On 14/09/2021 11:12, Maxim Levitsky wrote:
On Tue, 2021-09-14 at 12:02 +0300, Maxim Levitsky wrote:
On Tue, 2021-09-14 at 10:20 +0200, Emanuele Giuseppe Esposito wrote:
On 12/09/2021 12:42, Maxim Levitsky wrote:
- if (!nested_vmcb_valid_sregs(vcpu, &vmcb12->save) ||
+ if (!nested_vmcb_valid_sregs(vcpu, &svm->nested.save) ||
!nested_vmcb_check_controls(vcpu, &svm->nested.ctl)) {
If you use a different struct for the copied fields, then it makes
sense IMHO to drop the 'control' parameter from nested_vmcb_check_controls,
and just use the svm->nested.save there directly.
Ok, what you say in patch 2 makes sense to me. I can create a new struct
vmcb_save_area_cached, but I need to keep nested.ctl because 1) it is
used also elsewhere, and different fields from the one checked here are
read/set and 2) using another structure (or the same
Yes, keep nested.ctl, since vast majority of the fields are copied I think.
But actually that you mention it, I'll say why not to create vmcb_control_area_cached
as well indeed and change the type of svm->nested.save to it. (in a separate patch)
I see what you mean that we modify it a bit (but we shoudn't to be honest) and such, but
all of this can be fixed.
So basically you are proposing:
struct svm_nested_state {
...
struct vmcb_control_area ctl; // we need this because it is used
everywhere, I think
struct vmcb_control_area_cached ctl_cached;
struct vmcb_save_area_cached save_cached;
...
}
and then
if (!nested_vmcb_valid_sregs(vcpu, &svm->nested.save_cached) ||
!nested_vmcb_check_controls(vcpu, &svm->nested.ctl_cached)) {
like that?
Or do you want to delete nested.ctl completely and just keep the fields
actually used in ctl_cached?
Also, note that as I am trying to use vmcb_save_area_cached, it is worth
noticing that nested_vmcb_valid_sregs() is also used in
svm_set_nested_state(), so it requires some additional little changes.
Thank you,
Emanuele
The advantage of having vmcb_control_area_cached is that it becomes impossible to use
by mistake a non copied field from the guest.
It would also emphasize that this stuff came from the guest and should be treated as
a toxic waste.
Note again that this should be done if we agree as a separate patch.
Best regards,
Maxim Levitsky
vmcb_save_area_cached) in its place would just duplicate the same fields
of nested.ctl, creating even more confusion and possible inconsistency.
Let me know if you disagree.
Thank you,
Emanuele
