Jan Kiszka <jan.kiszka@xxxxxxxxxxx> writes:
> On 2014-03-20 04:28, Bandan Das wrote:
>> Some L1 hypervisors such as Xen seem to be calling invept after
>> vmclear or before vmptrld on L2. In this case, proceed with
>> falling through and syncing roots as a case where
>> context wide invalidation can't be supported
>
> Can we also base this behaviour on a statement in the SDM? But on first
> glance, I do not find anything like this over there.
The SDM has nothing of this sort explicitly mentioned but 28.3.3.1
"Operations that invalidate Cached Mappings" does mention that
the instruction may invalidate mappings associated with other
EP4TAs (even in single context).
Note that I based this on what we currently do for context invalidation -
static inline void ept_sync_context(u64 eptp)
{
if (enable_ept) {
if (cpu_has_vmx_invept_context())
__invept(VMX_EPT_EXTENT_CONTEXT, eptp, 0);
else
ept_sync_global();
}
}
Seemed easier and cleaner than having a cached eptp after vmcs12 is
long gone :)
If you prefer, I can modify the commit message to reflect this.
> Jan
>
>>
>> Signed-off-by: Bandan Das <bsd@xxxxxxxxxx>
>> ---
>> arch/x86/kvm/vmx.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index c707389..b407b3a 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -6435,8 +6435,9 @@ static int handle_invept(struct kvm_vcpu *vcpu)
>>
>> switch (type) {
>> case VMX_EPT_EXTENT_CONTEXT:
>> - if ((operand.eptp & eptp_mask) !=
>> - (nested_ept_get_cr3(vcpu) & eptp_mask))
>> + if (get_vmcs12(vcpu) &&
>> + ((operand.eptp & eptp_mask) != (nested_ept_get_cr3(vcpu) &
>> + eptp_mask)))
>> break;
>> case VMX_EPT_EXTENT_GLOBAL:
>> kvm_mmu_sync_roots(vcpu);
>>
--
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