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.
Marc Orr
authored
The nested_vmx_prepare_msr_bitmap() function doesn't directly guard the x2APIC MSR intercepts with the "virtualize x2APIC mode" MSR. As a result, we discovered the potential for a buggy or malicious L1 to get access to L0's x2APIC MSRs, via an L2, as follows. 1. L1 executes WRMSR(IA32_SPEC_CTRL, 1). This causes the spec_ctrl variable, in nested_vmx_prepare_msr_bitmap() to become true. 2. L1 disables "virtualize x2APIC mode" in VMCS12. 3. L1 enables "APIC-register virtualization" in VMCS12. Now, KVM will set VMCS02's x2APIC MSR intercepts from VMCS12, and then set "virtualize x2APIC mode" to 0 in VMCS02. Oops. This patch closes the leak by explicitly guarding VMCS02's x2APIC MSR intercepts with VMCS12's "virtualize x2APIC mode" control. The scenario outlined above and fix prescribed here, were verified with a related patch in kvm-unit-tests titled "Add leak scenario to virt_x2apic_mode_test". Note, it looks like this issue may have been introduced inadvertently during a merge---see 15303ba5. Signed-off-by:Marc Orr <marcorr@google.com> Reviewed-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
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| samples | ||
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| sound | ||
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| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README |