Messages in this thread | | | Date | Mon, 29 Nov 2021 10:52:26 +0100 | Subject | Re: [patch 00/22] genirq/msi, PCI/MSI: Spring cleaning - Part 1 | From | Cédric Le Goater <> |
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On 11/27/21 02:18, Thomas Gleixner wrote: > The [PCI] MSI code has gained quite some warts over time. A recent > discussion unearthed a shortcoming: the lack of support for expanding > PCI/MSI-X vectors after initialization of MSI-X. > > PCI/MSI-X has no requirement to setup all vectors when MSI-X is enabled in > the device. The non-used vectors have just to be masked in the vector > table. For PCI/MSI this is not possible because the number of vectors > cannot be changed after initialization. > > The PCI/MSI code, but also the core MSI irq domain code are built around > the assumption that all required vectors are installed at initialization > time and freed when the device is shut down by the driver. > > Supporting dynamic expansion at least for MSI-X is important for VFIO so > that the host side interrupts for passthrough devices can be installed on > demand. > > This is the first part of a large (total 101 patches) series which > refactors the [PCI]MSI infrastructure to make runtime expansion of MSI-X > vectors possible. The last part (10 patches) provide this functionality. > > The first part is mostly a cleanup which consolidates code, moves the PCI > MSI code into a separate directory and splits it up into several parts. > > No functional change intended except for patch 2/N which changes the > behaviour of pci_get_vector()/affinity() to get rid of the assumption that > the provided index is the "index" into the descriptor list instead of using > it as the actual MSI[X] index as seen by the hardware. This would break > users of sparse allocated MSI-X entries, but non of them use these > functions. > > This series is based on 5.16-rc2 and also available via git: > > git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git msi-v1-part-1 > > For the curious who can't wait for the next part to arrive the full series > is available via: > > git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git msi-v1-part-4
After fixing the compile failures, I didn't see any regressions on these platforms :
PowerNV, pSeries under KVM and PowerVM, using POWER8/9 processors.
Thanks,
C.
> Thanks, > > tglx > --- > arch/powerpc/platforms/4xx/msi.c | 281 ------------ > b/Documentation/driver-api/pci/pci.rst | 2 > b/arch/mips/pci/msi-octeon.c | 32 - > b/arch/powerpc/platforms/4xx/Makefile | 1 > b/arch/powerpc/platforms/cell/axon_msi.c | 2 > b/arch/powerpc/platforms/powernv/pci-ioda.c | 4 > b/arch/powerpc/platforms/pseries/msi.c | 6 > b/arch/powerpc/sysdev/Kconfig | 6 > b/arch/s390/pci/pci_irq.c | 4 > b/arch/sparc/kernel/pci_msi.c | 4 > b/arch/x86/hyperv/irqdomain.c | 55 -- > b/arch/x86/include/asm/x86_init.h | 6 > b/arch/x86/include/asm/xen/hypervisor.h | 8 > b/arch/x86/kernel/apic/msi.c | 8 > b/arch/x86/kernel/x86_init.c | 12 > b/arch/x86/pci/xen.c | 19 > b/drivers/irqchip/irq-gic-v2m.c | 1 > b/drivers/irqchip/irq-gic-v3-its-pci-msi.c | 1 > b/drivers/irqchip/irq-gic-v3-mbi.c | 1 > b/drivers/net/wireless/ath/ath11k/pci.c | 2 > b/drivers/pci/Makefile | 3 > b/drivers/pci/msi/Makefile | 7 > b/drivers/pci/msi/irqdomain.c | 267 +++++++++++ > b/drivers/pci/msi/legacy.c | 79 +++ > b/drivers/pci/msi/msi.c | 645 ++++------------------------ > b/drivers/pci/msi/msi.h | 39 + > b/drivers/pci/msi/pcidev_msi.c | 43 + > b/drivers/pci/pci-sysfs.c | 7 > b/drivers/pci/xen-pcifront.c | 2 > b/include/linux/msi.h | 135 ++--- > b/include/linux/pci.h | 1 > b/kernel/irq/msi.c | 41 + > 32 files changed, 696 insertions(+), 1028 deletions(-) >
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