arm, arm64: KVM: allow forced dcache flush on page faults
To allow handling of incoherent memslots in a subsequent patch, this
patch adds a paramater 'ipa_uncached' to cache_coherent_guest_page()
so that we can instruct it to flush the page's contents to DRAM even
if the guest has caching globally enabled.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index acb0d57..f867060 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -161,9 +161,10 @@
}
static inline void coherent_cache_guest_page(struct kvm_vcpu *vcpu, hva_t hva,
- unsigned long size)
+ unsigned long size,
+ bool ipa_uncached)
{
- if (!vcpu_has_cache_enabled(vcpu))
+ if (!vcpu_has_cache_enabled(vcpu) || ipa_uncached)
kvm_flush_dcache_to_poc((void *)hva, size);
/*
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index b007438..cb924c6 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -852,6 +852,7 @@
struct vm_area_struct *vma;
pfn_t pfn;
pgprot_t mem_type = PAGE_S2;
+ bool fault_ipa_uncached;
write_fault = kvm_is_write_fault(vcpu);
if (fault_status == FSC_PERM && !write_fault) {
@@ -918,6 +919,8 @@
if (!hugetlb && !force_pte)
hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
+ fault_ipa_uncached = false;
+
if (hugetlb) {
pmd_t new_pmd = pfn_pmd(pfn, mem_type);
new_pmd = pmd_mkhuge(new_pmd);
@@ -925,7 +928,8 @@
kvm_set_s2pmd_writable(&new_pmd);
kvm_set_pfn_dirty(pfn);
}
- coherent_cache_guest_page(vcpu, hva & PMD_MASK, PMD_SIZE);
+ coherent_cache_guest_page(vcpu, hva & PMD_MASK, PMD_SIZE,
+ fault_ipa_uncached);
ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
} else {
pte_t new_pte = pfn_pte(pfn, mem_type);
@@ -933,7 +937,8 @@
kvm_set_s2pte_writable(&new_pte);
kvm_set_pfn_dirty(pfn);
}
- coherent_cache_guest_page(vcpu, hva, PAGE_SIZE);
+ coherent_cache_guest_page(vcpu, hva, PAGE_SIZE,
+ fault_ipa_uncached);
ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte,
pgprot_val(mem_type) == pgprot_val(PAGE_S2_DEVICE));
}