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Bail out of the loop in kvm_tdp_map_page() when a VM is dead. Otherwise, kvm_tdp_map_page() may get stuck in the kernel loop when there's only one vCPU in the VM (or if the other vCPUs are not executing ioctls), even if fatal errors have occurred. kvm_tdp_map_page() is called by the ioctl KVM_PRE_FAULT_MEMORY or the TDX ioctl KVM_TDX_INIT_MEM_REGION. It loops in the kernel whenever RET_PF_RETRY is returned. In the TDP MMU, kvm_tdp_mmu_map() always returns RET_PF_RETRY, regardless of the specific error code from tdp_mmu_set_spte_atomic(), tdp_mmu_link_sp(), or tdp_mmu_split_huge_page(). While this is acceptable in general cases where the only possible error code from these functions is -EBUSY, TDX introduces an additional error code, -EIO, due to SEAMCALL errors. Since this -EIO error is also a fatal error, check for VM dead in the kvm_tdp_map_page() to avoid unnecessary retries until a signal is pending. The error -EIO is uncommon and has not been observed in real workloads. Currently, it is only hypothetically triggered by bypassing the real SEAMCALL and faking an error in the SEAMCALL wrapper. Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Message-ID: <20250220102728.24546-1-yan.y.zhao@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.