On 6/18/25 5:53 PM, Jan Beulich wrote:
On 10.06.2025 15:05, Oleksii Kurochko wrote:
@@ -18,10 +20,20 @@ struct arch_vcpu_io {
struct arch_vcpu {
};
+struct paging_domain {
+ spinlock_t lock;
+ /* Free P2M pages from the pre-allocated P2M pool */
+ struct page_list_head p2m_freelist;
+ /* Number of pages from the pre-allocated P2M pool */
+ unsigned long p2m_total_pages;
+};
+
struct arch_domain {
struct hvm_domain hvm;
struct p2m_domain p2m;
+
+ struct paging_domain paging;
With the separate structures, do you have plans to implement e.g. shadow paging?
Or some other paging mode beyond the basic one based on the H extension?
No, there is no such plans.
If the
structures are to remain separate, may I suggest that you keep things properly
separated (no matter how e.g. Arm may have it) in terms of naming? I.e. no
single "p2m" inside struct paging_domain.
Arm doesn't implement shadow paging too (AFAIK) and probably this approach was
copied from x86, and then to RISC-V.
I thought that a reason for that was just to have two separate entities: one
which
covers page tables and which covers the full available guest memory.
And if the only idea of that was to have shadow paging then I don't how it
should
be done better. As p2m code is based on Arm's, perhaps, it makes sense to have
this stuff separated, so easier porting will be.
@@ -105,6 +106,9 @@ int p2m_init(struct domain *d)
struct p2m_domain *p2m = p2m_get_hostp2m(d);
int rc;
+ spin_lock_init(&d->arch.paging.lock);
+ INIT_PAGE_LIST_HEAD(&d->arch.paging.p2m_freelist);
If you want p2m and paging to be separate, you will want to put these in a new
paging_init().
I am not really understand what is wrong to have it here, but likely it is
because
I don't really get an initial purpose of having p2m and paging separately.
It seems like p2m and paging are connected between each other, so it is fine
to init them together.
~ Oleksii
