commit 86bdd16e8f390d51bae9e77a4bc4164ca2f580fe upstream.

The Hyper-V vPCI MSI irqchip never installs an irq_retrigger() callback.

On CPU hot-unplug fixup_irqs() migrates the interrupts which are affine to
the outgoing CPU to a new target. If an interrupt still has its pending bit
set in the outgoing CPU's IRR at that point, fixup_irqs() resends it on the
new target through the irqchip's irq_retrigger() callback. As the Hyper-V
PCI/MSI chip does not provide that callback, the pending interrupt is
silently dropped, which can result in lost interrupts, stalls and "No irq
handler for vector" messages during CPU hotplug.

Install irq_chip_retrigger_hierarchy() as the irq_retrigger() callback for
the Hyper-V PCI/MSI irqchip, so that a pending interrupt is resent on its
new target CPU via the parent x86 vector domain.

Fixes: 4daace0d8ce85 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Cc: stable@vger.kernel.org
Suggested-by: Long Li <longli@microsoft.com>
Suggested-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Aditya Garg <gargaditya@linux.microsoft.com>
Reviewed-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 7b3b1e5a87b2f5e35c52b5386d7c327be869454f ]

When hv_pci_assign_numa_node() processes a device that does not have
HV_PCI_DEVICE_FLAG_NUMA_AFFINITY set or has an out-of-range
virtual_numa_node, the device NUMA node is left unset. On x86_64,
the uninitialized default happens to be 0, but on ARM64 it is
NUMA_NO_NODE (-1).

Tests show that when no NUMA information is available from the Hyper-V
host, devices perform best when assigned to node 0. With NUMA_NO_NODE
the kernel may spread work across NUMA nodes, which degrades
performance on Hyper-V, particularly for high-throughput devices like
MANA.

Always set the device NUMA node to 0 before the conditional NUMA
affinity check, so that devices get a performant default when the host
provides no NUMA information, and behavior is consistent on both
x86_64 and ARM64.

Fixes: 999dd956d838 ("PCI: hv: Add support for protocol 1.3 and support PCI_BUS_RELATIONS2")
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

The 'info' parameter of hv_msi_free() is unused. Delete it.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Wei Liu <wei.liu@kernel.org>

Cross-merge networking fixes after downstream PR (net-6.16-rc8).

Conflicts:

drivers/net/ethernet/microsoft/mana/gdma_main.c
  9669ddda18fb ("net: mana: Fix warnings for missing export.h header inclusion")
  755391121038 ("net: mana: Allocate MSI-X vectors dynamically")
https://lore.kernel.org/20250711130752.23023d98@canb.auug.org.au

Adjacent changes:

drivers/net/ethernet/ti/icssg/icssg_prueth.h
  6e86fb73de0f ("net: ti: icssg-prueth: Fix buffer allocation for ICSSG")
  ffe8a4909176 ("net: ti: icssg-prueth: Read firmware-names from device tree")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Running as nested root on MSHV imposes a different requirement
for the pci-hyperv controller.

In this setup, the interrupt will first come to the L1 (nested) hypervisor,
which will deliver it to the appropriate root CPU. Instead of issuing the
RETARGET hypercall, issue the MAP_DEVICE_INTERRUPT hypercall to L1 to
complete the setup.

Rename hv_arch_irq_unmask() to hv_irq_retarget_interrupt().

Co-developed-by: Jinank Jain <jinankjain@linux.microsoft.com>
Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com>
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/1752261532-7225-4-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1752261532-7225-4-git-send-email-nunodasneves@linux.microsoft.com>

Move away from the legacy MSI domain setup, switch to use
msi_create_parent_irq_domain().

While doing the conversion, I noticed that hv_compose_msi_msg() is doing
more than it is supposed to (composing message). This function also
allocates and populates struct tran_int_desc, which should be done in
hv_pcie_domain_alloc() instead. It works, but it is not the correct design.
However, I have no hardware to test such change, therefore I leave a TODO
note.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The root partition only uses VMBus when running nested.

When running on baremetal the Hyper-V PCI driver is not needed,
so do not initialize it.

Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/1751582677-30930-2-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1751582677-30930-2-git-send-email-nunodasneves@linux.microsoft.com>

Allow dynamic MSI-X vector allocation for pci_hyperv PCI controller
by adding support for the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN and using
pci_msix_prepare_desc() to prepare the MSI-X descriptors.

Feature support added for both x86 and ARM64

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Pull hyperv updates from Wei Liu:

 - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel)

 - Fixes for Hyper-V UIO driver (Long Li)

 - Fixes for Hyper-V PCI driver (Michael Kelley)

 - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley)

 - Documentation updates for Hyper-V VMBus (Michael Kelley)

 - Enhance logging for hv_kvp_daemon (Shradha Gupta)

* tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits)
  Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests
  Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir
  Documentation: hyperv: Update VMBus doc with new features and info
  PCI: hv: Remove unnecessary flex array in struct pci_packet
  Drivers: hv: Remove hv_alloc/free_* helpers
  Drivers: hv: Use kzalloc for panic page allocation
  uio_hv_generic: Align ring size to system page
  uio_hv_generic: Use correct size for interrupt and monitor pages
  Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary
  arch/x86: Provide the CPU number in the wakeup AP callback
  x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap()
  PCI: hv: Get vPCI MSI IRQ domain from DeviceTree
  ACPI: irq: Introduce acpi_get_gsi_dispatcher()
  Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()
  Drivers: hv: vmbus: Get the IRQ number from DeviceTree
  dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties
  arm64, x86: hyperv: Report the VTL the system boots in
  arm64: hyperv: Initialize the Virtual Trust Level field
  Drivers: hv: Provide arch-neutral implementation of get_vtl()
  Drivers: hv: Enable VTL mode for arm64
  ...

struct pci_packet contains a "message" field that is a flex array
of struct pci_message. struct pci_packet is usually followed by a
second struct in a containing struct that is defined locally in
individual functions in pci-hyperv.c. As such, the compiler
flag -Wflex-array-member-not-at-end (introduced in gcc-14) generates
multiple warnings such as:

drivers/pci/controller/pci-hyperv.c:3809:35: warning: structure
    containing a flexible array member is not at the end of another
    structure [-Wflex-array-member-not-at-end]

The Linux kernel intends to introduce this compiler flag in standard
builds, so the current code is problematic in generating these warnings.

The "message" field is used only to locate the start of the second
struct, and not as an array. Because the second struct can be
addressed directly, the "message" field is not really necessary.
Rather than try to fix its usage to meet the requirements of
-Wflex-array-member-not-at-end, just eliminate the field and
either directly reference the second struct, or use "pkt + 1"
when "pkt" is dynamically allocated.

Reported-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250514044440.48924-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250514044440.48924-1-mhklinux@outlook.com>