KVM: Portability: Move x86 emulation and mmio device hook to x86.c

This patch moves the following functions to from kvm_main.c to x86.c:
emulator_read/write_std, vcpu_find_pervcpu_dev, vcpu_find_mmio_dev,
emulator_read/write_emulated, emulator_write_phys,
emulator_write_emulated_onepage, emulator_cmpxchg_emulated,
get_setment_base, emulate_invlpg, emulate_clts, emulator_get/set_dr,
kvm_report_emulation_failure, emulate_instruction

The following data type is moved to x86.c:
struct x86_emulate_ops emulate_ops

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Acked-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 358 insertions, 0 deletions

diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index 78627434751..fe3733d8ece 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -983,6 +983,364 @@ static __init void kvm_init_msr_list(void)
 	num_msrs_to_save = j;
 }
 
+/*
+ * Only apic need an MMIO device hook, so shortcut now..
+ */
+static struct kvm_io_device *vcpu_find_pervcpu_dev(struct kvm_vcpu *vcpu,
+						gpa_t addr)
+{
+	struct kvm_io_device *dev;
+
+	if (vcpu->apic) {
+		dev = &vcpu->apic->dev;
+		if (dev->in_range(dev, addr))
+			return dev;
+	}
+	return NULL;
+}
+
+
+static struct kvm_io_device *vcpu_find_mmio_dev(struct kvm_vcpu *vcpu,
+						gpa_t addr)
+{
+	struct kvm_io_device *dev;
+
+	dev = vcpu_find_pervcpu_dev(vcpu, addr);
+	if (dev == NULL)
+		dev = kvm_io_bus_find_dev(&vcpu->kvm->mmio_bus, addr);
+	return dev;
+}
+
+int emulator_read_std(unsigned long addr,
+			     void *val,
+			     unsigned int bytes,
+			     struct kvm_vcpu *vcpu)
+{
+	void *data = val;
+
+	while (bytes) {
+		gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+		unsigned offset = addr & (PAGE_SIZE-1);
+		unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
+		int ret;
+
+		if (gpa == UNMAPPED_GVA)
+			return X86EMUL_PROPAGATE_FAULT;
+		ret = kvm_read_guest(vcpu->kvm, gpa, data, tocopy);
+		if (ret < 0)
+			return X86EMUL_UNHANDLEABLE;
+
+		bytes -= tocopy;
+		data += tocopy;
+		addr += tocopy;
+	}
+
+	return X86EMUL_CONTINUE;
+}
+EXPORT_SYMBOL_GPL(emulator_read_std);
+
+static int emulator_write_std(unsigned long addr,
+			      const void *val,
+			      unsigned int bytes,
+			      struct kvm_vcpu *vcpu)
+{
+	pr_unimpl(vcpu, "emulator_write_std: addr %lx n %d\n", addr, bytes);
+	return X86EMUL_UNHANDLEABLE;
+}
+
+static int emulator_read_emulated(unsigned long addr,
+				  void *val,
+				  unsigned int bytes,
+				  struct kvm_vcpu *vcpu)
+{
+	struct kvm_io_device *mmio_dev;
+	gpa_t                 gpa;
+
+	if (vcpu->mmio_read_completed) {
+		memcpy(val, vcpu->mmio_data, bytes);
+		vcpu->mmio_read_completed = 0;
+		return X86EMUL_CONTINUE;
+	}
+
+	gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+
+	/* For APIC access vmexit */
+	if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
+		goto mmio;
+
+	if (emulator_read_std(addr, val, bytes, vcpu)
+			== X86EMUL_CONTINUE)
+		return X86EMUL_CONTINUE;
+	if (gpa == UNMAPPED_GVA)
+		return X86EMUL_PROPAGATE_FAULT;
+
+mmio:
+	/*
+	 * Is this MMIO handled locally?
+	 */
+	mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
+	if (mmio_dev) {
+		kvm_iodevice_read(mmio_dev, gpa, bytes, val);
+		return X86EMUL_CONTINUE;
+	}
+
+	vcpu->mmio_needed = 1;
+	vcpu->mmio_phys_addr = gpa;
+	vcpu->mmio_size = bytes;
+	vcpu->mmio_is_write = 0;
+
+	return X86EMUL_UNHANDLEABLE;
+}
+
+static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
+			       const void *val, int bytes)
+{
+	int ret;
+
+	ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes);
+	if (ret < 0)
+		return 0;
+	kvm_mmu_pte_write(vcpu, gpa, val, bytes);
+	return 1;
+}
+
+static int emulator_write_emulated_onepage(unsigned long addr,
+					   const void *val,
+					   unsigned int bytes,
+					   struct kvm_vcpu *vcpu)
+{
+	struct kvm_io_device *mmio_dev;
+	gpa_t                 gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+
+	if (gpa == UNMAPPED_GVA) {
+		kvm_x86_ops->inject_page_fault(vcpu, addr, 2);
+		return X86EMUL_PROPAGATE_FAULT;
+	}
+
+	/* For APIC access vmexit */
+	if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
+		goto mmio;
+
+	if (emulator_write_phys(vcpu, gpa, val, bytes))
+		return X86EMUL_CONTINUE;
+
+mmio:
+	/*
+	 * Is this MMIO handled locally?
+	 */
+	mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
+	if (mmio_dev) {
+		kvm_iodevice_write(mmio_dev, gpa, bytes, val);
+		return X86EMUL_CONTINUE;
+	}
+
+	vcpu->mmio_needed = 1;
+	vcpu->mmio_phys_addr = gpa;
+	vcpu->mmio_size = bytes;
+	vcpu->mmio_is_write = 1;
+	memcpy(vcpu->mmio_data, val, bytes);
+
+	return X86EMUL_CONTINUE;
+}
+
+int emulator_write_emulated(unsigned long addr,
+				   const void *val,
+				   unsigned int bytes,
+				   struct kvm_vcpu *vcpu)
+{
+	/* Crossing a page boundary? */
+	if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
+		int rc, now;
+
+		now = -addr & ~PAGE_MASK;
+		rc = emulator_write_emulated_onepage(addr, val, now, vcpu);
+		if (rc != X86EMUL_CONTINUE)
+			return rc;
+		addr += now;
+		val += now;
+		bytes -= now;
+	}
+	return emulator_write_emulated_onepage(addr, val, bytes, vcpu);
+}
+EXPORT_SYMBOL_GPL(emulator_write_emulated);
+
+static int emulator_cmpxchg_emulated(unsigned long addr,
+				     const void *old,
+				     const void *new,
+				     unsigned int bytes,
+				     struct kvm_vcpu *vcpu)
+{
+	static int reported;
+
+	if (!reported) {
+		reported = 1;
+		printk(KERN_WARNING "kvm: emulating exchange as write\n");
+	}
+	return emulator_write_emulated(addr, new, bytes, vcpu);
+}
+
+static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
+{
+	return kvm_x86_ops->get_segment_base(vcpu, seg);
+}
+
+int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
+{
+	return X86EMUL_CONTINUE;
+}
+
+int emulate_clts(struct kvm_vcpu *vcpu)
+{
+	kvm_x86_ops->set_cr0(vcpu, vcpu->cr0 & ~X86_CR0_TS);
+	return X86EMUL_CONTINUE;
+}
+
+int emulator_get_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long *dest)
+{
+	struct kvm_vcpu *vcpu = ctxt->vcpu;
+
+	switch (dr) {
+	case 0 ... 3:
+		*dest = kvm_x86_ops->get_dr(vcpu, dr);
+		return X86EMUL_CONTINUE;
+	default:
+		pr_unimpl(vcpu, "%s: unexpected dr %u\n", __FUNCTION__, dr);
+		return X86EMUL_UNHANDLEABLE;
+	}
+}
+
+int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value)
+{
+	unsigned long mask = (ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U;
+	int exception;
+
+	kvm_x86_ops->set_dr(ctxt->vcpu, dr, value & mask, &exception);
+	if (exception) {
+		/* FIXME: better handling */
+		return X86EMUL_UNHANDLEABLE;
+	}
+	return X86EMUL_CONTINUE;
+}
+
+void kvm_report_emulation_failure(struct kvm_vcpu *vcpu, const char *context)
+{
+	static int reported;
+	u8 opcodes[4];
+	unsigned long rip = vcpu->rip;
+	unsigned long rip_linear;
+
+	rip_linear = rip + get_segment_base(vcpu, VCPU_SREG_CS);
+
+	if (reported)
+		return;
+
+	emulator_read_std(rip_linear, (void *)opcodes, 4, vcpu);
+
+	printk(KERN_ERR "emulation failed (%s) rip %lx %02x %02x %02x %02x\n",
+	       context, rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]);
+	reported = 1;
+}
+EXPORT_SYMBOL_GPL(kvm_report_emulation_failure);
+
+struct x86_emulate_ops emulate_ops = {
+	.read_std            = emulator_read_std,
+	.write_std           = emulator_write_std,
+	.read_emulated       = emulator_read_emulated,
+	.write_emulated      = emulator_write_emulated,
+	.cmpxchg_emulated    = emulator_cmpxchg_emulated,
+};
+
+int emulate_instruction(struct kvm_vcpu *vcpu,
+			struct kvm_run *run,
+			unsigned long cr2,
+			u16 error_code,
+			int no_decode)
+{
+	int r;
+
+	vcpu->mmio_fault_cr2 = cr2;
+	kvm_x86_ops->cache_regs(vcpu);
+
+	vcpu->mmio_is_write = 0;
+	vcpu->pio.string = 0;
+
+	if (!no_decode) {
+		int cs_db, cs_l;
+		kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
+
+		vcpu->emulate_ctxt.vcpu = vcpu;
+		vcpu->emulate_ctxt.eflags = kvm_x86_ops->get_rflags(vcpu);
+		vcpu->emulate_ctxt.cr2 = cr2;
+		vcpu->emulate_ctxt.mode =
+			(vcpu->emulate_ctxt.eflags & X86_EFLAGS_VM)
+			? X86EMUL_MODE_REAL : cs_l
+			? X86EMUL_MODE_PROT64 :	cs_db
+			? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
+
+		if (vcpu->emulate_ctxt.mode == X86EMUL_MODE_PROT64) {
+			vcpu->emulate_ctxt.cs_base = 0;
+			vcpu->emulate_ctxt.ds_base = 0;
+			vcpu->emulate_ctxt.es_base = 0;
+			vcpu->emulate_ctxt.ss_base = 0;
+		} else {
+			vcpu->emulate_ctxt.cs_base =
+					get_segment_base(vcpu, VCPU_SREG_CS);
+			vcpu->emulate_ctxt.ds_base =
+					get_segment_base(vcpu, VCPU_SREG_DS);
+			vcpu->emulate_ctxt.es_base =
+					get_segment_base(vcpu, VCPU_SREG_ES);
+			vcpu->emulate_ctxt.ss_base =
+					get_segment_base(vcpu, VCPU_SREG_SS);
+		}
+
+		vcpu->emulate_ctxt.gs_base =
+					get_segment_base(vcpu, VCPU_SREG_GS);
+		vcpu->emulate_ctxt.fs_base =
+					get_segment_base(vcpu, VCPU_SREG_FS);
+
+		r = x86_decode_insn(&vcpu->emulate_ctxt, &emulate_ops);
+		if (r)  {
+			if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
+				return EMULATE_DONE;
+			return EMULATE_FAIL;
+		}
+	}
+
+	r = x86_emulate_insn(&vcpu->emulate_ctxt, &emulate_ops);
+
+	if (vcpu->pio.string)
+		return EMULATE_DO_MMIO;
+
+	if ((r || vcpu->mmio_is_write) && run) {
+		run->exit_reason = KVM_EXIT_MMIO;
+		run->mmio.phys_addr = vcpu->mmio_phys_addr;
+		memcpy(run->mmio.data, vcpu->mmio_data, 8);
+		run->mmio.len = vcpu->mmio_size;
+		run->mmio.is_write = vcpu->mmio_is_write;
+	}
+
+	if (r) {
+		if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
+			return EMULATE_DONE;
+		if (!vcpu->mmio_needed) {
+			kvm_report_emulation_failure(vcpu, "mmio");
+			return EMULATE_FAIL;
+		}
+		return EMULATE_DO_MMIO;
+	}
+
+	kvm_x86_ops->decache_regs(vcpu);
+	kvm_x86_ops->set_rflags(vcpu, vcpu->emulate_ctxt.eflags);
+
+	if (vcpu->mmio_is_write) {
+		vcpu->mmio_needed = 0;
+		return EMULATE_DO_MMIO;
+	}
+
+	return EMULATE_DONE;
+}
+EXPORT_SYMBOL_GPL(emulate_instruction);
+
 __init void kvm_arch_init(void)
 {
 	kvm_init_msr_list();