The hypercall in hv_mark_gpa_visibility() is invoked with an input argument and an output argument. The output argument ostensibly returns the number of pages that were processed. But in fact, the hypercall does not provide any output, so the output argument is spurious. The spurious argument is harmless because Hyper-V ignores it, but in the interest of correctness and to avoid the potential for future problems, remove it. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/20250226200612.2062-2-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250226200612.2062-2-mhklinux@outlook.com>
For Linux, running in Hyper-V VTL (Virtual Trust Level), kernel in VTL2 tries to access VTL0 low memory in probe_roms. This memory is not described in the e820 map. Initialize probe_roms call to no-ops during boot for VTL2 kernel to avoid this. The issue got identified in OpenVMM which detects invalid accesses initiated from kernel running in VTL2. Co-developed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Tested-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/20250116061224.1701-1-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250116061224.1701-1-namjain@linux.microsoft.com>
Pull hyperv updates from Wei Liu: - Introduce a new set of Hyper-V headers in include/hyperv and replace the old hyperv-tlfs.h with the new headers (Nuno Das Neves) - Fixes for the Hyper-V VTL mode (Roman Kisel) - Fixes for cpu mask usage in Hyper-V code (Michael Kelley) - Document the guest VM hibernation behaviour (Michael Kelley) - Miscellaneous fixes and cleanups (Jacob Pan, John Starks, Naman Jain) * tag 'hyperv-next-signed-20250123' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Documentation: hyperv: Add overview of guest VM hibernation hyperv: Do not overlap the hvcall IO areas in hv_vtl_apicid_to_vp_id() hyperv: Do not overlap the hvcall IO areas in get_vtl() hyperv: Enable the hypercall output page for the VTL mode hv_balloon: Fallback to generic_online_page() for non-HV hot added mem Drivers: hv: vmbus: Log on missing offers if any Drivers: hv: vmbus: Wait for boot-time offers during boot and resume uio_hv_generic: Add a check for HV_NIC for send, receive buffers setup iommu/hyper-v: Don't assume cpu_possible_mask is dense Drivers: hv: Don't assume cpu_possible_mask is dense x86/hyperv: Don't assume cpu_possible_mask is dense hyperv: Remove the now unused hyperv-tlfs.h files hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h hyperv: Add new Hyper-V headers in include/hyperv hyperv: Clean up unnecessary #includes hyperv: Move hv_connection_id to hyperv-tlfs.h
Pull interrupt subsystem updates from Thomas Gleixner: - Consolidate the machine_kexec_mask_interrupts() by providing a generic implementation and replacing the copy & pasta orgy in the relevant architectures. - Prevent unconditional operations on interrupt chips during kexec shutdown, which can trigger warnings in certain cases when the underlying interrupt has been shut down before. - Make the enforcement of interrupt handling in interrupt context unconditionally available, so that it actually works for non x86 related interrupt chips. The earlier enablement for ARM GIC chips set the required chip flag, but did not notice that the check was hidden behind a config switch which is not selected by ARM[64]. - Decrapify the handling of deferred interrupt affinity setting. Some interrupt chips require that affinity changes are made from the context of handling an interrupt to avoid certain race conditions. For x86 this was the default, but with interrupt remapping this requirement was lifted and a flag was introduced which tells the core code that affinity changes can be done in any context. Unrestricted affinity changes are the default for the majority of interrupt chips. RISCV has the requirement to add the deferred mode to one of it's interrupt controllers, but with the original implementation this would require to add the any context flag to all other RISC-V interrupt chips. That's backwards, so reverse the logic and require that chips, which need the deferred mode have to be marked accordingly. That avoids chasing the 'sane' chips and marking them. - Add multi-node support to the Loongarch AVEC interrupt controller driver. - The usual tiny cleanups, fixes and improvements all over the place. * tag 'irq-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/generic_chip: Export irq_gc_mask_disable_and_ack_set() genirq/timings: Add kernel-doc for a function parameter genirq: Remove IRQ_MOVE_PCNTXT and related code x86/apic: Convert to IRQCHIP_MOVE_DEFERRED genirq: Provide IRQCHIP_MOVE_DEFERRED hexagon: Remove GENERIC_PENDING_IRQ leftover ARC: Remove GENERIC_PENDING_IRQ genirq: Remove handle_enforce_irqctx() wrapper genirq: Make handle_enforce_irqctx() unconditionally available irqchip/loongarch-avec: Add multi-nodes topology support irqchip/ts4800: Replace seq_printf() by seq_puts() irqchip/ti-sci-inta : Add module build support irqchip/ti-sci-intr: Add module build support irqchip/irq-brcmstb-l2: Replace brcmstb_l2_mask_and_ack() by generic function irqchip: keystone: Use syscon_regmap_lookup_by_phandle_args genirq/kexec: Prevent redundant IRQ masking by checking state before shutdown kexec: Consolidate machine_kexec_mask_interrupts() implementation genirq: Reuse irq_thread_fn() for forced thread case genirq: Move irq_thread_fn() further up in the code
Instead of marking individual interrupts as safe to be migrated in arbitrary contexts, mark the interrupt chips, which require the interrupt to be moved in actual interrupt context, with the new IRQCHIP_MOVE_DEFERRED flag. This makes more sense because this is a per interrupt chip property and not restricted to individual interrupts. That flips the logic from the historical opt-out to a opt-in model. This is simpler to handle for other architectures, which default to unrestricted affinity setting. It also allows to cleanup the redundant core logic significantly. All interrupt chips, which belong to a top-level domain sitting directly on top of the x86 vector domain are marked accordingly, unless the related setup code marks the interrupts with IRQ_MOVE_PCNTXT, i.e. XEN. No functional change intended. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steve Wahl <steve.wahl@hpe.com> Acked-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/all/20241210103335.563277044@linutronix.de
The Top-Level Functional Specification for Hyper-V, Section 3.6 [1, 2], disallows overlapping of the input and output hypercall areas, and hv_vtl_apicid_to_vp_id() overlaps them. Use the output hypercall page of the current vCPU for the hypercall. [1] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/hypercall-interface [2] https://github.com/MicrosoftDocs/Virtualization-Documentation/tree/main/tlfs Reported-by: Michael Kelley <mhklinux@outlook.com> Closes: https://lore.kernel.org/lkml/SN6PR02MB4157B98CD34781CC87A9D921D40D2@SN6PR02MB4157.namprd02.prod.outlook.com/ Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/20250108222138.1623703-6-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250108222138.1623703-6-romank@linux.microsoft.com>
The Top-Level Functional Specification for Hyper-V, Section 3.6 [1, 2],
disallows overlapping of the input and output hypercall areas, and
get_vtl(void) does overlap them.
Use the output hypercall page of the current vCPU for the hypercall.
[1] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/hypercall-interface
[2] https://github.com/MicrosoftDocs/Virtualization-Documentation/tree/main/tlfs
Fixes: 8387ce06d70b ("x86/hyperv: Set Virtual Trust Level in VMBus init message")
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250108222138.1623703-5-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250108222138.1623703-5-romank@linux.microsoft.com>
Current code allocates the hv_vp_assist_page array with size num_possible_cpus(). This code assumes cpu_possible_mask is dense, which is not true in the general case per [1]. If cpu_possible_mask is sparse, the array might be indexed by a value beyond the size of the array. However, the configurations that Hyper-V provides to guest VMs on x86 hardware, in combination with how x86 code assigns Linux CPU numbers, *does* always produce a dense cpu_possible_mask. So the dense assumption is not currently causing failures. But for robustness against future changes in how cpu_possible_mask is populated, update the code to no longer assume dense. The correct approach is to allocate the array with size "nr_cpu_ids". While this leaves unused array entries corresponding to holes in cpu_possible_mask, the holes are assumed to be minimal and hence the amount of memory wasted by unused entries is minimal. [1] https://lore.kernel.org/lkml/SN6PR02MB4157210CC36B2593F8572E5ED4692@SN6PR02MB4157.namprd02.prod.outlook.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241003035333.49261-2-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241003035333.49261-2-mhklinux@outlook.com>
Switch to using hvhdk.h everywhere in the kernel. This header includes all the new Hyper-V headers in include/hyperv, which form a superset of the definitions found in hyperv-tlfs.h. This makes it easier to add new Hyper-V interfaces without being restricted to those in the TLFS doc (reflected in hyperv-tlfs.h). To be more consistent with the original Hyper-V code, the names of some definitions are changed slightly. Update those where needed. Update comments in mshyperv.h files to point to include/hyperv for adding new definitions. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Link: https://lore.kernel.org/r/1732577084-2122-5-git-send-email-nunodasneves@linux.microsoft.com Link: https://lore.kernel.org/r/20250108222138.1623703-3-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Remove includes of linux/hyperv.h, mshyperv.h, and hyperv-tlfs.h where they are not used. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Link: https://lore.kernel.org/r/1732577084-2122-3-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1732577084-2122-3-git-send-email-nunodasneves@linux.microsoft.com>