On 12/09/21 12:39, Maxim Levitsky wrote:
On Fri, 2021-09-03 at 12:20 +0200, Emanuele Giuseppe Esposito wrote:
This is useful in next patch, to avoid having temporary
copies of vmcb12 registers and passing them manually.
This is NOT what I had in mind, but I do like that idea very much,
IMHO this is much better than what I had in mind!
The only thing that I would change is that I woudn't reuse 'struct vmcb_save_area'
for the copy, as this both wastes space (minor issue),
and introduces a chance of someone later using non copied
fields from it (can cause a bug later on).
I would just define a new struct for that (but keep same names
for readability)
Maybe something like 'struct vmcb_save_area_cached'?
I agree, I like this too. However, it needs a comment that this new
struct is not kept up-to-date, and is only valid until enter_svm_guest_mode.
I might even propose a
#ifdef CONFIG_DEBUG_KERNEL
memset(&svm->nested.save, 0xaf, sizeof(svm->nested.save));
#endif
but there are no uses of CONFIG_DEBUG_KERNEL in all of Linux so it's
probably not the way one should use that symbol. Can anybody think of a
similar alternative? Or should the memset simply be unconditional?
Paolo
