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Joao Martins c3ff24625a iommu/amd: Don't block updates to GATag if guest mode is on
[ Upstream commit ed8a2f4dde ]

On KVM GSI routing table updates, specially those where they have vIOMMUs
with interrupt remapping enabled (to boot >255vcpus setups without relying
on KVM_FEATURE_MSI_EXT_DEST_ID), a VMM may update the backing VF MSIs
with a new VCPU affinity.

On AMD with AVIC enabled, the new vcpu affinity info is updated via:
	avic_pi_update_irte()
		irq_set_vcpu_affinity()
			amd_ir_set_vcpu_affinity()
				amd_iommu_{de}activate_guest_mode()

Where the IRTE[GATag] is updated with the new vcpu affinity. The GATag
contains VM ID and VCPU ID, and is used by IOMMU hardware to signal KVM
(via GALog) when interrupt cannot be delivered due to vCPU is in
blocking state.

The issue is that amd_iommu_activate_guest_mode() will essentially
only change IRTE fields on transitions from non-guest-mode to guest-mode
and otherwise returns *with no changes to IRTE* on already configured
guest-mode interrupts. To the guest this means that the VF interrupts
remain affined to the first vCPU they were first configured, and guest
will be unable to issue VF interrupts and receive messages like this
from spurious interrupts (e.g. from waking the wrong vCPU in GALog):

[  167.759472] __common_interrupt: 3.34 No irq handler for vector
[  230.680927] mlx5_core 0000:00:02.0: mlx5_cmd_eq_recover:247:(pid
3122): Recovered 1 EQEs on cmd_eq
[  230.681799] mlx5_core 0000:00:02.0:
wait_func_handle_exec_timeout:1113:(pid 3122): cmd[0]: CREATE_CQ(0x400)
recovered after timeout
[  230.683266] __common_interrupt: 3.34 No irq handler for vector

Given the fact that amd_ir_set_vcpu_affinity() uses
amd_iommu_activate_guest_mode() underneath it essentially means that VCPU
affinity changes of IRTEs are nops. Fix it by dropping the check for
guest-mode at amd_iommu_activate_guest_mode(). Same thing is applicable to
amd_iommu_deactivate_guest_mode() although, even if the IRTE doesn't change
underlying DestID on the host, the VFIO IRQ handler will still be able to
poke at the right guest-vCPU.

Fixes: b9c6ff94e4 ("iommu/amd: Re-factor guest virtual APIC (de-)activation code")
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20230419201154.83880-2-joao.m.martins@oracle.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2023-06-09 10:33:59 +02:00
arch arm64: dts: imx8mn-var-som: fix PHY detection bug by adding deassert delay 2023-05-30 14:03:33 +01:00
block block: fix bio-cache for passthru IO 2023-06-05 09:26:21 +02:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: testmgr - fix RNG performance in fuzz tests 2023-05-24 17:32:53 +01:00
Documentation dt-binding: cdns,usb3: Fix cdns,on-chip-buff-size type 2023-05-30 14:03:19 +01:00
drivers iommu/amd: Don't block updates to GATag if guest mode is on 2023-06-09 10:33:59 +02:00
fs cifs: mapchars mount option ignored 2023-05-30 14:03:21 +01:00
include page_pool: fix inconsistency for page_pool_ring_[un]lock() 2023-06-05 09:26:20 +02:00
init gcc: disable '-Warray-bounds' for gcc-13 too 2023-04-26 14:28:43 +02:00
io_uring io_uring/rsrc: use nospec'ed indexes 2023-05-11 23:03:24 +09:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel x86/pci/xen: populate MSI sysfs entries 2023-05-30 14:03:22 +01:00
lib debugobjects: Don't wake up kswapd from fill_pool() 2023-05-30 14:03:20 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm: fix zswap writeback race condition 2023-05-24 17:32:51 +01:00
net netfilter: ctnetlink: Support offloaded conntrack entry deletion 2023-06-05 09:26:22 +02:00
rust rust: kernel: Mark rust_fmt_argument as extern "C" 2023-04-26 14:28:38 +02:00
samples samples/bpf: Fix fout leak in hbm's run_bpf_prog 2023-05-24 17:32:38 +01:00
scripts recordmcount: Fix memory leaks in the uwrite function 2023-05-24 17:32:41 +01:00
security selinux: ensure av_permissions.h is built when needed 2023-05-11 23:03:06 +09:00
sound ASoC: Intel: avs: Access path components under lock 2023-05-30 14:03:32 +01:00
tools tools headers UAPI: Sync the linux/in.h with the kernel sources 2023-06-05 09:26:22 +02:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Fix vcpu_array[0] races 2023-05-24 17:32:50 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS platform/x86: Move existing HP drivers to a new hp subdir 2023-05-24 17:32:42 +01:00
Makefile Linux 6.1.32 2023-06-05 09:26:22 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.