On 14.11.2018 7:50, Guo, Chaohong wrote:
-----Original Message-----
From: Sergei Shtylyov [mailto:sergei.shtylyov@xxxxxxxxxxxxxxxxxx]
Sent: Tuesday, November 6, 2018 11:34 PM
To: Guo, Chaohong <chaohong.guo@xxxxxxxxx>; linux-ide@xxxxxxxxxxxxxxx
Cc: b.zolnierkie@xxxxxxxxxxx; axboe@xxxxxxxxx; vireshk@xxxxxxxxxx
Subject: Re: [PATCH v3 1/4] Allow system to allocate IRQ 0 to ATA devices
On 11/06/2018 05:42 AM, Chaohong guo wrote:
Interrupt vector 0 can be used on some platform.
It exists even on x86. However, it's never passed to request_irq() there IIRC,
just to setup_irq()...
[Guo, Chaohong]
Yes. normally on x86 platform, the vector 0 won't be allocated to device. It is a system vector for handling the exception of dividing zero.
You are clearly mixing the interrupt vectors with IRQs. IRQ0 on x86 is used
by the i8254 (timer).
After my changing, the AHCI driver can work with vector 0 in non-root jailhouse cell just because jailhouse will remap it via VT-D interrupt remapping.
How do you think about it ? Do we fix it in somewhere else to prevent kernel in non-root cell from allocating vector less than 0x20 ?
-minskey
MBR, Sergei
