jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
vga-pci: add qext region to mmio
Add a qemu extented register range to the standard vga mmio bar.
Right nowe there are two registers: One readonly register returning the
size of the region (so we can easily add more registers there if needed)
and one endian control register, so guests (especially ppc) can flip
the framebuffer endianness as they need it.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
+87
+9
docs/specs/standard-vga.txt
+9
docs/specs/standard-vga.txt
···
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0500 - 0515 : bochs dispi interface registers, mapped flat
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without index/data ports. Use (index << 1)
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as offset for (16bit) register access.
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+
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0600 - 0607 : qemu extended registers. qemu 2.2+ only.
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The pci revision is 2 (or greater) when
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these registers are present. The registers
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are 32bit.
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0600 : qemu extended register region size, in bytes.
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0604 : framebuffer endianness register.
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- 0xbebebebe indicates big endian.
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- 0x1e1e1e1e indicates little endian.
+70
hw/display/vga-pci.c
+70
hw/display/vga-pci.c
···
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#define PCI_VGA_IOPORT_SIZE (0x3e0 - 0x3c0)
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#define PCI_VGA_BOCHS_OFFSET 0x500
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#define PCI_VGA_BOCHS_SIZE (0x0b * 2)
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+
#define PCI_VGA_QEXT_OFFSET 0x600
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#define PCI_VGA_QEXT_SIZE (2 * 4)
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#define PCI_VGA_MMIO_SIZE 0x1000
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#define PCI_VGA_QEXT_REG_SIZE (0 * 4)
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#define PCI_VGA_QEXT_REG_BYTEORDER (1 * 4)
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#define PCI_VGA_QEXT_LITTLE_ENDIAN 0x1e1e1e1e
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#define PCI_VGA_QEXT_BIG_ENDIAN 0xbebebebe
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+
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enum vga_pci_flags {
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PCI_VGA_FLAG_ENABLE_MMIO = 1,
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PCI_VGA_FLAG_ENABLE_QEXT = 2,
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};
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typedef struct PCIVGAState {
···
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MemoryRegion mmio;
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MemoryRegion ioport;
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MemoryRegion bochs;
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+
MemoryRegion qext;
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} PCIVGAState;
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static const VMStateDescription vmstate_vga_pci = {
···
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.endianness = DEVICE_LITTLE_ENDIAN,
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};
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+
static uint64_t pci_vga_qext_read(void *ptr, hwaddr addr, unsigned size)
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{
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PCIVGAState *d = ptr;
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+
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switch (addr) {
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case PCI_VGA_QEXT_REG_SIZE:
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return PCI_VGA_QEXT_SIZE;
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case PCI_VGA_QEXT_REG_BYTEORDER:
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return d->vga.big_endian_fb ?
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PCI_VGA_QEXT_BIG_ENDIAN : PCI_VGA_QEXT_LITTLE_ENDIAN;
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default:
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return 0;
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}
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}
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+
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static void pci_vga_qext_write(void *ptr, hwaddr addr,
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uint64_t val, unsigned size)
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{
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PCIVGAState *d = ptr;
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+
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switch (addr) {
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case PCI_VGA_QEXT_REG_BYTEORDER:
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if (val == PCI_VGA_QEXT_BIG_ENDIAN) {
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d->vga.big_endian_fb = true;
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}
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if (val == PCI_VGA_QEXT_LITTLE_ENDIAN) {
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d->vga.big_endian_fb = false;
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}
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break;
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}
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}
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static const MemoryRegionOps pci_vga_qext_ops = {
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.read = pci_vga_qext_read,
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.write = pci_vga_qext_write,
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.valid.min_access_size = 4,
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.valid.max_access_size = 4,
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.endianness = DEVICE_LITTLE_ENDIAN,
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};
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static int pci_std_vga_initfn(PCIDevice *dev)
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{
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PCIVGAState *d = DO_UPCAST(PCIVGAState, dev, dev);
···
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&d->ioport);
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memory_region_add_subregion(&d->mmio, PCI_VGA_BOCHS_OFFSET,
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&d->bochs);
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+
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if (d->flags & (1 << PCI_VGA_FLAG_ENABLE_QEXT)) {
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memory_region_init_io(&d->qext, NULL, &pci_vga_qext_ops, d,
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"qemu extended regs", PCI_VGA_QEXT_SIZE);
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memory_region_add_subregion(&d->mmio, PCI_VGA_QEXT_OFFSET,
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&d->qext);
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pci_set_byte(&d->dev.config[PCI_REVISION_ID], 2);
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}
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+
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pci_register_bar(&d->dev, 2, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mmio);
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}
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···
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memory_region_add_subregion(&d->mmio, PCI_VGA_BOCHS_OFFSET,
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&d->bochs);
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+
if (d->flags & (1 << PCI_VGA_FLAG_ENABLE_QEXT)) {
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memory_region_init_io(&d->qext, NULL, &pci_vga_qext_ops, d,
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"qemu extended regs", PCI_VGA_QEXT_SIZE);
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memory_region_add_subregion(&d->mmio, PCI_VGA_QEXT_OFFSET,
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&d->qext);
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pci_set_byte(&d->dev.config[PCI_REVISION_ID], 2);
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}
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+
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pci_register_bar(&d->dev, 0, PCI_BASE_ADDRESS_MEM_PREFETCH, &s->vram);
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pci_register_bar(&d->dev, 2, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mmio);
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···
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static Property vga_pci_properties[] = {
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DEFINE_PROP_UINT32("vgamem_mb", PCIVGAState, vga.vram_size_mb, 16),
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DEFINE_PROP_BIT("mmio", PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_MMIO, true),
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DEFINE_PROP_BIT("qemu-extended-regs",
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PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_QEXT, true),
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DEFINE_PROP_END_OF_LIST(),
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};
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static Property secondary_pci_properties[] = {
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DEFINE_PROP_UINT32("vgamem_mb", PCIVGAState, vga.vram_size_mb, 16),
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+
DEFINE_PROP_BIT("qemu-extended-regs",
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PCIVGAState, flags, PCI_VGA_FLAG_ENABLE_QEXT, true),
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DEFINE_PROP_END_OF_LIST(),
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};
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+8
include/hw/i386/pc.h
+8
include/hw/i386/pc.h
···
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.driver = "intel-hda",\
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.property = "old_msi_addr",\
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.value = "on",\
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+
},{\
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.driver = "VGA",\
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.property = "qemu-extended-regs",\
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.value = "off",\
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},{\
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.driver = "secondary-vga",\
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.property = "qemu-extended-regs",\
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.value = "off",\
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}
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#define PC_COMPAT_2_0 \