diff options
| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2018-04-25 22:04:19 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-22 16:57:59 +0200 |
| commit | cf21f58ae6f264e0a10d9736be97342627cf9837 (patch) | |
| tree | a034219c26f05bafdceb6363388f5427503a2b84 /drivers/base | |
| parent | 0f5dd651397b264903e8becc511af6cf384c273e (diff) | |
x86/bugs, KVM: Support the combination of guest and host IBRS
commit 5cf687548705412da47c9cec342fd952d71ed3d5 upstream
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>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
0 files changed, 0 insertions, 0 deletions