| Message ID | 20200319080117.7725-14-kraxel@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | microvm: add acpi support | expand |
On Thu, Mar 19, 2020 at 09:01:17AM +0100, Gerd Hoffmann wrote: > With ACPI enabled and IO-APIC being properly declared in the ACPI tables > we can use interrupt lines 16-23 for virtio and avoid shared interrupts. 7 interrupt lines? Is there a specific requirements of which ones should be assigned to what device? Or perhaps - could you include /proc/interrupts in the commit if that is OK? > > With acpi disabled we continue to use lines 8-15. > > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> > --- > hw/i386/microvm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c > index 834b10aee0a2..139181daed06 100644 > --- a/hw/i386/microvm.c > +++ b/hw/i386/microvm.c > @@ -122,7 +122,7 @@ static void microvm_devices_init(MicrovmMachineState *mms) > > kvmclock_create(); > > - mms->virtio_irq_base = 8; > + mms->virtio_irq_base = acpi_enabled ? 16 : 8; > for (i = 0; i < VIRTIO_NUM_TRANSPORTS; i++) { > sysbus_create_simple("virtio-mmio", > VIRTIO_MMIO_BASE + i * 512, > -- > 2.18.2 >
On Fri, Mar 20, 2020 at 11:30:16AM -0400, Konrad Rzeszutek Wilk wrote: > On Thu, Mar 19, 2020 at 09:01:17AM +0100, Gerd Hoffmann wrote: > > With ACPI enabled and IO-APIC being properly declared in the ACPI tables > > we can use interrupt lines 16-23 for virtio and avoid shared interrupts. > > 7 interrupt lines? Is there a specific requirements of which > ones should be assigned to what device? 8 lines (23 is inclusive), one for each virtio device. It wouldn't give you separate config change or per-queue interrupts (I think virtio-mmio doesn't support that). It only avoids sharing interrupts with legacy pc devices like rtc and acpi. cheers, Gerd
diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c index 834b10aee0a2..139181daed06 100644 --- a/hw/i386/microvm.c +++ b/hw/i386/microvm.c @@ -122,7 +122,7 @@ static void microvm_devices_init(MicrovmMachineState *mms) kvmclock_create(); - mms->virtio_irq_base = 8; + mms->virtio_irq_base = acpi_enabled ? 16 : 8; for (i = 0; i < VIRTIO_NUM_TRANSPORTS; i++) { sysbus_create_simple("virtio-mmio", VIRTIO_MMIO_BASE + i * 512,
With ACPI enabled and IO-APIC being properly declared in the ACPI tables we can use interrupt lines 16-23 for virtio and avoid shared interrupts. With acpi disabled we continue to use lines 8-15. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- hw/i386/microvm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)