ANDROID: KVM: arm64: Allow non-coallescable pages in a hyp_pool

All the contiguous pages used to initialize a hyp_pool are considered
coalesceable, which means that the hyp page allocator will actively
try to merge them with their buddies on the hyp_put_page() path.
However, using hyp_put_page() on a page that is not part of the inital
memory range given to a hyp_pool() is currently unsupported.

In order to allow dynamically extending hyp pools at run-time, add a
check to __hyp_attach_page() to allow inserting 'external' pages into
the free-list of order 0. This will be necessary to allow lazy
donation of pages from the host to the hypervisor when allocating guest
stage-2 page-table pages at EL2.

Signed-off-by: Quentin Perret <qperret@google.com>
Bug: 209580772
Change-Id: I3e3a6cb513f4fcc8b9683784c41fa6d3af119ac4
Signed-off-by: Will Deacon <willdeacon@google.com>
This commit is contained in:
Quentin Perret
2021-05-27 16:15:15 +00:00
committed by Will Deacon
parent f42a0f7153
commit a437069d13

View File

@@ -93,11 +93,15 @@ static inline struct hyp_page *node_to_page(struct list_head *node)
static void __hyp_attach_page(struct hyp_pool *pool,
struct hyp_page *p)
{
phys_addr_t phys = hyp_page_to_phys(p);
unsigned short order = p->order;
struct hyp_page *buddy;
memset(hyp_page_to_virt(p), 0, PAGE_SIZE << p->order);
if (phys < pool->range_start || phys >= pool->range_end)
goto insert;
/*
* Only the first struct hyp_page of a high-order page (otherwise known
* as the 'head') should have p->order set. The non-head pages should
@@ -116,6 +120,7 @@ static void __hyp_attach_page(struct hyp_pool *pool,
p = min(p, buddy);
}
insert:
/* Mark the new head, and insert it */
p->order = order;
page_add_to_list(p, &pool->free_area[order]);