diff options
| author | Andrew Cooper <andrew.cooper3@citrix.com> | 2022-01-19 19:55:02 +0000 |
|---|---|---|
| committer | Andrew Cooper <andrew.cooper3@citrix.com> | 2022-02-04 15:45:24 +0000 |
| commit | 5f27e51cce99c422a7e506f9a0eeda195b767464 (patch) | |
| tree | 91932e988b2a1d339d0cad4e2da0a6cd373cf367 /xen/include | |
| parent | 47dbbe3878a002bb9bfa7ab24c0e7dc57b894ac7 (diff) | |
x86/msr: Fix migration compatibility issue with MSR_SPEC_CTRL
This bug existed in early in 2018 between MSR_SPEC_CTRL arriving in microcode,
and SSBD arriving a few months later. It went unnoticed presumably because
everyone was busy rebooting everything.
The same bug will reappear when adding PSFD support.
Clamp the guest MSR_SPEC_CTRL value to that permitted by CPUID on migrate.
The guest is already playing with reserved bits at this point, and clamping
the value will prevent a migration to a less capable host from failing.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 969a57f73f6b011b2ebf4c0ab1715efc65837335)
Diffstat (limited to 'xen/include')
| -rw-r--r-- | xen/include/asm-x86/msr.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/xen/include/asm-x86/msr.h b/xen/include/asm-x86/msr.h index 10039c2d22..657a329561 100644 --- a/xen/include/asm-x86/msr.h +++ b/xen/include/asm-x86/msr.h @@ -277,6 +277,8 @@ static inline void wrmsr_tsc_aux(uint32_t val) } } +uint64_t msr_spec_ctrl_valid_bits(const struct cpuid_policy *cp); + extern struct msr_policy raw_msr_policy, host_msr_policy, pv_max_msr_policy, |