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Re: [Qemu-arm] [Qemu-devel] [PATCH V6 5/6] hw/arm/virt: add pvpanic devi
From: |
Andrew Jones |
Subject: |
Re: [Qemu-arm] [Qemu-devel] [PATCH V6 5/6] hw/arm/virt: add pvpanic device invirt acpi table |
Date: |
Fri, 16 Nov 2018 10:07:51 +0100 |
User-agent: |
NeoMutt/20180716 |
On Fri, Nov 16, 2018 at 09:45:42AM +0800, address@hidden wrote:
> >> add pvpanic device in virt acpi table, so when kenrel command line uses
> >> acpi=force, kernel can get info from acpi table in aarch64.
>
> [...]
>
> >>
> >> +static void acpi_dsdt_add_pvpanic(Aml *scope, const MemMapEntry
> >> *pvpanic_memmap)
> >> +{
> >> + Aml *dev = aml_device("PANC");
> >
> >Shouldn't this be "PEVT" ("panic event"), like it is for x86?
> >
> yeah, I will change it.
> >> + aml_append(dev, aml_name_decl("_HID", aml_string("QEMU0001")));
> >> + aml_append(dev, aml_name_decl("_UID", aml_int(0)));
> >
> >Why add _UID? Also, I see x86 had some issues with not having _STA and
> >then having a _STA without the UI flag. It now has _STA=0xf
> >(PRESENT|ENABLED|UI|FUNCTIONING). I'm not saying we need to do that to,
> >but I'd like to know if it was considered and decided we don't need to.
> >
> The way the kernel code processes _STA is that if _STA is not found, the
> default
> setting is (PRESENT|ENABLED|UI|FUNCTIONING). So I think it is not necessary
> to add it. It is only parsed in the pvpanic driver.
Good enough for me.
> for _UID, I think it is used for device index. I just fill it with 0 because
> there is
> only one pvpanic device.
OK, but I'm still not sure it's necessary.
>
> by the way, How to get the value of ACPI conveniently? how dou you get the
> value of _STA?
Not sure what you mean here. From where do you want to check the value?
If you mean from guest userspace, then there's nothing convenient that I
know of. You'll have to disassemble the tables you extract from sysfs,
afaik.
Thanks,
drew
>
> Thanks.
> >> +
> >> + Aml *crs = aml_resource_template();
> >> + aml_append(crs, aml_memory32_fixed(pvpanic_memmap->base,
> >> + pvpanic_memmap->size,
> >> AML_READ_WRITE));
> >> +
> >> + aml_append(dev, aml_name_decl("_CRS", crs));
> >> +
> >> + aml_append(scope, dev);
> >> +}
> >> +
> >> static void acpi_dsdt_add_uart(Aml *scope, const MemMapEntry *uart_memmap,
> >> uint32_t uart_irq)
> >> {
> >> @@ -770,6 +785,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
> >> VirtMachineState *vms)
> >> acpi_dsdt_add_cpus(scope, vms->smp_cpus);
> >> acpi_dsdt_add_uart(scope, &memmap[VIRT_UART],
> >> (irqmap[VIRT_UART] + ARM_SPI_BASE));
> >> + acpi_dsdt_add_pvpanic(scope, &memmap[VIRT_PVPANIC]);
> >> acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]);
> >> acpi_dsdt_add_fw_cfg(scope, &memmap[VIRT_FW_CFG]);
> >> acpi_dsdt_add_virtio(scope, &memmap[VIRT_MMIO],
> >> --
> >> 1.8.3.1
> >>
> >>
> >
> >Thanks,
> >drew
[Qemu-arm] [PATCH V6 4/6] hw/arm/virt: Use the pvpanic device, Peng Hao, 2018/11/11
[Qemu-arm] [PATCH V6 1/6] hw/misc/pvpanic: Build the pvpanic device in $(common-obj), Peng Hao, 2018/11/11