Hi Marc, I tested the series on Calxeda Midway with VFIO use case. Also reviewed it again without finding anything new. Tested-by: Eric Auger <eric.auger@xxxxxxxxxx> Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> Best Regards Eric On 08/26/2015 06:00 PM, Marc Zyngier wrote: > The GICv2 and GICv3 architectures allow an active physical interrupt > to be forwarded to a guest, and the guest to indirectly perform the > deactivation of the interrupt by performing an EOI on the virtual > interrupt (see for example the GICv2 spec, 3.2.1). > > This allows some substantial performance improvement for level > triggered interrupts that otherwise have to be masked/unmasked in > VFIO, not to mention the required trap back to KVM when the guest > performs an EOI. > > To enable this, the GICs need to be switched to a different EOImode, > where a taken interrupt can be left "active" (which prevents the same > interrupt from being taken again), while other interrupts are still > being processed normally. > > We also use the new irq_set_vcpu_affinity hook that was introduced for > Intel's "Posted Interrupts" to determine whether or not to perform the > deactivation at EOI-time. > > As all of this only makes sense when the kernel can behave as a > hypervisor, we only enable this mode on detecting that the kernel was > actually booted in HYP mode, and that the GIC supports this feature. > > This series is a complete rework of a RFC I sent over a year ago: > > http://lists.infradead.org/pipermail/linux-arm-kernel/2014-June/266328.html > > Since then, a lot has been either merged (the irqchip_state) or reworked > (my active-timer series: http://www.spinics.net/lists/kvm/msg118768.html), > and this implements the last few bits for Eric Auger's series to > finally make it into the kernel: > > https://lkml.org/lkml/2015/7/2/268 > https://lkml.org/lkml/2015/7/6/291 > > With all these patches combined, physical interrupt routing from the > kernel into a VM becomes possible. > > Note that the implementation makes use of the static_key mechanism, > which is undergoing an extensive rework in 4.3. I intend to convert > this code once both are in mainline. > > This has been tested on Juno (GICv2) and FastModel (GICv3). A branch > is available at: > > git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git irq/gic-irq-vcpu-affinity-v4 > > * From v3: > - Use separate irq_chip structures, leading to much nicer code (tglx) > - Dropped Eric's Tested/Reviewed-by as there is significant changes > > * From v2: > - Another small fix from Eric > - Some commit message cleanups > > * From v1: > - Fixes after review from Eric > - Got rid of the cascaded GICv2 hack (it was broken anyway) > - Folded the LPI deactivation patch (it makes more sense as part of > the main one. > - Some clarifying comments about the "deactivate on mask" > - I haven't retained Eric's Reviewed/Tested-by, as the code as > significantly changed on GICv2 > > Marc Zyngier (4): > irqchip: GICv3: Convert to EOImode == 1 > irqchip: GICv3: Don't deactivate interrupts forwarded to a guest > irqchip: GIC: Convert to EOImode == 1 > irqchip: GIC: Don't deactivate interrupts forwarded to a guest > > drivers/irqchip/irq-gic-v3.c | 70 +++++++++++++++++++++-- > drivers/irqchip/irq-gic.c | 111 ++++++++++++++++++++++++++++++++++++- > include/linux/irqchip/arm-gic-v3.h | 9 +++ > include/linux/irqchip/arm-gic.h | 4 ++ > 4 files changed, 188 insertions(+), 6 deletions(-) > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
