From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Maxim Levitsky <mlevitsk@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org,
Emanuele Giuseppe Esposito <eesposit@redhat.com>
Subject: [PATCH v3 0/8] KVM: nSVM: avoid TOC/TOU race when checking vmcb12
Date: Mon, 11 Oct 2021 10:36:54 -0400 [thread overview]
Message-ID: <20211011143702.1786568-1-eesposit@redhat.com> (raw)
Currently there is a TOC/TOU race between the check of vmcb12's
efer, cr0 and cr4 registers and the later save of their values in
svm_set_*, because the guest could modify the values in the meanwhile.
To solve this issue, this series introduces and uses svm->nested.save
structure in enter_svm_guest_mode to save the current value of efer,
cr0 and cr4 and later use these to set the vcpu->arch.* state.
Similarly, svm->nested.ctl contains fields that are not used, so having
a full vmcb_control_area means passing uninitialized fields.
Patches 1,3 and 8 take care of renaming and refactoring code.
Patches 2 and 6 introduce respectively vmcb_ctrl_area_cached and
vmcb_save_area_cached.
Patches 4 and 5 use vmcb_save_area_cached to avoid TOC/TOU, and patch
7 uses vmcb_ctrl_area_cached.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
v3:
* merge this series with "KVM: nSVM: use vmcb_ctrl_area_cached instead
of vmcb_control_area in nested state"
* rename "nested_load_save_from_vmcb12" in
"nested_copy_vmcb_save_to_cache"
* rename "nested_load_control_from_vmcb12" in
"nested_copy_vmcb_control_to_cache"
* change check functions (nested_vmcb_valid_sregs and nested_vmcb_valid_sregs)
to accept only the vcpu parameter, since we only check
nested state now
* rename "vmcb_is_intercept_cached" in "vmcb12_is_intercept"
and duplicate the implementation instead of calling vmcb_is_intercept
v2:
* svm->nested.save is a separate struct vmcb_save_area_cached,
and not vmcb_save_area.
* update also vmcb02->cr3 with svm->nested.save.cr3
RFC:
* use svm->nested.save instead of local variables.
* not dependent anymore from "KVM: nSVM: remove useless kvm_clear_*_queue"
* simplified patches, we just use the struct and not move the check
nearer to the TOU.
Emanuele Giuseppe Esposito (8):
KVM: nSVM: move nested_vmcb_check_cr3_cr4 logic in
nested_vmcb_valid_sregs
nSVM: introduce smv->nested.save to cache save area fields
nSVM: rename nested_load_control_from_vmcb12 in
nested_copy_vmcb_control_to_cache
nSVM: use vmcb_save_area_cached in nested_vmcb_valid_sregs()
nSVM: use svm->nested.save to load vmcb12 registers and avoid TOC/TOU
races
nSVM: introduce struct vmcb_ctrl_area_cached
nSVM: use vmcb_ctrl_area_cached instead of vmcb_control_area in struct
svm_nested_state
nSVM: remove unnecessary parameter in nested_vmcb_check_controls
arch/x86/kvm/svm/nested.c | 235 ++++++++++++++++++++++----------------
arch/x86/kvm/svm/svm.c | 7 +-
arch/x86/kvm/svm/svm.h | 57 ++++++++-
3 files changed, 192 insertions(+), 107 deletions(-)
--
2.27.0
next reply other threads:[~2021-10-11 14:37 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-11 14:36 Emanuele Giuseppe Esposito [this message]
2021-10-11 14:36 ` [PATCH v3 1/8] KVM: nSVM: move nested_vmcb_check_cr3_cr4 logic in nested_vmcb_valid_sregs Emanuele Giuseppe Esposito
2021-10-11 14:36 ` [PATCH v3 2/8] nSVM: introduce smv->nested.save to cache save area fields Emanuele Giuseppe Esposito
2021-10-22 14:46 ` Maxim Levitsky
2021-10-11 14:36 ` [PATCH v3 3/8] nSVM: rename nested_load_control_from_vmcb12 in nested_copy_vmcb_control_to_cache Emanuele Giuseppe Esposito
2021-10-22 14:46 ` Maxim Levitsky
2021-10-11 14:36 ` [PATCH v3 4/8] nSVM: use vmcb_save_area_cached in nested_vmcb_valid_sregs() Emanuele Giuseppe Esposito
2021-10-22 7:14 ` Paolo Bonzini
2021-10-22 13:48 ` Emanuele Giuseppe Esposito
2021-10-22 14:48 ` Maxim Levitsky
2021-10-11 14:36 ` [PATCH v3 5/8] nSVM: use svm->nested.save to load vmcb12 registers and avoid TOC/TOU races Emanuele Giuseppe Esposito
2021-10-22 14:48 ` Maxim Levitsky
2021-10-11 14:37 ` [PATCH v3 6/8] nSVM: introduce struct vmcb_ctrl_area_cached Emanuele Giuseppe Esposito
2021-10-22 14:49 ` Maxim Levitsky
2021-10-11 14:37 ` [PATCH v3 7/8] nSVM: use vmcb_ctrl_area_cached instead of vmcb_control_area in struct svm_nested_state Emanuele Giuseppe Esposito
2021-10-22 7:14 ` Paolo Bonzini
2021-10-22 14:50 ` Maxim Levitsky
2021-10-11 14:37 ` [PATCH v3 8/8] nSVM: remove unnecessary parameter in nested_vmcb_check_controls Emanuele Giuseppe Esposito
2021-10-22 14:51 ` Maxim Levitsky
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