KVM: Portability: Move pio emulation functions to x86.c

This patch moves implementation of the following functions from
kvm_main.c to x86.c:
free_pio_guest_pages, vcpu_find_pio_dev, pio_copy_data, complete_pio,
kernel_pio, pio_string_write, kvm_emulate_pio, kvm_emulate_pio_string

The function inject_gp, which was duplicated by yesterday's patch
series, is removed from kvm_main.c now because it is not needed anymore.

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, 243 insertions, 0 deletions

diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index fe3733d8ece5..f75e7d7d9ead 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -1341,6 +1341,249 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
 }
 EXPORT_SYMBOL_GPL(emulate_instruction);
 
+static void free_pio_guest_pages(struct kvm_vcpu *vcpu)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(vcpu->pio.guest_pages); ++i)
+		if (vcpu->pio.guest_pages[i]) {
+			kvm_release_page(vcpu->pio.guest_pages[i]);
+			vcpu->pio.guest_pages[i] = NULL;
+		}
+}
+
+static int pio_copy_data(struct kvm_vcpu *vcpu)
+{
+	void *p = vcpu->pio_data;
+	void *q;
+	unsigned bytes;
+	int nr_pages = vcpu->pio.guest_pages[1] ? 2 : 1;
+
+	q = vmap(vcpu->pio.guest_pages, nr_pages, VM_READ|VM_WRITE,
+		 PAGE_KERNEL);
+	if (!q) {
+		free_pio_guest_pages(vcpu);
+		return -ENOMEM;
+	}
+	q += vcpu->pio.guest_page_offset;
+	bytes = vcpu->pio.size * vcpu->pio.cur_count;
+	if (vcpu->pio.in)
+		memcpy(q, p, bytes);
+	else
+		memcpy(p, q, bytes);
+	q -= vcpu->pio.guest_page_offset;
+	vunmap(q);
+	free_pio_guest_pages(vcpu);
+	return 0;
+}
+
+int complete_pio(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pio_request *io = &vcpu->pio;
+	long delta;
+	int r;
+
+	kvm_x86_ops->cache_regs(vcpu);
+
+	if (!io->string) {
+		if (io->in)
+			memcpy(&vcpu->regs[VCPU_REGS_RAX], vcpu->pio_data,
+			       io->size);
+	} else {
+		if (io->in) {
+			r = pio_copy_data(vcpu);
+			if (r) {
+				kvm_x86_ops->cache_regs(vcpu);
+				return r;
+			}
+		}
+
+		delta = 1;
+		if (io->rep) {
+			delta *= io->cur_count;
+			/*
+			 * The size of the register should really depend on
+			 * current address size.
+			 */
+			vcpu->regs[VCPU_REGS_RCX] -= delta;
+		}
+		if (io->down)
+			delta = -delta;
+		delta *= io->size;
+		if (io->in)
+			vcpu->regs[VCPU_REGS_RDI] += delta;
+		else
+			vcpu->regs[VCPU_REGS_RSI] += delta;
+	}
+
+	kvm_x86_ops->decache_regs(vcpu);
+
+	io->count -= io->cur_count;
+	io->cur_count = 0;
+
+	return 0;
+}
+
+static void kernel_pio(struct kvm_io_device *pio_dev,
+		       struct kvm_vcpu *vcpu,
+		       void *pd)
+{
+	/* TODO: String I/O for in kernel device */
+
+	mutex_lock(&vcpu->kvm->lock);
+	if (vcpu->pio.in)
+		kvm_iodevice_read(pio_dev, vcpu->pio.port,
+				  vcpu->pio.size,
+				  pd);
+	else
+		kvm_iodevice_write(pio_dev, vcpu->pio.port,
+				   vcpu->pio.size,
+				   pd);
+	mutex_unlock(&vcpu->kvm->lock);
+}
+
+static void pio_string_write(struct kvm_io_device *pio_dev,
+			     struct kvm_vcpu *vcpu)
+{
+	struct kvm_pio_request *io = &vcpu->pio;
+	void *pd = vcpu->pio_data;
+	int i;
+
+	mutex_lock(&vcpu->kvm->lock);
+	for (i = 0; i < io->cur_count; i++) {
+		kvm_iodevice_write(pio_dev, io->port,
+				   io->size,
+				   pd);
+		pd += io->size;
+	}
+	mutex_unlock(&vcpu->kvm->lock);
+}
+
+static struct kvm_io_device *vcpu_find_pio_dev(struct kvm_vcpu *vcpu,
+					       gpa_t addr)
+{
+	return kvm_io_bus_find_dev(&vcpu->kvm->pio_bus, addr);
+}
+
+int kvm_emulate_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
+		  int size, unsigned port)
+{
+	struct kvm_io_device *pio_dev;
+
+	vcpu->run->exit_reason = KVM_EXIT_IO;
+	vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
+	vcpu->run->io.size = vcpu->pio.size = size;
+	vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
+	vcpu->run->io.count = vcpu->pio.count = vcpu->pio.cur_count = 1;
+	vcpu->run->io.port = vcpu->pio.port = port;
+	vcpu->pio.in = in;
+	vcpu->pio.string = 0;
+	vcpu->pio.down = 0;
+	vcpu->pio.guest_page_offset = 0;
+	vcpu->pio.rep = 0;
+
+	kvm_x86_ops->cache_regs(vcpu);
+	memcpy(vcpu->pio_data, &vcpu->regs[VCPU_REGS_RAX], 4);
+	kvm_x86_ops->decache_regs(vcpu);
+
+	kvm_x86_ops->skip_emulated_instruction(vcpu);
+
+	pio_dev = vcpu_find_pio_dev(vcpu, port);
+	if (pio_dev) {
+		kernel_pio(pio_dev, vcpu, vcpu->pio_data);
+		complete_pio(vcpu);
+		return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_pio);
+
+int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
+		  int size, unsigned long count, int down,
+		  gva_t address, int rep, unsigned port)
+{
+	unsigned now, in_page;
+	int i, ret = 0;
+	int nr_pages = 1;
+	struct page *page;
+	struct kvm_io_device *pio_dev;
+
+	vcpu->run->exit_reason = KVM_EXIT_IO;
+	vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
+	vcpu->run->io.size = vcpu->pio.size = size;
+	vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
+	vcpu->run->io.count = vcpu->pio.count = vcpu->pio.cur_count = count;
+	vcpu->run->io.port = vcpu->pio.port = port;
+	vcpu->pio.in = in;
+	vcpu->pio.string = 1;
+	vcpu->pio.down = down;
+	vcpu->pio.guest_page_offset = offset_in_page(address);
+	vcpu->pio.rep = rep;
+
+	if (!count) {
+		kvm_x86_ops->skip_emulated_instruction(vcpu);
+		return 1;
+	}
+
+	if (!down)
+		in_page = PAGE_SIZE - offset_in_page(address);
+	else
+		in_page = offset_in_page(address) + size;
+	now = min(count, (unsigned long)in_page / size);
+	if (!now) {
+		/*
+		 * String I/O straddles page boundary.  Pin two guest pages
+		 * so that we satisfy atomicity constraints.  Do just one
+		 * transaction to avoid complexity.
+		 */
+		nr_pages = 2;
+		now = 1;
+	}
+	if (down) {
+		/*
+		 * String I/O in reverse.  Yuck.  Kill the guest, fix later.
+		 */
+		pr_unimpl(vcpu, "guest string pio down\n");
+		inject_gp(vcpu);
+		return 1;
+	}
+	vcpu->run->io.count = now;
+	vcpu->pio.cur_count = now;
+
+	if (vcpu->pio.cur_count == vcpu->pio.count)
+		kvm_x86_ops->skip_emulated_instruction(vcpu);
+
+	for (i = 0; i < nr_pages; ++i) {
+		mutex_lock(&vcpu->kvm->lock);
+		page = gva_to_page(vcpu, address + i * PAGE_SIZE);
+		vcpu->pio.guest_pages[i] = page;
+		mutex_unlock(&vcpu->kvm->lock);
+		if (!page) {
+			inject_gp(vcpu);
+			free_pio_guest_pages(vcpu);
+			return 1;
+		}
+	}
+
+	pio_dev = vcpu_find_pio_dev(vcpu, port);
+	if (!vcpu->pio.in) {
+		/* string PIO write */
+		ret = pio_copy_data(vcpu);
+		if (ret >= 0 && pio_dev) {
+			pio_string_write(pio_dev, vcpu);
+			complete_pio(vcpu);
+			if (vcpu->pio.count == 0)
+				ret = 1;
+		}
+	} else if (pio_dev)
+		pr_unimpl(vcpu, "no string pio read support yet, "
+		       "port %x size %d count %ld\n",
+			port, size, count);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_pio_string);
+
 __init void kvm_arch_init(void)
 {
 	kvm_init_msr_list();