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A mirror of the official Linux kernel repository just in case
c4d2188206
The CPUID bits of OSXSAVE (function=0x1) and OSPKE (func=0x7, leaf=0x0) allows user apps to detect if OS has set CR4.OSXSAVE or CR4.PKE. KVM is supposed to update these CPUID bits when CR4 is updated. Current KVM code doesn't handle some special cases when updates come from emulator. Here is one example: Step 1: guest boots Step 2: guest OS enables XSAVE ==> CR4.OSXSAVE=1 and CPUID.OSXSAVE=1 Step 3: guest hot reboot ==> QEMU reset CR4 to 0, but CPUID.OSXAVE==1 Step 4: guest os checks CPUID.OSXAVE, detects 1, then executes xgetbv Step 4 above will cause an #UD and guest crash because guest OS hasn't turned on OSXAVE yet. This patch solves the problem by comparing the the old_cr4 with cr4. If the related bits have been changed, kvm_update_cpuid() needs to be called. Signed-off-by: Wei Huang <wei@redhat.com> Reviewed-by: Bandan Das <bsd@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> |
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| certs | ||
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| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| 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 Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
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.