OpenE2K/qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

virtio-mmio: improve virtio-mmio get_dev_path alog

Browse Source 
At the moment the following QEMU command line triggers an assertion
failure On xlnx-versal SOC:
  qemu-system-aarch64 \
      -machine xlnx-versal-virt -nographic -smp 2 -m 128 \
      -fsdev local,id=shareid,path=${HOME}/work,security_model=none \
      -device virtio-9p-device,fsdev=shareid,mount_tag=share \
      -fsdev local,id=shareid1,path=${HOME}/Music,security_model=none \
      -device virtio-9p-device,fsdev=shareid1,mount_tag=share1

  qemu-system-aarch64: ../migration/savevm.c:860:
  vmstate_register_with_alias_id:
  Assertion `!se->compat || se->instance_id == 0' failed.

This problem was fixed on arm virt platform in commit f58b39d2d5
("virtio-mmio: format transport base address in BusClass.get_dev_path")

It works perfectly on arm virt platform. but there is still there on
xlnx-versal SOC.

The main difference between arm virt and xlnx-versal is they use
different way to create virtio-mmio qdev. on arm virt, it calls
sysbus_create_simple("virtio-mmio", base, pic[irq]); which will call
sysbus_mmio_map internally and assign base address to subsys device
mmio correctly. but xlnx-versal's implements won't do this.

However, xlnx-versal can't switch to sysbus_create_simple() to create
virtio-mmio device. It's because xlnx-versal's cpu use
VersalVirt.soc.fpd.apu.mr as it's memory. which is subregion of
system_memory. sysbus_create_simple will add virtio to system_memory,
which can't be accessed by cpu.

Besides, xlnx-versal can't add sysbus_mmio_map api call too, because
this will add memory region to system_memory, and it can't be added
to VersalVirt.soc.fpd.apu.mr again.

We can solve this by assign correct base address offset on dev_path.

This path was test on aarch64 virt & xlnx-versal platform.

Signed-off-by: schspa <schspa@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
schspa 2021-02-25 13:36:06 +08:00 committed by Peter Maydell
parent 5dfbfefaad
commit 819b349619
1 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
hw/virtio/virtio-mmio.c
View File

@ -737,8 +737,8 @@ static char *virtio_mmio_bus_get_dev_path(DeviceState *dev)
BusState *virtio_mmio_bus;
VirtIOMMIOProxy *virtio_mmio_proxy;
char *proxy_path;
SysBusDevice *proxy_sbd;
char *path;
MemoryRegionSection section;
virtio_mmio_bus = qdev_get_parent_bus(dev);
virtio_mmio_proxy = VIRTIO_MMIO(virtio_mmio_bus->parent);
@ -757,17 +757,18 @@ static char *virtio_mmio_bus_get_dev_path(DeviceState *dev)
}
/* Otherwise, we append the base address of the transport. */
proxy_sbd = SYS_BUS_DEVICE(virtio_mmio_proxy);
assert(proxy_sbd->num_mmio == 1);
assert(proxy_sbd->mmio[0].memory == &virtio_mmio_proxy->iomem);
section = memory_region_find(&virtio_mmio_proxy->iomem, 0, 0x200);
assert(section.mr);
if (proxy_path) {
path = g_strdup_printf("%s/virtio-mmio@" TARGET_FMT_plx, proxy_path,
proxy_sbd->mmio[0].addr);
section.offset_within_address_space);
} else {
path = g_strdup_printf("virtio-mmio@" TARGET_FMT_plx,
proxy_sbd->mmio[0].addr);
section.offset_within_address_space);
}
memory_region_unref(section.mr);
g_free(proxy_path);
return path;
}