From: Peter Xu <peterx@redhat.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
peterx@redhat.com
Subject: [PATCH] KVM: No need to retry for hva_to_pfn_remapped()
Date: Thu, 16 Apr 2020 11:59:06 -0400 [thread overview]
Message-ID: <20200416155906.267462-1-peterx@redhat.com> (raw)
hva_to_pfn_remapped() calls fixup_user_fault(), which has already
handled the retry gracefully. Even if "unlocked" is set to true, it
means that we've got a VM_FAULT_RETRY inside fixup_user_fault(),
however the page fault has already retried and we should have the pfn
set correctly. No need to do that again.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
virt/kvm/kvm_main.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2f1f2f56e93d..6aaed69641a5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1824,8 +1824,6 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma,
r = fixup_user_fault(current, current->mm, addr,
(write_fault ? FAULT_FLAG_WRITE : 0),
&unlocked);
- if (unlocked)
- return -EAGAIN;
if (r)
return r;
@@ -1896,15 +1894,12 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
goto exit;
}
-retry:
vma = find_vma_intersection(current->mm, addr, addr + 1);
if (vma == NULL)
pfn = KVM_PFN_ERR_FAULT;
else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
r = hva_to_pfn_remapped(vma, addr, write_fault, writable, &pfn);
- if (r == -EAGAIN)
- goto retry;
if (r < 0)
pfn = KVM_PFN_ERR_FAULT;
} else {
--
2.24.1
next reply other threads:[~2020-04-16 15:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-16 15:59 Peter Xu [this message]
2020-05-04 16:59 ` [PATCH] KVM: No need to retry for hva_to_pfn_remapped() Paolo Bonzini
2020-05-08 2:25 ` Peter Xu
2020-05-08 7:07 ` Paolo Bonzini
2020-05-29 9:45 ` Paolo Bonzini
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