[PATCH 3/3] KVM: arm64: nv: Avoid block mapping if max_map_size is smaller than block size.

[Ganapatrao Kulkarni]

In NV case, Shadow stage 2 page table is created using host hypervisor
page table configuration like page size, block size etc. Also, the shadow
stage 2 table uses block level mapping if the Guest Hypervisor IPA is
backed by the THP pages. However, this is resulting in illegal mapping of
NestedVM IPA to Host Hypervisor PA, when Guest Hypervisor and Host
hypervisor are configured with different pagesize.

Adding fix to avoid block level mapping in stage 2 mapping if
max_map_size is smaller than the block size.

Signed-off-by: Ganapatrao Kulkarni <gankulkarni at os.amperecomputing.com>
---
 arch/arm64/kvm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 6caa48da1b2e..3d4b53f153a1 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1304,7 +1304,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	 * backed by a THP and thus use block mapping if possible.
 	 */
 	if (vma_pagesize == PAGE_SIZE &&
-	    !(max_map_size == PAGE_SIZE || device)) {
+	    !(max_map_size < PMD_SIZE || device)) {
 		if (fault_status == FSC_PERM && fault_granule > PAGE_SIZE)
 			vma_pagesize = fault_granule;
 		else
-- 
2.33.1