Hi all Here we propose this patch series to make Linux run as the root partition [0] on Microsoft Hypervisor [1]. Microsoft wants to create a complete virtualization stack with Linux and Microsoft Hypervisor. There will be a subsequent patch series to provide a device node (/dev/mshv) such that userspace programs can create and run virtual machines. We've also ported Cloud Hypervisor [3] over and have been able to boot a Linux guest with Virtio devices since late July. Being an RFC sereis, this implements only the absolutely necessary components to get things running. I will break down this series a bit. A large portion of this series consists of patches that augment hyperv-tlfs.h. They should be rather uncontroversial and can be applied right away. A few key things other than the changes to hyperv-tlfs.h: 1. Linux needs to setup existing Hyper-V facilities differently. 2. Linux needs to make a few hypercalls to bring up APs. 3. Interrupts are remapped by IOMMU, which is controlled by the hypervisor. Linux needs to make hypercalls to map and unmap interrupts. This is done by introducing a new MSI irqdomain and new irqchips. #3 is perhaps the thing that we feel least confident about. We drew inspiration from the Xen code in Linux. We are of course open to criticism and sugguestions on how to make it better / acceptable to upstream. We're aware of tglx's series to change some of the MSI code, so we may need to change some of the code after that series is upstreamed. But it wouldn't hurt to throw this out as soon as possible for feedback. Comments and suggestions are welcome. Thanks, Wei. [0] Just think of it like Xen's Dom0. [1] Hyper-V is more well-known, but it really refers to the whole stack including the hypervisor and other components that run in Windows kernel and userspace. [3] https://github.com/cloud-hypervisor/ Cc: x86@xxxxxxxxxx Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Cc: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx> Cc: Nuno Das Neves <nudasnev@xxxxxxxxxxxxx> Cc: Vineeth Pillai <viremana@xxxxxxxxxxxxxxxxxxx> Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> Wei Liu (18): asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT x86/hyperv: detect if Linux is the root partition Drivers: hv: vmbus: skip VMBus initialization if Linux is root iommu/hyperv: don't setup IRQ remapping when running as root clocksource/hyperv: use MSR-based access if running as root x86/hyperv: allocate output arg pages if required x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary x86/hyperv: handling hypercall page setup for root x86/hyperv: provide a bunch of helper functions x86/hyperv: implement and use hv_smp_prepare_cpus asm-generic/hyperv: update hv_msi_entry asm-generic/hyperv: update hv_interrupt_entry asm-generic/hyperv: introduce hv_device_id and auxiliary structures asm-generic/hyperv: import data structures for mapping device interrupts x86/apic/msi: export pci_msi_get_hwirq x86/hyperv: implement MSI domain for root partition x86/ioapic: export a few functions and data structures via io_apic.h x86/hyperv: handle IO-APIC when running as root arch/x86/hyperv/Makefile | 4 +- arch/x86/hyperv/hv_init.c | 126 +++++- arch/x86/hyperv/hv_proc.c | 209 ++++++++++ arch/x86/hyperv/irqdomain.c | 580 ++++++++++++++++++++++++++++ arch/x86/include/asm/hyperv-tlfs.h | 23 ++ arch/x86/include/asm/io_apic.h | 20 + arch/x86/include/asm/mshyperv.h | 13 +- arch/x86/include/asm/msi.h | 3 + arch/x86/kernel/apic/io_apic.c | 28 +- arch/x86/kernel/apic/msi.c | 3 +- arch/x86/kernel/cpu/mshyperv.c | 43 +++ drivers/clocksource/hyperv_timer.c | 3 + drivers/hv/vmbus_drv.c | 3 + drivers/iommu/hyperv-iommu.c | 3 +- drivers/pci/controller/pci-hyperv.c | 2 +- include/asm-generic/hyperv-tlfs.h | 243 +++++++++++- 16 files changed, 1268 insertions(+), 38 deletions(-) create mode 100644 arch/x86/hyperv/hv_proc.c create mode 100644 arch/x86/hyperv/irqdomain.c -- 2.20.1