kernel/linux.git/drivers/xen, branch v6.6.39

drivers/xen: Improve the late XenStore init protocol

2024-06-12T09:12:51+00:00

[ Upstream commit a3607581cd49c17128a486a526a36a97bafcb2bb ] Currently, the late XenStore init protocol is only triggered properly for the case that HVM_PARAM_STORE_PFN is ~0ULL (invalid). For the case that XenStore interface is allocated but not ready (the connection status is not XENSTORE_CONNECTED), Linux should also wait until the XenStore is set up properly. Introduce a macro to describe the XenStore interface is ready, use it in xenbus_probe_initcall() to select the code path of doing the late XenStore init protocol or not. Since now we have more than one condition for XenStore late init, rework the check in xenbus_probe() for the free_irq(). Take the opportunity to enhance the check of the allocated XenStore interface can be properly mapped, and return error early if the memremap() fails. Fixes: 5b3353949e89 ("xen: add support for initializing xenstore later as HVM domain") Signed-off-by: Henry Wang Signed-off-by: Michal Orzel Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/20240517011516.1451087-1-xin.wang2@amd.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

x86/xen: attempt to inflate the memory balloon on PVH

2024-04-13T11:07:39+00:00

[ Upstream commit 38620fc4e8934f1801c7811ef39a041914ac4c1d ] When running as PVH or HVM Linux will use holes in the memory map as scratch space to map grants, foreign domain pages and possibly miscellaneous other stuff. However the usage of such memory map holes for Xen purposes can be problematic. The request of holesby Xen happen quite early in the kernel boot process (grant table setup already uses scratch map space), and it's possible that by then not all devices have reclaimed their MMIO space. It's not unlikely for chunks of Xen scratch map space to end up using PCI bridge MMIO window memory, which (as expected) causes quite a lot of issues in the system. At least for PVH dom0 we have the possibility of using regions marked as UNUSABLE in the e820 memory map. Either if the region is UNUSABLE in the native memory map, or it has been converted into UNUSABLE in order to hide RAM regions from dom0, the second stage translation page-tables can populate those areas without issues. PV already has this kind of logic, where the balloon driver is inflated at boot. Re-use the current logic in order to also inflate it when running as PVH. onvert UNUSABLE regions up to the ratio specified in EXTRA_MEM_RATIO to RAM, while reserving them using xen_add_extra_mem() (which is also moved so it's no longer tied to CONFIG_PV). [jgross: fixed build for CONFIG_PVH without CONFIG_XEN_PVH] Signed-off-by: Roger Pau Monné Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20240220174341.56131-1-roger.pau@citrix.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/events: increment refcnt only if event channel is refcounted

2024-03-26T22:20:09+00:00

[ Upstream commit d277f9d82802223f242cd9b60c988cfdda1d6be0 ] In bind_evtchn_to_irq_chip() don't increment the refcnt of the event channel blindly. In case the event channel is NOT refcounted, issue a warning instead. Add an additional safety net by doing the refcnt increment only if the caller has specified IRQF_SHARED in the irqflags parameter. Fixes: 9e90e58c11b7 ("xen: evtchn: Allow shared registration of IRQ handers") Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Link: https://lore.kernel.org/r/20240313071409.25913-3-jgross@suse.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/evtchn: avoid WARN() when unbinding an event channel

2024-03-26T22:20:09+00:00

[ Upstream commit 51c23bd691c0f1fb95b29731c356c6fd69925d17 ] When unbinding a user event channel, the related handler might be called a last time in case the kernel was built with CONFIG_DEBUG_SHIRQ. This might cause a WARN() in the handler. Avoid that by adding an "unbinding" flag to struct user_event which will short circuit the handler. Fixes: 9e90e58c11b7 ("xen: evtchn: Allow shared registration of IRQ handers") Reported-by: Demi Marie Obenour Tested-by: Demi Marie Obenour Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Link: https://lore.kernel.org/r/20240313071409.25913-2-jgross@suse.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/events: fix error code in xen_bind_pirq_msi_to_irq()

2024-03-01T12:35:04+00:00

commit 7f3da4b698bcc21a6df0e7f114af71d53a3e26ac upstream. Return -ENOMEM if xen_irq_init() fails. currently the code returns an uninitialized variable or zero. Fixes: 5dd9ad32d775 ("xen/events: drop xen_allocate_irqs_dynamic()") Signed-off-by: Dan Carpenter Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/3b9ab040-a92e-4e35-b687-3a95890a9ace@moroto.mountain Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

xen/events: close evtchn after mapping cleanup

2024-03-01T12:34:58+00:00

[ Upstream commit fa765c4b4aed2d64266b694520ecb025c862c5a9 ] shutdown_pirq and startup_pirq are not taking the irq_mapping_update_lock because they can't due to lock inversion. Both are called with the irq_desc->lock being taking. The lock order, however, is first irq_mapping_update_lock and then irq_desc->lock. This opens multiple races: - shutdown_pirq can be interrupted by a function that allocates an event channel: CPU0 CPU1 shutdown_pirq { xen_evtchn_close(e) __startup_pirq { EVTCHNOP_bind_pirq -> returns just freed evtchn e set_evtchn_to_irq(e, irq) } xen_irq_info_cleanup() { set_evtchn_to_irq(e, -1) } } Assume here event channel e refers here to the same event channel number. After this race the evtchn_to_irq mapping for e is invalid (-1). - __startup_pirq races with __unbind_from_irq in a similar way. Because __startup_pirq doesn't take irq_mapping_update_lock it can grab the evtchn that __unbind_from_irq is currently freeing and cleaning up. In this case even though the event channel is allocated, its mapping can be unset in evtchn_to_irq. The fix is to first cleanup the mappings and then close the event channel. In this way, when an event channel gets allocated it's potential previous evtchn_to_irq mappings are guaranteed to be unset already. This is also the reverse order of the allocation where first the event channel is allocated and then the mappings are setup. On a 5.10 kernel prior to commit 3fcdaf3d7634 ("xen/events: modify internal [un]bind interfaces"), we hit a BUG like the following during probing of NVMe devices. The issue is that during nvme_setup_io_queues, pci_free_irq is called for every device which results in a call to shutdown_pirq. With many nvme devices it's therefore likely to hit this race during boot because there will be multiple calls to shutdown_pirq and startup_pirq are running potentially in parallel. ------------[ cut here ]------------ blkfront: xvda: barrier or flush: disabled; persistent grants: enabled; indirect descriptors: enabled; bounce buffer: enabled kernel BUG at drivers/xen/events/events_base.c:499! invalid opcode: 0000 [#1] SMP PTI CPU: 44 PID: 375 Comm: kworker/u257:23 Not tainted 5.10.201-191.748.amzn2.x86_64 #1 Hardware name: Xen HVM domU, BIOS 4.11.amazon 08/24/2006 Workqueue: nvme-reset-wq nvme_reset_work RIP: 0010:bind_evtchn_to_cpu+0xdf/0xf0 Code: 5d 41 5e c3 cc cc cc cc 44 89 f7 e8 2b 55 ad ff 49 89 c5 48 85 c0 0f 84 64 ff ff ff 4c 8b 68 30 41 83 fe ff 0f 85 60 ff ff ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00 RSP: 0000:ffffc9000d533b08 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006 RDX: 0000000000000028 RSI: 00000000ffffffff RDI: 00000000ffffffff RBP: ffff888107419680 R08: 0000000000000000 R09: ffffffff82d72b00 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000001ed R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff88bc8b500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000002610001 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? show_trace_log_lvl+0x1c1/0x2d9 ? show_trace_log_lvl+0x1c1/0x2d9 ? set_affinity_irq+0xdc/0x1c0 ? __die_body.cold+0x8/0xd ? die+0x2b/0x50 ? do_trap+0x90/0x110 ? bind_evtchn_to_cpu+0xdf/0xf0 ? do_error_trap+0x65/0x80 ? bind_evtchn_to_cpu+0xdf/0xf0 ? exc_invalid_op+0x4e/0x70 ? bind_evtchn_to_cpu+0xdf/0xf0 ? asm_exc_invalid_op+0x12/0x20 ? bind_evtchn_to_cpu+0xdf/0xf0 ? bind_evtchn_to_cpu+0xc5/0xf0 set_affinity_irq+0xdc/0x1c0 irq_do_set_affinity+0x1d7/0x1f0 irq_setup_affinity+0xd6/0x1a0 irq_startup+0x8a/0xf0 __setup_irq+0x639/0x6d0 ? nvme_suspend+0x150/0x150 request_threaded_irq+0x10c/0x180 ? nvme_suspend+0x150/0x150 pci_request_irq+0xa8/0xf0 ? __blk_mq_free_request+0x74/0xa0 queue_request_irq+0x6f/0x80 nvme_create_queue+0x1af/0x200 nvme_create_io_queues+0xbd/0xf0 nvme_setup_io_queues+0x246/0x320 ? nvme_irq_check+0x30/0x30 nvme_reset_work+0x1c8/0x400 process_one_work+0x1b0/0x350 worker_thread+0x49/0x310 ? process_one_work+0x350/0x350 kthread+0x11b/0x140 ? __kthread_bind_mask+0x60/0x60 ret_from_fork+0x22/0x30 Modules linked in: ---[ end trace a11715de1eee1873 ]--- Fixes: d46a78b05c0e ("xen: implement pirq type event channels") Cc: stable@vger.kernel.org Co-debugged-by: Andrew Panyakin Signed-off-by: Maximilian Heyne Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20240124163130.31324-1-mheyne@amazon.de Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/events: modify internal [un]bind interfaces

2024-03-01T12:34:58+00:00

[ Upstream commit 3fcdaf3d7634338c3f5cbfa7451eb0b6b0024844 ] Modify the internal bind- and unbind-interfaces to take a struct irq_info parameter. When allocating a new IRQ pass the pointer from the allocating function further up. This will reduce the number of info_for_irq() calls and make the code more efficient. Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Signed-off-by: Juergen Gross Stable-dep-of: fa765c4b4aed ("xen/events: close evtchn after mapping cleanup") Signed-off-by: Sasha Levin

xen/events: drop xen_allocate_irqs_dynamic()

2024-03-01T12:34:57+00:00

[ Upstream commit 5dd9ad32d7758b1a76742f394acf0eb3ac8a636a ] Instead of having a common function for allocating a single IRQ or a consecutive number of IRQs, split up the functionality into the callers of xen_allocate_irqs_dynamic(). This allows to handle any allocation error in xen_irq_init() gracefully instead of panicing the system. Let xen_irq_init() return the irq_info pointer or NULL in case of an allocation error. Additionally set the IRQ into irq_info already at allocation time, as otherwise the IRQ would be '0' (which is a valid IRQ number) until being set. Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Signed-off-by: Juergen Gross Stable-dep-of: fa765c4b4aed ("xen/events: close evtchn after mapping cleanup") Signed-off-by: Sasha Levin

xen/events: remove some simple helpers from events_base.c

2024-03-01T12:34:57+00:00

[ Upstream commit 3bdb0ac350fe5e6301562143e4573971dd01ae0b ] The helper functions type_from_irq() and cpu_from_irq() are just one line functions used only internally. Open code them where needed. At the same time modify and rename get_evtchn_to_irq() to return a struct irq_info instead of the IRQ number. Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Signed-off-by: Juergen Gross Stable-dep-of: fa765c4b4aed ("xen/events: close evtchn after mapping cleanup") Signed-off-by: Sasha Levin

xen/events: reduce externally visible helper functions

2024-03-01T12:34:57+00:00

[ Upstream commit 686464514fbebb6c8de4415238319e414c3500a4 ] get_evtchn_to_irq() has only one external user while irq_from_evtchn() provides the same functionality and is exported for a wider user base. Modify the only external user of get_evtchn_to_irq() to use irq_from_evtchn() instead and make get_evtchn_to_irq() static. evtchn_from_irq() and irq_from_virq() have a single external user and can easily be combined to a new helper irq_evtchn_from_virq() allowing to drop irq_from_virq() and to make evtchn_from_irq() static. Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Signed-off-by: Juergen Gross Stable-dep-of: fa765c4b4aed ("xen/events: close evtchn after mapping cleanup") Signed-off-by: Sasha Levin