On Wed, Feb 03, 2021 at 12:56:44PM -0800, Megha Dey wrote: > From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > > The pci_subdevice_msi_create_irq_domain() should fail if the underlying > platform is not able to support IMS (Interrupt Message Storage). Otherwise, > the isolation of interrupt is not guaranteed. > > For x86, IMS is only supported on bare metal for now. We could enable it > in the virtualization environments in the future if interrupt HYPERCALL > domain is supported or the hardware has the capability of interrupt > isolation for subdevices. > > Cc: David Woodhouse <dwmw@xxxxxxxxxxxx> > Cc: Leon Romanovsky <leon@xxxxxxxxxx> > Cc: Kevin Tian <kevin.tian@xxxxxxxxx> > Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/linux-pci/87pn4nk7nn.fsf@xxxxxxxxxxxxxxxxxxxxxxx/ > Link: https://lore.kernel.org/linux-pci/877dqrnzr3.fsf@xxxxxxxxxxxxxxxxxxxxxxx/ > Link: https://lore.kernel.org/linux-pci/877dqqmc2h.fsf@xxxxxxxxxxxxxxxxxxxxxxx/ > Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > Signed-off-by: Megha Dey <megha.dey@xxxxxxxxx> > --- > arch/x86/pci/common.c | 74 +++++++++++++++++++++++++++++++++++++++++++++ > drivers/base/platform-msi.c | 8 +++++ > include/linux/msi.h | 1 + > 3 files changed, 83 insertions(+) > > diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c > index 3507f45..263ccf6 100644 > --- a/arch/x86/pci/common.c > +++ b/arch/x86/pci/common.c > @@ -12,6 +12,8 @@ > #include <linux/init.h> > #include <linux/dmi.h> > #include <linux/slab.h> > +#include <linux/iommu.h> > +#include <linux/msi.h> > > #include <asm/acpi.h> > #include <asm/segment.h> > @@ -724,3 +726,75 @@ struct pci_dev *pci_real_dma_dev(struct pci_dev *dev) > return dev; > } > #endif > + > +#ifdef CONFIG_DEVICE_MSI Sorry for my naive question, but I see it in all your patches in this series and wonder why did you wrap everything with ifdefs?. All *.c code is wrapped with those ifdefs, which is hard to navigate and unlikely to give any code/size optimization benefit if kernel is compiled without CONFIG_DEVICE_MSI. The more common approach is to put those ifdef in the public header files and leave to the compiler to drop not called functions. Thanks
