[PATCH v3 24/32] KVM: arm64: Reserve memory for host stage 2

Quentin Perret
2021-03-03T15:37:51Z

Extend the memory pool allocated for the hypervisor to include enough
pages to map all of memory at page granularity for the host stage 2.
While at it, also reserve some memory for device mappings.

Signed-off-by: Quentin Perret <qperret@google.com>
---
arch/arm64/kvm/hyp/include/nvhe/mm.h | 23 ++++++++++++++++++++++-
arch/arm64/kvm/hyp/nvhe/setup.c | 12 ++++++++++++
arch/arm64/kvm/hyp/reserved_mem.c | 2 ++
3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index ac0f7fcffd08..411a35db949c 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -53,7 +53,7 @@ static inline unsigned long __hyp_pgtable_max_pages(unsigned long nr_pages)
return total;
}

-static inline unsigned long hyp_s1_pgtable_pages(void)
+static inline unsigned long __hyp_pgtable_total_pages(void)
{
unsigned long res = 0, i;

@@ -63,9 +63,30 @@ static inline unsigned long hyp_s1_pgtable_pages(void)
res += __hyp_pgtable_max_pages(reg->size >> PAGE_SHIFT);
}

+ return res;
+}
+
+static inline unsigned long hyp_s1_pgtable_pages(void)
+{
+ unsigned long res;
+
+ res = __hyp_pgtable_total_pages();
+
/* Allow 1 GiB for private mappings */
res += __hyp_pgtable_max_pages(SZ_1G >> PAGE_SHIFT);

return res;
}
+
+static inline unsigned long host_s2_mem_pgtable_pages(void)
+{
+ return __hyp_pgtable_total_pages() + 16;
+}
+
+static inline unsigned long host_s2_dev_pgtable_pages(void)
+{
+ /* Allow 1 GiB for private mappings */
+ return __hyp_pgtable_max_pages(SZ_1G >> PAGE_SHIFT);
+}
+
#endif /* __KVM_HYP_MM_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 178ec06f2b49..7e923b25271c 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -24,6 +24,8 @@ unsigned long hyp_nr_cpus;

static void *vmemmap_base;
static void *hyp_pgt_base;
+static void *host_s2_mem_pgt_base;
+static void *host_s2_dev_pgt_base;

static int divide_memory_pool(void *virt, unsigned long size)
{
@@ -42,6 +44,16 @@ static int divide_memory_pool(void *virt, unsigned long size)
if (!hyp_pgt_base)
return -ENOMEM;

+ nr_pages = host_s2_mem_pgtable_pages();
+ host_s2_mem_pgt_base = hyp_early_alloc_contig(nr_pages);
+ if (!host_s2_mem_pgt_base)
+ return -ENOMEM;
+
+ nr_pages = host_s2_dev_pgtable_pages();
+ host_s2_dev_pgt_base = hyp_early_alloc_contig(nr_pages);
+ if (!host_s2_dev_pgt_base)
+ return -ENOMEM;
+
return 0;
}

diff --git a/arch/arm64/kvm/hyp/reserved_mem.c b/arch/arm64/kvm/hyp/reserved_mem.c
index 9bc6a6d27904..fd42705a3c26 100644
--- a/arch/arm64/kvm/hyp/reserved_mem.c
+++ b/arch/arm64/kvm/hyp/reserved_mem.c
@@ -52,6 +52,8 @@ void __init kvm_hyp_reserve(void)
}

hyp_mem_pages += hyp_s1_pgtable_pages();
+ hyp_mem_pages += host_s2_mem_pgtable_pages();
+ hyp_mem_pages += host_s2_dev_pgtable_pages();

/*
* The hyp_vmemmap needs to be backed by pages, but these pages