From 819b3496196c2a7de89ed2372182c24053443990 Mon Sep 17 00:00:00 2001 From: schspa Date: Thu, 25 Feb 2021 13:36:06 +0800 Subject: virtio-mmio: improve virtio-mmio get_dev_path alog 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 f58b39d2d5b ("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 Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/virtio/virtio-mmio.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'hw/virtio') diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c index 610661d6a5..6990b9879c 100644 --- a/hw/virtio/virtio-mmio.c +++ b/hw/virtio/virtio-mmio.c @@ -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; } -- cgit v1.2.3-55-g7522