Longlimsft/mana eq rebase net next7 #2
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To prepare for assigning vPorts to dedicated MSIx vectors, removing EQ sharing among the vPorts and create dedicated EQs for each vPort. Move the EQ definition from struct mana_context to struct mana_port_context and change related support functions. Also, export mana_create_eq and mana_destroy_eq for use by MANA RDMA driver.
When querying the device, adjust the max number of queues to allow dedicated MSIx vectors for each vPort. The number of queues per vPort is clamped down to no less than 16. MSIx sharing among vPort is disabled by default and it is turned on only when it's not possible. Rename mana_query_device_cfg() to mana_gd_query_device_cfg() as it is used at GDMA device probe time for querying device capabilities.
To allow Ethernet EQ to share or use separate MSI and RDMA EQs on the same MSI, introduce gic context and allow driver to create an interrupt context on an assigned/unassigned MSI.
Replace the GDMA global interrupt setup code with new GIC functions.
Use GIC functions to create a dedicated interrupt context or acquire a shared interrupt context for this EQ.
Use the newly introduced GIC function to allocate interrupt context for EQs. Those interrupt contexts may be shared with Ethernet EQs. Now the driver supports allocating dedicated MSI for each EQ. Indicate this feature through driver capability bits.
With dedicated EQ created on each vPort and no longer shared between different net devices, move the NAPI code from CQ to EQ. This allows the driver to arm the EQ when NAPI is done, thus avoiding unncessary arming and results in less interrupts from the MANA device.
longlimsft
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5da3d94 ("PCI: mvebu: Use for_each_of_range() iterator for parsing "ranges"") simplified code by using the for_each_of_range() iterator, but it broke PCI enumeration on Turris Omnia (and probably other mvebu targets). Issue #1: To determine range.flags, of_pci_range_parser_one() uses bus->get_flags(), which resolves to of_bus_pci_get_flags(), which already returns an IORESOURCE bit field, and NOT the original flags from the "ranges" resource. Then mvebu_get_tgt_attr() attempts the very same conversion again. Remove the misinterpretation of range.flags in mvebu_get_tgt_attr(), to restore the intended behavior. Issue #2: The driver needs target and attributes, which are encoded in the raw address values of the "/soc/pcie/ranges" resource. According to of_pci_range_parser_one(), the raw values are stored in range.bus_addr and range.parent_bus_addr, respectively. range.cpu_addr is a translated version of range.parent_bus_addr, and not relevant here. Use the correct range structure member, to extract target and attributes. This restores the intended behavior. Fixes: 5da3d94 ("PCI: mvebu: Use for_each_of_range() iterator for parsing "ranges"") Reported-by: Jan Palus <[email protected]> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220479 Signed-off-by: Klaus Kudielka <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Tested-by: Tony Dinh <[email protected]> Tested-by: Jan Palus <[email protected]> Link: https://patch.msgid.link/[email protected]
longlimsft
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syzkaller has caught us red-handed once more, this time nesting regular
spinlocks behind raw spinlocks:
=============================
[ BUG: Invalid wait context ]
6.16.0-rc3-syzkaller-g7b8346bd9fce #0 Not tainted
-----------------------------
syz.0.29/3743 is trying to lock:
a3ff80008e2e9e18 (&xa->xa_lock#20){....}-{3:3}, at: vgic_put_irq+0xb4/0x190 arch/arm64/kvm/vgic/vgic.c:137
other info that might help us debug this:
context-{5:5}
3 locks held by syz.0.29/3743:
#0: a3ff80008e2e90a8 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vgic_destroy+0x50/0x624 arch/arm64/kvm/vgic/vgic-init.c:499
#1: a3ff80008e2e9fa0 (&kvm->arch.config_lock){+.+.}-{4:4}, at: kvm_vgic_destroy+0x5c/0x624 arch/arm64/kvm/vgic/vgic-init.c:500
#2: 58f0000021be1428 (&vgic_cpu->ap_list_lock){....}-{2:2}, at: vgic_flush_pending_lpis+0x3c/0x31c arch/arm64/kvm/vgic/vgic.c:150
stack backtrace:
CPU: 0 UID: 0 PID: 3743 Comm: syz.0.29 Not tainted 6.16.0-rc3-syzkaller-g7b8346bd9fce #0 PREEMPT
Hardware name: linux,dummy-virt (DT)
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
__dump_stack+0x30/0x40 lib/dump_stack.c:94
dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
dump_stack+0x1c/0x28 lib/dump_stack.c:129
print_lock_invalid_wait_context kernel/locking/lockdep.c:4833 [inline]
check_wait_context kernel/locking/lockdep.c:4905 [inline]
__lock_acquire+0x978/0x299c kernel/locking/lockdep.c:5190
lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5871
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162
vgic_put_irq+0xb4/0x190 arch/arm64/kvm/vgic/vgic.c:137
vgic_flush_pending_lpis+0x24c/0x31c arch/arm64/kvm/vgic/vgic.c:158
__kvm_vgic_vcpu_destroy+0x44/0x500 arch/arm64/kvm/vgic/vgic-init.c:455
kvm_vgic_destroy+0x100/0x624 arch/arm64/kvm/vgic/vgic-init.c:505
kvm_arch_destroy_vm+0x80/0x138 arch/arm64/kvm/arm.c:244
kvm_destroy_vm virt/kvm/kvm_main.c:1308 [inline]
kvm_put_kvm+0x800/0xff8 virt/kvm/kvm_main.c:1344
kvm_vm_release+0x58/0x78 virt/kvm/kvm_main.c:1367
__fput+0x4ac/0x980 fs/file_table.c:465
____fput+0x20/0x58 fs/file_table.c:493
task_work_run+0x1bc/0x254 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
do_notify_resume+0x1b4/0x270 arch/arm64/kernel/entry-common.c:151
exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]
el0_svc+0xb4/0x160 arch/arm64/kernel/entry-common.c:768
el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
This is of course no good, but is at odds with how LPI refcounts are
managed. Solve the locking mess by deferring the release of unreferenced
LPIs after the ap_list_lock is released. Mark these to-be-released LPIs
specially to avoid racing with vgic_put_irq() and causing a double-free.
Since references can only be taken on LPIs with a nonzero refcount,
extending the lifetime of freed LPIs is still safe.
Reviewed-by: Marc Zyngier <[email protected]>
Reported-by: [email protected]
Closes: https://lore.kernel.org/kvmarm/[email protected]/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Oliver Upton <[email protected]>
longlimsft
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Nov 19, 2025
…ostcopy When you run a KVM guest with vhost-net and migrate that guest to another host, and you immediately enable postcopy after starting the migration, there is a big chance that the network connection of the guest won't work anymore on the destination side after the migration. With a debug kernel v6.16.0, there is also a call trace that looks like this: FAULT_FLAG_ALLOW_RETRY missing 881 CPU: 6 UID: 0 PID: 549 Comm: kworker/6:2 Kdump: loaded Not tainted 6.16.0 torvalds#56 NONE Hardware name: IBM 3931 LA1 400 (LPAR) Workqueue: events irqfd_inject [kvm] Call Trace: [<00003173cbecc634>] dump_stack_lvl+0x104/0x168 [<00003173cca69588>] handle_userfault+0xde8/0x1310 [<00003173cc756f0c>] handle_pte_fault+0x4fc/0x760 [<00003173cc759212>] __handle_mm_fault+0x452/0xa00 [<00003173cc7599ba>] handle_mm_fault+0x1fa/0x6a0 [<00003173cc73409a>] __get_user_pages+0x4aa/0xba0 [<00003173cc7349e8>] get_user_pages_remote+0x258/0x770 [<000031734be6f052>] get_map_page+0xe2/0x190 [kvm] [<000031734be6f910>] adapter_indicators_set+0x50/0x4a0 [kvm] [<000031734be7f674>] set_adapter_int+0xc4/0x170 [kvm] [<000031734be2f268>] kvm_set_irq+0x228/0x3f0 [kvm] [<000031734be27000>] irqfd_inject+0xd0/0x150 [kvm] [<00003173cc00c9ec>] process_one_work+0x87c/0x1490 [<00003173cc00dda6>] worker_thread+0x7a6/0x1010 [<00003173cc02dc36>] kthread+0x3b6/0x710 [<00003173cbed2f0c>] __ret_from_fork+0xdc/0x7f0 [<00003173cdd737ca>] ret_from_fork+0xa/0x30 3 locks held by kworker/6:2/549: #0: 00000000800bc958 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7ee/0x1490 #1: 000030f3d527fbd0 ((work_completion)(&irqfd->inject)){+.+.}-{0:0}, at: process_one_work+0x81c/0x1490 #2: 00000000f99862b0 (&mm->mmap_lock){++++}-{3:3}, at: get_map_page+0xa8/0x190 [kvm] The "FAULT_FLAG_ALLOW_RETRY missing" indicates that handle_userfaultfd() saw a page fault request without ALLOW_RETRY flag set, hence userfaultfd cannot remotely resolve it (because the caller was asking for an immediate resolution, aka, FAULT_FLAG_NOWAIT, while remote faults can take time). With that, get_map_page() failed and the irq was lost. We should not be strictly in an atomic environment here and the worker should be sleepable (the call is done during an ioctl from userspace), so we can allow adapter_indicators_set() to just sleep waiting for the remote fault instead. Link: https://issues.redhat.com/browse/RHEL-42486 Signed-off-by: Peter Xu <[email protected]> [thuth: Assembled patch description and fixed some cosmetical issues] Signed-off-by: Thomas Huth <[email protected]> Reviewed-by: Claudio Imbrenda <[email protected]> Acked-by: Janosch Frank <[email protected]> Fixes: f654706 ("KVM: s390/interrupt: do not pin adapter interrupt pages") [frankja: Added fixes tag] Signed-off-by: Janosch Frank <[email protected]>
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The MANA driver uses shared EQs for all the vPorts. This presents
two problems:
This patchset creates dedicated EQs for each vPort, and depending on the
MANA hardware MSI capability it creates dedicated or shared MSI for each EQ.
When dedicated MSIs are created for vPort, the system allows a user to isolate
vPort interrupt activity by binding certain CPUs to certain vPorts.
With dedicated EQ created on each vPort, move NAPI from CQ to EQ when
serving interrupts. This allows the driver to arm the EQ only when NAPI is
completed, reducing the number of interrupts from MANA hardware.
The changes only appl to the MANA Ethernet device, the HWC and RDMA
device behavior remains unchanged. The HWC continues to use MSI 0. The
RDMA device continue to use MSI 0 for hardware event queue, and MSI 1 through
supported number of completion vectors for EQs.