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author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2018-04-26 05:04:19 +0300 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2018-05-03 14:55:47 +0300 |
commit | 5cf687548705412da47c9cec342fd952d71ed3d5 (patch) | |
tree | 5b868ec35064f655e390b04a8ff520af0a660e7e /include/linux/cpu.h | |
parent | 1b86883ccb8d5d9506529d42dbe1a5257cb30b18 (diff) | |
download | linux-5cf687548705412da47c9cec342fd952d71ed3d5.tar.xz |
x86/bugs, KVM: Support the combination of guest and host IBRS
A guest may modify the SPEC_CTRL MSR from the value used by the
kernel. Since the kernel doesn't use IBRS, this means a value of zero is
what is needed in the host.
But the 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to
the other bits as reserved so the kernel should respect the boot time
SPEC_CTRL value and use that.
This allows to deal with future extensions to the SPEC_CTRL interface if
any at all.
Note: This uses wrmsrl() instead of native_wrmsl(). I does not make any
difference as paravirt will over-write the callq *0xfff.. with the wrmsrl
assembler code.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/cpu.h')
0 files changed, 0 insertions, 0 deletions