diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2015-11-12 14:49:17 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-02-13 10:34:04 +0000 |
| commit | bc48f6f5a8c6d628a1af649306eaf906493bb986 (patch) | |
| tree | 135628ac9c6a1e278ca36392344950937a4b1342 /arch/x86 | |
| parent | 558c1f07308ed4bf6c74aa6432cce9f90cc0e221 (diff) | |
KVM: x86: expose MSR_TSC_AUX to userspace
commit 9dbe6cf941a6fe82933aef565e4095fb10f65023 upstream.
If we do not do this, it is not properly saved and restored across
migration. Windows notices due to its self-protection mechanisms,
and is very upset about it (blue screen of death).
Cc: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2:
- We didn't yet have the switch() in kvm_init_msr_list as MPX is not
supported at all
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/x86.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 80c6d6835805..d47d1537afc4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -834,7 +834,8 @@ static u32 msrs_to_save[] = { #ifdef CONFIG_X86_64 MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR, #endif - MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA + MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA, + MSR_TSC_AUX, }; static unsigned num_msrs_to_save; @@ -3867,6 +3868,20 @@ static void kvm_init_msr_list(void) for (i = j = KVM_SAVE_MSRS_BEGIN; i < ARRAY_SIZE(msrs_to_save); i++) { if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0) continue; + + /* + * Even MSRs that are valid in the host may not be exposed + * to the guests in some cases. + */ + switch (msrs_to_save[i]) { + case MSR_TSC_AUX: + if (!kvm_x86_ops->rdtscp_supported()) + continue; + break; + default: + break; + } + if (j < i) msrs_to_save[j] = msrs_to_save[i]; j++; |