linux-kernel - [PATCH v2 0/2] KVM: x86/mmu: Fix a TDP MMU leak and optimize zap all

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210812181414.3376143-1-seanjc@google.com>
Date:   Thu, 12 Aug 2021 11:14:12 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Ben Gardon <bgardon@...gle.com>
Subject: [PATCH v2 0/2] KVM: x86/mmu: Fix a TDP MMU leak and optimize zap all

Patch 1 fixes a leak of root-1 shadow pages, patch 2 is a minor
optimization to the zap all flow that avoids re-reading and re-checking
the root-1 SPTEs after they've been zapped by "zap all" flows.

I'm still somewhat on the fence for patch 2, feel free to drop it.

v2:
 - Replaced magic number silliness with Paolo's much more clever suggestion.
 - Elaborated on the benefits of the optimization.
 - Add Ben's somewhat reluctant review for the optimization.

v1: https://lkml.kernel.org/r/20210812050717.3176478-1-seanjc@google.com

Sean Christopherson (2):
  KVM: x86/mmu: Don't leak non-leaf SPTEs when zapping all SPTEs
  KVM: x86/mmu: Don't step down in the TDP iterator when zapping all
    SPTEs

 arch/x86/kvm/mmu/tdp_mmu.c | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

-- 
2.33.0.rc1.237.g0d66db33f3-goog