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| author | Quentin Perret <qperret@google.com> | 2022-11-10 19:02:35 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-11-11 16:40:54 +0000 |
| commit | 72a5bc0f153ce8ca80e9abbd1d9adec7d586915a (patch) | |
| tree | 54709247309ddc8d80d9908c216c7ebcb01685dd /arch/arm64/kvm/hyp | |
| parent | 0f4f7ae10ee4e6403659b2d9ddf05424eecde45b (diff) | |
| download | linux-stable-72a5bc0f153ce8ca80e9abbd1d9adec7d586915a.tar.gz linux-stable-72a5bc0f153ce8ca80e9abbd1d9adec7d586915a.tar.bz2 linux-stable-72a5bc0f153ce8ca80e9abbd1d9adec7d586915a.zip | |
KVM: arm64: Allow attaching of non-coalescable pages to a hyp pool
All the contiguous pages used to initialize a 'struct hyp_pool' are
considered coalescable, 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.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-3-will@kernel.org
Diffstat (limited to 'arch/arm64/kvm/hyp')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/page_alloc.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c index 1ded09fc9b10..dad88e203598 100644 --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -93,11 +93,16 @@ 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); + /* Skip coalescing for 'external' pages being freed into the pool. */ + 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 +121,7 @@ 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]); |