[PULL 19/28] KVM: arm/arm64: Only clean the dcache on translation fault
From: Christoffer Dall <hidden>
Date: 2018-01-31 09:34:58
Also in:
kvm, kvmarm
Subsystem:
kernel virtual machine (kvm), the rest · Maintainers:
Paolo Bonzini, Linus Torvalds
From: Marc Zyngier <redacted> The only case where we actually need to perform a dcache maintenance is when we map the page for the first time, and subsequent permission faults do not require cache maintenance. Let's make it conditional on not being a permission fault (and thus a translation fault). Reviewed-by: Christoffer Dall <redacted> Signed-off-by: Marc Zyngier <redacted> Signed-off-by: Christoffer Dall <redacted> --- virt/kvm/arm/mmu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 0417c8e2a81c..f956efbd933d 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c@@ -1400,7 +1400,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, new_pmd = kvm_s2pmd_mkwrite(new_pmd); kvm_set_pfn_dirty(pfn); } - clean_dcache_guest_page(vcpu, pfn, PMD_SIZE); + + if (fault_status != FSC_PERM) + clean_dcache_guest_page(vcpu, pfn, PMD_SIZE); if (exec_fault) { new_pmd = kvm_s2pmd_mkexec(new_pmd);
@@ -1416,7 +1418,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, kvm_set_pfn_dirty(pfn); mark_page_dirty(kvm, gfn); } - clean_dcache_guest_page(vcpu, pfn, PAGE_SIZE); + + if (fault_status != FSC_PERM) + clean_dcache_guest_page(vcpu, pfn, PAGE_SIZE); if (exec_fault) { new_pte = kvm_s2pte_mkexec(new_pte);
--
2.14.2