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David Woodhouse 8e62bf2bfa KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled
Linux guests since commit b1c3497e60 ("x86/xen: Add support for
HVMOP_set_evtchn_upcall_vector") in v6.0 onwards will use the per-vCPU
upcall vector when it's advertised in the Xen CPUID leaves.

This upcall is injected through the guest's local APIC as an MSI, unlike
the older system vector which was merely injected by the hypervisor any
time the CPU was able to receive an interrupt and the upcall_pending
flags is set in its vcpu_info.

Effectively, that makes the per-CPU upcall edge triggered instead of
level triggered, which results in the upcall being lost if the MSI is
delivered when the local APIC is *disabled*.

Xen checks the vcpu_info->evtchn_upcall_pending flag when the local APIC
for a vCPU is software enabled (in fact, on any write to the SPIV
register which doesn't disable the APIC). Do the same in KVM since KVM
doesn't provide a way for userspace to intervene and trap accesses to
the SPIV register of a local APIC emulated by KVM.

Fixes: fde0451be8 ("KVM: x86/xen: Support per-vCPU event channel upcall via local APIC")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240227115648.3104-3-dwmw2@infradead.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-03-04 16:22:36 -08:00
arch KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled 2024-03-04 16:22:36 -08:00
block block: Fix where bio IO priority gets set 2024-02-01 11:00:06 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: algif_hash - Remove bogus SGL free on zero-length error path 2024-02-02 18:08:12 +08:00
Documentation KVM: x86/xen: allow vcpu_info to be mapped by fixed HVA 2024-02-22 07:01:17 -08:00
drivers This push fixes regressions in cbc and algif_hash, as well as an 2024-02-08 06:12:14 +00:00
fs nfsd-6.8 fixes: 2024-02-07 17:48:15 +00:00
include KVM: pfncache: allow a cache to be activated with a fixed (userspace) HVA 2024-02-20 07:37:46 -08:00
init Kconfig: Disable -Wstringop-overflow for GCC globally 2024-02-01 14:57:17 -08:00
io_uring io_uring/net: fix sr->len for IORING_OP_RECV with MSG_WAITALL and buffers 2024-02-01 06:42:36 -07:00
ipc shm: Slim down dependencies 2023-12-20 19:26:31 -05:00
kernel Tracing and eventfs fixes for v6.8: 2024-02-02 15:32:58 -08:00
lib linux_kselftest-kunit-fixes-6.8-rc3 2024-01-30 15:12:58 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm 22 hotfixes. 11 are cc:stable and the remainder address post-6.7 issues 2024-01-29 17:12:16 -08:00
net Including fixes from netfilter. 2024-02-01 12:39:54 -08:00
rust Rust changes for v6.8 2024-01-11 13:05:41 -08:00
samples samples/cgroup: add .gitignore file for generated samples 2024-01-24 11:52:40 -08:00
scripts Kbuild fixes for v6.8 2024-02-01 11:57:42 -08:00
security lsm/stable-6.8 PR 20240131 2024-02-01 10:00:28 -08:00
sound ASoC: Fixes for v6.8 2024-02-01 19:40:42 +01:00
tools KVM: selftests: re-map Xen's vcpu_info using HVA rather than GPA 2024-02-22 07:01:19 -08:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM: pfncache: check the need for invalidation under read lock first 2024-02-22 07:01:20 -08:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.mailmap Char/Misc and other Driver changes for 6.8-rc1 2024-01-17 16:47:17 -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: supplement of zswap maintainers update 2024-01-25 23:52:21 -08:00
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 MAINTAINERS update to point people to the new tree for i2c host driver 2024-02-04 06:47:45 +00:00
Makefile Linux 6.8-rc3 2024-02-04 12:20:36 +00:00
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.