KVM: ppc: PowerPC 440 KVM implementation

This functionality is definitely experimental, but is capable of running
unmodified PowerPC 440 Linux kernels as guests on a PowerPC 440 host. (Only
tested with 440EP "Bamboo" guests so far, but with appropriate userspace
support other SoC/board combinations should work.)

See Documentation/powerpc/kvm_440.txt for technical details.

[stephen: build fix]

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 436 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
new file mode 100644
index 00000000000..bad40bd2d3a
--- /dev/null
+++ b/arch/powerpc/kvm/powerpc.c
@@ -0,0 +1,436 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * Copyright IBM Corp. 2007
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <asm/cputable.h>
+#include <asm/uaccess.h>
+#include <asm/kvm_ppc.h>
+
+
+gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
+{
+	return gfn;
+}
+
+int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
+{
+	/* XXX implement me */
+	return 0;
+}
+
+int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
+{
+	return 1;
+}
+
+
+int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
+{
+	enum emulation_result er;
+	int r;
+
+	er = kvmppc_emulate_instruction(run, vcpu);
+	switch (er) {
+	case EMULATE_DONE:
+		/* Future optimization: only reload non-volatiles if they were
+		 * actually modified. */
+		r = RESUME_GUEST_NV;
+		break;
+	case EMULATE_DO_MMIO:
+		run->exit_reason = KVM_EXIT_MMIO;
+		/* We must reload nonvolatiles because "update" load/store
+		 * instructions modify register state. */
+		/* Future optimization: only reload non-volatiles if they were
+		 * actually modified. */
+		r = RESUME_HOST_NV;
+		break;
+	case EMULATE_FAIL:
+		/* XXX Deliver Program interrupt to guest. */
+		printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
+		       vcpu->arch.last_inst);
+		r = RESUME_HOST;
+		break;
+	default:
+		BUG();
+	}
+
+	return r;
+}
+
+void kvm_arch_hardware_enable(void *garbage)
+{
+}
+
+void kvm_arch_hardware_disable(void *garbage)
+{
+}
+
+int kvm_arch_hardware_setup(void)
+{
+	return 0;
+}
+
+void kvm_arch_hardware_unsetup(void)
+{
+}
+
+void kvm_arch_check_processor_compat(void *rtn)
+{
+	int r;
+
+	if (strcmp(cur_cpu_spec->platform, "ppc440") == 0)
+		r = 0;
+	else
+		r = -ENOTSUPP;
+
+	*(int *)rtn = r;
+}
+
+struct kvm *kvm_arch_create_vm(void)
+{
+	struct kvm *kvm;
+
+	kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
+	if (!kvm)
+		return ERR_PTR(-ENOMEM);
+
+	return kvm;
+}
+
+static void kvmppc_free_vcpus(struct kvm *kvm)
+{
+	unsigned int i;
+
+	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+		if (kvm->vcpus[i]) {
+			kvm_arch_vcpu_free(kvm->vcpus[i]);
+			kvm->vcpus[i] = NULL;
+		}
+	}
+}
+
+void kvm_arch_destroy_vm(struct kvm *kvm)
+{
+	kvmppc_free_vcpus(kvm);
+	kvm_free_physmem(kvm);
+	kfree(kvm);
+}
+
+int kvm_dev_ioctl_check_extension(long ext)
+{
+	int r;
+
+	switch (ext) {
+	case KVM_CAP_USER_MEMORY:
+		r = 1;
+		break;
+	default:
+		r = 0;
+		break;
+	}
+	return r;
+
+}
+
+long kvm_arch_dev_ioctl(struct file *filp,
+                        unsigned int ioctl, unsigned long arg)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_set_memory_region(struct kvm *kvm,
+                               struct kvm_userspace_memory_region *mem,
+                               struct kvm_memory_slot old,
+                               int user_alloc)
+{
+	return 0;
+}
+
+struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
+{
+	struct kvm_vcpu *vcpu;
+	int err;
+
+	vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
+	if (!vcpu) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = kvm_vcpu_init(vcpu, kvm, id);
+	if (err)
+		goto free_vcpu;
+
+	return vcpu;
+
+free_vcpu:
+	kmem_cache_free(kvm_vcpu_cache, vcpu);
+out:
+	return ERR_PTR(err);
+}
+
+void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
+{
+	kvm_vcpu_uninit(vcpu);
+	kmem_cache_free(kvm_vcpu_cache, vcpu);
+}
+
+void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
+{
+	kvm_arch_vcpu_free(vcpu);
+}
+
+int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+	unsigned int priority = exception_priority[BOOKE_INTERRUPT_DECREMENTER];
+
+	return test_bit(priority, &vcpu->arch.pending_exceptions);
+}
+
+static void kvmppc_decrementer_func(unsigned long data)
+{
+	struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
+
+	kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_DECREMENTER);
+}
+
+int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
+{
+	setup_timer(&vcpu->arch.dec_timer, kvmppc_decrementer_func,
+	            (unsigned long)vcpu);
+
+	return 0;
+}
+
+void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+}
+
+void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+}
+
+void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
+{
+}
+
+void decache_vcpus_on_cpu(int cpu)
+{
+}
+
+int kvm_arch_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
+                                    struct kvm_debug_guest *dbg)
+{
+	return -ENOTSUPP;
+}
+
+static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu,
+                                     struct kvm_run *run)
+{
+	u32 *gpr = &vcpu->arch.gpr[vcpu->arch.io_gpr];
+	*gpr = run->dcr.data;
+}
+
+static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
+                                      struct kvm_run *run)
+{
+	u32 *gpr = &vcpu->arch.gpr[vcpu->arch.io_gpr];
+
+	if (run->mmio.len > sizeof(*gpr)) {
+		printk(KERN_ERR "bad MMIO length: %d\n", run->mmio.len);
+		return;
+	}
+
+	if (vcpu->arch.mmio_is_bigendian) {
+		switch (run->mmio.len) {
+		case 4: *gpr = *(u32 *)run->mmio.data; break;
+		case 2: *gpr = *(u16 *)run->mmio.data; break;
+		case 1: *gpr = *(u8 *)run->mmio.data; break;
+		}
+	} else {
+		/* Convert BE data from userland back to LE. */
+		switch (run->mmio.len) {
+		case 4: *gpr = ld_le32((u32 *)run->mmio.data); break;
+		case 2: *gpr = ld_le16((u16 *)run->mmio.data); break;
+		case 1: *gpr = *(u8 *)run->mmio.data; break;
+		}
+	}
+}
+
+int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
+                       unsigned int rt, unsigned int bytes, int is_bigendian)
+{
+	if (bytes > sizeof(run->mmio.data)) {
+		printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
+		       run->mmio.len);
+	}
+
+	run->mmio.phys_addr = vcpu->arch.paddr_accessed;
+	run->mmio.len = bytes;
+	run->mmio.is_write = 0;
+
+	vcpu->arch.io_gpr = rt;
+	vcpu->arch.mmio_is_bigendian = is_bigendian;
+	vcpu->mmio_needed = 1;
+	vcpu->mmio_is_write = 0;
+
+	return EMULATE_DO_MMIO;
+}
+
+int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
+                        u32 val, unsigned int bytes, int is_bigendian)
+{
+	void *data = run->mmio.data;
+
+	if (bytes > sizeof(run->mmio.data)) {
+		printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
+		       run->mmio.len);
+	}
+
+	run->mmio.phys_addr = vcpu->arch.paddr_accessed;
+	run->mmio.len = bytes;
+	run->mmio.is_write = 1;
+	vcpu->mmio_needed = 1;
+	vcpu->mmio_is_write = 1;
+
+	/* Store the value at the lowest bytes in 'data'. */
+	if (is_bigendian) {
+		switch (bytes) {
+		case 4: *(u32 *)data = val; break;
+		case 2: *(u16 *)data = val; break;
+		case 1: *(u8  *)data = val; break;
+		}
+	} else {
+		/* Store LE value into 'data'. */
+		switch (bytes) {
+		case 4: st_le32(data, val); break;
+		case 2: st_le16(data, val); break;
+		case 1: *(u8 *)data = val; break;
+		}
+	}
+
+	return EMULATE_DO_MMIO;
+}
+
+int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	int r;
+	sigset_t sigsaved;
+
+	if (vcpu->sigset_active)
+		sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
+
+	if (vcpu->mmio_needed) {
+		if (!vcpu->mmio_is_write)
+			kvmppc_complete_mmio_load(vcpu, run);
+		vcpu->mmio_needed = 0;
+	} else if (vcpu->arch.dcr_needed) {
+		if (!vcpu->arch.dcr_is_write)
+			kvmppc_complete_dcr_load(vcpu, run);
+		vcpu->arch.dcr_needed = 0;
+	}
+
+	kvmppc_check_and_deliver_interrupts(vcpu);
+
+	local_irq_disable();
+	kvm_guest_enter();
+	r = __kvmppc_vcpu_run(run, vcpu);
+	kvm_guest_exit();
+	local_irq_enable();
+
+	if (vcpu->sigset_active)
+		sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+
+	return r;
+}
+
+int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
+{
+	kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_EXTERNAL);
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
+                                    struct kvm_mp_state *mp_state)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
+                                    struct kvm_mp_state *mp_state)
+{
+	return -EINVAL;
+}
+
+long kvm_arch_vcpu_ioctl(struct file *filp,
+                         unsigned int ioctl, unsigned long arg)
+{
+	struct kvm_vcpu *vcpu = filp->private_data;
+	void __user *argp = (void __user *)arg;
+	long r;
+
+	switch (ioctl) {
+	case KVM_INTERRUPT: {
+		struct kvm_interrupt irq;
+		r = -EFAULT;
+		if (copy_from_user(&irq, argp, sizeof(irq)))
+			goto out;
+		r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
+		break;
+	}
+	default:
+		r = -EINVAL;
+	}
+
+out:
+	return r;
+}
+
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return -ENOTSUPP;
+}
+
+long kvm_arch_vm_ioctl(struct file *filp,
+                       unsigned int ioctl, unsigned long arg)
+{
+	long r;
+
+	switch (ioctl) {
+	default:
+		r = -EINVAL;
+	}
+
+	return r;
+}
+
+int kvm_arch_init(void *opaque)
+{
+	return 0;
+}
+
+void kvm_arch_exit(void)
+{
+}