[Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-26 Thread Michael S. Tsirkin
On Thu, Nov 26, 2009 at 12:21:46PM +0900, Isaku Yamahata wrote: On Wed, Nov 25, 2009 at 06:58:34PM +0200, Michael S. Tsirkin wrote: This patchset adds support for mandatory interupt status and interrupt disable bits to all PCI devices. This is required for PCI compliancy. These

[Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-26 Thread Michael S. Tsirkin
On Thu, Nov 26, 2009 at 12:21:46PM +0900, Isaku Yamahata wrote: At least I think irq_disable can be removed The following patch on top of mine removes irq_disabled field in PCIDevice. I am of two minds whether this makes the code better. What is your opinion? diff --git a/hw/pci.c b/hw/pci.c

Re: [Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-26 Thread Paul Brook
No, this would slow us down because these are per-pin. We need a sum of interrupts so that config space can be updated by a single command. Interrupts are a fastpath, extra loops there should be avoided. It's really not that much of a fast path. Unless you're doing something particularly

Re: [Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-26 Thread Michael S. Tsirkin
On Thu, Nov 26, 2009 at 12:41:03PM +, Paul Brook wrote: No, this would slow us down because these are per-pin. We need a sum of interrupts so that config space can be updated by a single command. Interrupts are a fastpath, extra loops there should be avoided. It's really not that

[Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-26 Thread Michael S. Tsirkin
On Thu, Nov 26, 2009 at 12:38:20PM +0200, Michael S. Tsirkin wrote: On Thu, Nov 26, 2009 at 12:21:46PM +0900, Isaku Yamahata wrote: At least I think irq_disable can be removed The following patch on top of mine removes irq_disabled field in PCIDevice. I am of two minds whether this makes

Re: [Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-26 Thread Paul Brook
It's really not that much of a fast path. Unless you're doing something particularly obscure then even under heavy load you're unlikely to exceed a few kHz. I think with kvm, heavy disk stressing benchmark can get higher. I'd still expect this to be the least of your problems. If nothing

Re: [Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-26 Thread Michael S. Tsirkin
On Thu, Nov 26, 2009 at 01:21:39PM +, Paul Brook wrote: It's really not that much of a fast path. Unless you're doing something particularly obscure then even under heavy load you're unlikely to exceed a few kHz. I think with kvm, heavy disk stressing benchmark can get higher. I'd

[Qemu-devel] Re: [PATCH 0/4] pci: interrupt status/interrupt disable support

2009-11-25 Thread Isaku Yamahata
On Wed, Nov 25, 2009 at 06:58:34PM +0200, Michael S. Tsirkin wrote: This patchset adds support for mandatory interupt status and interrupt disable bits to all PCI devices. This is required for PCI compliancy. These patches are on top of my pci tree, including Isaku Yamahata's fixes. If