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FROMGIT: KVM: arm64: Mark the page dirty only if the fault is handled successfully

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We now set the pfn dirty and mark the page dirty before calling fault
handlers in user_mem_abort(), so we might end up having spurious dirty
pages if update of permissions or mapping has failed. Let's move these
two operations after the fault handlers, and they will be done only if
the fault has been handled successfully.

When an -EAGAIN errno is returned from the map handler, we hope to the
vcpu to enter guest directly instead of exiting back to userspace, so
adjust the return value at the end of function.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210114121350.123684-4-wangyanan55@huawei.com
(cherry picked from commit 509552e65a
 git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git next)
Signed-off-by: Will Deacon <willdeacon@google.com>
Change-Id: Ic34f97c2a71d49109544552be884a3b9483cd320
Bug: 178098380
Test: atest VirtualizationHostTestCases on an EL2-enabled device
This commit is contained in:
Yanan Wang
2021-01-14 20:13:50 +08:00
committed by Will Deacon
parent 57166e07d9
commit 744c46b8dd
1 changed files with 8 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
arch/arm64/kvm/mmu.c
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@@ -879,11 +879,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
if (vma_pagesize == PAGE_SIZE && !force_pte)
vma_pagesize = transparent_hugepage_adjust(memslot, hva,
&pfn, &fault_ipa);
if (writable) {
if (writable)
prot |= KVM_PGTABLE_PROT_W;
kvm_set_pfn_dirty(pfn);
mark_page_dirty(kvm, gfn);
}
if (fault_status != FSC_PERM && !device)
clean_dcache_guest_page(pfn, vma_pagesize);
@@ -911,11 +908,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
memcache);
}
/* Mark the page dirty only if the fault is handled successfully */
if (writable && !ret) {
kvm_set_pfn_dirty(pfn);
mark_page_dirty(kvm, gfn);
}
out_unlock:
spin_unlock(&kvm->mmu_lock);
kvm_set_pfn_accessed(pfn);
kvm_release_pfn_clean(pfn);
return ret;
return ret != -EAGAIN ? ret : 0;
}
/* Resolve the access fault by making the page young again. */