basic gfx passthrough support:
- add a vga type for gfx passthrough
- retrieve VGA bios from sysfs, then load it to guest at 0xC0000
- register/unregister legacy VGA I/O ports and MMIOs for passthrough GFX
The original patch is from Weidong Han <weidong....@intel.com>
Signed-off-by: Yang Zhang <yang.z.zh...@intel.com>
Signed-off-by: Tiejun Chen <tiejun.c...@intel.com>
Cc: Weidong Han <weidong....@intel.com>
---
v4:
* Fix some typos in the patch head description.
* Improve some comments.
* Given that xen_pt_register_vga_regions()/xen_pt_unregister_vga_regions()
are called unconditionally, so we just return 0 there.
* Remove one spurious change.
v3:
* Fix some typos.
* Add more comments to make that readable.
* Improve some return paths.
v2:
* retrieve VGA bios from sysfs properly.
* redefine some function name.
hw/xen/Makefile.objs | 2 +-
hw/xen/xen-host-pci-device.c | 5 +
hw/xen/xen-host-pci-device.h | 1 +
hw/xen/xen_pt.c | 10 ++
hw/xen/xen_pt.h | 4 +
hw/xen/xen_pt_graphics.c | 232 +++++++++++++++++++++++++++++++++++++++++++
qemu-options.hx | 9 ++
vl.c | 10 ++
8 files changed, 272 insertions(+), 1 deletion(-)
create mode 100644 hw/xen/xen_pt_graphics.c
diff --git a/hw/xen/Makefile.objs b/hw/xen/Makefile.objs
index a0ca0aa..77b7dae 100644
--- a/hw/xen/Makefile.objs
+++ b/hw/xen/Makefile.objs
@@ -2,4 +2,4 @@
common-obj-$(CONFIG_XEN_BACKEND) += xen_backend.o xen_devconfig.o
obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o
-obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o xen_pt_msi.o
+obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o
xen_pt_msi.o xen_pt_graphics.o
diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c
index 743b37b..a54b7de 100644
--- a/hw/xen/xen-host-pci-device.c
+++ b/hw/xen/xen-host-pci-device.c
@@ -376,6 +376,11 @@ int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t
domain,
goto error;
}
d->irq = v;
+ rc = xen_host_pci_get_hex_value(d, "class", &v);
+ if (rc) {
+ goto error;
+ }
+ d->class_code = v;
d->is_virtfn = xen_host_pci_dev_is_virtfn(d);
return 0;
diff --git a/hw/xen/xen-host-pci-device.h b/hw/xen/xen-host-pci-device.h
index c2486f0..f1e1c30 100644
--- a/hw/xen/xen-host-pci-device.h
+++ b/hw/xen/xen-host-pci-device.h
@@ -25,6 +25,7 @@ typedef struct XenHostPCIDevice {
uint16_t vendor_id;
uint16_t device_id;
+ uint32_t class_code;
int irq;
XenHostPCIIORegion io_regions[PCI_NUM_REGIONS - 1];
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index be4220b..dac4238 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -450,6 +450,7 @@ static int xen_pt_register_regions(XenPCIPassthroughState
*s)
d->rom.size, d->rom.base_addr);
}
+ xen_pt_register_vga_regions(d);
return 0;
}
@@ -470,6 +471,8 @@ static void
xen_pt_unregister_regions(XenPCIPassthroughState *s)
if (d->rom.base_addr && d->rom.size) {
memory_region_destroy(&s->rom);
}
+
+ xen_pt_unregister_vga_regions(d);
}
/* region mapping */
@@ -693,6 +696,13 @@ static int xen_pt_initfn(PCIDevice *d)
/* Handle real device's MMIO/PIO BARs */
xen_pt_register_regions(s);
+ /* Setup VGA bios for passthrough GFX */
+ if (xen_pt_setup_vga(&s->real_device) < 0) {
+ XEN_PT_ERR(d, "Setup VGA BIOS of passthrough GFX failed!\n");
+ xen_host_pci_device_put(&s->real_device);
+ return -1;
+ }
+
/* reinitialize each config register to be emulated */
if (xen_pt_config_init(s)) {
XEN_PT_ERR(d, "PCI Config space initialisation failed.\n");
diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h
index 942dc60..4d3a18d 100644
--- a/hw/xen/xen_pt.h
+++ b/hw/xen/xen_pt.h
@@ -298,5 +298,9 @@ static inline bool
xen_pt_has_msix_mapping(XenPCIPassthroughState *s, int bar)
return s->msix && s->msix->bar_index == bar;
}
+extern int xen_has_gfx_passthru;
+int xen_pt_register_vga_regions(XenHostPCIDevice *dev);
+int xen_pt_unregister_vga_regions(XenHostPCIDevice *dev);
+int xen_pt_setup_vga(XenHostPCIDevice *dev);
#endif /* !XEN_PT_H */
diff --git a/hw/xen/xen_pt_graphics.c b/hw/xen/xen_pt_graphics.c
new file mode 100644
index 0000000..461e526
--- /dev/null
+++ b/hw/xen/xen_pt_graphics.c
@@ -0,0 +1,232 @@
+/*
+ * graphics passthrough
+ */
+#include "xen_pt.h"
+#include "xen-host-pci-device.h"
+#include "hw/xen/xen_backend.h"
+
+static int is_vga_passthrough(XenHostPCIDevice *dev)
+{
+ return (xen_has_gfx_passthru
+ && ((dev->class_code >> 0x8) == PCI_CLASS_DISPLAY_VGA));
+}
+
+typedef struct VGARegion {
+ int type; /* Memory or port I/O */
+ uint64_t guest_base_addr;
+ uint64_t machine_base_addr;
+ uint64_t size; /* size of the region */
+ int rc;
+} VGARegion;
+
+#define IORESOURCE_IO 0x00000100
+#define IORESOURCE_MEM 0x00000200
+
+static struct VGARegion vga_args[] = {
+ {
+ .type = IORESOURCE_IO,
+ .guest_base_addr = 0x3B0,
+ .machine_base_addr = 0x3B0,
+ .size = 0xC,
+ .rc = -1,
+ },
+ {
+ .type = IORESOURCE_IO,
+ .guest_base_addr = 0x3C0,
+ .machine_base_addr = 0x3C0,
+ .size = 0x20,
+ .rc = -1,
+ },
+ {
+ .type = IORESOURCE_MEM,
+ .guest_base_addr = 0xa0000 >> XC_PAGE_SHIFT,
+ .machine_base_addr = 0xa0000 >> XC_PAGE_SHIFT,
+ .size = 0x20,
+ .rc = -1,
+ },
+};
+
+/*
+ * register VGA resources for the domain with assigned gfx
+ */
+int xen_pt_register_vga_regions(XenHostPCIDevice *dev)
+{
+ int i = 0;
+
+ if (!is_vga_passthrough(dev)) {
+ return 0;
+ }
+
+ for (i = 0 ; i < ARRAY_SIZE(vga_args); i++) {
+ if (vga_args[i].type == IORESOURCE_IO) {
+ vga_args[i].rc = xc_domain_ioport_mapping(xen_xc, xen_domid,
+ vga_args[i].guest_base_addr,
+ vga_args[i].machine_base_addr,
+ vga_args[i].size, DPCI_ADD_MAPPING);
+ } else {
+ vga_args[i].rc = xc_domain_memory_mapping(xen_xc, xen_domid,
+ vga_args[i].guest_base_addr,
+ vga_args[i].machine_base_addr,
+ vga_args[i].size, DPCI_ADD_MAPPING);
+ }
+
+ if (vga_args[i].rc) {
+ XEN_PT_ERR(NULL, "VGA %s mapping failed! (rc: %i)\n",
+ vga_args[i].type == IORESOURCE_IO ? "ioport" : "memory",
+ vga_args[i].rc);
+ return vga_args[i].rc;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * unregister VGA resources for the domain with assigned gfx
+ */
+int xen_pt_unregister_vga_regions(XenHostPCIDevice *dev)
+{
+ int i = 0;
+
+ if (!is_vga_passthrough(dev)) {
+ return 0;
+ }
+
+ for (i = 0 ; i < ARRAY_SIZE(vga_args); i++) {
+ if (vga_args[i].type == IORESOURCE_IO) {
+ vga_args[i].rc = xc_domain_ioport_mapping(xen_xc, xen_domid,
+ vga_args[i].guest_base_addr,
+ vga_args[i].machine_base_addr,
+ vga_args[i].size, DPCI_REMOVE_MAPPING);
+ } else {
+ vga_args[i].rc = xc_domain_memory_mapping(xen_xc, xen_domid,
+ vga_args[i].guest_base_addr,
+ vga_args[i].machine_base_addr,
+ vga_args[i].size, DPCI_REMOVE_MAPPING);
+ }
+
+ if (vga_args[i].rc) {
+ XEN_PT_ERR(NULL, "VGA %s unmapping failed! (rc: %i)\n",
+ vga_args[i].type == IORESOURCE_IO ? "ioport" : "memory",
+ vga_args[i].rc);
+ return vga_args[i].rc;
+ }
+ }
+
+ return 0;
+}
+
+static int get_vgabios(unsigned char *buf, XenHostPCIDevice *dev)
+{
+ char rom_file[64];
+ FILE *fp;
+ uint8_t val;
+ struct stat st;
+ uint16_t magic = 0;
+ int ret = 0;
+
+ snprintf(rom_file, sizeof(rom_file),
+ "/sys/bus/pci/devices/%04x:%02x:%02x.%d/rom",
+ dev->domain, dev->bus, dev->dev,
+ dev->func);
+
+ if (stat(rom_file, &st)) {
+ return -ENODEV;
+ }
+
+ if (access(rom_file, F_OK)) {
+ XEN_PT_ERR(NULL, "pci-assign: Insufficient privileges for %s",
+ rom_file);
+ return -ENODEV;
+ }
+
+ /* Write "1" to the ROM file to enable it */
+ fp = fopen(rom_file, "r+");
+ if (fp == NULL) {
+ return -EACCES;
+ }
+ val = 1;
+ if (fwrite(&val, 1, 1, fp) != 1) {
+ XEN_PT_LOG("%s\n", "Failed to enable pci-sysfs rom file");
+ ret = -EIO;
+ goto close_rom;
+ }
+ fseek(fp, 0, SEEK_SET);
+
+ /*
+ * Check if it a real bios extension.
+ * The magic number is 0xAA55.
+ */
+ if (!fread(&magic, sizeof(magic), 1, fp)) {
+ XEN_PT_ERR(NULL, "VGA: can't get magic.\n");
+ ret = -ENODEV;
+ goto close_rom;
+ }
+ if (magic != 0xAA55) {
+ XEN_PT_ERR(NULL, "VGA: wrong magic %x.\n", magic);
+ ret = -ENODEV;
+ goto close_rom;
+ }
+ fseek(fp, 0, SEEK_SET);
+
+ if (!fread(buf, 1, st.st_size, fp)) {
+ XEN_PT_ERR(NULL, "VGA: pci-assign: Cannot read from host %s",
rom_file);
+ XEN_PT_LOG(NULL, "VGA: Device option ROM contents are probably invalid
"
+ "(check dmesg).\nSkip option ROM probe with rombar=0, "
+ "or load from file with romfile=\n");
+ }
+
+close_rom:
+ /* Write "0" to disable ROM */
+ fseek(fp, 0, SEEK_SET);
+ val = 0;
+ if (!fwrite(&val, 1, 1, fp)) {
+ ret = -EIO;
+ XEN_PT_LOG("%s\n", "Failed to disable pci-sysfs rom file");
+ }
+ fclose(fp);
+ return ret;
+}
+
+/* Allocated 128K for the vga bios */
+#define VGA_BIOS_DEFAULT_SIZE (0x20000)
+
+int xen_pt_setup_vga(XenHostPCIDevice *dev)
+{
+ unsigned char *bios = NULL;
+ int bios_size = 0;
+ char *c = NULL;
+ char checksum = 0;
+ int rc = 0;
+
+ if (!is_vga_passthrough(dev)) {
+ return rc;
+ }
+
+ bios = g_malloc0(VGA_BIOS_DEFAULT_SIZE);
+
+ bios_size = get_vgabios(bios, dev);
+ if (bios_size) {
+ XEN_PT_ERR(NULL, "VGA: Error %d getting VBIOS!\n", bios_size);
+ if (bios_size < 0) {
+ XEN_PT_ERR(NULL, "VGA: Error (%s).\n", strerror(bios_size));
+ }
+ rc = -1;
+ goto out;
+ }
+
+ /* Adjust the bios checksum */
+ for (c = (char *)bios; c < ((char *)bios + bios_size); c++) {
+ checksum += *c;
+ }
+ if (checksum) {
+ bios[bios_size - 1] -= checksum;
+ XEN_PT_LOG(NULL, "vga bios checksum is adjusted!\n");
+ }
+
+ /* Currently we fixed this address as a primary. */
+ cpu_physical_memory_rw(0xc0000, bios, bios_size, 1);
+out:
+ g_free(bios);
+ return rc;
+}
diff --git a/qemu-options.hx b/qemu-options.hx
index c2c0823..9cb324f 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1053,6 +1053,15 @@ STEXI
Rotate graphical output some deg left (only PXA LCD).
ETEXI
+DEF("gfx_passthru", 0, QEMU_OPTION_gfx_passthru,
+ "-gfx_passthru enable Intel IGD passthrough by XEN\n",
+ QEMU_ARCH_ALL)
+STEXI
+@item -gfx_passthru
+@findex -gfx_passthru
+Enable Intel IGD passthrough by XEN
+ETEXI
+
DEF("vga", HAS_ARG, QEMU_OPTION_vga,
"-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|none]\n"
" select video card type\n", QEMU_ARCH_ALL)
diff --git a/vl.c b/vl.c
index 673148e..c615b41 100644
--- a/vl.c
+++ b/vl.c
@@ -1438,6 +1438,13 @@ static void smp_parse(QemuOpts *opts)
}
+/* We still need this for compatibility with XEN. */
+int xen_has_gfx_passthru;
+static void xen_gfx_passthru(const char *optarg)
+{
+ xen_has_gfx_passthru = 1;
+}
+
static void configure_realtime(QemuOpts *opts)
{
bool enable_mlock;
@@ -3957,6 +3964,9 @@ int main(int argc, char **argv, char **envp)
}
configure_msg(opts);
break;
+ case QEMU_OPTION_gfx_passthru:
+ xen_gfx_passthru(optarg);
+ break;
default:
os_parse_cmd_args(popt->index, optarg);
}
--
1.9.1
