After dirty-logging is stopped for a VM configured with huge mappings,
KVM will recover the table mappings back to block mappings. As we only
replace the existing page tables with a block entry and the cacheability
has not been changed, the cache maintenance opreations can be skipped.
Signed-off-by: Yanan Wang <wangyanan55@xxxxxxxxxx>
---
arch/arm64/kvm/mmu.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 8e8549ea1d70..37b427dcbc4f 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -744,7 +744,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
{
int ret = 0;
bool write_fault, writable, force_pte = false;
- bool exec_fault;
+ bool exec_fault, adjust_hugepage;
bool device = false;
unsigned long mmu_seq;
struct kvm *kvm = vcpu->kvm;
@@ -872,12 +872,18 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
mark_page_dirty(kvm, gfn);
}
- if (fault_status != FSC_PERM && !device)
+ /*
+ * There is no necessity to perform cache maintenance operations if we
+ * will only replace the existing table mappings with a block mapping.
+ */
+ adjust_hugepage = fault_granule < vma_pagesize ? true : false;
+ if (fault_status != FSC_PERM && !device && !adjust_hugepage)
clean_dcache_guest_page(pfn, vma_pagesize);
if (exec_fault) {
prot |= KVM_PGTABLE_PROT_X;
- invalidate_icache_guest_page(pfn, vma_pagesize);
+ if (!adjust_hugepage)
+ invalidate_icache_guest_page(pfn, vma_pagesize);
}
if (device)
--
2.19.1
