Re: [PATCH for-5.0] xive/kvm: Trigger interrupts from userspace

2019-11-19 Thread David Gibson
On Tue, Nov 19, 2019 at 09:15:52AM +0100, Cédric Le Goater wrote: > On 19/11/2019 01:47, David Gibson wrote: > > On Mon, Nov 18, 2019 at 04:37:16PM +0100, Cédric Le Goater wrote: > >> On 18/11/2019 16:12, Greg Kurz wrote: > >>> When using the XIVE KVM device, the trigger page is directly accessible

Re: [PATCH for-5.0] xive/kvm: Trigger interrupts from userspace

2019-11-19 Thread Greg Kurz
On Tue, 19 Nov 2019 09:15:52 +0100 Cédric Le Goater wrote: > On 19/11/2019 01:47, David Gibson wrote: > > On Mon, Nov 18, 2019 at 04:37:16PM +0100, Cédric Le Goater wrote: > >> On 18/11/2019 16:12, Greg Kurz wrote: > >>> When using the XIVE KVM device, the trigger page is directly accessible > >>

Re: [PATCH for-5.0] xive/kvm: Trigger interrupts from userspace

2019-11-19 Thread Cédric Le Goater
On 19/11/2019 01:47, David Gibson wrote: > On Mon, Nov 18, 2019 at 04:37:16PM +0100, Cédric Le Goater wrote: >> On 18/11/2019 16:12, Greg Kurz wrote: >>> When using the XIVE KVM device, the trigger page is directly accessible >>> in QEMU. Unlike with XICS, no need to ask KVM to fire the interrupt.

Re: [PATCH for-5.0] xive/kvm: Trigger interrupts from userspace

2019-11-18 Thread David Gibson
On Mon, Nov 18, 2019 at 04:37:16PM +0100, Cédric Le Goater wrote: > On 18/11/2019 16:12, Greg Kurz wrote: > > When using the XIVE KVM device, the trigger page is directly accessible > > in QEMU. Unlike with XICS, no need to ask KVM to fire the interrupt. A > > simple store on the trigger page does

Re: [PATCH for-5.0] xive/kvm: Trigger interrupts from userspace

2019-11-18 Thread Greg Kurz
On Mon, 18 Nov 2019 16:37:16 +0100 Cédric Le Goater wrote: > On 18/11/2019 16:12, Greg Kurz wrote: > > When using the XIVE KVM device, the trigger page is directly accessible > > in QEMU. Unlike with XICS, no need to ask KVM to fire the interrupt. A > > simple store on the trigger page does the j

Re: [PATCH for-5.0] xive/kvm: Trigger interrupts from userspace

2019-11-18 Thread Cédric Le Goater
On 18/11/2019 16:12, Greg Kurz wrote: > When using the XIVE KVM device, the trigger page is directly accessible > in QEMU. Unlike with XICS, no need to ask KVM to fire the interrupt. A > simple store on the trigger page does the job. > > Just call xive_esb_trigger(). Yes but the KVM XIVE device d

[PATCH for-5.0] xive/kvm: Trigger interrupts from userspace

2019-11-18 Thread Greg Kurz
When using the XIVE KVM device, the trigger page is directly accessible in QEMU. Unlike with XICS, no need to ask KVM to fire the interrupt. A simple store on the trigger page does the job. Just call xive_esb_trigger(). This may improve performance of emulated devices that go through qemu_set_irq