Merge branch 'xenfv-kvm-15' of git://git.infradead.org/users/dwmw2/qemu into HEAD

This adds support for emulating Xen under Linux/KVM, based on kernel
patches which have been present since Linux v5.12. As with the kernel
support, it's derived from work started by João Martins of Oracle in
2018.

This series just adds the basic platform support — CPUID, hypercalls,
event channels, a stub of XenStore.

A full single-tenant internal implementation of XenStore, and patches
to make QEMU's Xen PV drivers work with this Xen emulation, are waiting
in the wings to be submitted in a follow-on patch series.

As noted in the documentation, it's enabled by setting the xen-version
property on the KVM accelerator, e.g.:

 qemu-system-x86_64 -serial mon:stdio -M q35 -display none -m 1G -smp 2 \
    -accel kvm,xen-version=0x4000e,kernel-irqchip=split \
    -kernel vmlinuz-6.0.7-301.fc37.x86_64 \
    -append "console=ttyS0 root=/dev/sda1" \
    -drive file=/var/lib/libvirt/images/fedora28.qcow2,if=none,id=disk \
    -device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0

Even before this was merged, we've already been using it to find and fix
bugs in the Linux kernel Xen guest support:

https://lore.kernel.org/all/4bffa69a949bfdc92c4a18e5a1c3cbb3b94a0d32.camel@infradead.org/
https://lore.kernel.org/all/871qnunycr.ffs@tglx/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 21 insertions, 11 deletions

diff --git a/hw/isa/isa-bus.c b/hw/isa/isa-bus.c
index f155b80010..a289eccfb1 100644
--- a/hw/isa/isa-bus.c
+++ b/hw/isa/isa-bus.c
@@ -67,13 +67,20 @@ ISABus *isa_bus_new(DeviceState *dev, MemoryRegion* address_space,
     return isabus;
 }
 
-void isa_bus_irqs(ISABus *bus, qemu_irq *irqs)
+void isa_bus_register_input_irqs(ISABus *bus, qemu_irq *irqs_in)
 {
-    bus->irqs = irqs;
+    bus->irqs_in = irqs_in;
+}
+
+qemu_irq isa_bus_get_irq(ISABus *bus, unsigned irqnum)
+{
+    assert(irqnum < ISA_NUM_IRQS);
+    assert(bus->irqs_in);
+    return bus->irqs_in[irqnum];
 }
 
 /*
- * isa_get_irq() returns the corresponding qemu_irq entry for the i8259.
+ * isa_get_irq() returns the corresponding input qemu_irq entry for the i8259.
  *
  * This function is only for special cases such as the 'ferr', and
  * temporary use for normal devices until they are converted to qdev.
@@ -81,14 +88,13 @@ void isa_bus_irqs(ISABus *bus, qemu_irq *irqs)
 qemu_irq isa_get_irq(ISADevice *dev, unsigned isairq)
 {
     assert(!dev || ISA_BUS(qdev_get_parent_bus(DEVICE(dev))) == isabus);
-    assert(isairq < ISA_NUM_IRQS);
-    return isabus->irqs[isairq];
+    return isa_bus_get_irq(isabus, isairq);
 }
 
 void isa_connect_gpio_out(ISADevice *isadev, int gpioirq, unsigned isairq)
 {
-    qemu_irq irq = isa_get_irq(isadev, isairq);
-    qdev_connect_gpio_out(DEVICE(isadev), gpioirq, irq);
+    qemu_irq input_irq = isa_get_irq(isadev, isairq);
+    qdev_connect_gpio_out(DEVICE(isadev), gpioirq, input_irq);
 }
 
 void isa_bus_dma(ISABus *bus, IsaDma *dma8, IsaDma *dma16)
@@ -99,7 +105,7 @@ void isa_bus_dma(ISABus *bus, IsaDma *dma8, IsaDma *dma16)
     bus->dma[1] = dma16;
 }
 
-IsaDma *isa_get_dma(ISABus *bus, int nchan)
+IsaDma *isa_bus_get_dma(ISABus *bus, int nchan)
 {
     assert(bus);
     return bus->dma[nchan > 3 ? 1 : 0];
@@ -114,7 +120,7 @@ static inline void isa_init_ioport(ISADevice *dev, uint16_t ioport)
 
 void isa_register_ioport(ISADevice *dev, MemoryRegion *io, uint16_t start)
 {
-    memory_region_add_subregion(isabus->address_space_io, start, io);
+    memory_region_add_subregion(isa_address_space_io(dev), start, io);
     isa_init_ioport(dev, start);
 }
 
@@ -135,7 +141,7 @@ int isa_register_portio_list(ISADevice *dev,
     isa_init_ioport(dev, start);
 
     portio_list_init(piolist, OBJECT(dev), pio_start, opaque, name);
-    portio_list_add(piolist, isabus->address_space_io, start);
+    portio_list_add(piolist, isa_address_space_io(dev), start);
 
     return 0;
 }
@@ -164,6 +170,11 @@ bool isa_realize_and_unref(ISADevice *dev, ISABus *bus, Error **errp)
     return qdev_realize_and_unref(&dev->parent_obj, &bus->parent_obj, errp);
 }
 
+ISABus *isa_bus_from_device(ISADevice *dev)
+{
+    return ISA_BUS(qdev_get_parent_bus(DEVICE(dev)));
+}
+
 ISADevice *isa_vga_init(ISABus *bus)
 {
     vga_interface_created = true;
@@ -213,7 +224,6 @@ static const TypeInfo isa_device_type_info = {
     .parent = TYPE_DEVICE,
     .instance_size = sizeof(ISADevice),
     .abstract = true,
-    .class_size = sizeof(ISADeviceClass),
     .class_init = isa_device_class_init,
 };