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Manuel Andreas f1b3ad11ec KVM: x86/hyper-v: Skip non-canonical addresses during PV TLB flush
[ Upstream commit fa787ac07b ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 #14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 260970862c ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: stable@vger.kernel.org
Signed-off-by: Manuel Andreas <manuel.andreas@tum.de>
Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/c090efb3-ef82-499f-a5e0-360fc8420fb7@tum.de
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-08-01 09:48:46 +01:00
arch KVM: x86/hyper-v: Skip non-canonical addresses during PV TLB flush 2025-08-01 09:48:46 +01:00
block block: fix kobject leak in blk_unregister_queue 2025-07-24 08:56:30 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP() 2025-07-17 18:37:24 +02:00
Documentation bpf: Adjust free target to avoid global starvation of LRU map 2025-07-17 18:37:22 +02:00
drivers mtd: rawnand: qcom: Fix last codeword read in qcom_param_page_type_exec() 2025-08-01 09:48:45 +01:00
fs ext4: fix out of bounds punch offset 2025-08-01 09:48:46 +01:00
include sprintf.h requires stdarg.h 2025-08-01 09:48:43 +01:00
init rust: clean Rust 1.88.0's unnecessary_transmutes lint 2025-05-18 08:24:51 +02:00
io_uring io_uring/poll: fix POLLERR handling 2025-07-24 08:56:23 +02:00
ipc ipc: fix to protect IPCS lookups using RCU 2025-06-27 11:11:22 +01:00
kernel selftests/bpf: Add tests with stack ptr register in conditional jmp 2025-08-01 09:48:44 +01:00
lib lib/alloc_tag: do not acquire non-existent lock in alloc_tag_top_users() 2025-07-17 18:37:14 +02:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm/zsmalloc: do not pass __GFP_MOVABLE if CONFIG_COMPACTION=n 2025-08-01 09:48:44 +01:00
net net/sched: sch_qfq: Avoid triggering might_sleep in atomic context in qfq_delete_class 2025-08-01 09:48:41 +01:00
rust rust: use #[used(compiler)] to fix build and modpost with Rust >= 1.89.0 2025-07-24 08:56:37 +02:00
samples samples/bpf: Fix compilation failure for samples/bpf on LoongArch Fedora 2025-05-29 11:02:01 +02:00
scripts rust: use #[used(compiler)] to fix build and modpost with Rust >= 1.89.0 2025-07-24 08:56:37 +02:00
security selinux: change security_compute_sid to return the ssid or tsid on match 2025-07-10 16:05:04 +02:00
sound ALSA: hda/realtek - Add mute LED support for HP Victus 15-fa0xxx 2025-08-01 09:48:43 +01:00
tools selftests/bpf: Add tests with stack ptr register in conditional jmp 2025-08-01 09:48:44 +01:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-13 13:02:18 +01:00
virt KVM: Allow CPU to reschedule while setting per-page memory attributes 2025-07-17 18:37:08 +02:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-08-01 09:48:44 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: introduce .clippy.toml 2025-03-13 13:01:42 +01:00
.mailmap mailmap: add entry for Thorsten Blum 2024-11-07 14:14:59 -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 self from DSA entry 2024-11-03 12:52:38 -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 Alexey Makhalov's email address 2025-05-22 14:29:46 +02:00
Makefile Linux 6.12.40 2025-07-24 08:56:38 +02:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.