)vcpu->arch.hi;
                break;
        case KVM_REG_MIPS_LO:
                v = (long)vcpu->arch.lo;
                break;
+#endif
        case KVM_REG_MIPS_PC:
                v = (long)vcpu->arch.pc;
                break;
@@ -873,12 +903,14 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
        case KVM_REG_MIPS_R1 ... KVM_REG_MIPS_R31:
                vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0] = v;
                break;
+#ifndef CONFIG_CPU_MIPSR6
        case KVM_REG_MIPS_HI:
                vcpu->arch.hi = v;
                break;
        case KVM_REG_MIPS_LO:
                vcpu->arch.lo = v;
                break;
+#endif
        case KVM_REG_MIPS_PC:
                vcpu->arch.pc = v;
                break;
@@ -1763,6 +1795,10 @@ static int __init kvm_mips_init(void)
 {
        int ret;
 
+       ret = kvm_mips_entry_setup();
+       if (ret)
+               return ret;
+
        ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 
        if (ret)