Re: Problems with irq mapping in qemu v5.2 - Mark Cave-Ayland

From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
To: Guenter Roeck <linux@roeck-us.net>,
	QEMU Developers <qemu-devel@nongnu.org>
Cc: "Philippe Mathieu-Daudé" <f4bug@amsat.org>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: Problems with irq mapping in qemu v5.2
Date: Wed, 23 Dec 2020 10:24:43 +0000	[thread overview]
Message-ID: <ee005fd0-1eb0-2bfd-6be3-10f616cc7aad@ilande.co.uk> (raw)
In-Reply-To: <5849da05-a063-cd56-7709-c4760c8aa71f@roeck-us.net>

On 22/12/2020 21:23, Guenter Roeck wrote:

(Added jiaxun.yang@flygoat.com as CC)

>>> I don't really have a good solution for pci_bonito_map_irq(). It may not
>>> matter much - I have not been able to boot fuloong_2e since qemu v4.0,
>>> and afaics that is the only platform using it. Maybe it is just completely
>>> broken ?
>>
>> It looks like you want this patchset posted last week: https://patchew.org/QEMU/20201216022513.89451-1-jiaxun.yang@flygoat.com/ (specifically: https://patchew.org/QEMU/20201216022513.89451-1-jiaxun.yang@flygoat.com/20201216022513.89451-4-jiaxun.yang@flygoat.com/). Zoltan was working on the VIA southbridge wiring at the start of the year and provided me a test case that would boot Linux on the fulong2e machine, so at that point in time it wasn't completely broken.
>>
> Those patches don't help for my tests. Problem is that I try to boot from ide drive.
> 
> qemu-system-mips64el -M fulong2e \
>      -kernel vmlinux -no-reboot -m 256 -snapshot \
>      -drive file=rootfs.mipsel.ext3,format=raw,if=ide \
>      -vga none -nographic \
>      --append "root=/dev/sda console=ttyS0"
>      -serial stdio -monitor none
> 
> This works just fine with qemu v3.1. With qemu v5.2 (after applying the
> fuloong patch series), I get:
> 
> VFS: Cannot open root device "sda" or unknown-block(0,0): error -6
> 
> This used to work up to qemu v3.1. Since qemu v4.0, there has been a variety
> of failures. Common denominator is that the ide drive is no longer recognized,
> presumably due to related changes in the via and/or pci code between v3.1
> and v4.0.
> 
> Difference in log messages:
> 
> v3.1:
> 
> pci 0000:00:05.1: [Firmware Bug]: reg 0x10: invalid BAR (can't size)
> pci 0000:00:05.1: [Firmware Bug]: reg 0x14: invalid BAR (can't size)
> pci 0000:00:05.1: [Firmware Bug]: reg 0x18: invalid BAR (can't size)
> pci 0000:00:05.1: reg 0x1c: [mem 0x100000370-0x10000037f 64bit]
> ...
> pata_via 0000:00:05.1: BMDMA: BAR4 is zero, falling back to PIO
> ata1: PATA max PIO4 cmd 0x1f0 ctl 0x3f6 irq 14
> ata2: PATA max PIO4 cmd 0x170 ctl 0x376 irq 15
> ata1.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100
> ...
> 
> ----
> 
> v5.2:
> 
> pci 0000:00:05.1: reg 0x10: [io  0x0000-0x0007]
> pci 0000:00:05.1: reg 0x14: [io  0x0000-0x0003]
> pci 0000:00:05.1: reg 0x18: [io  0x0000-0x0007]
> pci 0000:00:05.1: reg 0x1c: [io  0x0000-0x0003]
> pci 0000:00:05.1: reg 0x20: [io  0x0000-0x000f]
> pci 0000:00:05.1: BAR 4: assigned [io  0x4440-0x444f]
> ...
> ata1: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0x4440 irq 14
> ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0x4448 irq 15
> [and nothing else]
> 
> Guenter

Jiaxun: Guenter is reporting that even with your latest series at 
https://lists.gnu.org/archive/html/qemu-devel/2020-12/msg04293.html he is unable to 
boot from an IDE drive. Your cover letter suggests that it should be possible to boot 
the Debian installer: can you provide any insight here?

ATB,

Mark.