From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Sean Christopherson <seanjc@google.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
David Woodhouse <dwmw@amazon.co.uk>,
Mingwei Zhang <mizhang@google.com>
Subject: [PATCH v3 5/8] KVM: Do not incorporate page offset into gfn=>pfn cache user address
Date: Fri, 29 Apr 2022 21:00:22 +0000 [thread overview]
Message-ID: <20220429210025.3293691-6-seanjc@google.com> (raw)
In-Reply-To: <20220429210025.3293691-1-seanjc@google.com>
Don't adjust the userspace address in the gfn=>pfn cache by the page
offset from the gpa. KVM should never use the user address directly, and
all KVM operations that translate a user address to something else
require the user address to be page aligned. Ignoring the offset will
allow the cache to reuse a gfn=>hva translation in the unlikely event
that the page offset of the gpa changes, but the gfn does not. And more
importantly, not having to (un)adjust the user address will simplify a
future bug fix.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
virt/kvm/pfncache.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 40cbe90d52e0..05cb0bcbf662 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -179,8 +179,6 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
ret = -EFAULT;
goto out;
}
-
- gpc->uhva += page_offset;
}
/*
--
2.36.0.464.gb9c8b46e94-goog
next prev parent reply other threads:[~2022-04-29 21:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 21:00 [PATCH v3 0/8] KVM: Fix mmu_notifier vs. pfncache vs. pfncache races Sean Christopherson
2022-04-29 21:00 ` [PATCH v3 1/8] Revert "KVM: Do not speculatively mark pfn cache valid to "fix" race" Sean Christopherson
2022-04-29 21:00 ` [PATCH v3 2/8] Revert "KVM: Fix race between mmu_notifier invalidation and pfncache refresh" Sean Christopherson
2022-04-29 21:00 ` [PATCH v3 3/8] KVM: Drop unused @gpa param from gfn=>pfn cache's __release_gpc() helper Sean Christopherson
2022-04-29 21:00 ` [PATCH v3 4/8] KVM: Put the extra pfn reference when reusing a pfn in the gpc cache Sean Christopherson
2022-04-29 21:00 ` Sean Christopherson [this message]
2022-04-29 21:00 ` [PATCH v3 6/8] KVM: Fully serialize gfn=>pfn cache refresh via mutex Sean Christopherson
2022-05-20 15:24 ` Paolo Bonzini
2022-05-20 15:53 ` Sean Christopherson
2022-05-20 16:01 ` Paolo Bonzini
2022-04-29 21:00 ` [PATCH v3 7/8] KVM: Fix multiple races in gfn=>pfn cache refresh Sean Christopherson
2022-04-29 21:00 ` [PATCH v3 8/8] KVM: Do not pin pages tracked by gfn=>pfn caches Sean Christopherson
2022-05-20 16:04 ` [PATCH v3 0/8] KVM: Fix mmu_notifier vs. pfncache vs. pfncache races Paolo Bonzini
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